Elastic and Non-Elastic
Narrow Fabrics
By Samuel Brown
and a Chapter on Narrow Fabrics
Made on Knitting Machines
By William Davis, M.A.
This book originally appeared serially in TEXTILE WORLD
and has been republished in this form at
the urgent request of many readers.
BRAGDON, LORD & NAGLE CO.
TEXTILE PUBLISHERS
334 FOURTH AVENUE NEW YORK
Copyright 1923
Bragdon, Lord & Nagle Co.
New York
Elastic and Non-Elastic Narrow Fabrics
Chapter I.
Growth of Webbing Business—Attempts to Substitute Cut Products for Individually Woven Webs Made on Gang Looms—Loom Setting to Reduce Vibration—Capacity of Looms and Explanation of the Various Motions That Are Employed
When we think of the discovery of rubber vulcanization and the effect it has had on world affairs our minds naturally turn to the big things, such as the automobile industry with its millions of rubber tires in constant use. These may crowd from our notice a thousand and one smaller things of importance. It is difficult to fully realize how many comforts and conveniences we derive from rubber and not the least among them is the multiplicity of woven fabrics which are used both for comfort and convenience in a variety of ways and for innumerable purposes. It is not only in such things as garters and suspenders, with which our minds may first associate elastic webs, that these fabrics are used, but they find employment in a variety of other products, which are growing more numerous all the time. Today there are in operation thousands of looms and braiders, in which many millions of dollars are invested and in the operation of which, together with complementary machinery, about ten thousand people are employed.
It was about the year 1840 when the idea of weaving threads of elastic in connection with other materials was first conceived. After long experiments this was accomplished in the very simplest form of weaving. New ideas were from time to time introduced, and new uses found for the product, until now it covers a large variety of both plain and fancy weaves, and the multiplicity of uses are so varied that few realize them who are not closely associated with the business.
American Industry Started About 1860
It was not until about the year 1860 that elastic web weaving was introduced into this country, although for a number of years previous England and Germany, and also France in a small way, had found here a market for their product, particularly in cords, braids and shoe goring, which at that particular time was fast growing in popularity. About 1860, a few looms which had been used, were brought over from England and located at Easthampton, Mass., and the manufacture of shoe goring commenced. The rubber thread required was for some time imported from England. The business grew rapidly, and factories were established in a number of cities, more particularly at Boston, Lowell and Brockton, Mass., Bridgeport, Conn., and Camden, N. J. An unfortunate labor dispute took place about the year 1890, which developed into a long-drawn out strike, ultimately precipitating friction between the shoe trade and the goring web manufacturers, which finally ended in a positive boycott of this product from which the trade has never recovered. Most of the looms which were up to this time devoted to shoe goring have been remodeled and are now used in the making of other types of elastic fabrics. In passing, it may be interesting to note that some of the looms originally brought from England 60 years ago are still in operation and doing excellent work along other lines.
Attempts to Use Wide Looms
Attempts have been made from time to time to weave elastics on wide looms, the cloth being divided at intervals by open spaces in the warps at the front reed, at either side of which spaces binding threads were woven in. These narrow strips were spaced in the front reed according to the different widths which might be required, and could easily be changed to meet the varying requirements by redrawing a few threads, inasmuch as the whole weave was uniform throughout the full width of the cloth. Between these spaces, but at a point away from the weaving line, were arranged stationary knives by which the cloth was cut into the requisite widths while it was being woven, and as it gradually passed by the knife edges. These knives were so arranged that they could be adjusted to new positions when it became necessary to change the widths of the individual strips.
While this method was more economical than weaving individual webs in gang looms, the labor cost being much less, the narrow webs produced having the cut selvages lacked the finished appearance which the individually woven webs had. And sometimes the binding threads would give way, so that the fabrics were not well received by the trade, and ultimately the demand for them died out.
Attempts were made to supersede the individually woven strips in another direction by the use of two finely woven pieces of cloth, one to form the back, and the other to form the face of the goods, with an elastic substance mechanically stretched out and inserted between the two. These different parts were calendered together and afterward cut into strips of the desired widths. This method was not without many advantages. Strips of different widths were easily made without the costly method of redrawing the warps in the looms. An unlimited choice of both plain and fancy fabrics could be used, having if desired distinctly different appearances and constructions for face and back, and this alone opened up a wide range of possibilities. The finished cloth lent itself admirably to fancy embossing and printing and to various other forms of elaboration. But somehow the trade did not take to it, and this also finally died out.
The trade ultimately settled down to the weaving of elastic goods of all kinds, both plains and fancies, in gang looms, and the business has steadily grown ever since along these lines.
Straight Shuttle and Circular Shuttle Looms
The looms employed are very varied, inasmuch as the requirements cover a wide range and new uses are constantly arising with new demands. The simplest form of weaving is that employed on the making of webs such as are mostly used for garters, and which are also used for many other simple purposes in nearly every household. These webs are commonly known as loom webs, lisles and cables. They are generally made on plain, narrow, cam looms, some of which are capable of accommodating as many as 56 pieces or strips at one time.
There are two distinct types of loom employed, one of which is known as the straight shuttle and the other the circular shuttle loom. In the former type, the straight shuttle, in traveling across the different spaces, takes up more room than the circular shuttle, and thus somewhat curtails the number of pieces which can be operated in the loom, limiting capacity of production, and relatively increasing the cost. Very few of the straight shuttle looms accommodate more than 36 shuttles, according to the width of the goods required. The circular shuttles travel over a segment of a circle and cross over each other’s tracks in their movement through the shed, as shown in Fig. 1. This permits the crowding of the pieces of web closer together, so that many more can be accommodated in the same loom space than when the straight shuttle is used. This type sometimes runs as high as 56 shuttles to the loom.
Fig. 1.—Circular Shuttle Webbing Loom
Fig. 2.—Rack and Pinion Movement for Actuating Shuttles
Prevent Loom Vibration
These looms often are speeded as high as 180 picks per minute. To operate at this speed with so many pieces of web and make satisfactory goods, free from thick and thin places through irregularities of speed or variable momentum in running, a very heavy type of loom is necessary. They should be erected on solid foundations so as to eliminate all possible vibration. A solid concrete floor into which timbers have been properly set so that the feet of the looms may be securely anchored into them is the ideal way, but where this is not practicable at least heavy foundation timbers for anchoring the loom feet to should be arranged. The frames of the looms should be heavy; also the main driving shaft, which should have wide bearings so as to prolong the life of the shaft at the wearing points and obviate loose play in the boxes.
The crankshafts must also be very heavy and there should be enough of them so as to rigidly withstand the repeated beat of the lay without liability to take on any loose motion, which would be fatal to the production of perfect goods. Weight and strength here is very essential, inasmuch as it is not practical to get a direct line from the shaft to the lay on account of the harness movement, and they must be built to drop below the harnesses which form makes them subject to heavy strain at the beat of the lay. They should also be made adjustable, each arm having a heavy left and right threaded insert, so that the length of the weaving line may be changed to meet the varying requirements of different webs. They should also be constructed so that any wear may be taken up.
The lay itself must necessarily be very heavy. It is generally constructed of several thicknesses of timber of different kinds, so as to avoid any possibility of warping and shrinkage. The shuttles used are mostly made of applewood. While they must run smooth and be free from the risk of slivers they must at the same time be very light so as to be freely drawn across the multiple of web spaces. It will be easily seen that the drawing of so many shuttles over a space of about three times their length, at possibly 180 picks per minute, carrying and delivering the necessary weft to the webs, each thread of weft being checked to a certain extent by friction springs, requires great care and thought in construction. Shuttle wood must be thoroughly seasoned by age or it will not serve the purpose.
The shuttles themselves are very ingeniously constructed so as to accommodate the greatest possible amount of filling, together with the necessary space for springs to properly manipulate the tensions. Each shuttle is bored through at either side so as to allow for the insertion of a fine recoil spring, which is made fast at one end of the drilled hole at the back of the shuttle. To the other end of the spring is attached a small porcelain eye, through which is threaded the weft, making it possible to govern and take up by the action of the spring the loose filling which is thrown off as the shuttle passes and repasses through the shed. These side recoil springs are not only useful for the taking up of the loose filling but allow for a variety of threading up methods, so as to assist in the governing of the tension of the weft at one or both sides of the web, and thus afford a means of weaving the goods level. They aid in correcting any tendency to long and short sided goods, of which we will say more later.
At the back of the quill or shuttle spool is arranged another spring on which is swivelled a porcelain device which presses against the quill, and can be so regulated as to govern the tension. This spring is so tempered that the most delicate adjustment of tension can be made.
Rack and Pinion Movement
The shuttles across the entire width of the loom are drawn to and fro by what is known as the rack and pinion movement. (See Fig. 2). This method has pretty generally superseded the old-time plan of rise and fall pegs. The rack runs back and forth in a slot grooved in the top of the lay bed, A, the entire length of the loom. To the rack is attached leather straps G, or heavily woven fabric straps, with which the rack B is pulled to and fro at each pick of the loom. The rack is of wood, having rounded teeth-paced approximately one-third of an inch apart. Into the rack are meshed pinions C, two to carry each shuttle E, the teeth of which are correspondingly spaced. The rack is set into a wood carrier which is about one inch deep and one inch wide, and the full length of the lay. The pinions are made of either raw hide or paper fibre, and these pinions again mesh into a series of racks D, grooved in on the under side of each shuttle, and thus drive the shuttle to and fro across the web spaces J.
The constant travel of the driving rack running in the groove at the top of the lay bed necessarily produces more or less wear at the bottom of the rack. It therefore is advisable to place underneath this rack a false bottom of wood of about ¼-inch thick, which after becoming worn by constant use and contact with the ever-moving rack may be easily taken out and replaced by a new one, thus keeping the rack and pinions and shuttles at all times in proper mesh with each other.
The rack is drawn backwards and forwards by the before-mentioned straps, which are passed over pulleys and are either fastened to the rack by means of wood screws, or securely locked with a metal clamp designed for this purpose. These straps are sometimes separated by a pair of cams set on a shaft making one revolution to each two picks of the loom. The power from these cams is first communicated to eccentrically-shaped wood pulleys, moving backwards and forwards, which are so formed as to start and stop the shuttles slowly, and to operate them at a higher rate of speed during their passage through the middle of the shed. This movement is necessary to avoid a too early entrance of the shuttle into the weaving shed before the harness is properly settled, and also to soften the hammering at the close of its travel so as to reduce the wear and tear.
It might be well to note here also that this hammering is also softened by the placing of a piece of soft rubber H at each end of the rack run, so that the rack strikes this soft cushion each time it goes home. While the cam method has been extensively used to produce the kind of movement most desirable for the travel of the shuttle, it has its drawback in the momentum produced, which it is often found difficult to control.
The Crompton & Knowles Loom Works have designed a shuttle motion which effectively governs the desired speeds in the travel of the shuttles while they are entering, passing through, and leaving the shed, by a dwelling movement operated by a series of gear wheels and oscillating slotted rocker. It is absolutely positive in action and does away with the uncontrollable and erratic movement so often met with in the cam drive.
Movement of Harnesses
Four-pick cams are all that are necessary to produce the plain webs which are used for ordinary purposes. However, it is not the practice to confine looms to the limitations of this capacity, but to put in either 8 or 12-pick cams. These, besides providing means to make the plain weave, open up possibilities for a number of other weaves and combinations of weaves, which add materially to the usefulness of the loom.
Fig. 3.—Direct Cam Movement
Fig. 4.—Loom with Side Cam Method of Harness Control
There are two distinct types of cam movements used in looms of this character for the making of ordinary webs. One is known as the direct cam drive, where the cams are fitted on a 4 to 1 shaft, as shown in Fig. 3, which runs lengthwise of the loom and from which the power is communicated to the harnesses through a series of levers A, rocking poles B, levers C, and lifting wires to the harness D.
The other movement is known as the end-cam method, where a small shaft is set at the end of the loom, running at right angles to the driving shaft (See Fig. 4) from which it is driven by bevel gears. On this short shaft are set the cams, usually 8 or 12 in number, which have a series of grooves at their center so as to afford means of timing them in different positions on a feather key which runs the full length of the shaft. These cams operate what is known as the cam jacks, which may also be seen in Fig. 4.
The jacks are hung at the middle and are moved backwards and forwards by the cams, communicating movement to the various harnesses. The harnesses are connected at both the top and bottom of the jacks. This connection at both ends of the jacks makes it possible to run the looms at a very high rate of speed, as there are no weights or springs to contend with, which limits speed.
While the first described method of direct cams has some advantages over the end cams, such looms are not nearly so economical to operate as the end cams on account of the limited speed attainable. While the harnesses are lifted by means of the cams they have to be pulled down by weights or springs. The means of shed adjustment, however, enables the attaining of a well graded shed. Furthermore, the cams themselves can be so set on the shaft as to afford means of timing the movements of the different harnesses so that excellent and easy shedding results may be obtained. But the one great disadvantage is the limitation of the weaves attainable, which limitation is largely overcome by the end-cam method.
When the direct cam movement is used, and where the goods being woven are of such a character as to demand a very slow speed of the loom, it is practicable to bring the harnesses down by weighting them with wide flat weights of the requisite size. But where higher speed is required than is advisable for weighted harnesses, springs are more desirable.
The simplest form of pulling do the harnesses is by the use of floor blocks and direct springs. There is, however, a disadvantage in using the direct spring on account of the pull increasing until the extreme lift of the harness is reached, which necessarily increases materially the power expended in operating same and makes an unnecessary strain. The better way is to use what is known as spring jacks, which have an easier pull than the direct spring inasmuch as the load eases off on the pull, diminishing from the greatest pull at the start to the lightest pull at the extreme lift on the lever, so that the load is uniformly distributed all through the movement and less power is employed.
Chapter II.
Looms Should Be Adapted to Make a Wide Variety of Goods—Take-Up and Let-Off Motions—Making the Rubber Warps for Different Classes of Web—Importance of Uniform Tension—Defects from Uneven Tension and Chafing of Threads
The greatest care is necessary in planning out the details of the harness. On account of the great length it becomes necessary that everything possible be done to avoid any chance of warping or sagging, for the least irregularity which may be developed will of course interfere with the evenness of the shed. The harness frames must be made of the very best stock obtainable, thoroughly seasoned, and absolutely straight grained. Each frame must be supported at regular and frequent intervals by stays or supports mortised in the runners. These stays are slotted at top and bottom to receive the heddle bars and keep them accurately in line, and thus prevent them from catching on the neighboring harness during the operation of the shedding process.
It is necessary also that the top and bottom heddle bars be accurately spaced so as to allow proper freedom for the heddles to ride easily on the bars, and thus avoid any binding of heddles which would have a tendency to crowd the warp stock together and prevent clearance of the shed. Steel heddles are preferable to ones that bend and twist more or less and get out of alignment. They are made from tempered steel which is very flexible and they have round cornerless eyes that cannot possibly catch or chafe the warp threads. They adjust themselves automatically to the frame and cannot twist or bend while at work, and are made to accommodate themselves to every conceivable kind of goods.
Install Looms for Wide Range
In installing looms for narrow elastic fabrics it is advisable to make ample provision for creeling the warps necessary for the different fabrics which may from time to time be required. In the manufacture of the light single cloth garter webs, not more than two warps to the piece are required, a face warp and a gut warp, and the temptation to save a little in the initial cost possibly may suggest a limitation of creel spaces to immediate requirements. Added expense may seem for the time being an unnecessary burden. But very soon there may arise a call for other goods which cannot be made within the limitations of the two bank creel; therefore changes become necessary which are generally much heavier than first cost would have been.
Nothing less than a five bank creel should be installed. Many times the availability of six banks has solved knotty problems of warp division to care for the various weaves and materials employed in some constructions. If the entire capacity of the larger creel is not required when first starting it will not be necessary to clothe all of it with levers, buttons, etc., which may be procured later. But by all means ample provision should be made for the full frame work and supporting rods for same.
Take-Up Motion
Another important consideration is to make proper provision for a reliable take-up motion, so that the goods may be taken away from the reed while weaving without any liability to variableness. This liability was present in many of the earlier looms and exists in some of the mills today. The old-time fine ratchet gear, even when provided with a number of pawls, is always liable to erratic picking, which alone will ruin an otherwise perfect piece of goods and materially change the cost of manufacturing. A slight irregularity of picking may not be discernible in non-elastic goods, which will be satisfactory so long as the variableness is not easily seen and a reasonable average of picks per inch is maintained. But in elastic goods, where the contraction takes place after they leave the press rolls, every irregularity is revealed and intensified so there is no room to take chances. The only safe way is to employ picking gears making one tooth to each pick of the loom, and then to change the gears when different picking becomes necessary.
In many of the existing looms there has been no adequate provision made for the weaver to let the web back to the reed mechanically when a joining becomes necessary through the breaking of the filling while weaving, or where a quill may have run off unnoticed. It is almost impossible to make a joining satisfactorily without proper mechanism being provided for this purpose. In some of the slow running looms provision is made for this by the operation of each set of rolls independently (see Fig. 1), by means of the ratchet gear and pawl A and worm motion B. This plan has the one disadvantage of taking up too much space between the individual pieces. Where the fabric woven is say four or five inches wide, and the space will admit, it is all that can be desired, and the individually weighted rollers C associated with the motion are admirably adapted to variable pressure.
For the very narrow elastic fabrics, which require considerable roller pressure to hold the web snug and firm while weaving, and where it is necessary to make very accurate joinings after a break has occurred, a better movement is one in which the web roll is placed on the main take-up shaft in the form of a sleeve. It is carried around by the shaft as it turns while the goods are being woven, but can be released and turned both backwards and forwards by a conveniently placed hand wheel, which operates a series of differential gears. This movement is entirely independent of the movement of the main take-up shaft drive.
Tension on Rubber Warp
Too much importance cannot be attached to properly controlling the tension of the rubber warp. On its uniformity depends not only the quality, but also the cost of the web. The greater the weight of slack rubber woven into the web the more costly it becomes and the poorer the quality. A very accurate sense of touch is required in testing the tension of the rubber threads as they are being delivered into the goods.
The rubber warp requires the highest possible tension before breaking or chafing of the thread takes place. Each rubber thread should be under this high tension so that when the goods come through the press roll the desired contraction will take place uniformly, and a flat piece of web will be produced that will have plenty of life.
It must always be remembered that the individual threads of rubber which constitute a rubber warp will act as a series of small springs, working in unison with each other. Each one should have equal power to contract the fabric at its own particular part. If any one of these strands or springs is chafed and weakened, it lessens the contracting power, and the result is that the weakened or less contracted part is of relatively greater length than the parts where the rubber threads have retained their full power.
Moreover, the appearance of the goods will be spoiled by the chafed particles of rubber pricking through the face, particularly on the white and lighter colored goods. Before such webs can be marketed they must be subjected to a buffing operation to remove these dirty particles, which is accomplished by passing them over a highly speeded, cloth covered roller, which will remove the loose particles by friction and high velocity. But this operation adds to the cost.
A high and uniform tension of the rubber warp is so important that most manufacturers keep men specially employed in the testing of the threads, instead of leaving this matter to the weavers. These testers acquire such a keen sense of touch that they can obtain very economical and satisfactory results. Talc or soapstone is freely used as a lubricant to reduce the risk of chafing and breaking of the rubber threads. The warps are arranged so as to allow the threads to pass through a bed of plush, loaded with talc, which adheres to the rubber threads and makes them work very smoothly. This is especially important in damp weather, which is the worst condition for the weaving of elastic goods. At times factories have stopped operations when the weather was especially humid.
Let-Off Motion
Fig. 1.—Individual Take-Up Motion for Wide Space Looms
Fig. 2.—Individual Rubber Warp Let-Off Motion
When we remember that the front reed will pass by the rubber threads possibly six or seven hundred times from their entrance into the shed to their reaching the leaving line, it is not to be wondered at that chafing is liable to take place. With all this liability of spoiling goods it becomes readily apparent that any device employed to regulate such an important feature as the tension of the rubber warps must be very sensitive and dependable.
On looms making wide goods, and where space will allow, regulation is accomplished by a worm and gear movement as shown in Fig. 2. The iron rubber beam is threaded on to a square shaft A, at one end of which a gear wheel B is fastened. In this gear is meshed the worm C, which is operated by a heavy linen cord D passed twice around a pulley E. The cord derives its movement from a rocking shaft F, on which there is fastened a screw extension G, by which adjustment can be made so as to deliver very accurately any amount from the rubber beam.
With this kind of movement, and in order to feed the thread uniformly into the web, it becomes necessary to use mechanically made warps where the same uniformity has been maintained in putting the warps on the beams. The warps so made must come from the thread manufacturer in individual warps, which are done up in chain form, each warp containing the requisite number of threads.
Making Rubber Warps
The machine used for making the warps, shown at Fig. 3, is mounted on an iron frame A, which carries the power driven warp beam B. Behind this is an open top expansion reed C, the dents of which are regulated to open, coarse or fine by an internal spring which is regulated by a hand wheel. This reed also has a screw sidewise adjustment for centering. Behind the reed C are fixed two pairs of nip rolls, D and E, and an open roller F, which is followed by a belt-driven beater roll G, used to beat the threads out straight as they leave the chain.
The rubber warp is first laid on a cloth on the floor, under the beater roll. The end is then passed over the beater roll G, over the open roll F, through the two pairs of nip rolls D and E, over the expansion reed C, and then looped to a leader on the rubber beam, where the knot is put in a counter-sink on the beam barrel, so as not to interfere with the lay of the warp. The section of the warp between the two pairs of nip rolls is brought down in loop form, shown at H, and the nip rolls are then closed while the warp is in this position. The two sets of nip rolls are speeded alike and the rubber is always kept slack between the gripping points, so that all threads passing through the last set of nip rolls, D, are perfectly gauged in length and tension when passing through the reed C and on to the beam B. The threads of rubber are under considerable tension, inasmuch as the beam B is driven faster than the nip rolls D and E.
Friction Let-Off
Where there is limited loom space, and where a small number of threads are employed, as in the narrower garter fabrics, it is not as practical to have the warps made mechanically, and for this reason they are not likely to be put on the beams with as much uniformity of tension. In such cases it becomes necessary to have some automatic device that will correct any irregularities and maintain a uniform delivery throughout. The device for doing this is shown at Fig. 4.
The warp carrier A is fastened to the back rail, which carries the warp, over which is passed the friction cloth G which is hung from a rod D. The friction cloth is fastened at the bottom to the graduated warp lever E, which is bolted to the bottom rail H, as shown. The rubber threads constituting the warp pass in a direct line to the harness C, and then to the breast beam B. The lever E, and the weights F, allow for proper adjustment of the friction cloth so as to keep the lever level as the warp beam empties.
Fig. 3.—Rubber Warping Machine
In making the rubber warps for narrow fabrics such as garters and suspenders, where the last described method of warp delivery takes place, it is customary to work from an entire sheet of rubber, splitting it up into the required sections or strips of the various sizes called for in the warps. This splitting and warping process must be done in a long room where the warp can be stretched out to its full length, if possible, after it is unchained. These warps are usually about 60 yards long. The “head” of the sheet, or the part where the cutting knife has not gone through, is spread out flat on a series of hooks at the beaming machine and the tail end is fixed securely on a strong hook at the other end of the room.
The requisite number of threads for the several warps which are to be beamed are counted off and each different section is fastened to a beam. The end knot is laid snugly in the counter-sink made in the beam barrel for this purpose. A wide reed is used, covering the number of beams operated in the machine, which is usually about four, and the threads are reeded over spaces opposite the different beams. This reed can be moved sidewise across the face of the beams and each warp properly centered so as to keep the warp level. The operator then starts the beaming machine, which may be operated either by hand or power, and the warps are wound up. At the same time a helper walks towards the beamer carrying the tail end of the warps and keeping the tension as nearly uniform as possible. When the warps are all wound on the several beams, a lease is taken in each of them in the ordinary manner, and each separate section is securely fastened.
Fig. 4.—Automatic Friction Let-Off for Rubber Warps
Should floor space be limited, a horizontal reel is used, which is about six feet long and about five feet in diameter. On this the sheet of rubber is wound after being split in proper sections at the head end and divided by a coarse reed, so as to be able to distribute the different sections all across the reel. Each section can then be taken off the reel as required for the beams. The tension of the threads is governed by a weighted leather strap passed over the face of the reel.
Chapter III.
Head Motion Looms and Dobbies for Making Fancy Effects—Tying Up Harness—Construction of Loom Webs, Lisle Webs, French Web or Railroad Weave and Cable Webs—Making Good Selvages and Preventing Long-Sided Effect
So far we have mentioned only plain looms, or those limited to the capacity of eight or twelve pick cams. Before we consider any of the varied constructions relating to elastic webs it will be well to speak of fancy looms. There are different types, adapted to a wide range of fancy effects, but the fancy loom most generally used is what is known as the chain head, an example of which is shown at Fig. 1. Such looms are usually of 18 and 24 harness capacity, and are operated by a figure chain of the length required to produce the desired figure. Chains are made up of a series of bars, one bar operating with each pick of the loom and having on it space for a roller or sinker for each harness to be operated.
Wherever a roller is placed on the bar, the corresponding harness will be raised, and wherever a sinker is used, the corresponding harness will be dropped. A series of rollers following each other will hold the harness up, and likewise a series of sinkers following each other will keep the harness down, thus maintaining at all times an open shed.
The Shedding Operation
The shedding operation is very simple. In the fancy head there are two cylinders, each of which has gear teeth running the entire length. These cylinders operate continuously in opposite directions. The teeth of the cylinders do not go around the entire circumference as will be noticed on the upper cylinder shown in Fig. 1, but there is a blank space provided so as to allow for the engaging of the gear wheels brought into position at the right time as the cylinders revolve.
Between the two cylinders are vibrator gears, one for each harness, and to these gears are attached arms which are connected with the different harnesses. These vibrator gears can be thrown into position by the chain rollers or sinkers, so as to come in contact with the teeth of either the upper or lower cylinder, and are so timed that they take their position at the moment when the blank part of the cylinder presents itself. A vibrator gear engaging the upper cylinder is turned so as to lift the harness connected with it, while a vibrator gear engaging the lower cylinder drops that particular harness. The harnesses stay in their relative positions until the chain calls for another change.
Both cylinders and engaging gears are made of hard chilled steel, so that wear and tear by hammering at the time of engagement are reduced to a minimum. To further soften the engagement, the speed of the cylinder is controlled by elliptical driving gears, which reduce the speed of travel just at the moment when the engagement takes place.
The timing of the various movements of the head is so well controlled that there is little risk of any part failing to maintain proper relationship with the other parts. But in the event of any accident or breakage occurring which interferes with the free motion of the head, such strain is taken care of by a soft pointed set screw on the head driving shaft, which shears off and so prevents further serious damage.
The capacity of the head is such that by careful arrangement of figures and repeats it is quite possible to make several simple designs to run side by side in the same harnesses and this is often done. Of this we may write more later.
Fig. 1.—Fancy Loom for Weaving Narrow Fabrics
Fig. 2.—Double Index Dobby
Fig. 3.—Overshot Dobby
The Overhead Dobby
A popular machine for light fancy warp figures is the overhead dobby shown at Fig. 2, which may be used as auxiliary either to the plain cam loom or the fancy head loom. It is placed on a well braced, rigid frame and built as high as convenient so as to reduce the angle of the harness strings. It is driven directly from a two to one shaft, which may be either underneath the loom or at the end, and is connected with a threaded adjustable rod, which is attached to a slotted lever and can be adjusted to govern the depth of the dobby shed.
It is customary to put two of these dobby machines over each loom, but having only one main drive the two machines are coupled together and work in unison. Such an arrangement has the double advantage of a less acute angle at the harness tie-up, and also affords facilities for a distinctly different pattern on either half of the loom. It minimizes the risk of the harness threads cutting into the compart boards, and prolongs relatively the life of the dobby harness. Furthermore it allows for a straight tie-up on either machine so that there is no limitation to the length or character of the design, as is often the case where two patterns are run together on the same machine, or where point tie-ups are used, as would very likely be necessary if only one machine was installed to cover different designs on both halves of the loom. As we have previously stated it is not advisable to limit capacity for the saving of a few dollars in the initial cost.
Overshot Dobby
Another type of loom employed in the making of fancy goods is what is known as the overshot loom. It is used for the introduction of a silk weft figure effect, and is probably the most pronounced form of elaboration introduced. It differs from the old rise and fall method in the economy of operation. The overshot continues to weave the body of the goods right along while the auxiliary shuttle is putting the silk figure in at the same time. Not only is it economical in the respect of greater yardage, but the method employed in binding the figure limits the use of silk to the actual figure displayed, and does not carry the silk, which is the most expensive material in the fabric, to the extreme selvage at every pick, as is the case where the rise and fall method is employed.
In the overshot system a specially designed dobby, shown at Fig. 3, is used for operating the lightly weighted threads of the binder warps. Two pairs of knives are employed, one of each pair operating far enough to raise the threads used in the binder warp to the level of the top main shed, while the other one of each pair carries the threads which are used for figure purposes to a higher level, so that the overshot shuttle may pass under them. This occurs every alternate pick of the loom, the body shuttle making two picks while the upper or overshot shuttle makes only one.
In levelling the harness, setting or timing of the loom, and making the shed for overshot work, the plans followed are identically the same as in ordinary single shuttle work, as the upper shuttle and upper shed are distinctly auxiliary and subordinate to the main shed. The binder warp, being necessarily but lightly weighted in its relationship to the upper and lower cloths it is binding together, allows for the figure threads to be strained out of their normal position, so that the upper shuttle may pass under them. In order to conform to this strained position of the binder figure threads, the upper shuttle must be acutely pitched downward at the nose so as to get a good clearance, and thus avoid any binding in its passages through the shed. This peculiar downward pitch of the shuttle is very important and cannot be over emphasized. It is shown in Fig. 4.
The overshot dobby is so constructed that a different set of draw knives operate on each alternate pick of the loom, one on the binder lift and the other on the rubber lift. This not only allows for a silk figure made with the shuttle but affords facilities for the introduction of a warp figure also, a combination which can often be made very effective, as shown in Fig. 5.
Fig. 4.—Showing Auxiliary Shed and Pitched Shuttle as Used in Overshot Work
Importance of Dobby Harness
Too much importance cannot be attached to the rigging of the dobby harness. A 30/9 ply linen cord is desirable and a lingo of about 16 to the pound. After deciding on the character of the tie-up required, and when the harness has been threaded in the compart boards, the lingoes should be looped on the strings, and then left to stand and settle for a couple of days before leveling. It is better still to run the dobby machine for a few hours, lifting all the harness and then dropping them, so as to settle the strings and take out any kinks or loose places which are bound to exist in a highly cabled linen cord of this character.
The labor required in the tying up and leveling of a string harness suggests the advisability of great care in determining the tie-up to be used, so that changes of pattern can be made easily without involving changes in the tie-up. In order to prolong the life of the harness, in the adjustment of which so much time and care must necessarily be spent, it is advisable to apply a dressing of boiled linseed oil, which should be thoroughly worked into the strings by running the harness for several hours, using one and one change cards. This should be followed by a dusting of talc or soapstone, which will add much to the smoothness of the finish.
To reduce the friction of the strings which operate in the several outside compart boards, where the strain and wear are particularly acute, and also to prevent the strings from cutting into the boards themselves, it is good practice to fix strips of ground glass between the different rows of strings, just above the compart boards. These strips of glass may be threaded through drilled holes in the compart board frame.
Construction of Simple Webs
Before enlarging further on details of fancy looms, it will be well to retrace our steps and consider the construction of some of the simpler forms of web, such as are made on what we have described as plain looms. The webs best known, perhaps, are those such as are used for men’s ordinary garter wear, and for cutting up to retail in the regular dry goods and notions trade. They vary from one-quarter to 2 inches in width. There are several distinct classes of these goods, the best known of which are the loom webs, the lisles and the cables, all of which are of single cloth construction, in which the filling is the main feature. There are generally two cotton warps used in such goods, one of which is commonly called the binder and weaves two up and two down, while the other is called the gut or filler, and works with the rubber warp, one up and one down. The selvages of these webs are made with the filling, which passes around a wire at each pick, the wire remaining stationary while the web is taken away from it in the process of weaving. An illustration of a loom web of this character is shown at Fig. 6. The draft and cam arrangement are shown at Fig. 6A.
Fig. 5.—Combination Warp and Shuttle Figure Produced on Overshot Dobby.
Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10
It is customary in some factories to use only one harness to carry both rubber and gut, inasmuch as the weaving of the two are the same and they both go in the same cavity or pocket of the web. Where such a method is employed there is always a tendency for the gut threads to get out of their proper places, and to fall together in pairs at irregular points, which will produce an objectionable “rowey” appearance in the goods. This will be noticed more particularly in white and light colored webs.
Fig. 6A.—Harness Draft and Weave for Three-Quarter Inch Loom Web
Fig. 7A.—Harness Draft and Weave for One-Half Inch Lisle Web
Fig. 8A.—Harness Draft and Weave for Three-Quarter Inch French Web
Fig. 9A.—Harness Draft and Weave for Three-Quarter Inch Cable Web
In the harness draft shown, it will be seen that one harness is employed for the rubber and one for the gut. It is thus possible to shed the gut harness so as to open more than the rubber, having it travel both higher and lower than the rubber harness at each alternate pick of the loom. By this movement the gut threads will be kept in the desired position, and at the same relative side of the rubber threads in each of the several pockets designed to carry them both. If, from any unusual cause, any of the gut threads get away from their proper places it is easy by this arrangement of separation to lift the gut harness at any time, insert a thread of cotton between the gut and rubber threads, and put them in their proper places when commencing to weave again.
The weave employed in the making of webs of this kind, although of a very simple character, involves a condition which does not favor a straight well woven fabric unless great care is taken to offset troublesome tendencies. The nature of the weave is such that at one pick the binder harness changes, while on the next pick it remains open and does not change, the rubber and gut harness changing only. The result of this movement is such that one shed clears for the reception of the filling much better than the other, so that at one side of the web the filling will hug the edge wire, shown at W in Fig. 6A, while at the other side of the web the failure to get a good clearance prevents the filling getting so snugly around the wire. Therefore, as the web draws away from the edge wire in the process of weaving, the tendency is for one selvage rubber cavity to be small, while the other is large, which means that at the open side there is a freedom for contraction of the edge rubber which is not present at the other side, and a long-sided uneven web is the result.
Making a Good Selvage
To counteract this it is essential that great care should be taken to get a good clearance of the shed. The shed should be timed as early as possible, so as to give every particle of fibre on the warp a good chance to separate and clear itself. When space permits, the front reed should be set slightly over on one side of the reed space, so as to create a little longer pull on the filling as it draws from the shuttle on the open side, and correspondingly eases up the draw of the filling on the other side. The warp stock used, however, may be of such a character that the loose fibre on it makes even these precautions ineffective altogether to counteract the trouble, and it may then become advisable to put in a fine edge wire on the open side of the web to offset the creeping tendency of the selvage rubber thread when contraction takes place after the web comes through the press rolls.
The feature which is aimed at, and which is most desirable in the appearance of such goods, is a clean cut prominent rib at the rubber line, and the avoidance of a flat paper-like look and feel of the web generally. The prominence of the rib varies, of course, according to the size of the rubber thread used, and the binder warp employed in dividing the same, but even the very best of conditions may be spoiled if proper care is not taken to get all the prominence of rib possible. Use as fine a binder warp as is practicable, compensating for any loss of weight or excess of contraction by using a heavier gut, which again of itself helps to fill in the rubber cavity and thereby lends additional prominence to the rib. All the weight possible should be carried on the binder warp up to a point of safety, and care should be taken to get a very easy, uniform delivery of the warp from the beam so as to avoid any erratic jerky movement of the warp lever.
The warp beams which are used on this delicate type of work should be well balanced and true to center, and the flanges free from any irregularity which would in any way interfere with the easy and uniform operation of the warp lever.
The gut, which weaves in with the rubber thread, is used for the two-fold purpose of giving additional body to the fabric and of regulating in a measure the length of stretch in the goods. The more gut there is used, the less becomes the power of contraction of the rubber warp, and the shorter the stretch produced.
Aside from the fineness and body of the goods, the element of stretch largely governs the market value of the fabric, so that good judgment and great care must be exercised in the assembling of the different sizes of yarns used. Weft, binder and gut all play their part in the governing of the stretch, as also does the number of picks put in the goods. Any excess of weight on the binder warp also materially reduces the stretch. In fact, any one of these features, wrongly adjusted, may result in the difference between the profit and loss.
In making the selvage of these goods a hard steel wire is used, around which the filling passes at each pick. This wire, shown at W in Fig. 6A, is highly tempered piano wire, of the very best quality obtainable. Sharpened to a needle point at one end, with a loop turned at the other end, it is fastened at the back of the loom by a cord which has an adjustable slip knot, so as to be able easily and quickly to regulate the length of wire running in the web. It is then passed through a harness heddle eye on the rubber or gut shaft, and through a reed space next outside the selvage rubber thread. The constant wear of this wire on the reed dent makes it necessary to have this dent of hardened steel so as to withstand the constant wear of the wire, which is always being crowded against the dent by the nipping action of the filling as it draws against the wire in the process of weaving, and the repeated beat at the same place in the dent at the weaving line. In any event, after a short time the dents in the reed will be cut so that it becomes necessary to frequently replace them with new ones, and for this reason it should be so arranged that they can be easily and quickly removed from and replaced in the reeds.
The Lisle Web
The lisle web, being perfectly plain, is similar in general character to the loom web, except that it is made with high grade combed and gassed yarns for the filling in place of cheaper stock used on the loom webs, and is woven with four threads for the binder warp between each strand of rubber, instead of two as in the loom web. The harness draft of the one-half inch lisle web shown at Fig. 7, together with the weave, is shown at Fig. 7A. The construction is as follows: Binder, 36 ends 80/2; gut, 8 ends 40/2; rubber, 10 ends 32s; reed, 21 dent; picks, 78 per inch; stretch, 75 per cent.
It will be seen that all the binder threads operate two up and two down, but change at each pick in rotation, making the repeat every four picks of the loom. In a weave of this character the changes of the harness are distributed uniformly at each pick, thus making it much easier to get uniform conditions on each selvage. It differs from the loom web in this respect, where the alternating light and heavy pick has to be contended with.
Like the loom webs, prominence of the rib over the rubber thread is the main feature aimed at in the general appearance of the fabrics, and therefore everything possible should be done which will emphasize this. The binder warp must be of fine yarns, and the warp must be weighted so as to cut the warp line down sharp and clear up to a point of safety, being careful at the same time not to go to excess so as to narrow in the goods or cause undue chafing of the rubber warp. The yarn most generally used for filling is 26-2 comber and gassed high grade stock, of about 15 turns per inch. It should be a well-rounded lofty yarn so as to obtain all the covering property possible. It should be spun with the utmost uniformity, as the slightest irregularity in the yarn will be noticeable in the goods.
The dyeing and bleaching of the yarn used for filling is also of the greatest importance. It is not an unusual occurrence to find otherwise perfect goods made unmarketable as first class by the use of a filling yarn which has not been properly processed. This faulty condition of the yarn may be caused in a variety of ways; such as an irregular boil, poor circulation of liquor in the kier, irregular drying, etc. Even when the color appears to be perfect, poor processing will often prevent the smooth running of the yarn from the shuttle, causing it to drag and thus create irregular and crooked selvages which result in the repeated breaking of the selvage rubber threads and ruin the goods.
The many difficulties of this character which were encountered when skein yarn was more generally used for filling led to the introduction and almost general use of warp yarns for filling purposes, inasmuch as the method of processing the warp yarns gives results which are not nearly so variable. Furthermore the long unbroken runs of thread obtainable by quilling avoid the many knots which are present when using skein yarn. Knots are unsightly and objectionable when appearing on the face of the goods.
Chafed and broken edge rubber threads, however, are not always the result of the conditions named, by any means, but may be caused by a variety of other things. Not infrequently the edge wire may be weaving too long in the web so as not to draw out freely. Sometimes it may be a bent wire that causes the trouble, or it may be the rubber rolling around the wire. Many times defects are caused by the edge wire having cut into the dent, so that it has a file-like effect as the rubber thread passes by in weaving. All these things require looking into, and when trouble comes the cause should be found and not guessed at.
French Web or Railroad Weave
Another plain web which has attained considerable popularity, and which is a kind of intermediate grade between the loom web and the lisle, is what is known as the French web or railroad weave, shown at Fig. 8. In almost all respects the general treatment of this web is the same as already described, and it differs only in the draft, which is shown at Fig. 8A. It allows for the use of a somewhat finer yarn than is generally employed in the loom web, and the draft changes at every two cords, which gives it a peculiar “rowey” appearance from which it derives the name of railroad weave.
There is one feature associated with all these plain webs which it might be well to speak of. The high tension at which it is necessary to work the rubber warp, together with the light weight required on the cotton warp and the crowding together of the picking, creates a tendency for the goods to rebound at the front reed, accompanied by a backward and forward sliding movement when passing over the rod at the breast beam. This movement is liable to polish the goods, which is an objectionable feature. To counteract this it is advisable to let the web pass over a small, felt-covered wood tube, which revolves and responds to the movement of the bounding web. In this way there is no friction to glaze or polish the web and interfere with the bloom of the yarn. The same polish will occur as the goods pass through the press rolls, unless they are felt covered.
Cable Web
The most popular web now made up into men’s garters is what is known as the cable web, shown at Fig. 9. With the pronounced prominence of the two-dent rib, which gives it a character peculiarly different from the plain web, it is well adapted to this class of goods. Simple in appearance, it nevertheless requires special care to manufacture, particularly when we remember that it is not unusual to be required to make a finished stretch of not less than 100 per cent. The harness draft and weave are shown at Fig. 9A. The construction is as follows: Binder, 34 ends 80/2; Gut, 24 ends 20/2; Rubber, 18 ends 28s; Reed, 20 dent; Picks, 80 per inch; Stretch, 100 per cent.
The filling, floating across the wide spaces under which lie the rubber threads in pairs, is very easily thrown out of place, the result of which may be an unsightly seersucker appearance, as shown in Fig. 10, which the process of finishing aggravates rather than corrects.
Trouble may manifest itself by the filling over the ribs opening up and allowing the gut threads to prick through. To prevent this objectionable feature it is necessary to use a good quality of moderately soft yarn for the gut, not necessarily of high grade stock, but a yarn which is uniformly spun and not at all hard or wiry. As these goods are being woven and on full stretch, the gut threads, of course, are perfectly straight and accurate in line, but when contraction takes place, to probably one-half the former length, these heavy threads, which form probably about 25 per cent. of the weight of the entire web, should bend or fold uniformly and dispose of themselves in such a manner as not to appear in any way on the face of the web, snugly housed away in the several pockets or cavities. If the yarn composing these gut threads is spotty or irregularly spun, this uniformity of fold inside the pockets will be broken up and the appearance of the face of the goods is likely to be marred by unsightly specks of cotton pricking through, which can be both seen and felt.
Chapter IV.
Elaboration of Honeycomb Effects by Parti-Dyed and Printed Fillings—Bandage and Surgical Webs Made with Plain and Covered Rubber—Frill Web Woven on Cam Looms—Double Cloths—Importance of Securing Balance Between Back and Face of Goods
Among the group of single cloth webs confined to the capacity of plain looms, is what is commonly known as the honeycomb, shown at Fig. 1 and Fig. 1A. This is generally made with silk, wood silk, or schappe filling. The smooth filling floating over two cords gives the web a smooth feel, there being no rib effect noticeable whatever, making it well adapted for a fine trade. The warp lines are almost entirely hidden by the filling, so that it is not practicable to introduce any sharp stripe fancy effects, which can be done both in the plain web and the cable. The honeycomb is thus confined to plain solid colors or such elaboration as can be obtained from the filling.
Fancy effects are often secured by dyeing skein yarn in two or more colors. Such yarns when woven in the goods produce alternating effects at regular distances in different colors, such distances being governed by the length of the dips and the width of the goods. The effects which can be produced are quite varied. The simplest way of accomplishing this is to use the regular 54-inch skein, having white or some light shade as a base, and then dyeing a given portion of the skein another color. This process is carried out by hanging the skeins on sticks placed in a rack at the required distance above the color liquor, and then lowering them into the vat and dyeing the immersed part in the usual manner.
Where cotton is used for the filling and more elaborate effects are desired, long reeled skeins are used, sometimes 108 or 216 inches, which have been reeled on specially designed collapsible reels. Such skeins are not practicable to handle in the dye house in the manner already described. Sections of such skeins are wrapped in heavy waterproof paper and tied tightly, so that the dye liquor cannot penetrate that portion, and then the whole is put in the liquor, when the exposed part only will be dyed.
Then again sometimes wood clamps are used, like that shown at Fig. 2, having a recess into which part of the skein is laid after being carefully folded. The two halves are clamped together tightly in such a manner that the dye cannot penetrate the clamped part of the skein while the part left outside the clamp is dyed when the whole is immersed in the dye liquor.
Printed Filling
Another form of elaboration used in such goods is printing the skein yarn used for the filling. This is done by using a machine having a pair of fluted brass printing rolls, one of which is made to open on a hinge like a gate so that a skein of yarn can be put around it. This roller is then closed to its original position, so that with the two rollers parallel and close together, and the skein of yarn hugged tightly between them, the turning of the rollers imprints color on the skein. The skein is then taken out and dryed before spooling. Different sets of rolls are used so as to get fine and coarse effects and various colors are used in printing.
Where plaid or printed fillings are used for the elaboration of webs of the honeycomb type, it is not unusual to introduce a couple of plain cords in the center of the web, or possibly on either side, so as to break up the flatness of the weave. This opens up the opportunity of using lines of a different color in the warp which properly arranged will produce a plaid-like effect.
Fig. 1.—Honeycomb
Fig. 1A.—Harness Draft and Weave for Honeycomb.
Fig. 2.—Clamp Used for Dying Parti-Colored Skeins
Bandage Webs
There is quite a large demand for surgical and bandage webs, Fig. 3, in widths ranging from 2 to 4 inches. These webs are used for binding the limbs and other purposes and are in the pure white or natural yarns. They require to be made with a long soft easy stretch. An open reed of about 12 dents per inch is employed. Four threads are generally used for the binder, weaving two up and two down. The goods are similar in construction to a regular lisle web, except that the gut is omitted in order to get the easiest possible movement.
Fig. 3.—Bandage Webs; Fabric at Left Made with Plain Rubber; Web at Right Made With Covered Rubber
The yarn is generally the same quality and size for both warp and filling, and is usually a soft spun 2-20s. The side of rubber is generally about 38 or 40, with 40 picks per inch and a finished stretch of 100 per cent. The use such webs are put to, necessitating as we have already said a soft and sluggish stretch, prevents the use of a heavy rubber thread, the result being that when the bandage is kept in close contact with the warm body, the life of the fine rubber is of short duration.
This condition, and the open weave necessary to get the easy stretch, have made it expedient to use in many of these goods strands of rubber which have been covered with cotton threads before weaving. This process not only prolongs the life of the web, but allows for even more open weaving, the use of different weaves than would be possible where the uncovered rubber thread is used, and the production of a fabric more suitable for the purpose.
In order to get the soft easy stretch which is the most desirable characteristic of a bandage web, and yet have the necessary width, it is not unusual to introduce a seersucker effect, as shown in Fig. 4, in sections of the web so as to reduce the strong elasticity of the whole. In an ordinary cotton cloth the seersucker or crinkle effect is usually produced by the use of a separate warp of heavier yarn than the rest of the fabric, which warp must be weighted differently and often a different weave is employed to emphasize the contrast in the puckered seersucker effect.
In the elastic web all this special preparation is unnecessary. Wherever the seersucker stripe is desired, strands of rubber are left out which of course takes away from these portions that element which contracts the other part of the web, and a seersucker effect is the result. Such stripes are often used for the ornamentation of some webs by having narrow sections introduced for border effects, or running down the center, and in fact they may be employed in a variety of ways, inasmuch as they lend themselves effectively to different forms of coloring, in relief to the main fabric.
Fig. 4.—Seersucker Effect
Fig. 5.—Frill Web Made on Cam Loom
Fig. 6.—Plain Web
Fig. 6A.—Harness Draft and Weave for Fig. 6, Simplest Form of Double Cloth
In passing it might be well to note that where it is necessary to use covered rubber threads special arrangements are required for making the warps, as the covered thread cannot be handled like the ordinary thread. The spools are placed in a rack which is required for each warp. Arrangements have been made so that to each spool is attached a special head, which can be weighted either by a lever brake or weight attached to a cord running in a groove on the auxiliary head. By this arrangement uniform delivery of the threads can be made to the warp beam so as to avoid any puckering caused by irregular warping.
Frill Web on Cam Loom
In single cloth webs as already stated, the scope for ornamental effects is necessarily limited. The bulk of such webs, particularly those made with a wire edge, are for the most part plain. There is a type of garter web, however, characterized as “frill” and shown at Fig. 5, which may be made within the narrow limitation of cam looms, although the frill feature is more generally used in connection with more elaborate fancy effects.
The frill part is practically a section of non-elastic of any desired width woven on to a section of elastic, which likewise may be of variable width. The strands of rubber used in the central section, being woven under tension, contract this portion of the fabric after it leaves the press rolls. The side sections having no rubber in them do not contract, but frill up uniformly on either side of the web in regular fluted folds. No wire is required for the selvage when a frill is made, and the tension of the filling is adjusted so as to hug the outside threads of the frill warp and make a neat selvage without narrowing it in beyond the width of the reed space occupied by the warp.
The frill part must be on a separate warp, apart from the binder threads which are used in the central section. The elastic section is made in the regular manner already described for webs of four harness capacity. The frill is likewise constructed from the same harnesses, but the draft is so arranged that two of the harnesses are used for one frill and two for the other. This arrangement is made in order that the filling may only be bound in alternating picks on the frill part, whereas in the body it is bound at every pick. This method makes the frill soft and pliable, so that it readily responds to the contraction which takes place in the body part, and thus makes for regularity in the formation of the folds.
Should an exceptionally fine frill be desired, the same two harnesses are used for the frill at either side, and the filling is bound or woven in at each passage of the shuttle. Wherever this method is employed, however, it becomes necessary to use a much finer yarn for the frill warp, or a fewer number of threads spread over the front reed in the frill. If such precautions are not taken the frill will be harsh and stiff and will not fold uniformly as the center contracts. It may even retard the desired contraction of the body.
It is not advisable in making frill webs to use a regular front reed having the same spacing of dents all across. There is a liability of getting a coarse looking frill, showing up the marks of the reed dents. The plan more desirable is to use a reed with the dents required for the frill part of the fabric spaced very much finer than those used for the body, generally in the ratio of two to one, so that the frill threads may be evenly distributed in ribbon-like formation and not show the coarse lines of the dents.
Occasional calls are made for webs having a frill on one selvage only. In this case it becomes necessary to use an edge wire on the side having no frill, and exceptional care must be taken in this class of goods to produce the proper balance. A soft frill is required and a limited contraction of the body part.
Double Cloth Webs
Our remarks so far have been confined exclusively to single cloth webs of a simple character, where, apart from the rubber and gut there is only one warp used, and where both back and face of the web are alike. We will now turn our attention to what are known as double cloth webs, where two distinct cloths are woven, one for the face and one for the back, each working independently of the other, but tied together by another warp known as the binder, or else the two cloths interlock each other in such a manner as to bind them together without the assistance of another warp.
By this method of weaving much thicker and heavier webs may be produced with a limitation of elasticity which cannot be obtained by the single cloth method. The weaves and materials employed in the face and back of the goods may be identical, or weaves of a different character and stock of different qualities, sizes and colors may be used. Fancy effects may be used to embellish the face, while the back may be perfectly plain and free from any coloring whatever.
There are certain features associated with the construction of double cloth webs which make them entirely different to deal with. The different weaves and the different stock employed necessitate splitting up the warps into sections to accommodate such conditions. A separate warp is required for both back and face and also one for the binder, which delivers a much greater length of warp than either, necessitated by the character of the weave used in binding the upper and lower cloths together. A separate warp is also required for the gut, which goes in the web perfectly straight and is shorter in length than any of the other sections. Such goods also require a special warp for the selvage, so that in the simplest form of such webs a bank of five warps is necessary. On fancy goods the introduction of fancy warps may add to this number.
Balance Between Back and Face
The element of a right balance between the back and face has to be considered, and if care be not taken in the proper adjustment of the stock the result may be that one side of the goods will assert control over the other in such a manner as to prevent it lying flat and even. When such a web is cut it will curl up so as to be almost uncontrollable. Such a condition may arise from a variety of causes. If the weaves of the face and back cloths are identical then it will be necessary to have the face and back warps of the same size yarn or its equivalent. For instance, should the face be a four-thread plain and 40/2 is used, and the back only two threads, then the yarn used for the back warp must be 20/2 so as to equal the four threads of 40/2 in the face. Should, however, the face be a more open weave than the back, then an equal weight of yarn in both cloths will not be right, and it will be necessary to use yarn of a heavier weight for the face to compensate for the freedom of the more open weave and effect a proper balance with the more tightly woven back. There can be no fixed rule to apply to this, and only experience will indicate the proper relationship between the two. In Figs. 6 and 6A are shown the simplest form of double cloth, known as a plain web.
By carefully following the weave it will be seen that while the face weaves 3 up and 1 down, and the back 1 up and 3 down, the filling will appear both on the face and back of the goods as 1 up and 1 down. If the binder was not there it would be a tubular web, having the same appearance all around. The binder, however, intersects the upper and lower cloths at each pick and binds the two together in one complete whole, while the rubber lies between the two, each strand being separated by the interlocking binder threads.
It becomes necessary in order properly to connect the upper and lower cloths at their extreme edges to use a selvage warp, which as will be seen in Fig. 6A is drawn in on all four face and back harnesses, and the threads of which are arranged so as to complete the weave all around. To do this it will be seen that there is an odd thread at one side, otherwise the weave at this point would show two threads operating together next to each other, and would break up the continuity of the weave.
Fig. 7.—Method of Banking a Set of Warps for Double Cloth Webs
The selvage plays an important part in the structure and weaving of the web. It forms the pocket for covering in which lies the outside rubber threads, and it must be so arranged that these threads can function properly so as to make a piece of goods that will lie flat. In the first place the yarn must be of such a size that with the proper number of threads employed the selvage will contract uniformly with the body of the goods, so that the web will not “frill” on account of a too heavy selvage, or “belly” because it is too light.
Care for Selvage
The threads must be properly divided in the front reed so as to make a good clearance for the filling, which otherwise would “nib” up and make an unsightly selvage. Then again, a careful adjustment of the weight carried on the selvage warp must be made so as to accommodate it to the requisite tension of the filling as it is delivered from the shuttle, otherwise the edge rubber threads will be liable to chafe and cut off when strained out of proper alignment with the front reed. It will be observed in the draft that two rubber threads are used in each selvage, which is necessary in order to control the additional yarn used in the construction of the selvage.
Chapter V.
Three Leaf Twill or Satin Face Woven in Conjunction with Plain Back—Position of Back Rolls in Relation to Harness Shed—Use of Four Leaf Twill—Filling Fancy Effects and Stitch Figures—Interchanging Figure and Face
Turning our attention from plain webs to combination weaves, we will take up what is popularly known as the three-leaf twill, or satin face, woven in conjunction with a plain back. This is a type of web not only used for suspenders, but employed extensively for corset garter attachments also. A web of this character when properly constructed has a smooth velvet-like face. The threads are uniformly distributed across the width without showing any of the “rowy” effect from the binder warps, which are completely hidden by the heavy pile produced by the float of the face threads. When the contraction of the web takes place, these floating face threads mass together in a velvet-like pile, not only producing a smooth handling web but materially increasing the thickness. Such webs are generally constructed with a six-thread face and a four-thread back, and have what is termed a round edge, similar to the selvage used on a plain web. This arrangement shows up the twill face by contrast and gives the fabric a much finer appearance.
Harness and Chain Draft
Fig. 1 shows the harness and chain draft of such a web, together with the construction of a properly balanced web for standard goods of 1⅛ inches wide. It will be noticed that the face, consisting of 150 threads, is split up into two warps of 75 threads each. This arrangement is necessary in order properly to weigh them so as to get a good clearance in the shed. The warp has to be divided likewise in the harnesses and put on six harness frames, although the weave could be produced on three. It would not be practicable to crowd 50 threads on one harness frame in the narrow space available, as the harness eyes would shoulder and crowd too much when changing.
In drawing-in this web, one face warp should be arranged so that the threads are drawn on the first, third and fifth harnesses, and the other face warp should be on the second, fourth and sixth. Such an arrangement in the distribution of the warps makes it much easier on the mechanism, and minimizes the risk of breakages. It is also important to make proper divisions of the warps at the back rolls, inasmuch as some of the warps have to be weighted heavily while others are only lightly weighted, and also on account of the different take-up of the varied weaves.
The back rolls should be set in a graded position so as to prevent undue friction of one warp against another. The binder warp should be worked under the front roll on account of the extremely light weight this must carry. Fig. 2 shows the proper position of the back rolls in relation to the harness shed.
In a web of this character where the warp stock is somewhat crowded in the front reed, there is always a tendency for a fibrous yarn to prevent a perfect clearance in the shed, with a liability of producing occasional floats through the shuttle skipping these threads. Such floats will pearl up when the web contracts and make an imperfect face. This trouble may be prevented by setting the back rolls a trifle higher than the breast beam rod, so that the stock in the harness which is down will be slightly tighter than that which is in the upper harness.
The chain draft is so arranged that the face harness will operate to produce a twill which will be reverse to the twist of the yarn employed, and thus reduce the prominence of the twill weave all possible. The filling yarn should be soft, of about 15 turns per inch, and of good uniform quality, in order to produce a nice selvage and not cut the rubber. The reed dent inside the selvage rubber should be carefully twisted at an angle to conform to the nipped in position to the rubber thread, so that the outside edge of the dent will not cut the rubber when the reed beats against the goods at the weaving line.
Fig. 1.—Three Leaf Twill, or Satin Face. Woven in Conjunction With a Plain Back
Fig. 2.—Showing Position of Back Rolls in Relation to Shed
Use of Coarser Yarn
A fine looking twill may be produced with a somewhat coarser face yarn by using a five threaded face over a six-thread repeat. This is shown in the harness draft at Fig. 3.
In non-elastic fabrics there are available a variety of twill and satin weaves for the production of soft lustrous surfaces, but this is not so in elastic webs, as the contraction of the goods after weaving would produce a ragged, spongy surface. A float of three picks on the face is about the limit it is practicable to go on an elastic web, with few exceptions, and even this only in connection with fine picking.
Use of Four Leaf Twill
A four leaf twill, however, can be used to great advantage when a heavy body is desired, as for example what is known as “farmer’s web.” These are usually made about two inches wide, and to further add to their weight they have what is termed a cushion back, the weave of which is 7 down and 1 up. The use of these soft weaves on both face and back, while giving the web great thickness on account of the deep velvet-like pile produced, deprives it of much of its firmness. This condition is met by the introduction of an auxiliary back warp, underneath the main back warp, weaving 3 down and 1 up, which knits the upper and lower cloth more firmly together, thus increasing the firmness of handles of the goods.
Fig. 3.—Five Thread Face Over 6 Dent Repeat
Another web among the plain loom products calling for passing mention is that specially made for the police and fireman’s brace. While this has a 7 down and 1 up cushion back similar to the farmer’s web, it differs in having a smooth plain face in place of a twill. This arrangement of combining a plain face with a cushion back necessitates selection of the sizes of yarn used for the various warps so as to maintain a proper balance of the different weaves employed in the face and back. Otherwise the goods would curl up and it would be impracticable to cut them up for manufacture. Consideration must also be given to the effect of padding the size upon such goods in the finishing process, of which we will say more later.
Filling Fancy Effects
All the webs so far described have been such as could be produced on cam looms of various capacities. We will now turn our attention to what are generally understood as fancy effects. It might be well to treat these under two distinct headings. Those made with the shuttle, or what are called filling patterns, and those made from the warp, or what are called stitch patterns.
The figures or fancy effects produced by floating the filling over sections of the warp show up the filling with increased luster in contrast to the warp. They are confined to no particular character of design, and may range from the simplest effect produced on the fancy harness loom or dobby to the more elaborate jacquard design. The ground or body may be either plain or twill, or any other acceptable weave suitable as a base for figuring, while the filling may be of a contrasting color, either of silk or cotton as desired. The figure or design may be made from the same shuttle used for the ground or it may be made by an auxiliary shuttle, either used as an overshot or rise and fall, according to the character of web desired.
Where the figure is made from the ground shuttle it is produced as a sunken effect. It is made by burying sections of the face warp at intervals so that in place of the face warp the filling is seen at these points. No additional figure warps are required for this class of goods, and elaborate designs are obtainable, although there is not the scope for cross coloring that there is in the warp figure method.
Stitch Fancy Patterns
When the design is made from the warp, the figure threads are made to float on the face of the goods so that upon contraction of the web after weaving, these floats pearl up in prominence above the level of the face, and make what is termed a stitch figure.
Fig. 4.—Point Draw Stitch Figure
Fig. 4A.—Harness and Chain Draft for Fig. 4
It is not our purpose here to particularize in design, which is practically unlimited, but only to refer to those features which govern the construction and illustrate as necessary. In order to maintain a proper balance where figures are introduced on single cloth weaves, it is necessary to distribute the figure warp uniformly over both the face and back of the goods so as to maintain a proper balance between the two. In the double cloth webs the figure warp, when not appearing on the face of the goods, is allowed to run straight between the upper and lower cloths, going in the same cavity or pocket as the rubber threads, and it works at these times as a gut. This, of course, in a measure interferes with the contraction of the goods and has to be taken into consideration in the construction. Here again we must note the effect of the contraction in piling up the floating-figure threads, and the necessity of limiting the floats in making the design so as to avoid any ragged appearance.
Fig. 5.—Interchanging Figure and Face
Fig. 5A.—Harness and Chain Draft for Fig. 5
Fig. 4 shows a design of this character, with the harness and chain draft at Fig. 4A. In this particular web there are six harnesses used for the main body and ten for the figure, which is a point draw. While the figure is evenly distributed on the web, wherever it is not seen it is running between the upper and lower cloths, as already described, and acting as a gut.
In order to get a proper balance of the web it is necessary to put gut threads into the two outer cords where no figure appears, which must be equivalent in size to the figure threads employed in each of the 21 center cords. If this is not done the web will contract unduly at the edges and make it “belly.” The method here used of burying the figure between the upper and lower cloths when not needed in carrying out the design, affords opportunity for introducing additional warp threads of different colors, so as to be able to bring up either one color or another as desired in a design.
As most of the fancy head looms have not more than 18 harnesses, it will be seen that the scope of design in this class of loom is somewhat limited, therefore much ingenuity is required to get elaborate designs from such limited capacity. But careful study opens up a variety of methods by which a big range of designs is possible.
Interchanging Figure and Face
Fig. 5 shows another type of design known as the “interchanging” fancy in which the figure warp does not pile up above the surface as it does in the stitch figure, but remains flat with the face of the web. The harness and chain drafts are shown at Fig. 5A. In this character of design a given number of face threads are duplicated by a like number of figure threads, the same size of yarn being used for both. These face and figure threads are drawn in duplicate harnesses and operated just reverse to each other, so that when the figure is up at any particular part, the interchanging face threads are down, and vice versa. The figure weaves only three picks up on the chain draft, which is one face pick seen on the face cloth, and this produces a perfectly flat web.
Another form of elaboration is shown in this web, known as the “picot” edge. It is generally made of a well cabled thread of silk and is woven in the selvage, being bound in for several picks and then allowed to float outside, so that upon the contraction of the web it will pearl out in small loops, adding much to the elaboration of the web.
Chapter VI.
Combination of Weaves in a Fine Web—Sunken Effects Made on Head Motion and Jacquard Looms—Employment of More Than One Bank of Shuttles—The Overshot Method—Use of Different Colors and Grades of Stock—Binding Long Floats
A very effective combination of weaves in a fine web is seen at Fig. 1. The middle of this web has for the face a 7 up and 1 down weave, but the yarn and picking are fine. The yarn piles up just enough next to the plain edge weave to set off the weaves in contrast to each other. It will be noted that on either side of the silk figure there are two cords with the binder thread left out between each, which further sharpens up the contrast. The fancy effect is produced by the use of a heavy cabled cord, the two outside threads being of reverse twist, so that when they pearl up on contraction of the web, one turns to the right and the other turns to the left, making an effective border.
Sunken Effects
An altogether different type of figuring is seen in Figs. 2 and 3. Both of these webs illustrate what is known as the sunken effect. In both cases the face is a three-leaf twill, which character of weave is most effective in hiding the filling beneath it. Therefore, the figure may be worked out in sharp contrast. In Fig. 2, which is made on a fancy head loom, it will be noticed that the face threads on the fifth cord on either side are left out in order to assist in the carrying out of the plaid effect aimed at in the figure. It will also be seen that the face warp is striped in color. The character of the figure is such that the major part of the face warp is operated in one solid block, making it practicable to produce this on harnesses worked on a chain loom.
In the web illustrated at Fig. 3, each thread is operated in the design independently. Such designs are only producible on a jacquard loom. But inasmuch as the threads used in forming the figure are confined to the face warp, it is not necessary to operate the back or binder threads from the jacquard. It is more convenient to have these worked from the cams or fancy head in combination with the jacquard, for the reason that a truer and clearer shed can be obtained.
Furthermore, by having the back harness and the jacquard operated from two distinct movements it becomes possible to time them differently so as to obtain better results in the clearance of the stock in the shed. A 208 hook machine affords ample capacity for the making of these goods, allowing for 26 rows of 8 hooks each, which will cover the requirements of nearly all classes of web, giving an entire row to each cord. Such arrangements will allow for six hooks for the face, one for the binder and one for the gut on each row. Thus it will be practicable to use different colored threads for the gut, which may be brought up in the design in relief effects to the main figure as required.
Calculation for Figure Distribution
In this type of figuring, calculation must be made to distribute the figure uniformly so as to get a well balanced flat effect of the web. As already stated, wherever the filling is shown, all the face stock at these points is buried between the upper and the lower cloths, and is acting as filler or gut in these places, preventing contraction. Should heavy blocks be thus designed, the web would pucker up in an unseemly manner. The filling used should be soft and uniformly spun, so that it will mass well together and in a great measure prevent the buried face stock from pricking through.
In designing webs of this character, calculations have to be made from the web after it is woven and finished, otherwise the design may be out of the desired proportion. A web may have 60 picks per inch on the breast plate while weaving, but when contraction has taken place after going through the press, it may have shrunk as much as 50 per cent. The steaming and finishing process may further contract it another 10 per cent. which might make the picks about 100 per inch. Of these only one-half appear on the face and the other half on the back. Therefore 50 picks per inch will be the proportion in which the design should be made, and paper scaled according must be used.
Cross Shot Weaving
We have so far confined our remarks to webs made on single shuttle looms. Turning our attention to the use of more than one bank of shuttles we would first make note of what is known as the cross shot. This is a form of weaving which largely increases the output and has in it the further element of economy, inasmuch as by this method the rubber warp can be worked at a much higher tension than by the single shuttle method.
In the construction of single shuttle webs, the rubber harness rises and falls at each passage of the shuttle across the shed. This movement creates a friction on the rubber thread at the harness eye and an added friction at the front reed by its passing up and down in the dent. Friction is still further increased by the backward and forward movement of the lay, which makes two such passages to one made by the cross shot.
In the cross shot method, the rubber remains stationary, with no upward and downward motion, which enables the rubber thread to be stretched out to its extreme limit while weaving, with little danger of chafing or breaking. Over and under this stationary rubber are two distinct sheds, one making the upper and the other the lower cloth. These two fabrics are stitched together by the binder warp, which travels up and down through both of these sheds.
In order to keep all the warp threads uniformly tight while shedding, it is necessary to run these under separate back rolls, fixed at different heights, properly centering the upper and lower sheds with the harness and breast beams.
Position of Rolls
Fig. 4 will explain the position of the various rolls in relation to the breast beam. It will also show the peculiar formation of the shuttles used for this type of weaving, both pointing to one common center, made necessary by the character of the two sheds. The bow of the upper shuttle must be tipped downwards, and the lower bank must be tipped upwards, so as to reduce the friction of the shuttles all possible when they are passing through the sheds.
The round edge or covering for the outside rubber threads is drawn in the harness on the upper shed, and while being woven this cloth is pulled around the rubbers by the tension of the filling which is carried in the lower shuttle. This tension is greater than that carried in the upper shuttle, and so asserts itself by pulling the edge cloth around the outside rubber until it meets the back cloth weave. The upper and lower fillings are connected by what are known as tie threads. These threads are drawn in the harness at each side of the body warp, next to the edge, and are part of the binder warp. They are operated from the binder harness, but are only allowed to travel through the lower shed as far as the center of the web, instead of going all through both sheds, as do the balance of the binder warp. This movement is accomplished by the use of long looped harness eyes, which only carry these particular threads through the one shed.