Thursday, January 10, 2013

Care of Knit Fabric

Care must be taken for Knit Fabrics 
Although there is a great variety in the quality of knitted goods sold, and the performance of any individual knit may differ markedly from that of other knits, some general guidelines for the care of knitted goods can be observed. The problems that consumers seem to encounter most often in the performance of knitted fabrics are in the areas of dimensional stability, snagging, and pilling.

Dimensional Stability

One reason for the popularity of knits for wearing apparel is their comfort. The looped construction of knit fabrics permits the fabric to give with the body as it moves. But the stretchiness of knits also results in lessened dimensional stability. Consumers have complained about shrinkage, stretching, and distortion of knits, although interlock and double knit fabrics are usually more stable and display little or no shrinkage. Similarly, fabrics with weft or warp inserted yarns are more stable. Shrinkage control treatments, heat setting of synthetics, and special resin finishes can provide good dimensional stability for knits. Unfortunately, not all manufacturers provide such treatment for their products. Consumers should check labels for percentage of shrinkage or for other special treatments to judge potential dimensional stability. (About 3 percent shrinkage is one garment size.) If products fail to live up to specified performance standards, items should be returned to the retailer or the manufacturer.

Knits are considered to be easy-care fabrics, and many care labels recommend machine washing. Some labels will also specify that the fabric can be dried in an automatic dryer. In general, however, knits will shrink more in the dryer than if air dried. Knits maintain their shape best if they are dried flat. The weight of a wet knit, hung on a line, may cause the fabric to stretch out of shape. The dimensions of knits usually will be retained best by professional dry cleaning. Hand knits, sweaters of wool or animal hair fiber, and other knits with an open construction may require special hand laundering and blocking (stretching back into shape). Such items should be laid on a sheet of wrapping paper before washing, and the outlines traced. After washing, the garment should be stretched out on the paper to dry. While still damp, the garment should be gently stretched to fit the outline of the original dimensions.

Aside from stretching or shrinking, an additional problem with knitted items is skewing or twisting as the fabric is relaxed during laundering. Side seams of garments may pull to the front or back and hems may hang unevenly. In general, knits made of synthetics will have better resistance to stretching out of shape than will cotton, acetates, and rayons. Blending of synthetics with cottons, acetates, and rayons will improve the resiliency and dimensional stability of knitted fabrics made from these fibers. Price is a good guide-especially for children’s knits.

Mechanical Damage
The loop structure of knitted fabrics makes them especially susceptible to snagging. If a loop catches on another object, it may be pulled up from the fabric surface and a long snag, or pull, of yarn may be formed. If the yarn that has been snagged is not broken, it can be pulled to the back of the fabric. It may be possible to gently stretch the fabric and work the pulled yarn back into place. This is difficult to do with tightly knitted fabric structures. If the yarn has been broken, the snag may produce a hole in the fabric. A few hand stitches with needle and matching thread should be made to secure the yarns so that the hole does not become enlarged during wearing or laundering. Synthetic double knits or knits made from loosely twisted yarns may be subject to pilling. Weaker fibers, such as cotton, rayon, acetate, and wool, generally break off the fabric, but the stronger synthetic fibers cling to the fabric, making an unsightly area on the fabric surface. The use of textured yarns for knitting synthetics decreases the likelihood of pilling. Knits may be damaged by sharp objects puncturing the fabric. If yarns are cut, a hole will result, and further pressure and strain on the fabric may enlarge the open area, as loops are dropped in the interlocking structure.

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