The knitting industry can be divided into four main sectors. These include fully fashioned, flat-bed knitting, circular knitting and warp knitting.
Fully Fashioned Knitting
Fully fashioned knitting machines, sometimes referred to as straight bar machines or cotton machines, are traditionally used to produce plain classical-styled sweaters. It should be noted that cotton machines are nothing do with the cotton fibre, but named after the inventor William Cotton, who patented the first machine of this type in the mid-1800s. The machines produce shaped fashioned panels to a predetermined size, and then after knitting the back, front and sleeve panels are linked together.
Garments produced on fully fashioned knitting machines have distinctive fashioning marks, which run parallel to the garment seams.
Wool is used extensively in the production of fully fashioned garments, which are regarded has high class.
Most fully fashioned knitting machines can only produce garments of plain knit construction; however some machines have a stitch transfer mechanism which enables Intarsia garments to be produced such as the classic diamond pattern known as an Argyle.
Because fully fashioned machines only produce plain knit structures, the welt and cuffs of a garment - which are normally of rib knit construction - have to be made on special separate ribbing machines, then linked to the main body of the garment.
Fully fashioned knitting machines range from 9 gauge (gg) to 33 gauge (gg), and unlike other types of knitting machines where the gauge is based on the number of needles per 1 inch, for fully fashioned it is based on the number of needles per 1 and ½ inches.
Flat-bed or V-bed knitting
Flat-bed or V-bed knitting machines are named so due to the arrangement of the two knitting needle beds opposing each other in an inverted V-formation.
The carriage carrying the yarn being fed traverses across the needle beds and selects the needles to be knitted as it reciprocates from side to side.
Flatbed machines are the most commonly used type, primarily because of their versatility and the almost unlimited patterning capacity due to being able to transfer stitches from one needle bed to the other.
In addition, some parts of the garment such as pockets and trims can be knitted as part of the panel, and don’t have to be added separately by linking at a later stage.
Today, fully computerized, whole garment machines are available. As the name implies, whole garments can be knitted on these types of machines, with little or no further linking or sewing. The net result is that the garment comes off the machine almost ready to wear.
Circular knit fabrics are produced on circular knitting machines in a tubular form. Most fabrics are then slit open in the finishing stages after dyeing. Fabrics are either produced as a single knit jersey or a double knit jersey.
Single Knit machines (single jersey) have a single cylinder of needles and typically range from 18gg to 36gg, where gauge refers to the number of needles per inch. The lower the gauge, the courser the stitch and creates a heavier, thicker fabric. The higher the gauge, the finer the stich. This creates a lighter finer fabric.
Double Knit machines (double jersey) have two sets of needles in a cylinder and a ‘dial’ at right angles in a similar set of gauges.
Circular knit fabrics can be knitted using undyed yarns and then piece dyed to the required colour or they can be knitted with dyed yarns for striped of patterned/jacquard effects.
The benefits of the cut and sew route for garment construction include ease and speed of knitting the fabric, consistency of the cut panel sizes and the flexibility and relative ease of garment make up.
In this system, small diameter circular knitting machines are used to make body-sized tubes of fabric, which only need seams to attach the arms or to hem. The machines are versatile in terms of stitch structure which can be altered within the garment to create for example intarsia-type patterns or areas of high compressions for sportswear. Garments produced on seamless knitting machines are used in intimate apparel, sportswear, swimwear, outerwear and medical garments.
During warp knitting the yarn zigzags along the length of the fabric, following adjacent vertical columns such as wales. Weft knitting (fully fashioned, flat-bed and circular knitting) involves a single row (course) knitted horizontally, across the width of the fabric.
Unlike fully fashioned or flatbed knitting where only a single cone of yarn is needed, in warp knitting many cones of yarns are required. As a result warp knitting is more suitable for large lot sizes.
Although wool is not often used to produce warp knitted fabrics, there is some interest in the production of fabrics for jacketing and sports/outdoor wear.