WET PROCESSING: EXPLAINED COMPLETELY (PART 2)
by : Rahul Sharma
WET PROCESSING:
4. Dying : In view of the high cost of dyes compared to the material to be dyed, the dyeing operation can be the costliest of any wet processing treatment, and in order to obtain the desired dyed results commensureate with optimum costs of dyeing, one finds the various auxiliaries available as a reliable means to achieve this object. Among the many types the following can be considered as typical examples.
i) Restraining agents,
ii) Levelling Agents,
iii) Solvents,
iv) Dispersing Agents
v) Antimigration Agents,
vi) Stripping Agents, etc.
5. Mercerising : The main effect of mercerising is to cause the shrinkage and the accompanying swelling of the cotton fibers in the yarns or fabrics. The penetration of the mercerising liquor into the material and thereby the mercerising effect is enhanced considerably by the use of suitable wetting agents.
6. Printing : As in dyeing, auxiliaries in printing serve to obtain more efficient results in printing. The following are some of the typical results obtained when using the appropriate auxiliaries :
i) Better colour yield,
ii) Better fastness properties,
iii) Clarity of the prints,
v) Cleaner unprinted or reserved and etc.
7. Finishing : A wide spectrum of applications is encountered in the field of textile finishing for various types of auxiliaries where their use enables the finisher to achieve the desired results. The auxiliaries generally used are either film-for-ming agents or softening agents used either alone or in admixture with each other.
Besides the natural film forming agents like starches and seed gums, synthetic film forming agents also are now available. In addition synthetic resin forming chemicals have been put to scores of uses.
Among the softening agents also, there has been a spectacular growth of synthetic softeners because of the paucity of natural raw materials and also because of the ready availability of synthetic raw materials which are available in adequate supplies at competitive perices and tailor made to requirements. The latest softeners available for today's finishing are reactive softeners for the type of fibre under treatment, and are designed to impart permanent softners, a quality which was hitherto unknown. Similar is the case of synthetic perfumes which are not only potential deodourifiers but are also aesthetic agents which serve to increase the sales appeal of fabrics and garments.
