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1.First of all, the plastic you mentioned should be strictly a resin. It is a general term for polymer materials or polymers. It mainly includes common polyethylene PE, polypropylene PP, polyvinyl chloride PVC, polystyrene PS (common foam Raw materials), polycarbonate PC, polyester PET, nylon, and some special ones, such as polytetrafluoroethylene (raw material tape, non-stick pan raw material). And these resins are all white in nature. Of course, there are some polymers that are not white, such as aramid (Kevlar), which is yellow, but this cannot be made of plastic. Another example is polyphenylene sulfide, which is also a bit yellowish.
In the process of making these resins into plastic products, some additives, pigments, plasticizers, etc. will be added, and in this process, the resin will more or less degrade (or decompose).
In our country, the recycling of waste plastics is a big industry, and many plastics will be returned to the furnace several times, so there is a saying that the first material, the second material, and the three, four or five materials. However, if the number of reheating is too many, the resin will decompose too much, and it will lack toughness and become very brittle. Most of the reheating materials (after more reheating times), the color can only be made black, so it will give people the impression that the black material is very bad.
In fact, sometimes black pigments need to be added to the first material to make the product black for needs. The quality of this plastic is very good. For example, some PPR pipes are black now.
2.It should be possible to look at it in this way. White plastics are easily visible when used with recycled materials or garbage, such as black spots, variegated colors, etc.; black plastics with recycled materials or garbage are not easy to be seen, because the colors are all It is covered by black. So relatively speaking, in black plastics, factories are more likely to adulterate other poor-quality raw materials, while white plastics are less likely to adulterate other poor-quality raw materials. For the same type of products, sometimes the price of black plastic is more expensive than white plastic, and the quality is better.
3.If the recycled plastic is variegated, it is basically made black. Therefore, the mainstream cognition is that black = back material. There are also several grades of recycled materials, and the performance of the first-level recycled materials is still very good. Plastics cannot be distinguished by color. Each material has a specific recycling level, which is recycled and reused step by step, saving costs and energy. Among engineering plastics, the original black material is more expensive than the white material.
4.Generally speaking, the price of the same kind of plastic with a lighter color is better. Mainly because of the quality of the base material of recycled plastics: such as impurity content and plastic color sorting. If the white contains impurities (mainly by the source of the base material, cleaning, and filtering process control), it is easier to identify, and the color of the base material should be better sorted, and too much noise should not be mixed. Black recycled plastics may be worse in terms of impurities and color sorting control. In terms of physical properties, it is better to be white or light-colored. Of course, it is also possible that some customers need black, high-quality recycled plastics.