Softening Finishing Chemicals in Textiles
The concept of softness
Textile have a soft and comfortable feeling when people touch it, it’s a kind of subjective feeling. When people touch textiles their fingers have friction with fibers, handle and soft feeling are certain associated with coefficient of both kinetic friction and static friction. Besides, textile is fluffy, full and elastic which contribute a soft handle. It means that handle is related with surface area of fibers.
Softening agent processing mechanism
Surfacants have an oriented absorption on fibers which reduce the surface tension of fibers and make it easy to expand and to increase its length. As a consequence, textile become fluffy, full and elastic which produce a soft handle. The stronger the absorption that the surface active agent have on surface of fibers is the surface tension of fibers will be reduced more, then it lead to the more soft handle.
The oriented absorption of surfacants have on the surface of fibers can form a layer of film in which hydrophobic group are orderly outward arranged. The friction among fibers happen between hydrophobic groups which glide over each other, then this reduce friction coefficient a lot and make yarn easy to slide and also disperse the stress when textiles attacked by external force. What’s more, this layer of film can decrease flexural modulus and compression stress, it make textiles soft by returning fibers that attacked by strong force to its fluffy status during processing.
Softening agent is generally a kind of chemical compound which can absorb at the surface of fibers and make it smooth to enhance its softness.
General softening agents are surfacants and polymer softener. Polymer softeners are divided into two main kinds, silicone softeners and polyethylene emulsion.