Tuck Stitch Formation

Two consecutive strokes of the carriage are necessary to form the tuck stitch (picture 30).

Stitch Cam
Picture 30 - Tuck stitch formation

During the first stroke, the tucking cam of the cam is out and the looping cam is not working. Therefore the needle only raises as high as the tucking plane; the loop cannot slip on the stem, and therefore remains inside the hook after having completely opened the latch, in this way allowing the yarn to be fed.

During the second stroke both the tucking cam and the looping cam are activated; the needle rises up to the maximum height allowing the loop and the yarn to travel along the stem. Thereafter, the needle is fed with the thread for the second time; the loop and the first yarn close the latch and knock over on the new yarn.

The first yarn does not knock over as a knit stitch but takes a particular position, and fixes on top of the previous knit stitch and at the bottom of the new one, creating a particular effect on the fabric, called tuck stitch (picture 31).

Tuck Stitch
Picture 31 - Tuck-stitch effect on a single jersey fabric Miss Stitch Formation

High-butt and low-butt needles are also needed for the formation of the miss stitch (picture 32).

Needle Formation Miss Cam

The cam (with a half-way tucking cam and looping cam) meets with the needles: the high-butt needles rise while low-butt needles remain in a non-knitting position.

During the downward stroke, the needles which have raised till their maximum height and have transferred the loops on the stem, are fed with a new thread.

With the successive downward stroke the latches are closed and the loops is knocked over on the new thread.

The stitches are bound together by longer interloops while the stitch of the non-knitting needle, which can be only knocked over on the next stitch, shows a stretch effect (picture 33).

Single Jersey
Picture 33 - Miss-stitch and stretch effect on a single jersey fabric

Fabric Take-down

Knitted fabrics require a special system to take them down while they are formed on the knitting machine.

On manual flat knitting machines, after the first stroke of the carriage, a steel reed is fitted into the course (picture 34); the reed is hooked using a steel wire.

Picture 35 - Weight holder o o o

Picture 34 - Fabric take-down reed

Picture 35 - Weight holder

Once the manufacturing cycle comes to an end the steel wire is removed and the reed released.

The machine and the reed must have the same gauge; the holes in the lower part of the reed accommodate the weight-holder hooks (picture 35) to increase the tension on the fabric according to the specific needs.

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