Silicone finishes for textiles offer durable soft finish to cotton and its blended fabrics apart from offering aesthetic features. The performance of a silicone finish varies depending upon the functionality and molecular weight of the silicone polymer. The chemistry of silicones for textile treatment is big and the commonly used silicones in textiles have amino, amido, organo and epoxy functionalities. Depending upon the functionality in the polymer chain, they offer a wide range of performance properties like durable softness, sewability, lubricity, elasticity, hydrophobicity, hydrophilicity, wrinkle and stretch recovery.
As silicone finishes are increasingly preferred due to their versatility in finishing of fabrics, it is very important for the user to follow a set of 10 general precautions that need to be strictly adopted during handling and application.
- Pre-dilute the silicone that is ready for application in a ratio of 1:4 by adding clean water slowly into it while blending gently.
- Never use hot water to dilute silicones.
- Ensure a water PH of 4.50 5.00 in the tank before the addition of silicone emulsion.
- PH adjustment must be done using glacial acetic acid.
- Check the compatibility of the silicone emulsion with other auxiliaries before going for any combinations in bulk, as some cationic softeners tend to raise the PH to a level where the stability of the silicone emulsion gets affected severely.
- After every finishing, do clean the machinery thoroughly before going for the next lot. As the silicones have the tendency to dry out and form a sticky mass on the metal and ebonite surfaces that may affect the subsequent finishing, thorough cleaning between different lots is mandatory.
- Always keep the container closed and store the product in an area where there is no direct sunlight, as air and light may lead to rapid oxidation that could adversely affect the emulsion stability.
- Use separate jugs for silicones and do not mix up with other auxiliaries.
- Try to take only the required quantity precisely. Avoid pouring back excess material into the container.
- Hard water and chlorinated water must be strictly avoided in silicone finishing.
Follow these 10 rules and enjoy the luxury of silicone finishing.
Author is Head - R & D, Shri Meera Labs Pvt Ltd, Chennai, India