Knitting technology, Third Edition

24
Classes of warp knitting machines
24.1
Characteristics of tricot and raschel machines
The two major classes of warp knitting machines are 
tricots
and 
raschels
(NB: In
some countries tricot machines are termed 
automatic warp knitting machines
). In
the past, tricot machines mainly employed 
bearded needles
with a presser bar and
raschels used 
latch needles
together with a latch wire or blade. Now, despite wide-
spread use of the compound needle (Fig. 23.1), there are still distinctive differences
between the two types.
24.2
The tricot machine
Tricot machines
(Figures 24.1 and 24.2) have a gauge expressed in needles per inch
(E) and chain link numbering 0, 1, 2, 3, 4, etc., generally with three links per course.
Their sinkers, which are joined to each other at the front and back, never move clear
of the needles as they combine the functions of holding-down, knocking-over, and
supporting the fabric loops.
The fabric is drawn-away towards the batching roller almost at right angles to
the needle bar. The warp beams are accommodated in an inclined arc towards the
back of the machine, with the top beam supplying the front guide bar and the bottom
beam supplying the back guide bar. The warp sheets pass over the top of the guide
rocker-shaft to their tension rails situated at the front of the machine. The machines
have a simple construction and a short yarn path from the beams.
Mechanical attention to the knitting elements is carried out at the front of the
machine as the warp beams prevent access to the back. As all the warp sheets are
drawn over the rocker-shaft to the front of the machine it is easier to thread up the
guide bars commencing with the back bar; otherwise the front warp will obscure
this operation. The guide bars are therefore numbered from the back towards the
front of the machine because of this threading sequence.
The conventional tricot beam arrangement generally restricts the maximum

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