During wear and washing, fabrics are affected by friction forces during usage. Friction forces results in the abrasion and pilling of fabric.
Abrasion is the mechanical deterioration of fabric components by rubbing against another surface. Abrasion ultimately results in the loss of performance characteristics, such as strength, but it also affects the appearance of the fabric. Although maintenance of strength and other properties that enter into performance is crucial in the life of a fabric, often apparel and other textile items are discarded because the fabric appears worn, sometimes long before fabric strength is significantly compromised.
Types of abrasion
- As a fabric rubs on another fabric;
- As a fabric rubs against another object;
- As fibers or yarns within the fabric rub against each other when the fabric bends, flexes, or stretches;
- As dust, grit, or other particles held within the fabric rub against fibers inside the fabric.
In many end uses, two or more of these types of abrasion occur simultaneously.
Properties affecting abrasion resistance
1. Fabric properties
One of the most important influences on the abrasion resistance of a textile fabric is the fiber content. Some fibers are inherently more resistant to abrasion than others. For example, nylon and polyester have a high ability to absorb energy (i.e., toughness), which contributes to the abrasion resistance of fabrics made from these fibers. Nylon’s high resiliency and low coefficient of friction also contribute to good abrasion resistance, making nylon an appropriate choice for end uses such as jacket shells, rope, carpet, or luggage.
2. Other factors in abrasion resistance
In addition to fiber, yarn, and fabric properties, and fabric configuration during abrasion, abrasion is also influenced by moisture and by the direction of the abrasive force. Just as it affects the strength of textiles, moisture also affects abrasion resistance. The effect of moisture is complicated, in that it can either improve abrasion resistance or cause fibers to abrade more quickly. Moisture can serve as a lubricant, reducing the friction between a fabric and another surface, and slowing the abrasion process. However, in general, fabrics made of fibers that are stronger when wet have better resistance to wet abrasion than to dry abrasion.
Because of the difficulty of reproducing “in use” abrasion in the laboratory, there are probably more instrumental methods and instruments for testing abrasion than for any other textile property. One reason for the difficulty in reproducing abrasion in the laboratory is that laboratory abrasion tests are usually conducted on new fabrics while, in actual use, abrasion occurs both before and after laundering or dry cleaning. In actual use, many different abradant forces also act on a fabric at one time, while most laboratory tests simulate only one type of abrasion.
Pilling is a fabric surface fault characterized by little balls or ‘pills’ of entangled fibers clinging to the fabric surface. The unsightly pills are formed during use and laundering of the textile product, and most often are seen in areas of a garment that undergo the most rubbing, such as under the arms or inside the collar of a shirt. Pilling is due to yarn structure, both yarn type as well as degree of twist, and inherent fiber strength.