♦Paper car-wheels♦
One of its most curious uses in this field is in the manufacture of car-wheels. The material is calendered rye-straw board, or thick paper, and the credit of the invention belongs to Richard N. Allen, a locomotive engineer. The paper is sent to the car-wheel shops in circular sheets measuring from twenty-two to forty inches in diameter, and over each of these is spread an even coating of flour paste. The sheets are then placed one above the other until a dozen are pasted together, when all are subjected to a hydraulic pressure of five hundred tons or more. After two hours’ pressure, these twelve-sheet blocks of paper are kept for a whole week in a drying-room heated to a temperature of 120° Fahrenheit, after which a number are pasted together, pressed, and dried for a second week; a third combining of layers is then made, followed by a month’s drying, until there is obtained a solid block, containing from one hundred and twenty to one hundred and sixty thicknesses or sheets of the original paper. The thickness is only from four and one-half to five and one-half inches, and in weight, density, and solidity the block resembles more the finest grained, heaviest metal than it does the original paper product. It may be called car-wheel paper. To complete the wheel, there are required a steel tire, a cast-iron hub, wrought-iron plates to protect the paper on either side, and two circles of bolts, one set passing through the flange of the tire, the other through the flange of the hub, and both sets through the paper. The paper blocks are turned on a lathe, which also reams out the center-hole for the hub; two coats of paint are applied to keep out moisture; the cast-iron hub is pressed through by hydraulic pressure; the other parts are forced into place, and the paper center is forced into the steel tire by like hydraulic power; and there, a product of human ingenuity, is a paper car-wheel, which never is injured by vibrations, and is safer and longer-lived, though costing more, than any other car-wheel made.
♦Paper lumber♦
Paper lumber is another curious form of the staple. It is produced by making the ordinary strawboard on a cylinder machine, running it through a vat of resin and other waterproofing heated to a temperature of 350° Fahrenheit, then placing together the sheets so resined and subjecting them to hydraulic pressure. The result is a paper board three-sixteenths of an inch thick, and of a dark or blackish color. It can be cut with a saw or chisel, is very hard and solid, and has been marketed in slabs thirty-two inches in width by twelve feet in length at forty dollars a thousand. It is used for the interiors of railway-cars and for perforated chairs.
♦Chamois fiber♦
A product of the paper-mill has been used quite extensively the last few years for clothing. It is called chamois fiber or mangled fiber. It is made from a long-fibered, strong sulphite stock, and is passed through a specially constructed machine which mangles or crushes the fiber, giving it a soft and flexible character, like chamois. It has been used in dress-skirts and for under-vests, and has an added advantage over cloth in being practically impervious to air.
Paper boats are made of especially prepared paper pulp, molded and pressed into shape.
Paper flour-barrels, water-pails, and other like articles are made by stamping out their form from paper pulp or heavy cylinder-made paper possessing folding properties.
♦Papier-maché♦
Papier-maché is another product of paper almost unlimited in its uses. The materials of which it is made, for the commoner classes of work, are old waste and scrap paper, repulped and mixed with a strong size of glue and paste. To this are often added quantities of ground chalk, clay, and lime. For the finest class of work, a method invented in 1772 by Henry Clay, of Birmingham, England, is followed. Sheets of specially made paper are soaked together in a strong size of paste and glue, molded into the desired shape and dried in an oven, other layers being added, if necessary, to secure the required size and shape. The dried object is hardened by being dipped in oil, and is then trimmed and prepared for japanning and ornamentation. In delicate relief-work, a pulp is prepared of scrap paper, which is dried, then ground to powder and mixed with paste and a proportion of potash until a very fine, thin paste is formed. Papier-maché is an exceedingly strong, tough, durable substance, slightly elastic, and not liable to warp or fracture. The articles for which it is used make a long list, including ornamental boxes, trays, match-safes, dolls’ heads, toys, anatomical and botanical models, artists’ lay-figures, picture-frames, panels, and other mural ornaments. It has also been employed in the construction of coaches and for door-panels, while under the name of carton pierre, which is practically the same substance, are molded ornaments for walls and ceilings. Ordinary roofing and carpet felts are similar in manufacture. The use of moistened papier-maché in electrotyping, and the method followed, is too well known to need description.