Pretreatment Acrylic of yarn & Fabric
Scouring of acrylic/cellulosics blends:
Blended yarns of acrylic/cellulosic fibres are prepared on the woollen system.
Yams prepared in the cotton system of spinning may be scoured at 60~ (30~ for unrelaxed bulked yams) for 30 min in a liquor containing 1 g/1 non-ionic detergent and 0.5 ml/1 acetic acid (80%). Fabrics should be desized and scoured to remove sizes, spinning assistants and other impurities. Scouring can be carried out with 1 g/1 non-ionic detergent, 1 g/1 trisodium phosphate at 60~ for 30 min followed by rinsing well with s
Polyester/Acrylic Blended Yarn Pretreatment:
Scouring of polyester/acrylic fibre blended fabrics can be carried out in either a
weakly acid or alkaline bath using a combination of 0.5-1 g/1 non-ionic and anionic
detergents. The pH of the bath is adjusted to 5-6 with acetic acid or 8-7 with ammonia
or soda-ash and the treatment is done for 20-30 rain at 60~ (for acidic pH) and
40-50~ (for alkaline pH). The amount of detergent used depend on the degree of
soiling. After washing, rinsing proceeds until the cloth is free of alkali. It is an
advantage to sour the last rinsing with a little acetic acid
Scouring of acrylic/wool blends
Wool/acrylic fibre blend yarns are prepared on the woollen or worsted systems of spinning. Generally, fatty acid type of lubricants applied in woollen processing should be avoided to prevent discolouration of the acrylic fibres. High bulk acrylic fibres are also used in the wool industry. Blend yams containing unrelaxed highbulk
acrylic fibre should be completely relaxed before being dyed, either by steaming in an autoclave at 107~ for 10 min after preliminary evacution of the steamer, or by immersion in boiling water for 5 min.
For worsted yams, scouring can be conducted at a maximum temperature of 60~ for 30 min with 1 g/1 non-ionic detergent and 0.5 ml/1 acetic acid (80%).
Woollen spun yams lubricated with oleine are scoured at 30~ with soap or synthetic
detergent and sodium carbonate. The addition of solvent is sometimes advantageous
for the removal of oils. Tape scouring machines are generally used for
the scouring of hanks.
Acrylic/wool blended fibre fabrics may be prepared according to established
practice for wool, except that precautions are taken to allow for the thermoplastic
properties for the acrylic fibres. Relaxation is done to remove the inherent strain. Worsted fabrics are crabbed and then scoured in either a Dolly at temperature not exceeding 40~ or in winch.