Improved crocking and rubbing fastness

Fastness ratings, according to the grey scales for staining, range from 1 (poor rating) to 5 (best rating). Parameters of influence include  

Improved rubbing fastness can be achieved with partially hydrolysed poly vinylacetate (PVAc/PVA) or polyvinylether and the application of pigment binders, mostly based on acrylic copolymers similar to those nsed as hand builders (Chapter 4). Application methods mostly nse pad-dry techniqnes. 

Possible problems with finishes nsed to improve rubbing fastness include the following. 

Although silicones give very smooth films around any kind of fibre, silicone finishes (soft handle, water repellency, stretch) may reduce the crocking fastness. 

Softeners on dyed polyester often cause more disperse dye migration (especially thermomigration) and cause reduced crocking fastness. This is similar to softeners on the basis of fatty acids and azoic dyeings. 

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Properties provided by these finishes are mostly improved wet fastness, for example washing, water, perspiration and ironing fastness, then better light fastness and only to a small extent improved crocking and rubbing fastness. For other kinds of colour fastness, for example dry ironing, chlorine, peroxide and carbonisation, there are no known possibilities for improvement by an after treatment. The market importance of these finishes is based on customer preferences and economic production demands. For abetter understanding, each of these three quite different fastness improvements will be dealt with separately. 

References concerning finishes that improve crocking and rubbing fastness... 

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