Flat Braids
Where flat braids are made the rubber threads are passed separately through different holes in the machine bed and the yarn is braided in and out between these threads, binding them together side by side so that they are flat as in a woven fabric. By this method each of the different covering threads passes from one side of the flat web to the other, giving them a diagonal direction across the fabric. This diagonal crossing and recrossing of the covering threads allows for the introduction of different colors, which produce a plaid-like effect.
In making the flat braid, when the individual rubber threads pass through the separate holes on the outer part of the bed plate of the machine, they all gather to one common center after they are through. This causes the rubber threads, when they are at a very high tension, to draw at a very acute angle at the edge of the hole, which necessitates running them at a lower tension than is desirable for economy. It also introduces a liability to break under the strain. In some mills this is cared for by passing each thread over a small case hardened steel roller, thus avoiding the friction at the edge of the hole.