Wrap patterning was popular in single jersey, especially in underwear, for producing vertical stripe effects, often in conjunction with horizontal patterning (Fig. 14.7). The fingers or wrapping jacks, with their warp yarn pins, must rotate in unison with the cylinder in order for each to remain with its section of needles.
Solid-colour warp insertion can be achieved with the Camber wrapping method, which may be used on any of their needle selection machines. The first selection system of the sequence selects needles to receive the wrap yarn, and the second selects the remaining needles to receive the weft ground yarn. According to machine model, diameter, and gauge (E 5-32), up to 100 or more fingers will successively pass through each section and be capable of wrapping across up to eight or more selected adjacent needles.
As each finger in turn contacts a stationary cam at the wrapping section, it pivots out of the cylinder and rises up its clockwise moving post, wrapping its warp yarn into the passing hooks of those needles selected to rise to take it. It is then cammed to return to its inactive position inside the cylinder whilst the needles pass to the next system, where those previously unselected rise to take the ground yarn. On a 28-gauge machine, 70-200 denier yarn might be used for the warp and 1/30-1/50 (NeB) for the ground.
On the Mayer Vilonit machine, wrapping and striping are incorporated into fabrics in the form of tuck-miss inlay patterns, thus providing an opportunity to use a wide range of yarn counts. A 26-inch diameter machine has twenty-four feeders, six with four-colour striping and six using the 46 wrapping fingers. Needle selection is by punched-tape controlled peg drums. Cam sections are in sequences of eight. At feeders 1 and 5, needles are selected to tuck the striping yarn, at 3 and 7 they
are selected to tuck the wrap yarns, whilst at feeds 2, 4, 6 and 8 needles are selected to knit the ground yarn.
Wrap patterning produces small, vertically-arranged designs without restrictive horizontal floating threads, but it requires a more expensive machine, it is time-consuming to set-up patterns, and productivity in numbers of feeds and speed of production is slow.
Was this article helpful?