What is recycled cotton yarn

Regenerated cotton yarn, also known as waste spinning yarn, is a secondary brand yarn. It is the waste, waste silk, waste yarn, scrap, scrap cloth produced in the textile production process, as well as the scraps and leftovers produced in the clothing cutting process, as well as the textile discarded in daily activities. Fibers and their products are yarns made from centralized opening, impurity removal, dust removal, mixing, carding, drawing, drafting and twisting.

Regenerated cotton yarn generally uses a new type of open-end spinning machine. Because the raw fiber length of regenerated cotton yarn is shorter than that of raw cotton, it mainly produces rovings of about 4-13 counts (14-44tex).

Uses of regenerated cotton yarn

Depending on the product use, regenerated cotton is often dyed and then spun. The spinning fineness is determined according to the raw materials and uses.

Used for weaving cotton blankets, furniture cloths, wall coverings, labor protection products, work clothes, industrial wrapping cloths, floor coverings, wiping cloths, table blankets, sofa and chair covers, etc. Classification of regenerated cotton yarn Regenerated cotton yarn includes cotton-type regenerated yarn and chemical fiber regenerated yarn. Cotton-type recycled yarn is basically made from the scraps of cotton knitted clothing, and chemical fiber recycled yarn is basically made from the scraps of polyester clothing or products. Through professional fabric scrap management, recycled cotton yarn rotor spinning processing, yarn sales and other upstream and downstream links, it provides raw materials for denim, curtain fabrics, sofa cloths, gloves and mops.

2. The value of recycled cotton yarn

Our country is the world’s largest textile and apparel production and exporter. With the improvement of economic level and people’s living standards, the discharge of large amounts of textile waste is a manifestation of environmental pollution by the textile industry. These wastes not only waste resources but also cause environmental pollution. The so-called textile waste mainly includes short fibers produced due to chemical and mechanical effects during the textile process, waste yarn, waste silk, waste yarn, waste yarn, waste materials, scraps of cloth produced during the textile production process, and clothing cutting. The scraps and scraps produced during the process, as well as the textile fibers and their products discarded in daily activities. Internationally, it is customary to divide textile waste into soft and hard waste. Soft waste refers to textile waste that can be returned to spinning production without excessive further processing; while hard waste refers to textile waste with a yarn structure. As well as all textile waste in woven, knitted and non-woven structures.

For the treatment of textile waste, methods such as accumulation, landfill, and incineration were basically used in the past. However, the disadvantage is that the accumulation of textile waste will occupy land and easily cause collapse; the accumulated waste is exposed to the air In the textile waste, dust and impurities accumulate, affecting environmental sanitation; under the action of rain, the dyes and other harmful components on the textile waste will leach and seep into the ground, polluting the groundwater. The landfill is chosen to be carried out under the surface. Although it will not affect the ground environment, the landfilled site can hardly be reused in the city, and there will be an additional cost; due to the non-degradability of chemical fiber itself, especially synthetic Landfilling of fiber and chemical fiber waste will harden the soil; similarly,Harmful substances on waste materials will seep into the soil and underground with water. Contaminate soil and groundwater. The incineration of waste fabrics will produce a large amount of dust and harmful gases that pollute the atmosphere and affect environmental sanitation. Moreover, the chemical fiber residues after incineration are more difficult to handle.

Therefore, general treatment methods cannot completely solve the problem and will also cause pollution problems. From the perspective of textile processing ecology, people must not only consider how to easily handle textile waste, but also consider the impact of dyes and various auxiliaries on textiles, and the environmental impact of each component of textile waste during the treatment process, and Take effective measures to reduce the impact on the environment. As people’s requirements for environmental protection are getting higher and higher, the issue of waste disposal has attracted more and more attention.

According to statistics, textile and textile fiber waste account for 3.5%-4% of the total urban domestic waste. If the average cycle of clothes is 3-4 years, the current world fiber usage reaches more than 56 million tons per year, and textile waste is about 70%, so fiber waste reaches about 40 million tons per year. These Waste is mostly treated as garbage, which often causes environmental pollution. If comprehensively utilized properly, these wastes will achieve unexpected effects.

When the generation of textile waste is unavoidable, the reuse of harmless waste has become a key focus and development direction. There is no doubt that we must find ways to turn waste into a second source of textile raw materials. It reduces the amount of textile waste processing, saves raw materials and energy, improves the utilization level of resources, and reduces costs.

For decades, the textile industry has undisputedly entered the camp of recycling and reusing raw materials. There are many model examples at home and abroad. Textile waste is one of the important and valuable materials in the future. A large amount of waste around the world is now sent to modern treatment plants for recycling, which also brings considerable economic benefits to enterprises.

Relevant data shows that in 2010, the total amount of raw materials such as scrap materials used in domestic recycled cotton yarn reached about 3 million tons. It is estimated that 50% of the yarn is cotton-type recycled yarn, and based on a cotton output of 200 kilograms per mu, it is equivalent to the output of more than 7 million acres of cotton fields. Regenerated cotton yarn not only realizes the recycling of resources, saves limited resources, but also solves the problem of scrap material processing and contributes to environmental governance. Cangnan County, Wenzhou alone achieves a throughput of more than 3 million tons of corner materials a year.

As the most populous country in the world and a major textile country, the realization of “waste textile recycling” is of great significance to itself and the world. According to the “Twelfth Five-Year Plan” for the development of the textile industry, in the next five years, my country will gradually establish and improve a recycling system for recycled textile fibers. By 2015, the country’s total fiber processing volume is expected to reach 51.5 million tons, of which about 15% is recycled fiber.

Third-party professional organizationsTesting data shows that the environmental indicators of clothes made based on 65% recycled polyester and 35% recycled cotton yarn far exceed those of virgin materials. They can save 74% of water, 18% of electricity and reduce greenhouses by 53% respectively. Gas emissions.

The use of recycled textiles can be regarded as a long-term environmental protection undertaking.

3. Processing of recycled cotton yarn

Some textile wastes can be reprocessed to obtain the following types of products:

After textile wastes are reprocessed, the following types of products can be obtained:

(1) Reprocessed fiber non-woven fabrics (usually non-woven fabrics fall into this category). This is a very wide area of ​​fiber recycling and reuse, mainly used in industrial and agricultural production and various areas of life. Due to the short non-woven production process, low cost and good adaptability to raw materials, textile waste is used in non-woven fabrics. The processing is gradually expanding. Some chemical short fibers can be processed into needle-punched felt and other non-woven fabrics, which can be used as sound insulation nets in automobiles, seat linings, carpets, etc. They can also be used as decorative items in the furniture industry and geotechnical products in the civil engineering industry. cloth, filter products and more.

(2) Reprocessing fiber filling materials. Some low-quality, short-length regenerated fibers can be used as fillers after appropriate treatment. For example, when appropriate recycled fibers are added to the wadding materials for heat insulation and sound insulation layers, especially the polyester foam pads used in sports fields, their strength can be greatly increased and their service life extended.

(3) Regenerated fiber and paper. Cotton linters are stripped through three stripping machines. The first velvet is a type of lint with a length of 12-16mm. It can spin low-grade yarns of No. 49-97 and can weave cotton blankets, velvet jackets, velvet trousers, velvet cloth, and candles. wicks, lamp wicks, etc., and can also be used to produce high-grade paper, such as banknote paper, typing wax paper, coated paper, etc. And wear-resistant, lightweight steel paper; second-grade velvet is a second-class velvet with a fiber length of less than 12mm. After this type of velvet is made into pulp, it can be processed into nitrocellulose and spray-painted; third-grade velvet It is a type III short velvet with a velvet length of less than 3mm. This type of short velvet can be made into viscose fiber.

(4) Reprocessing fiber fabrics. Recycled natural cotton fibers are generally longer in length and can be woven into recycled cotton yarn through processing technology and used as raw materials for some fabrics.

Raw materials for the production of recycled cotton yarn

According to the ordinary spinning system, 100 kilograms of mixed cotton can be processed, and a total of 80-90 kilograms of yarn can be obtained. Therefore, it can be seen that the yarn yield rate of blended cotton is 80-90%. The remaining 10-20% is waste from spinning production.

When raw cotton is processed according to the combed spinning system, because the combing waste is 15-18%, the yarn yield is reduced to 65-75%. All waste from spinning production can be divided into the following categories:

1. Waste consisting of completely useful, clean and loosened fibers. This kind of waste is notIt needs to be pre-cleaned before it can be reclassified to the original cotton grade. Such waste is called waste. Shredded cotton rolls, shredded cotton slivers and shredded rovings all fall into this category. Shredded roving must be loosened on the roving end machine before reuse.

2. There are still fibers in the waste that can be spun, but they are very short and uneven in length, and they contain a lot of impurities (broken seeds, combed noil, needle waste, cover board waste) , and fibers that are useful but have been twisted into yarn. This waste material can be downgraded for use after pre-processing.

3. There are a small amount of short fibers in the waste that are not suitable for spinning. They are non-spinning waste. For example: ground flowers, etc. all fall into this category. 4. The fibers lose moisture during the production process, and the single short fibers and dust that are discharged outside the factory together with the unclean air are called invisible waste.

Usage of recycled cotton, reused cotton, and scraps

1. The quality of recycled cotton is relatively close to that of mixed raw cotton. The spinning performance of the previous process is better than that of the subsequent process. The recycled flowers are generally reused evenly in this number according to the proportion of production.

2. The fiber length of chopping cotton and needle cotton is shorter than that of mixed raw cotton, the uniformity is very poor, and the content of short fibers, neps, and impurities is large. After the chopped cotton is rolled and processed by the fiber impurity separator, the number of impurities is reduced, the number of spot particles increases, and the particles become smaller. Compared with needle-cut cotton, the quality of cut-knife cotton is slightly worse. Chopped cotton is generally reused after treatment. For low-grade cotton or coarse yarn, it can be used evenly without treatment. Chopped cotton with better quality can be used in small amounts in the cotton mix. Chopped cotton can be used in waste spinning according to requirements such as the quality of the chopped cotton, the amount of cotton used, and the use of the product.

3. Combed noil contains a high short fiber rate, and is generally controlled at a certain mixing ratio and used in yarn weaving with low quality requirements.

4. The scraps are usually packaged and processed uniformly. Using waste spinning equipment, after sorting, opening and removing impurities, it can be used with other chemical fibers in products such as recycled cotton yarn in a certain proportion.

Regenerated cotton yarn spinning system

After tearing off the scraps, fragmentary yarns, rag corners, cloth strips, etc. that are suitable for reuse, the regenerated fiber is obtained and recycled. It is processed by a spinning machine, then carded, drawn, and then made into roving by a spinning machine. The raw materials are cheap, the process is short, the output is high and the cost is low. The finished product feels soft and has a furry surface, but its strength is low.

The fiber raw materials used are of poor quality and the yarn count is relatively thick. In addition to the waste cotton waste produced by the cotton spinning mill itself, there are also waste products and wild fibers produced by the needle cotton weaving mill. And a comprehensive mix of recycled waste fabrics. Due to different fiber properties and different product requirements, the process processing is also inconsistent. It can be roughly divided into three processes: cotton blending, carding, and worsted spinning.

Cotton blending is actually a process of pre-processing waste fibers through opening and cleaning. Waste produced by cotton mills