Elastic and non-elastic narrow fabrics / and a chapter on narrow fabrics made on knitting machines

by Samuel Brown

Lappet Weaving

Lappet weaving on elastic fabrics is a method which has not been extensively used, probably on account of the limitations of design obtainable by this style of weaving. Nevertheless, it affords opportunity for considerable elaboration at a very small cost. The loom attachment which permits the making of these patterns, which are somewhat similar to embroidery, is known as the lappet motion. Wherever it has been used it has been found to be serviceable. It can be attached either to a plain loom or a fancy loom. It is a system of levers operated by a chain composed of different sized balls, arranged according to the pattern desired.

On the loom lay are one or two slides running the full length of the lay, which are moved laterally by the different sized chain balls. They can also be raised and lowered as required by the design. Both these slides have generally three needles for each suspender web, which are spaced at equal distances apart, one or all of which may be threaded and used. When slides are lowered into the web, the shuttle filling or weft passes over the yarn which is carried in the needle eyes and binds it into the cloth. Then by moving the slides backward and forward for succeeding picks, and each time binding the thread into the cloth, the various lappet patterns are produced.

Fig. 5.—Lappet Weaving

Fig. 6.—Broken Effect on Silk Frill

The figures are mostly irregular trailing patterns, as shown at Fig. 5, and well adapted to narrow goods. Dots of different sizes and in different positions may also be made, but it is not practical to get the finely finished lines which can be obtained from other methods where there is positive control of any particular warp threads or group of threads, as for instance in jacquards and overshots.

The sliding bar of the lappet motion may vary slightly in its movements so that the needles will not always pierce through at exactly the same points at each repeat of the pattern, although the general design will be maintained. The threads which feed the needles should be of good clear ply material, free from slubs and irregularities, so that they will pass freely through the needle eyes, and they should have enough turns to enable them to withstand the friction resulting from the backward and forward sliding movements of the lay passages. The yarn must be delivered from independent spools, which work with perfect freedom, and measures should be taken to control the stock by the use of delicate springs.

The material used for the lappet figure is perhaps best run from grooved spools which are so weighted that they feed easily through the needles at every forward movement of the lay.