The choice of additives is determined according to the variety of plastics and the degree of aging.

聚烯烃新料在加工成型时一般只添加少量助剂，如抗氧剂、紫外线吸收剂等，其废料再生时，一般只需加入少量着色剂即可，因此配方不难确定。除非这类塑料严重老化，变硬发脆，则需要根据具体情况确定配料的组成。

When the new polyolefin materials are processed, only a small amount of additives are added, such as antioxidants and ultraviolet absorbents. When the waste is recycled, only a small amount of coloring agent is added, so the formula is not difficult to determine. Unless such plastics are seriously aged, hard and brittle, it is necessary to determine the composition of the ingredients according to the specific circumstances.

聚氯乙烯塑料的组成比较复杂，尤其是软质聚氯乙烯，所含添加剂的种类较多，有增塑剂、稳定剂、紫外线吸收剂、润滑剂和颜料等，其中以增塑剂为主，用量最多。其制品在使用过程中受到光、热等气候条件的影响，增塑剂逐渐渗出，制品硬化，尤其是其物理性能大大下降，逐渐老化，不能满足使用要求而成为废品。利用这类废旧制品进行再生时必须补充足够数量的增塑剂及其他助剂，最大限度地恢复其机械性能，因此，合理确定配方十分重要。

The composition of PVC is more complex, especially soft PVC. There are many kinds of additives, such as plasticizer, stabilizer, ultraviolet absorbent, lubricant and pigment. The plasticizer is the main plasticizer and the amount is the most. Its products are affected by the weather conditions such as light and heat in the process of use. The plasticizer is gradually exuded out and hardened, especially its physical properties are greatly reduced and gradually aging, which can not meet the requirements of use and become waste products. Sufficient quantity of plasticizers and other auxiliaries must be added to the recycling of this kind of waste products to maximize their mechanical properties. Therefore, it is very important to determine the formula reasonably.

增塑剂的加入量主要由再生聚氯乙烯制品要求的硬度而定，为此应考虑回收的聚氯乙烯废制品中硬质与软质的比例。聚氯乙烯薄膜、人造革和壁纸等软质制品与硬质的管材、异型材等的制品中增塑剂的残留量很不相同，因此，只要将硬质和软质回收料相互掺用，调节二者的掺混比例，即可制得要求硬度的再生制品，可减少增塑剂的用量，甚至不使用增塑剂。

The addition of plasticizers is mainly determined by the required hardness of regenerated PVC products. Therefore, the proportion of hard and soft materials in the Recycled PVC waste products should be considered. The residual amount of plasticizers in the soft products such as PVC film, artificial leather and wallpaper and hard pipes and special-shaped materials are very different. So, as long as the hard and soft recycled materials are mixed with each other to adjust the mixing ratio of the two, the regenerated products which require hardness can be prepared, and the amount of plasticizers can be reduced. No plasticizer is used.

在配料时选用助剂的总原则是既保证再生制品具有一定的性能，符合使用要求，又不致于成本过高。一般说来，需要考虑如下几点：

The general principle of selecting auxiliaries in batching is to ensure that the regenerated products have certain properties, meet the requirements of use, and not cost too much. Generally speaking, we need to consider the following points:

(1)由于废旧塑料和再生制品的价格较低，因此所采用的添加剂的价格也要便宜。

(1) as the price of waste plastics and recycled products is low, the price of additives used is also cheaper.

(2)正因为废旧塑料往往是各种颜色废料的混合物，在再生加工时一般添加深色着色剂，故对所选用助剂的外观色泽要求不高。

(2) because the waste plastic is often a mixture of all kinds of color waste, a dark coloring agent is generally added in the process of reprocessing, so the color and lustre of the selected auxiliaries is not high.

(3)添加剂应能满足再生制品的一定性能要求。

(3) additives should meet certain performance requirements of recycled products.