Knitting technology, Third Edition

Fig. 24.9
Knitting elements in a crochet machine [
Knitting International
].

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Classes of warp knitting machines
309
finer the gauge. For example, ‘10’ means that the distance between one needle centre
and the next is 10 mm; therefore in one inch (25.4 mm) there will be 2.5 needles 
(E 2.5).
Machines run at speeds between 200 and 350 courses per minute (or much more
on simple structures). Crochet machines can process a range of filament yarns from
20 dtex to 1000 dtex.
24.5.1
The knitting action of the crochet machine
Figure 24.10 illustrates the knitting action of a crochet machine:
1
The inlay.
Whilst the needle is withdrawn into its trick during knock-over of the
previous warp overlap, the weft inlay tube is lowered. As it traverses in an under-
lap shog, the weft is laid below the level of the needle and on top of the warp
thread that extends from its head to the warp guide.
2
Clearing the warp overlap.
The weft tube rises slightly on completion of its 
traverse movement to allow the needle to move out of its trick to clear its old
warp overlap.
3
The warp overlap wrap.
The warp guide rises between the needles and 
Fig. 24.10
Knitting action of a crochet machine [
Knitting International
].

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310
Knitting technology
Fig. 24.11
A range of crochet fabrics [Comez].

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Classes of warp knitting machines
311
automatically overlaps from the left, lowering itself again on the right side of its
needle.
4
Warp knock-over and underlap.
The needle now retires into its trick to knock-
over the old overlap, whilst the warp guide is cammed under its needle to the
start position for its next overlap, thus completing the closed lap pillar. NB: The
closed lap is used for the carbine needle but the alternating overlap of the open
lap pillar stitch used with the conventional latch and bearded needles gives a
more balanced loop structure. Tricot lapping with two guide bars produces a
secure fabric which does not unrove.
A range of crochet fabrics is illustrated in Fig. 24.11.