Due to the impact of external conditions and the effects of light and heat, waste plastic products have been aged to varying degrees during use. The various additives contained in the waste plastic products have different degrees of loss, such as recycled soft PVC. The loss of plasticizer is relatively large, and its use in the production of recycled products has far worse performance than that produced with new materials. In order to maximize the quality of used plastic recycled products, it is necessary to add a certain amount of assistance in the process of recycling. Agents to improve the performance of waste plastic molding, machinery, thermal power, etc. How to control the amount of additives?
Selection of additive types
The choice of additives is based on the variety of plastics and the degree of aging to determine.
New polyolefin materials generally only add a small amount of auxiliaries such as antioxidants, UV absorbers, etc. during the processing and molding. When the waste is regenerated, only a small amount of coloring agent can be added, so the formulation can be easily determined. Unless such plastics Severe aging, hard and brittle, you need to determine the composition of the ingredients according to the specific circumstances.
The composition of polyvinyl chloride plastics is more responsible, especially for soft polyvinyl chloride, which contains more types of additives, including plasticizers, stabilizers, ultraviolet absorbers, lubricants, and pigments, among which are plasticizers. , The amount of most. Its products in the process of use by the light, heat and other climatic conditions, plasticizers gradually exudate, the product hardening, in particular, its physical properties greatly reduced, gradually aging, can not meet the requirements and become waste. When these waste products are regenerated, they must be replenished with a sufficient amount of plasticizers and other auxiliaries to maximally restore their mechanical properties, because it is very important to determine the formula reasonably.
The amount of plasticizer added is mainly determined by the required hardness of recycled polyvinyl chloride products. Therefore, the ratio of hard and soft polyvinyl chloride waste products should be considered. PVC film, artificial leather and wallpaper and other soft materials The residual amounts of plasticizers in products, rigid pipes, and profiled products are very different. Therefore, as long as the hard and soft recovery ratios are mixed with each other and the blending ratio of the two is adjusted, they can be obtained. Hardness-requiring recycled products can reduce the amount of plasticizer, even without plasticizers.
Selection of additives
The general principle of the selection of additives in the furnish is to ensure that the recycled products have certain properties, meet the requirements for use, and do not incur excessive costs. In general, consider the following points:
First of all, due to the low price of waste plastics and recycled products, the additives used are also cheaper.
Secondly, because waste plastics are often a mixture of various color wastes, dark colorants are generally added during reprocessing. Therefore, the appearance color of the selected additives is not high.
Finally, additives should be able to meet certain performance requirements of recycled products.
In general, waste plastic additives have to control a certain amount. At the same time, they should also take into account the plastic components. This requires us to fully understand the knowledge of waste plastics, and we can make good use of it in future needs.