Interpretation Of "Technical Specification For Recycling Of Waste Textiles"

?

The definition of waste textiles in "technical specification for recycling of waste textiles" is: textile materials and products that are discarded in the process of production and use. Waste textiles include waste textiles and used textiles. It refers to the waste produced in the process of textile and weaving, such as waste yarn produced in the process of spinning and weaving; Old textiles refer to the used textile products that have been eliminated by us, such as old clothing, old home textile products, etc.

According to the different components of waste textiles, the waste textiles are divided into the following categories according to GB / T 38923-2020 classification and code of waste textiles

1. Cotton waste textiles: refers to waste textiles with cotton fiber as the main body. The content of cotton fiber in waste cotton textiles is not less than 80%, and the content of cotton fiber in used cotton textiles is not less than 75%.

2. Waste wool textiles: it refers to waste textiles with wool fiber as the main body. The content of wool fiber in waste wool textiles shall not be less than 60%.

3. Polyester waste textiles: waste textiles with polyester as the main body. The content of polyester fiber in waste polyester textiles is not less than 65%.

4. Waste nylon textiles: waste textiles mainly made of nylon. The content of nylon fiber in waste nylon textiles is not less than 60%.

5. Waste acrylic fiber textiles: waste textiles with acrylic fiber as the main body. The content of acrylic fiber in waste acrylic fiber textiles is not less than 50%.

6. Other types of waste textiles: waste textiles with a certain fiber other than cotton, wool, polyester, nitrile and brocade as the main body. The fiber content of the main materials in other types of waste textiles shall not be less than 50%.

7. Mixed waste textiles: waste textiles composed of two or more main raw materials and difficult to define the main materials according to the above categories.

The recycling of waste textiles is to reprocess the waste textiles to make them into new raw materials or products meeting the corresponding standards. According to the different processing methods, the recycling technologies of waste textiles are as follows:

1. Simple mechanical processing: it is to loosen the waste textiles by mechanical method to restore them to the fiber state, which is generally applicable to the recycling of waste textiles of cotton and wool natural fibers; Or the raw materials of rags or mops are directly made from old textiles after simple processing.

2. Hot melt processing technology: for those waste textiles with thermoplastic properties, melt them into the spinning solution of melt spinning process, and then make them into chemical fibers, which is suitable for chemical fiber fibers that can be processed by melt spinning process.

3. Chemical regeneration process: the waste textiles are depolymerized, filtered and re polymerized by chemical methods, and then processed into new fibers by chemical fiber spinning process, which can be applied to the chemical fiber processed by melting method, or the regenerated fiber processed by solvent method or dissolution method.

For the textile raw materials obtained by recycling, the hygienic indexes of the recycled products should meet the requirements of GB / T 32479-2016 "basic safety technical requirements for reprocessed fibers"; The quality of regenerated staple fiber should meet the requirements of FZ / T 07002-2018 "waste textile reprocessing staple fiber".

According to GB / T 32479-2016 "basic safety technical requirements for reprocessing fiber", for class 1 reprocessing fiber, no pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus haemolyticus, no odor, pH value between 4.0 and 9.0, and free residual chlorine content no more than 10mg / kg; For class 2 reprocessed fibers, no pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus hemolysis should be detected, and the content of free residual chlorine should not be more than 20mg / kg

According to FZ / T 07002-2018 "waste textile reprocessing staple fiber", the main length of recycled staple fiber after mechanical processing should be more than 10 mm, and the dry breaking strength, length deviation rate, defect content, impurity content, formaldehyde content and the content of decomposable carcinogenic aromatic amine dyes must meet the requirements of the standard.

The recycling of waste textiles is to reduce the pressure of environmental protection. Therefore, in GBT 39781-2021 "technical specification for the recycling of waste textiles", the discharge of waste water, waste gas, noise and solid waste in the process of dismantling, cleaning, disinfection and regeneration of waste textiles is also required, The pollutants produced in the production process must meet the relevant requirements of national environmental protection.