In Chapter 2 the general principles of the production of cut stitch-shaped garments are outlined. Most cut stitch-shaped garments are upper body garments of the knitwear variety. Within this category a large variety of men's, ladies', and children's garments are produced in the form of jumpers, slipovers, cardigans, jackets and waistcoats. Most fashion knitwear falls in this category. The term fashion in this sense describes designs that are up to the minute, short-lived, appealing to younger age groups and mostly women's wear but including some men's wear. The term implies the opposite of classical.
Other garments made by cut stitch-shaped techniques are some forms of ladies' vests, dresses and skirts. Knitted dresses in particular are very fashion dependent and appear on the market infrequently.
The widest variety of stitch forms and colour pattern work also occurs in this classification, and these in fact form the main basis of a particular design. The shape of the garments is relatively simple, and while overall form in terms of the length of the garment and the relative looseness or tightness of fit are important, the main appeals are in the textile design content.
Garments tend to be classified according to neck opening style and sleeve head attachment. The latter is more important as it determines the size of the knitted blanks and the economics in terms of raw material utilization. Neck openings are regarded as a variable option that can be carried out on a standardized overall body shape. Popular neck openings/ treatment styles for jumpers include round neck, V-neck, turtle neck, polo neck and shirt collar types (see Glossary). Most cardigans are given a simple facing that varies with the nature of the ribbing or stalling used. Other designs are achieved by rolled revers and collars.
Economic considerations tend to impose limitations on the type of sleeve head shape used. With cut knitwear this limitation is mainly in the variations of set-in sleeve heads and drop shoulders. The sleeves for such shapes can be produced from smaller blanks than raglan or saddle shoulder types. Fig. 4.1 shows a comparison of blank sizes and the relative wastage levels for a set-in sleeve garment and raglan sleeved garment of similar size, shape and overall weight.
While percentage wastage levels are useful in comparing garments made from different cut processes with those fully fashioned, they are of little use in assessing garments cut from the same sizes of blanks. The raw material cost of a cut stitch-shaped garment is solely dependent on the size/weight of the blanks from which it is cut. Within the blank it is quite irrelevant whether the waste is 25% or 35%, except from a moral standpoint. The shapes themselves are usually very simple for cut stitch-shaped garments. Side body line is invariably straight below the underarm, with constriction caused by rib waistbands at the lower end; length is variable and the 'waist' can be in any position from just below the bust to below crotch level. Sometimes, when fashion demands tight fitting knitwear, some shaping from underarm to waist is inserted.
Sleeve heads are invariably symmetrical, as are front and back armholes on the body portions. The general fit of the garment over the contours of the body, and the articulations of the arms, depend almost wholly on the elastic deformation of the fabric. Darts are not generally used to generate bust shapes or upper back shoulder shaping.
Important dimensions in determining the overall appearance of knitwear garments are (Fig. 4.2):
(1)
bust width, measured underarm;
(2)
length, measured back neck to extremity;
(3)
sleeve head depth;
(4)
sleeve width;
(5)
underarm sleeve length.
Also of major importance to the overall fit, comfort and appearance is the angle that the sleeve makes with the body (Fig. 4.3). At 90° the sleeve/ body junction is very full and drapes, tending to pull the shoulder line downwards. At 75° the sleeve/body join is beginning to feel constricted. Most shoulder/sleeve slopes are of the order of 80° to 850.
This angle can also be expressed as shoulder slope. That is the angle formed between a line projected from the neck, perpendicular to the centre body line, and the upper edge of the sleeve.
Shoulder slope = 900 — body/sleeve angle
The above measurements are the ones that are the most important in quality control procedures and are the basis for specification.
If this so far appears restrictive of shape and fashion styles, that is not the intention. It is simply that this section caters for Quick Response fashion and almost anything goes in terms of garment definition and shape detail.
Cutting
Prior to making and cutting it is normal to subject the garment blanks to an open bed steam treatment. This has two objectives:
(1)
to relax the blank and stabilize its surface;
(2)
to regulate its size and shape.
To ensure the second objective metal forms are often used, inserted into the tube formed by two flat blanks temporarily seamed together, or one wide flat blank folded and seamed, or the tubular blank from a circular machine. The blanks are then steamed with the forms in place. In the main, most cut knitwear is produced from acrylic yarns, it being generally uneconomic to cut wool, cotton or other natural fibres to waste.
Acrylic fibres are very thermoplastic and great cart is needed, when the blanks are on the steam bed and hot, to avoid distorting them by undue handling. After steaming and cooling, acrylic fabrics are very stable and do not exhibit the dimensional instability of, say, cotton. When wool or cotton is used for cut knitwear it is often given an actual press at this stage to neaten and stabilize it.
Cutting is still mostly done by hand with shears on individual garment pieces. Cardboard pattern shapes are used and the cutting lines are chalked on to the fabric. Often such chalk lines are only approximate guides, it being more important to cut to a particular structural or pattern feature. It is also normal practice to cut along the wale line of the rib cuffs, waistbands or hems. Sometimes a tight specification demands that this is in a precise position, and the ribs are actually counted to achieve this.
Sometimes negative pattern shapes are used, i.e. the shape of the portion to be cut away rather than the shape of the garment. V-necks are commonly treated in this way, it being easier to align a small piece of card on what is quite an unstable surface.
The actual cutting takes place on a flat table of sufficient height that the cutter, who stands, feels comfortable and does not suffer back stress. Two body blanks are usually cut together, i.e. a front and back, or two sleeves. As already outlined these may already be in tubular form, or, if flat, tacked together. The body front and back are cut together for the sleeve insert and back neck; the body front is then cut for the neckline. If there is side body excess or length excess this is cut off initially.
To speed production, template or die cutters are used for large orders or when standardized shapes are used.
This involves two beds. On the lower one the garment portions are assembled, accurately aligned. The lower bed usually contains the cutting template, although it can be in the upper bed. The cutter itself consists of thin steel strips, razor sharp on one edge, embedded in a deformable plastic substrate. The steel strips define the outline of the garment and are specially made and assembled for each size and type of garment.
When the garment pile is ready to cut, the beds are aligned and pressure applied to force the template knives through the pile of gar¬ments. Safety is of prime importance and guards and two handed switches are fitted to prevent accidents. The device can handle up to eight pieces at a time. Front necks are usually cut out afterwards by hand. Separate machines are required to handle bodies and sleeves, and only one size can be cut at once.
Some firms use die cutters to cut single pieces of garments from blanks, i.e. front or back or sleeve. The usual practice is to fold the blank vertically down a centre line which is placed accurately on a mark on the lower bed. It is claimed that a dozen garments can be cut in seven minutes, not counting the time to change the knives. This is quick and simple as the knives merely slide off a plastic sheet, to be replaced with others.
The claim made for single garment piece cutting is high accuracy; there is a tendency for piles of fabric to distort under the pressure between the two beds.
Hybrid cut/fully fashioned garments
Mention should be made of hybrids between cut knitwear and fully fashioned knitwear. There are two sorts, varying only in the method of shaping on the V-bed flat knitting machines: press-off shaping and held-stitch shaping. The end results are the same: eliminating the cutting stage and saving raw materials.
Modern computer-controlled V-bed flat knitting machines equipped with presser feet (stitch pressers) or with loop holding sinkers are capable of knitting without imposing take-down load on the fabric being formed. This allows loops to be dropped off needles at the edge of the fabric without the fabric disintegrating into ladders and holes. Such pressing-off can be used to generate a sleeve head shape, or a sleeve insertion hole, or to form raglan sleeves which otherwise, as already outlined, are uneconomic. The pressing-off can be done gradually, loop by loop or in steps. Trimming is usually left to the knives of the overlock machine.
The held-stitch technique involves holding the loops at the edge of the knitting and reducing in stages the of the course being knitted. No pressing-off takes place until the shape is completed and two or three edge rows have been knitted. This technique is particularly useful for set-in sleeve heads and shoulder slopes.
Such narrowing techniques can be combined with needle introduction widening for sleeves, and very large savings can be made. In spite of the obvious advantages of such techniques in economic terms, with the saving of raw material and cutting time, and little or no increase in knitting time, they are still not widely practised.