Solvent Processing

[10] Advantages claimed for solvent technology:

• elimination of a pre-scour
;
• smaller, less costly equipment
;
• flexibility of making short, continuous runs
;
• low utility requirements
;
• considerable water usage reduction
;
• better leveling and uniformity
;
• better reproducibility between runs
;
• possibility to integrate dyeing and finishing
.

However, solvent technology did not meet wide acceptance due, according to the literature reviewed, to:

• chemical systems, dyes, specialities, etc. appropriate to solvent use were not available at a commercially competitive cost
;
• environmental regulations for airborne emissions from solvent processing equipment, storage facilities, and hazardous waste regulations on recovery by-products (still bottoms, etc) made many solvent processes uneconomic. A tight control over solvent systems is required to keep solvent losses below 5% of the fabric weight
;
• drawing solvent-laden air to dryers or tenter frames may result in their conversion to hydrochloric acid gas. Fabric weakening, browning of cellulose or dye degradation are some of the possible difficulties which should be anticipated
.