The Processing Technology Of Nonwovens Made Of Cellulose Fiber Is Becoming More And More Mature.

< p > < a href= "//www.sjfzxm.com/news/index_c.asp" > nonwovens > /a > cellulose fiber as raw material, after scouring and bleaching, it is not only clean in appearance and high in whiteness, but also has great changes in its water absorption, wettability, softness, and absorption and utilization of fuels and finishing agents.

In particular, scouring and bleaching are of great significance for the production and development of nonwovens sanitary materials.

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< p > scouring and bleaching are optional processing technologies in the production of nonwoven products. In actual production, reasonable selection can be made according to specific requirements.

For example, the whiteness of the nonwovens used for medical and cosmetic products is not the most important performance requirement. Especially for the products of fluff, hemostatic or wound accessories, it is more inclined to require that the fiber has the characteristics of high absorptive capacity and less chemical residues. At this time, the key to the process of boiling is to be done, while bleaching is secondary.

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< p > < strong > biological enzyme scouring method to improve cloth surface efficacy < /strong > < /p >

< p > cotton fiber is a natural cellulose fiber commonly used in nonwovens. The content of natural impurities in cotton fibers depends on the origin, maturity and other factors of raw cotton.

The purpose of scouring is to remove natural or man-made impurities, such as waxy substances and pectin substances on natural cotton fibers, and the remaining spinning oil and oil can be removed after being scoured.

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< p > scouring can significantly improve the wetting and water absorption properties of nonwovens, improve the appearance quality of products, and prevent the interference of these impurities to dyeing and finishing.

After the scouring, the capillary effect or the percentage of residual wax can be used to test and sort out the effect. The content of residual wax is generally about 0.2%.

In addition, because fiber is used in the process of scouring and removing impurities, it can be affected by chemicals. The degree of damage can be expressed by the copper ammonia fluidity, or it can be measured by the strong change of nonwoven fabrics.

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< p > because nonwovens themselves are not suitable for scouring and finishing of conventional fabrics after dyeing and finishing, the method of bulk fiber processing is usually used when products need to be scoured.

During the scouring process, the temperature required by the process is greater than or equal to 100 degrees C. if the equipment is allowed, it is best to use 120 ~130 C. Only this kind of scouring condition can remove the impurities in the fiber and ensure good water absorption.

When the dosage of scouring agent is constant, increasing the scouring temperature is conducive to the removal of magazines and shortening the boiling time. On the contrary, the temperature is low and the boiling time is short.

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< p > biological enzyme scouring is a popularizing technology of < a href= "//www.sjfzxm.com/news/index_s.asp" > cellulose fiber < /a > scouring and drying technology.

In the traditional scouring process, after scouring, a large amount of clean water is needed to rinse and produce a large amount of sewage, which has a great impact on the environment. However, using biological enzyme refining method can not only effectively remove impurities, but also greatly reduce environmental pollution.

Refining with enzymes not only does not affect the skeleton of cellulose, but also reduces the damage to nonwoven fabrics.

Proper mixing method can play a positive role in scouring effect.

If stirred in the process of enzyme scouring, it can shorten the time and reduce the amount of enzyme, and also improve the wool effect of nonwovens.

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< p > < strong > environmental protection type of acetic acid bleaching on the agenda < /strong > /p >

< p > the purpose of bleaching is to destroy natural and artificial pigments on Nonwovens and improve the whiteness of nonwoven products.

At present, the research on the structure and properties of natural cellulose is not yet thorough. Through the study of brown cotton, it is found that the brown pigment in cotton fiber is mainly phellodendrin and cotton pigment. They have the nature of acid dyes, and the molecular structure contains conjugated double bonds. The existence of pigment will undoubtedly affect the whiteness of cotton fibers.

When bleaching non-woven fabrics containing adhesives, we should consider the effect of bleaching agents on the adhesives. The effect of bleaching on non-woven fabrics of cotton fibers is better than that of non-woven fabrics.

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< p > commonly used bleaching agents are two types of reducibility and oxidation.

Reductive bleaching agents produce bleaching effects by reducing the pigments. However, after the bleached products are placed in the air for a long time, the restored pigments tend to be oxidized again, resulting in the persistence of Baidu products.

Oxidizing bleaching agents such as sodium hypochlorite and hydrogen peroxide are commonly used bleaching agents in industrial nonwovens processing.

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< p > the current bleaching methods include three kinds of bleaching, bleaching, bleaching and drifting, of which non-woven fabrics are mainly bleached and bleached, while cotton staple fibers are basically made of loose fibers.

The technological process of bulk fiber bleaching is batch processing. The processing sequence in actual production is: filling, boiling, washing, bleaching, washing and drying, or filling, bleaching, washing and drying.

Which sort of processing sequence is used depends on the type of fiber processed.

Generally, cotton lint with the lignin content is used in the first processing sequence. For the combed lint with less impurity content, second processing sequences can be used.

A nonwoven equipment manufacturer in Britain is now developing the world's first continuous production line, which is based on saturated impregnating machines and washing machines.

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P > peracetic acid bleaching is a recently widely studied and popularized "a href=" "http://cailiao.sjfzxm.com/" > bleaching technology < /a >.

Peracetic acid is an environmentally friendly bleach. It has basically no harmful substance emission and low energy consumption during bleaching.

The optimum conditions for bleaching of peracetic acid are: bleaching agent dosage 8%, temperature 70 C, pH value 7, bleaching time 60min.

Peracetic acid is prepared by reaction of acetic anhydride or glacial acetic acid with hydrogen peroxide. Due to its easy decomposition, safety precautions must be taken into account during the manufacture, pportation and handling of acetic acid.

The materials for acetic acid bleaching are stainless steel and aluminum (minimum content 95%), glass and ceramics.

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