Single and Double knits

Knit fabrics can be made
on more than one set of needles.

Unlike single-knit fabrics,
double-knit fabrics are produced

from two sets of needles.

You've seen how circular machines can be
used to produce single knits, but they

can also be set up to create double knits.

To accomplish this,
a second set of needles is arranged

in a dial above the cylinder.

This dial has slots that hold the needles
at a right angle to the

vertical cylinder needles.

This illustration shows you how a circular
knit machine has tricks in two places,

in the cylinder below
and the circular dial just above.

The dial has grooves cut in the outer
perimeter in the same cut

or gage as the cylinder.

Another view shows that the needles in the
dial rest horizontally in their grooves.

Also, there is a precise gap
between the cylinder and dial.

This distance is referred
to as dial height.

The dial height is important because it
directly affects the stitch length,

which controls physical parameters such as
weight, width, thickness,

strength, and hand.

When double-knit fabrics are produced,
the knitting cycles of knit, tuck,

and float are the same for the dial
as they are for the cylinder.

The needles in both the dial and cylinder
have butts and are cam activated.

Because two sets of needles are used,
sinkers are not needed.

As the yarns are knit and the fabric is
formed,

the tubular goods are removed
to the inside of the cylinder,

as with single knits.

Another type of weft-knitting machine
designed to make single and double-knit

fabrics is a flatbed machine.

These machines may have the two needle
beds in the same plane,

but usually they are set up in a V
configuration and then

referred to as V-bed machines.

These knitting machines are used
to produce tubular fabrics or flat panels

that can be put together
to form a garment.

Because the width within a panel can be
made to vary,

this system minimizes waste and sewing.

Also, the technology has matured so
that a complete garment can

be made on this machine.

Here's how V-bed machines create the loops
required to produce a double-knit fabric.

First, loops are at rest.

Then both loops clear the latch.

New yarn is received, and both loops
are cast off as new stitches form.

You may notice that these actions result
in a fabric that is structured

differently than a single knit.

You've seen how weft-knit fabrics can be
made on either circular or V-bed machines

with one or two sets of needles.

Remember, when it's two sets of needles,
we define it as double knit.