Recycle chemical fibers
Recycling of Chemical fiber (Recycled Chemical Fibers) are the waste Chemical fiber, textile, and other waste polymer materials, by physical to use after opening, or by melt spinning or dissolves, or to further cracking recycling of polymeric materials into small molecules to polymerization and spinning of Fibers. Regenerated Chemical Fiber is also named as Regenerated Chemical Fiber as it produces fibers by using waste fibers as raw materials.
Can recycle chemical fiber mainly include polyester, polyamide fiber, polypropylene fiber, polyurethane fiber, polyacrylonitrile fiber, PVC, etc., with the primary chemical fiber composition, structure, physical and chemical properties in the aspects of basic similar, relatively mature technology with polyester fibers and polyamide fibers, fiber main regeneration after recycling the other as monomers or polymers with similar material, basic cannot be directly used as textile material.
Recycle polyester fiber
According to the regeneration principle, the preparation methods of recycling recycled polyester fiber can be divided into physical and chemical methods. The physical method refers to the recycling method of directly spinning waste polyester materials as raw materials after sorting, cleaning and drying. The chemical method refers to the process in which the waste polyester materials are depolymerized into polymerized monomers or polymerized intermediates by chemical reaction, and then recycled polymerization and melt spinning are carried out after purification and separation.
Physical method is the leading polyester recycling method because of its simple production technology, simple process flow and low production cost. More than 70%~80% of the production capacity of recycled polyester is recovered by physical method (that is, the recycling method of coke bottle in video).
However, in recent years, through the innovation of equipment and process, the chemical method has shown a growing trend. Since 2002, Japan diren has been using chemical method to produce recycled polyester products on a large scale. In China, zhejiang jiaren new materials co., ltd. has been using diren's chemical method to produce recycled polyester products. At present, China has not independently developed the industrial technology of large-scale production of recycled polyester by chemical method.
Recycle and reuse polyamide fiber
Polyamides mainly include polyamides 6(PA6) and polyamides 66(PA66). As a thermoplastic polycondensation polymer material, the reuse methods of polyamide and polyester have many similarities, and the reuse methods can be divided into physical and chemical methods.
However, different from polyester, polyamide has higher reactivity of characteristic functional groups, so the thermal degradation is more serious when the physical method is adopted for recycling. The requirement for the purity of waste material is obviously higher than that of polyester, and it is not often used for recycling waste polyamide textiles with higher impurity. Due to the high reactivity, the depolymerization rate of polyamide is significantly higher than that of polyester. Therefore, chemical methods are often used for the reuse of polyamide.
BASF has been working on polyamide depolymerization for many years and has developed several methods for preparing caprolactam from PA6 waste. DuPont company has developed the recycling technology of acidolysis PA6 and PA6, which can also produce corresponding high-quality polyamide monomers, and has realized the industrialization promotion of a certain scale of polyamide closed-loop recycling technology. Japan ube has also publicly demonstrated that it has mastered the methods of PA depolymerization and the manufacture of PA monomers.
Certification of regenerated ingredients
(1) global recycling standard (GRS)
This is an international, voluntary, and comprehensive product standard for the implementation of supply chain manufacturers' requirements for product recovery/recycling ingredients, regulatory chain control, social responsibility and environmental regulations, and chemical restrictions, and certification by third-party certification bodies.
The newly updated GRS certification is a three-level system, which can be divided into copper standard, silver standard and gold standard according to the recycling standard of each product. The highest gold standard requires that the products contain 95%~100% recycled materials, silver standard products contain 70% ~ 95% recycled materials, and copper standard products should contain no less than 30% recycled materials.