The role of softener
1. Supplement the natural oils lost by natural fibers in scouring and bleaching processes, making the hand feel more ideal.
2. Attach to natural fiber or synthetic fiber to improve smoothness and strength, and improve hand feeling.
3. Improve the wearability of the fabric through some characteristics of the softener.
In order to achieve some of the above effects, softeners are generally grease-like smoothness and feel. Adhering to the surface of the fibers can reduce the frictional resistance between the fibers and make the fibers lubricate and soft. There are also some softeners that can cross-link with some reactive groups on the fiber to achieve the purpose of washing durability.
Requirements of softener
1. Under various soft processing conditions, the working fluid should be very stable.
2. Does not reduce the whiteness and color fastness of fibers or fabrics.
3. The softened fiber or fabric is not easy to be discolored by heat, and there should be no changes in color, feel, or odor during storage.
4. If the softener is emulsion, its emulsion stability is better.
5. According to different processing requirements, it can have proper water absorption or water repellency, anti-static properties and other properties (should be selected according to the different requirements of the fabric). It is resistant to washing or dry cleaning.
6. There is no adverse effect after human skin contact.
Due to the wide variety of textiles, different fibers used, different fabric specifications, different fabric uses, and different finishing requirements, the selection of softeners cannot be generalized. On the basis of softening mechanisms and functions of various softeners, select those that meet the requirements. Softener. In addition, the performance of each softener is always limited. To obtain good results for multiple performances, two or more softeners can be used in combination (or compounded into a new softener product). ). For example, the combined application of silicone softener and long-chain aliphatic softener can achieve a better effect of soft, plump and smooth hand feeling. It can also combine the application of softener with mechanical softening and often obtain good results. Effect.
The type of softener
Softeners are the most diverse and the largest amount of dyeing and finishing auxiliaries. According to reports, among the 920 domestic and foreign auxiliaries samples collected by the Shanghai Institute of Printing and Dyeing Technology from 1990 to 1999, there were 350 softeners, accounting for 38%. So many varieties of softeners, based on their chemical structure, basically fall into two categories: long-chain aliphatic or high-molecular polymers. In the molecular structure of long-chain aliphatic softeners, the long hydrocarbon chains can be randomly arranged in a crimped state to form molecular flexibility. The flexible molecules adsorb on the surface of the fiber to play a lubricating effect, reducing the fiber and The dynamic and static friction coefficient of the fiber.
Therefore, the long-chain aliphatic structure generally has a good softening effect. In the softening agent, there are not only many varieties, but also a relatively large amount. Such softeners can be divided into anionic, cationic, nonionic and amphoteric types according to their ionicity. In addition, natural oils and paraffin wax softeners, because they are natural lubricating substances, can also be regarded as a separate category, but they are also classified into different ionic categories according to the ionicity of the emulsifier used. . High molecular polymer softeners mainly include polyethylene and silicone. The variety of polyethylene softeners is relatively single, and the dosage is less, and the dosage is also less. The main thing that uses more is the silicone softener. Since the main chain of polysiloxane is a helical linear structure that is easy to bend, it can rotate freely in 360 degrees, and the energy required for rotation is almost zero. Therefore, the molecular structure of polysiloxane is in line with the softening mechanism of textiles. It can not only reduce the static and dynamic friction coefficients between fibers, but also reduce the intermolecular force and reduce the surface tension of fibers. It is a soft finishing agent for textiles. Ideal material. Silicone softener is the fastest growing softener variety in recent years.