Pilling is the appearance of bobbles on the fabric surface, the process consists of 3 stages;
1. Fuzz formation- fibres work loose and form a fuzz on the fabric surface
2. Pill formation- these loose fibres become entangled to form a pill
3. Wear off- The pill works it self loose or the anchor fibres snap and the pill becomes free of the fabric
The occurrence of pills is due to a complex relationship between fibre, yarn and fabric structure, and the resultant properties of each will influence the formation of pills over the 3 stages. The phenomenon is more predominant in Staple Fibres; however it can occur in Filament? yarns as a result of weakened fibres abrading and breaking, creating loose surface fibres.
Fuzz formation is a result of fibre migration to the surface of the fabric, a mechanical action then results in the formation of pills through friction. The frictional force can come from the rubbing against a fabric of its own type, or another object such as jewellery or accessories which does not have to be textile. Factors which influence the fibres becoming loose are;
• Surface texture
• Cross section? shape
• Bending Strength
• Abrasion resistance
The fibres then have to amalgamate to form the pill, foreign matter can act as a nucleus for the pill and can contribute to the pills appearing a different colour to the fabric to which they are attached. The laundering process provides conditions for both fibres to work loose and work into a pill, as the mechanical agitation required to remove soiling allows for fibre migration and frictional contact. The pills then wear off the fabric either by the fibres still anchored within the yarn also working loose, or by them snapping, therefore breaking strength is a contributing factor, and strong fibres will require more energy to break them.
Pilling in fabrics became more of a problem when synthetic fibres were introduced and blended with natural, such as polyester, acrylic and nylon. This is because they have a higher strength than natural fibres, and therefore require more energy to break; their electrostatic properties also attract foreign matter, resulting in an unsightly appearance that is difficult to remove. The smooth surface texture and round Cross section? of synthetic fibres also provides a lower surface friction, enabling further their ability to migrate and form fuzz and then pills. The high strength of the fibres anchoring them on the fabric surface results in a higher level of abrasion required to remove them, which may take a longer period of time.
It is mainly the negative appearance associated with pilling which makes it an aesthetical problem in apparel applications, reduced strength and comfort can also be a consequence. Pilling is unsightly in garments, reducing the garment life by creating a negative visual appearance unacceptable to the consumer.