As a commercial form of textile softener, softener flake have been flooding the market for more than 20 years. In recent years, there have been softener beads. It is a weak cationic surfactant, a high-grade fatty amide derivative, and has qualities common to all softener products.
Among textile dyeing and finishing auxiliaries, softeners have the largest variety and largest dosage. In the dyeing and finishing process, in order to make the fabric have a smooth and soft feel and improve the quality of the finished product, in addition to using preshrinking machine with oak blanket treatment to adjust the feel (to improve the displacement performance of the fabric's interweaving points), it is also treated with softeners. Softener is a textile auxiliary that reduces the friction coefficient between fibers to obtain softness and lubrication on the fiber surface. Softeners for textiles must have the following characteristics: good softness, applicability to a variety of fibers; good compatibility with other additives; no allergic or irritating effects on the human body, no bad gases emitted during processing; no fumes The phenomenon of yellowing and discoloration does not affect the light fastness and washing resistance of the dye; it meets the requirements for high-temperature treatment in dyeing and finishing; the price is moderate, the finishing process is simple, and the storage is stable; it is biodegradable.
Softeners rarely use a single chemical. Currently used softeners are roughly divided into four categories: non-surfactant type; surfactant type; reactive type and polymer emulsion type.
Non-surface active：
Natural oils and paraffins
Non-surface-active softeners were mainly of this type in the early days. They were made from natural oils and paraffins, and were formulated into emulsions under the action of emulsifiers. They could be used as textile oils and softening finishing agents.
The natural oils used are stearic acid, coconut oil, white oil, etc. Emulsifiers are commonly used anionic NEKAL BX or nonionic leveling agent O, (alkyl polyoxyethylene ether), etc. In order to increase the thickness of the emulsion, thickening agents such as carboxymethyl cellulose and bone glue are sometimes added. Paraffin emulsion is the most important. The paraffin emulsion has a pH value of 7, which is neutral and resistant to acid, alkali and hard water. It can be diluted with water in any proportion.
Ammonium salt soap of fatty acids
Neutralizing fatty acids with amines can produce stable amine salts, which, like metal salts of fatty acids, have the properties of soap, can be dissolved in water, are weakly alkaline (PH=8~9), and have good emulsifying properties. And it can make the fabric feel softer. For example, triethanolamine oleic acid soap is used in the milling process of the wool spinning industry to make wool fabrics feel soft and shiny.
Surfactants
Most softener varieties are surfactants. Anionic and nonionic softener flake were mainly used for cellulosic fibers in the past, but are now used less frequently. Cationic softener flake are suitable for both cellulose fibers and synthetic fibers. They are a widely used category.
Anionic softener
Anionic softeners were used earlier, but because the fibers have negative charges in the water, they are not easily adsorbed by the fibers, so the softening effect is weak. Due to its poor adsorption to fibers, it is easy to clean out, so some varieties are suitable for use as softening components in textile oils. Mainly include: sulfates of castor oil, olive oil, peanut oil, lanolin and whale oil, etc., which can make fabrics have a certain smoothness; sulfates of butyl ricinoleate; sulfates of fatty acids; partial sulfates of fatty alcohols.
The non-ionic softeners is similar to that of anionic softener flake. They will not be discolored by dyes and can be used with anionic or cationic softener flake. However, they have poor adsorption to fibers, low durability, and have almost no effect on synthetic fibers. They are mainly used in the finishing of cellulose fibers and as softening and smoothing components in synthetic fiber oils. Mainly include: pentaerythritol fatty acid ester, glyceryl fatty acid monoester, sorbitan fatty acid monoester, fatty acid ethanolamide, fatty acid polyethylene glycol ester, fatty amide polyethylene glycol condensate, hydroxymethyl fatty acid amide, polyether etc. Among the above nonionic softeners, pentaerythritol and sorbitol are the two most important.
Cationic softener flake have strong ability to combine with various natural fibers and synthetic fibers, can withstand high temperatures and washing, and have strong durability. They can be used to finish fabrics to obtain excellent softness effects, plump hand feel, and smoothness, giving synthetic fibers a certain Antistatic effect, and can improve the abrasion resistance and tear strength of fabrics. The disadvantage is that it has a yellowing phenomenon, discolors the dye, has an inhibitory effect on fluorescent whitening agents, reduces the sun and rubbing fastness, cannot be shared with anionic surfactants, and is irritating to human skin to a certain extent, so its use is restricted.
Amphoteric softener
Amphoteric softeners were developed to improve the shortcomings of cationic softener flake. They have strong affinity for synthetic fibers and have no problems such as yellowing, discoloration of dyes, or inhibition of fluorescent whitening. They can be used in a wide range of media. However, its softening effect is not as good as that of cationic softener flake, so it is often used in combination with cationic softener flake. Because the price is relatively expensive, there are currently not many varieties. This type of softener is generally an alkylamine lactone structure, including amino acid, betaine and imidazoline types.
Reactive softener
Reactive softeners, also known as active softeners, contain softeners in the molecule that can react directly with (-OH) of cellulose fibers to form ester bonds or ether bonds that are covalently bonded. It is wear-resistant and washable. Types include: acid anhydride derivatives, ethyleneimine derivatives, etc. Most reactive softeners require high-temperature baking under certain conditions during the finishing process. To promote chemical reactions with fiber molecules, this can significantly improve its washing resistance. Because its properties are generally relatively active, it is not suitable for long-term storage. When dissolving, use cold water below 40°C and use it with you.
High molecular polymer emulsion
This type of softener is mainly an emulsion made of polyethylene, silicone resin and other high-molecular polymers. It is used for fabric finishing without yellowing or discoloring dyes. It not only has a good softening effect, but also has a certain anti-wrinkle effect. and waterproof performance. When fabrics are treated with resin, if used in combination with this type of softener, it can not only improve the feel of the fabric, but also prevent or alleviate problems such as the decrease in fiber strength and wear resistance caused by resin finishing agents. However, their friction fastness is poor and their prices are relatively expensive, so they are only used for the finishing of high-end textiles. Including: polyethylene resin emulsion, silicone, etc.
Conclusion
The most commonly used raw material in the production of softener flake is fatty acids, which are aliphatic products. Different textiles and different fibers require different types of fatty acids. They are aliphatic products. Different textiles and different fibers require different types of softener flake. Therefore, There are many types of softener flake, and there are many brands. Most of them are cationic, there are also non-ionic and a small amount of anionic, and there are also anionic and amphoteric ionic. The cationic softener flake type has the best hand feel, but the fabric is easy to yellow. The non-ionic softener flake type has good hydrophilicity and does not yellow, but the feel is not as good as the cationic type.
