Knitting technology, Third Edition

29.5.4
Tubular articles
A seamless tube of fabric may be knitted on a rectilinear double needle bed raschel
in a similar manner to on a V-bed flat weft knitting machine. Each bed knits sepa-
rate single-faced fabrics that are joined together only by underlaps of other partly-
threaded guide bars between the beds at the two opposing selvedge needles at each
edge. The underlaps may be arranged to be the same as for the needle beds, thus
producing a seamless join to the fabric tube.
Figure 29.5 illustrates the basic principles using a base structure of single tricot
lapping and four guide bars. The front bar laps only the front bed, the back bar laps
only the back bed, and the two middle bars are threaded with only one thread to
each complete one selvedge join.
In the first underlap movement towards the 
right
, the warp threads will rotate
anticlockwise by one needle space in producing the tube on the machine beds.
Underlapping on the front bed will be towards the 
right
. The right-hand selvedge

---

364
Knitting technology
bar will underlap across from the front to the back bed. The back bar will underlap
towards the 
left
and the left-hand selvedge bar will underlap across from the back
to the front bed. In the next underlap movement, the direction of lapping will be
reversed for each of the guide bars, by a clockwise movement.
As one selvedge bar is always overlapping one needle in each bed, the thread-
ing of the front and back bars must be one less than the number of needles knit-
ting the fabric in that bed. Two selvedge guide bars are required because when one
is overlapping the front bed in a particular cycle, the other is overlapping the back
bed.
Whilst knitting the tube, no guide bar must overlap on both the front and back
beds during the same cycle, otherwise a single-thickness double-faced stitch is pro-
duced. If the base movement is a two-needle underlap, two selvedge threads will
cross over the beds at each selvedge and each will require a separate guide bar. If
the base movement was full tricot, a minimum of eight guide bars would be required,
two for each bed and two for each selvedge. Inlay net or part-sett threaded net
lapping movements may be used to produce tubes in a similar manner.
Some of the first tubular fabrics produced were for 
vests
or for 
fishnet stockings
,
knitting eight to twelve tubes side by side. In 1967, the American 
Kidde Cocker