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Fig. 29.5
Lapping diagram and notation of a seamless tube knitted on a double needle
bar raschel.
Double needle bar warp knitting machines
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company introduced the
Fashion Master
machine for knitting panty-hose and body
stockings. By changing the lapping movement of an extra four bars that are lapping
in the centre of the fabric, the large tube for the body portion can be divided into
two smaller tubes with two of the bars joining two opposing needles across the
needle beds for the inner selvedge of one leg, and the other two joining the adja-
cent needles for the other leg, thus knitting a bifurcated article. Graduating
stiffening is achieved by infinitely-variable control of the fabric take-down and
warp let-off, a shifting control moves the guide bar push-rods onto other chain
tracks when required, and reinforcement is achieved by double-needle overlapping.
For approximately two years, hosiery produced on these machines was highly
popular.
The
Karl Mayer
HDR 16 EEW machine was introduced in 1970 for producing a
range of simple garments such as seamless panties, brassieres and pocketings. The
technique used, which has undergone continuous development, is to form the tube
across the knitting width rather than down the wales.Although this causes the article
in use to have its courses in a vertical direction, this is no major disadvantage and
the possibilities for achieving simple shaping are considerably improved.
Figure 29.6 illustrates the production of a strip of briefs fabric; it is only neces-
sary to cut through the centre of the connecting joins to separate each article from
the next. These joins of short length are, in effect, knitted side seams, so the briefs
are turned inside out after knitting to hide this seam. The first side seam is produced
by guides lapping across between the two beds to form a solid double-faced fabric
section. Guide bars inlaying on the left selvedge form the knitted-in waist band
which is produced on each bed because the guide bars lap on the two needle beds
separately in order to produce the waist opening on the left and the first leg opening
on the right. Half-way through the courses for the sequence, the right selvedge
needles are joined together for a number of courses to complete the first leg opening
and close the crotch section of the brief. Single-bed fabric knitting then continues
for the second leg after which the bars knit between the beds to form the second
side seam and then commence the sequence for the next brief.
On a 75-inch (190 cm) wide machine, three brief fabric strips can be knitted side
by side giving a production of 360 briefs per hour. It is possible to achieve a cotton
terry effect on the inside if desired. Upper and lower pattern chain drums are
employed to control the guide bar shogging levers and these drums may have a split
drive and chain stop facilities to further economise on links and provide greater
versatility in lapping movements. The double needle bar raschel in 12–16 gauge
has proved particularly useful for the production of
packing sacks
for fruit and
vegetables made from polyolefin in fibrillated tape or mono-filament form [4,5].
The base structure is usually a pillar stitch inlay that provides a secure non-slip con-
struction (Fig. 29.7). The polyolefin sheets may, if necessary, be fed directly into the
back of the machine where they are split into separate ends without the need for
warping.
The sacks are knitted sideways at a rate of 250 courses per minute on each bed
in a similar manner to the briefs. Their depth can thus be varied according to the
number of needles knitting in each section. The two fabrics are joined together at
the top and bottom to form the side seams and at one selvedge to form the bottom
of the sack. At the open end, a draw-thread may be knitted into each side of the
fabric and separation of the sacks from the continuous warp knitted strip is achieved
afterwards with a hot wire.
366
Knitting technology
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