Problems in the production process of non-woven fabric production line

來源:  時間:2020-01-10

Now, there are many enterprises that produce textile fabrics. With the development of the times and the progress of people, non-woven fabrics were invented. In short, non-woven fabrics are non-woven fabrics that are not processed and formed, so they are also called non-woven fabrics. And now the application of non-woven fabrics is also very extensive, non-woven fabrics with moisture, breathable, non irritating, recyclable and other characteristics are favored. It is inevitable that the non-woven fabric production line will encounter some problems in the process of producing non-woven fabrics. The problems that may be encountered and the corresponding solutions are briefly analyzed as follows:


1、 Types of abnormal polyester cotton fibers

Answer: During the production of polyester cotton, it is inevitable that some abnormal fibers will be produced due to the problems of the pre spinning or post spinning vehicle conditions. Especially, the regenerated cotton produced with recycled chips is more likely to produce abnormal fibers; Abnormal fiber outsole can be divided into the following types:;

(1) Single thick fiber: a fiber with incomplete extension, which is easy to cause abnormal dyeing and has less impact on nonwoven fabrics that do not need dyeing, but has serious impact on water needle or needle punched fabrics used for artificial leather substrate.

(2) Blending: after extension, two or more fibers stick together, which is easy to cause abnormal dyeing, and has less impact on non-woven fabrics that do not need dyeing, but has serious impact on water needle or needle punched fabrics used for artificial leather substrate.

(3) Colloidal: Broken or twisted silk occurs during extension, so that the fiber does not extend to form hard cotton. This product can be divided into primary, secondary and tertiary colloidal. After carding, such abnormal fibers often deposit on the card clothing, causing problems such as poor web formation or broken web. Such raw materials will cause serious quality defects on most nonwoven products.

(4) Oil free cotton: during the extension period, there is no oil on the fiber due to the rough driving conditions. This fiber usually has a dry feel. In addition to generating static electricity in the nonwoven production process, it also causes problems in the finishing of semi-finished products.

(5) For the above four abnormal fibers, it is difficult to remove a single thick and blended fiber during the production of non-woven fabrics. Colloidal and oil-free cotton can be removed with the little attention of production personnel to reduce product quality defects.

2、 The reasons of influencing the flame retardancy of non-woven fabrics

Answer: The reasons for the flame-retardant effect of polyester cotton are as follows:

(1) The oxygen limiting index of conventional polyester cotton is 20-22 (the oxygen concentration in the air is 21%), which is a kind of combustible fiber, easy to ignite but slow to burn.

(2) If the polyester chip is modified and denatured, it will have a flame-retardant effect. Most of the long-acting flame-retardant fibers use modified polyester chips to produce flame-retardant polyester cotton. The main modifier is phosphorus series compounds, which can combine with oxygen in the air at high heat and reduce oxygen content to achieve good flame-retardant effect.

(3) Another method to make polyester cotton flame retardant is surface treatment. This product thinks that the flame retardant effect will be reduced after multiple processing of the treatment agent.

(4) Polyester cotton has the characteristic of shrinking when encountering high heat. When the fiber encounters the flame, it is difficult to ignite when it shrinks away from the flame, resulting in appropriate flame retardant effect.

(5) The polyester cotton will melt and drip when encountering high heat. The melting drip phenomenon produced by the polyester cotton after ignition can also take away part of the heat and flame to produce an appropriate flame retardant effect.

(6) However, if the fiber is stained with oil that is easy to support combustion or the silicone oil that can shape the polyester cotton is used, the flame retardant effect of the polyester cotton will be reduced. Especially when polyester cotton containing SILICONE oil meets the flame, the fiber cannot shrink and burn.

(7) In addition to the flame-retardant modified polyester chips used to produce the polyester cotton, the flame-retardant effect of the fiber can also be increased by post-treatment of the fiber surface with an oil agent with high phosphate content. Because the phosphorus molecules released by phosphate when encountering high heat will combine with the oxygen molecules in the air and reduce the oxygen content in the air, so as to increase the flame retardancy.

III. Appropriate processing qualitative temperature of low melting point fiber

A: The melting point of existing low melting point fibers is all advertised as 110 ℃, but this temperature is just the softening temperature of low melting point fibers. Whether it is 4080 in Japan, 4080 in South Korea, 4080 in South Asia, or 4080 in the Far East, it takes about 150 ℃ to completely melt. Therefore, the appropriate processing and setting temperature should be based on the requirement that the relatively low temperature part of the non-woven fabric reaches 150 ℃ x 3 minutes during heating.

4、 Causes of static electricity during nonwoven production

Answer: The problem of static electricity generated during the production of non-woven fabrics is mainly caused by the low moisture content in the air when the fibers are in contact with the card clothing, which can be divided into the following points:

(1) The weather is too dry and the humidity is not enough.

(2) When there is no oil on the fiber, there is no antistatic agent on the fiber. Because the moisture regain of polyester cotton is 0.3%, the lack of antistatic agent results in static electricity during production.

(3) Low fiber oil content and relatively low content of electrostatic agent will also produce static electricity.

(4) Because of the special molecular structure of SILICONE polyester cotton oil agent, the oil agent almost contains no water, which is relatively easy to generate static electricity during production. Generally, the more slippery the SILICONE cotton is, the greater the static electricity.

(5) The method to prevent static electricity is not only to increase humidity in the production room, but also to effectively eliminate oil-free cotton in the cotton feeding stage.

V. Why is the thickness of non-woven fabric produced under the same processing conditions uneven

Answer: The reasons for uneven thickness of non-woven fabrics under the same processing conditions may be as follows:

(1) Low melting point fiber and conventional fiber are mixed unevenly: different fibers have different cohesion. Generally speaking, low melting point fibers have greater cohesion than conventional fibers and are not easy to disperse. For example, Japan 4080, South Korea 4080, South Asia 4080 or the Far East 4080 all have different cohesion. If low melting point fibers are unevenly dispersed, the part with less low melting point fiber content cannot form an adequate mesh structure, The non-woven fabric is thin, which is relatively thicker in places with more low melting point fibers.

(2) Incomplete melting of low melting point fiber: the main reason for incomplete melting of low melting point fiber is insufficient temperature. For non-woven fabrics with low base weight, it is not easy to have insufficient temperature, but for products with high base weight and high thickness, special attention should be paid to whether it is sufficient. The non-woven fabric at the edge is usually thicker because it has enough heat, while the non-woven fabric at the middle part is easy to form thinner non-woven fabric because of insufficient heat,

(3) High shrinkage of fiber: whether it is conventional fiber or low melting point fiber, if the hot air shrinkage of fiber is high, the problem of uneven thickness is easy to occur due to shrinkage during the production of non-woven fabric.

VI. Why are the non-woven fabrics produced under the same processing conditions uneven in hardness and softness

Answer: The reasons for uneven softness and hardness of non-woven fabrics under the same processing conditions are generally similar to the reasons for uneven thickness. The main reasons may be as follows:

(1) Low melting point fiber and conventional fiber are mixed unevenly. The part with higher low melting point content is hard, and the part with lower content is soft.

(2) Incomplete melting of low melting point fiber causes soft non-woven fabric

(3) The high shrinkage of the fiber will also cause the uneven hardness of the non-woven fabric.

7: Reasons for short code of thinner non-woven fabrics

Answer: When the nonwoven fabric is taken up, the finished product will become larger and larger. At the same take-up speed, the linear speed will become larger and larger. The thinner nonwoven fabric is easy to be stretched because of the lower tension. After the nonwoven fabric is rolled up, the short yard problem will occur due to the release of tension. As for the products with thick and medium specifications, the production has a large tensile resistance, resulting in a small tensile, which is not easy to cause the problem of short size.

Reasons for hard cotton after cotton wrapping by eight working rollers

Answer: During production, the cotton is wrapped on the work roll. Most of the reasons are that the friction coefficient between the fiber and the clothing is abnormal due to the low oil content on the fiber. The cotton is wrapped on the work roll due to the fiber sinking below the clothing. The fiber wrapped on the work roll cannot be moved. It gradually melts into hard cotton after continuous friction and compression between the clothing and the clothing. To eliminate the cotton tangle, the method of lowering the work roll can be used to remove the cotton tangle on the roll. In addition, it is easy to form the problem of work roll entanglement in case of long sleep.

To sum up, there will always be some unavoidable problems in the production process of the non-woven fabric production line. We need to understand some basic information to prevent being overwhelmed when problems occur. In addition, non-woven fabrics are recyclable, cheap and colorful, and are recognized as environmental protection products to protect the earth's ecology. How can it not be loved by everyone because it is beautiful and environmentally friendly?






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