日期:2023/1/17 8:31:48 / 阅读: / 来源:本站

2.3.17 PVC/chlorinated polyethylene blends
PVC/chlorinated polyethylene blends can also be called chlorinated polyethylene modified PVC, PVC and chlorinated polyethylene plastic alloy, abbreviated as PVC/CPE.
(1) PVC/CPE blend performance blended PVC/CPE resin is a new type of polymer material. The compatibility of the two resins is related to the chlorine content in CPE (the chlorine content in CPE is 36%~48%) and the distribution of chlorine atoms on the ethylene main chain. After adding chlorinated polyethylene into the PVC resin, the processing performance of the blend was significantly improved compared with that of PVC resin, and the impact strength of the product was also improved, but the rigidity and tensile strength were slightly decreased. When PVC and CPE are mixed at a mass ratio of 100:10, their bending strength is 56MPa, tensile yield strength is 30MPa, and elongation at break is 120%.
See Table 2-86 for the technical indicators of Hoechst products.
(2) Preparation of PVC/CPE blends
① Firstly, the formula of PVC/CPE blend was designed and improved according to the product requirements.
② Measure various raw materials (PVC, CPE, stabilizer, filler pigment and lubricant) according to the formula requirements.
③ Add PVC resin into the mixer for mixing, heat up, gradually add stabilizer during mixing, and add fillers, pigments and CPE when the material temperature reaches 90 ℃
④ When the temperature of the mixed material reaches about 125 ℃, add lubricant and continue mixing to achieve uniform mixing of various materials.
⑤ Transfer the high-temperature mixture into the cold mixer and quickly cool the mixture to below 50 ℃.
⑥ The low temperature material is put into the extruder for mixing and plasticizing (material temperature is about 170 ℃) to form the PVC/CPE blend.
(3) PVC/CPE blend products and molding methods PVC/CPE blend molding products are mainly produced by extrusion. The screw length-diameter ratio of the extruder is required to be L/D=15:1, the compression ratio is 2:1, and the barrel heating temperature is 190~240 ℃.
Extrusion molding impact resistant, weather resistant and flame resistant hard products, including pipes, pipe fitting plates, profiled materials, wires and cables, hoses, films, transport belts, etc.
The production units of PVC/CPE blends include Shanghai Chemical Plant, Dalian No. 2 Plastic Plant and Wuhan No. 2 Plastic Plant.

2.3.18 PVC/ethylene-vinyl acetate copolymer blend

PVC/ethylene-vinyl acetate copolymer blends can also be called EVA modified PVC, abbreviated as PVC/EVA. It is a polymer material made of polyvinyl chloride, ethylene-vinyl acetate copolymer and other auxiliary materials by mixing and granulating in a certain proportion.
(1) Properties of PVC/EVA blends
The compatibility of PVC and EVA depends on the VA content in EVA. When the VA content is 65%~70%, EVA and PVC are completely compatible. When there is 45% VA in EVA, it will form a network multiphase structure after mixing with PVC, which can improve the impact resistance of PVC, improve the processing performance and thermal stability. The resin products after blending have good low-temperature impact resistance, cold resistance, processability, chemical resistance and hand feeling.
See Table 2-87 and Table 2-88 for the performance indicators of PVC/EVA blends.
(2) Preparation of PVC/EVA blends
① PVC and EVA (the content of vinyl acetate in EVA is required to be about 50% and the relative molecular weight is 100000, which is powder) and other materials (stabilizer, filler lubricant, etc.) are measured according to the requirements of the mixed formula. Note that the amount of EVA added should not be less than 15%.
② Add various materials with accurate measurement into the mixer and mix them evenly.
③ Mix and plasticize the raw materials evenly on the double-roll open-mill, and then slice and roll.

④ Use the pelletizer to cut the sheet into uniform pellets, that is, PVC/EVA blend 

(3) PVC/EVA blend products and molding methods 

PVC/EVA blend molding plastic products, can use extrusion, injection molding and calendering methods. The production products include impact resistant pipes, pipe fittings, plates, sheets, profiled materials and parts in industrial equipment. The soft products include cold resistant films, soft films, insulation protective layers for wires and cables, artificial leather and foam soles.

PVC/EVA blends are produced by Shanghai Chemical Plant, Tianjin Modern Chemical Plant, Beijing Organic Chemical Plant and other units in China.


Phone now 8618627187890 OR More contact information →

Go To Top