Basic Principles of Stain Resistance
Prior to the development of finishes, stain resistance of textiles was based on the fibres inherent characteristics of water or oil repellence. This is determined by the Surface Energy and Surface Tension? interaction between the fabric and the discolouring caused by a liquid stain. A Contact Angle? of under 90° defines a hydrophillic or wettable quality. The Surface Tension? varies greatly in liquids, thus altering their interaction with the fabric surface. Porosity will influence stain adherence to textiles, as pores can provide a space for foreign matter to penetrate, in liquid substances the ability to penetrate these pores is influence by the Capillary Forces are responsible to drive the liquid in capillary spaces. (Click here for more information)">capillary wicking forces. In solid states the staining potential is governed by the solids ability to break up in to particles small enough to sit in the pores. However a staining ability will only be possible if the staining product is allowed to interact with the surface and the Surface Tension? property defines this.
Fabrics which do not contain inherently hydrophobic fibres have this property imparted at the finishing stage. Laminates or membranes can be applied to provide this, however they can have a detrimental affect on both breathability and softness. Chemical coatings are applied to provide this attribute, such as fluorocarbons, resins and silicones.
Flurocarbon chemistry implemented in textile finishing processes was used to provide both a hydrophobic and oleophobic attribute. This created a problem of organic pollution; in certain instances the fluorocarbons particles were too large to break down in the environment and had a toxic effect. Flurocarbons require a binding agent to improve durability and the use of such provides further negative environmental affects.
fluorocarbons for textile finishing
Nano whiskers Powerpoint; api.ning.com/files/...MEuOq/FINALNANOWHISKERS.ppt
Nano-finishes can be applied during traditional finishing methods such as Padding?, drip or dry coating and can be applied to a range of natural and synthetic fibres.