The Role of Softener Flake in Textile Industry

1.Common quality problems in softening finishing:

① Failure to achieve the desired feel:

The soft style of softening finishing varies with customer requirements, such as soft, smooth, fluffy, soft and sticky, oily, dry and smooth, etc. Different softeners are selected according to different styles. For example, in soft films, there are soft films with different structures, and their softness, fluffiness, smoothness, yellowing, and the effect on fabric water absorption are all different; in silicone oil, the performance of modified silicone oil with different modified genes is also different, such as amino silicone oil, hydroxy silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, etc. The performance is different.

② Color change and yellowing:

Generally, yellowing is caused by amino groups in certain structure soft films and amino silicone oil. Among the films, cationic films are soft and have a good hand feel. They are easy to adsorb on fabrics, but they are easy to turn yellow and discolor, affecting hydrophilicity. If the cationic films are converted into soft oil essence, their yellowing will be greatly reduced and their hydrophilicity will also be improved. If the cationic films are compounded with hydrophilic silicone oil or with hydrophilic finishing agents, their hydrophilicity will be improved. Anionic films or nonionic films are not easy to turn yellow. Some films do not turn yellow and do not affect hydrophilicity. Amino silicone oil is the most widely used silicone oil at present, but because amino groups can cause discoloration and yellowing, the higher the ammonia value, the greater the yellowing. Low-yellowing amino silicone oil or polyether-modified, epoxy-modified silicone oils that are not easy to turn yellow should be used instead. In addition, cationic surfactants such as 1227, 1831, and 1631 are sometimes used as emulsifiers during emulsion polymerization. These emulsifiers will also cause yellowing. Different emulsifiers are used when silicone oil is emulsified, and their "stripping effects" are different, which will cause stripping and light color under different circumstances, which is already a color change.

③ Decreased hydrophilicity of fabric:

Generally, it is caused by the problem of film structure and the lack of water absorption genes after silicone oil film formation, as well as the closure of water absorption centers such as hydroxyl groups on cellulose fibers, carboxyl groups and amino groups on wool, which causes decreased water absorption. Anionic, non-ionic films and hydrophilic silicone oils should be used as much as possible.

④ Dark spots:

The main reason is that the oil stains on the fabric are not completely removed during pretreatment, and the color of the oil stains is darker during dyeing; or there is too much foam in the dyeing bath, and the mixture of foam, flower sweaters, dyes, etc. is stained on the fabric; or the defoamer floats oil to cause dark oil spots; or tar-like substances in the dyeing vat are stained on the fabric; or the dyes are agglomerated to form dark spots under different circumstances; or too many calcium and magnesium ions in the water combine with the dyes and stain the fabrics. Targeted treatment should be carried out, such as adding degreasing agents for refining during pretreatment, using low-foaming and non-foaming agents for dyeing auxiliaries, choosing defoamers that are not easy to float oil, adding chelating agents to improve water quality, adding solubilizing and dispersing agents to prevent dye agglomeration, and using cleaning agents to clean the vat in time.

⑤Light color spots:

The main reason is uneven pre-treatment, poor wool effect in some parts, resulting in a certain degree of dye repellency, or containing dye repellent substances, or calcium soap, magnesium soap, etc. on the cloth during pre-treatment, or uneven mercerization, or uneven drying of semi-finished products, or undissolved solids such as sodium sulfate and soda ash on the cloth surface, or water dripped on the dyed material before drying, or auxiliary stains brought by the dyed material during the post-finishing such as softening treatment. Similarly, targeted treatment is required, such as strengthening pre-treatment, the selection of pre-treatment auxiliary agents must not easily form calcium and magnesium soaps, the pre-treatment must be uniform and thorough (this is related to the selection of scouring agents, penetrants, chelating dispersants, mercerizing penetrants, etc.), sodium sulfate, soda ash, etc. must be well-treated and put into the cylinder, and production management must be strengthened.

⑥Alkali spots:

The main reason is that the alkali removal is not clean or uneven after pre-treatment (such as bleaching and mercerization), resulting in alkali spots, so the alkali removal process of the pre-treatment process must be strengthened.

⑦ Softener stains:

The causes are probably the following: a. The softening film is not good, and there are blocks of softener adhering to the fabric; b. There are too many foams after the softening film is made, and the fabric is stained with softener foam when it comes out of the vat; c. The water quality is poor, the hardness is too high, and the impurities in the water combine with the softener and condense on the fabric. Some factories even use sodium hexametaphosphate or alum to treat the water. These substances form floccules with impurities in the water, and after entering the softening bath, the fabric surface is stained; d. The fabric surface carries anionic substances, which combine with cationic softeners to form stains during the softening process, or the fabric surface carries alkali, causing the softener to condense; e. The softener structure is different, and some softeners are changed from emulsified state to slag-like substances adhering to the fabric at higher temperatures, etc. f. Tar-like softeners and other substances originally in the vat fall and stick to the fabric. ⑧ Silicone oil stains: This is the most difficult type of stain to treat. The main reasons are: a. The pH value of the fabric is not neutral, especially with alkali, which causes silicone oil to break and float; b. The quality of the treatment bath water is too poor and the hardness is too high. Silicone oil is very easy to float in water with a hardness of >150PPM; c. Silicone oil quality problems include poor emulsification (poor emulsifier selection, poor emulsification process, too large emulsified particles, etc.) and shear resistance (mainly silicone oil itself problems such as silicone oil quality, emulsification system, silicone oil variety, silicone oil synthesis process, etc.). You can choose silicone oil that is resistant to shear, electrolytes, and pH changes, but pay attention to the use of silicone oil and the environment, and you can also consider choosing hydrophilic silicone oil.

⑨ Poor fuzzing:

Poor fuzzing is closely related to the operation of the fuzzing machine (such as tension control, fuzzing roller speed, etc.). For fuzzing, when applying softener (commonly known as waxing), controlling the dynamic and static friction coefficients of the fabric is the key, so the preparation of fuzzing softener is the key. If the softener is not used well, it will directly cause poor fuzzing, and even cause the fabric to break or change in width.

2 Common quality problems in resin finishing:

① Formaldehyde problem:

The formaldehyde content exceeds the standard due to the free formaldehyde in the resin or the formaldehyde decomposed from the resin with N-hydroxymethyl structure. It is advisable to use ultra-low formaldehyde resin or formaldehyde-free resin. Of course, the source of formaldehyde problems is very wide, such as color fixer Y, M, softener MS-20, S-1, waterproof agent AEG, FTC, adhesive RF, flame retardant THPC and other additives sometimes cause formaldehyde to exceed the standard. At the same time, formaldehyde migration in the air may also cause formaldehyde to exceed the standard on the fabric.

② Yellowing or color change problem:

After resin finishing, yellowing will generally occur, so the pH value, acid content, and catalyst content of the resin finishing agent should be controlled to minimize yellowing and color change.

③ Strength reduction problem:

Generally, resin finishing will cause strength reduction, and fiber protective agents such as oxidized polyethylene wax emulsion can be added.

④ Hand feel problem:

Generally, resin finishing will cause the hand feel to become hard, and soft ingredients can be added, but be careful not to affect the quality of resin finishing. Improved hand feel will also greatly improve the problem of strength reduction. However, problems such as hard hand feel caused by surface resin are caused by the resin itself and drying, and targeted improvements should be made.

3 Other quality issues:

① Excessive metal ion:

Metal ions Cu, Cr, Co, Ni, Zn, Hg, As, Pb, Cd, etc. are tested in export products. If they exceed the standard, they will have serious consequences like formaldehyde exceeding the standard. In additives, such metal ions are less, but some additives will cause excessive levels, such as flame retardant antimony trioxide emulsion contains a lot of mercury, waterproofing agent CR, Phobo Tex CR (ciba), Cerolc (Sanders), etc. contain chromium. When using mordant dyes on wool spinning, the mordant dyes used are potassium dichromate or sodium dichromate or sodium chromate, and Cr6 will exceed the standard.

② Color change problem:

After finishing, there are many color change problems. This requires attention to the selection of dyes during dyeing. When dyeing proofing, the corresponding finishing must be carried out according to the process to determine whether the selected dyes will change color under the action of auxiliaries during finishing. Of course, it is best to choose a finishing agent that will not cause color change, which is the most ideal solution, but this often has limitations (such as copper-containing antibacterial agents have colors themselves, and chromium-containing waterproofing agents also have colors, which will cause color change of fabrics). At the same time, it is also necessary to consider factors such as light color and color change caused by dye sublimation during drying and baking of dyed fabrics and yellowing caused by excessive temperature.

③ APEO exceeds the standard:

APEO as an indicator is also strictly restricted by some countries. This indicator is related to the scouring agent and penetrant in pretreatment, the detergent and leveling agent in printing and dyeing, and the emulsifier in the softener during finishing. Under the current situation where TX and NP series surfactants are widely used as auxiliary raw materials, it is difficult to prevent them. The only way is for printing and dyeing factories to insist on using environmentally friendly auxiliaries and strictly prevent auxiliaries containing APEO and toxic and harmful substances from entering the factory.

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