What is modified plastics?
Time:2020-03-04
Views:155
In brief, modified plastics are plastic products. Their main raw materials are plastic raw materials, including general plastics such as PE, PP and PVC, and engineering plastics such as pet and PA6. In the application of these raw materials, their strength, flame retardancy, impact resistance and processing performance can not meet the requirements of the products. However, filling, blending, reinforcement and other processes can enhance the impact resistance, flame retardancy, strength, light weight, easy molding and other properties of the raw materials, The plastics made by these processes are collectively referred to as modified plastics. The typical representative of modified plastics is modified Pa. PA plastic is the most widely used in engineering plastics, so there are many requirements for its performance. At present, the varieties of modified PA include reinforced PA, flame retardant PA and filled PA. Enhanced PA must be dried before PA is modified. Because PA material is easy to absorb water, with a water absorption rate of 3.5%, once the humidity is greater than 0.2%, it needs to be dried for 8 hours under the hot air at 80 ℃. The most commonly used method for reinforcing PA is blending, that is, blending glass fiber or rubber (EPDM, SBR) with PA raw materials to enhance the impact resistance of PA. of course, LLDPE can also be used to toughen PA. Flame retardant PA as we all know, engineering plastics have high requirements for flame retardancy, but the flame retardancy of PA is relatively weak, so modification should be adopted to enhance its flame retardancy. The commonly used flame retardants for PA include red phosphorus, bromine flame retardants and nitrogen flame retardants. Generally, the use of red phosphorus and bromine flame retardants can increase the flame retardancy of PA to VO level. If only nitrogen flame retardants are used, their flame retardancy can only be increased to V2 level. If a small amount of red phosphorus, nitrogen flame retardants and bromine flame retardants are used, their flame retardancy can also be improved to V0 level. Filling PA filling carbon black in PA can enhance its weather resistance. Carbon black can effectively absorb ultraviolet rays, and also play a role in lubricating and reducing friction in the molding process. The above is a simple theoretical knowledge of modified plastics. Although it mainly focuses on the modification of PA plastics, the modification methods of other plastic raw materials are basically similar. The methods of blending, filling and strengthening are also applicable to PP plastics, PE plastics and other general plastics.
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