Braiding Elastic Fabrics
The braiding of elastic fabrics is a simple process when compared with weaving. It does not lend itself to any great variety of fancy effects, but a great variety of elastic goods are braided, which serve many purposes. Round cords are made in sizes from a single strand of rubber thread, such as is used for the protection of eye glasses, to the covering of multiple rubber threads for making a cord which may be one inch or more in diameter. Some of these cords are used by professional athletes in acrobatic work. Large quantities of heavy cord are now used for shock absorbers in the manufacture of airplanes, and they are much used for corset laces and doll cords.
Fig. 1.—Embossing Machine
Fig. 2.—End View
Fig. 3.—Embossed Water-Marked Effect on Middle stripe
Fig. 4.—At Top, Cord Used by Acrobats; At Bottom, Exercise Cord In Two Colors
The braiding machines are small and compact, and are generally operated in gangs on benches. One operator can care for many machines, as they stop automatically when a thread breaks. Each machine may consist of a variable number of spool carriers, according to the character of the work they are engaged on. Carriers are made to travel around cam-like grooves formed in the bed of the machine, being operated by a chain of gears which propel them around a predetermined course. Gears and slots are so arranged that the carriers are made to cross and recross each other in their passage, so that the various threads of yarn carried are plaited around the strands of rubber. The spools used on the carriers are specially designed, and have a series of notches on the upper end, into which a stop will drop upon the breaking of any of the different covering threads, automatically stopping the machine.
The rubber is carried on a beam such as is used in weaving. These beams are grooved on either side for receiving friction cords or belts, on which are hung weights so as to govern the let-off of the beams and keep the rubber at a high tension. The beams are hung on brackets underneath the machines. If cords are being made, the rubber is delivered through a central hole in the bed of the machine and fed up so that the covering threads may be plaited around it. As there is no friction on the rubber threads delivered in this manner (like the friction in weaving caused by the repeated passage of the reed), the rubber can be worked at the highest possible tension without fear of chafing or breaking, and economical results in this respect are obtainable.
Fig. 5.—At Bottom. Flat Braid Contracted; At Top, the Same Braid Before Contraction
Fig. 6.—At Bottom, Braided Frill; At Top, the Same Frill Before Contraction