The most important property of any apparel is comfort and handle. Due to the hydrophobicity and soiling properties of synthetic and its blends, it gives the wearer less comfort. Synthetic materials have the ability to resist most bacteria, microbes and insects, as the synthetic is not digestible. However, soiled synthetics can cultivate microbes because of the added source of food. This makes the wearer even less comfortable. To overcome this, moisture management, stain/ soil release and antimicrobial treatment on synthetic and its blends are necessary. Therefore multifunctional finishes using specialty chemicals are needed.
Moisture management often refers to the transport of both moisture vapour and liquid away from the body. Moisture management can be defined as 'The controlled movement of water vapour and liquid water (perspiration) from the surface of the skin to the atmosphere through the fabric'. When a synthetic material is subjected to this moisture management treatment, it develops improved hydrophilicity followed by very fast drying behaviour. In case of synthetic blends subjected to this treatment, their drying rate becomes much faster. In the case of natural fibres it is the reverse - very good absorbency and slow drying rate. The drying rate of polyester is four times greater than cotton. P/C blends subjected to moisture management treatment will have increased absorbency. The polyester will dry more quickly than cotton and while it dries it keeps on absorbing from cotton and quickens the drying process. Wicking, wetting and drying rate are test methods through which we can find out moisture management efficiency.
Soil/ Stain Release
When a textile substrate is made repellent in nature, it is able to repel only the liquid stains or soils. But, dry stains like grease, paint, grass stain, etc, leave their mark on the textile. These are difficult to remove from a surface made repellent in nature. Hence, the need for soil/ stain release finishes. Like the name implies, a soil release finish keeps dirt from binding to the substrate fibre and allows it to be more easily removed through vacuuming, laundering and other cleaning methods. Soil release finishes tend to come in either fluorochemical or silicone type varieties. Fluorochemical treatments protect against both water and oil-based soils and resist wetting by oily and watery liquids. Silicone treatments protect against water-based soils and watery liquids only.
Soil release chemicals help in easy laundering by releasing water and oil-based stains. Today, stain release finish for cotton fabric apparel is mostly imparted by the incorporation of low surface energy fluorochemicals. Stain release fluorochemical finishes allow oil and water stains to penetrate the fabric. However, when the fabric is laundered, the stains are easily removed. Fluorochemicals have the unique property to provide fabrics with a low surface energy film with both high oil and water repellency properties to resist penetration of oil and water-based stains (polar and non polar liquids). The 'repellent' products prevent the textile substrate from wetting and soiling by repelling the soiling substances and the adhesion of dry soil. Fluorochemical hybrid finishes, also called 'dual effect', and containing hydrophilic groups, have also been developed and improved successfully over recent years to impart both stain repellency and stain release properties.
The concept of soil release finish comes into play here. Originally, the soil release finish imparts hydrophilic properties to the substrate and lowers its static charges. The result is that the oil and water-based stains do stick, and penetrate but are very easily washed off in normal home laundering. Synthetic fibres such as polyester have more hydrophobic properties which limit their scope of usage. If such fibres are imparted with more hydrophilic properties, especially water/ perspiration absorbency with wash-fast resistance, their use will further broaden. Superior hydrophilic properties (water/ perspiration absorbency) will allow varieties of fibre materials, knits, wovens and industrial materials a broader scope of use.