1）Classification according to relative molecular weight

Processing aids have different functions according to different relative molecular weights. Processing aids with relative molecular weights of 50-1.5 million are widely used in the processing of common products, such as: ACR-201, 301, 401, etc. Processing aids with relative molecular weight above 1.5 million are widely used in blow moulding and rigid PVC foam products, such as ACR-530.

2）Classification according to product composition

At present, the main varieties of impact modifiers are chlorinated polyethylene (CPE), impact modifier (MBS) and acrylate impact modifier ACR. Which impact ACR compatibility with PVC, weathering performance is better than CPE and MBS, MBS transparency and compatibility with other additives, and impact performance is better than ACR and CPE, CPE performance is moderate, according to statistics, the current global consumption of impact modifiers proportion: MBS accounted for 45 percent of the amount of impact ACR accounted for 40 percent of the others accounted for 15 percent .

Impact modifier MBS is MMA grafted styrene-butadiene latex after drying by salinisation of the core - shell copolymer, with its modified PVC can improve its impact strength and overall performance, because of its refractive index is similar to that of PVC, so that modified PVC is a better transparency, and therefore widely used in transparent products. MBS was first developed by Rohm and Haas in the 1950s, and its output has reached 300,000 tonnes, accounting for the first place of all kinds of impact modifiers.

Impact modifier ACR and processing aids ACR are acrylate polymers, but due to the proportion of their formulations and structure of the different properties are very different, impact ACR in the methyl methacrylate accounted for about 10-20 percent , while the acrylate accounted for about 80-90 percent . Impact modifiers ACR like MBS with the same core-shell structure. Compared with MBS, CPE and other impact modifiers, its processing performance and weathering performance is good, high surface finish, especially for outdoor products, acrylate impact modifier because of its environmental protection, excellent performance, high weathering performance.

(1) accelerate the plasticisation process of PVC.

(2) Improve the rheological properties of thermoplastic melt.

(3) Improve the mechanical properties of the melt in the thermoelastic state.

(4) Improve the appearance quality of products and other comprehensive functions.