According to foreign standards, the material of plastic […]
According to foreign standards, the material of plastic bellows is usually made of high-density polyethylene plastic (PE) and polypropylene plastic (PP). High-density polyethylene plastics are basically used in China. The difference between the two materials is that polypropylene plastic (PP) material has higher strength, elastic modulus, and high temperature resistance (220°C) than polyethylene plastic (PE) and is slightly more expensive.
The plastic bellows with an inner diameter of 100 imported from the second bridge of the Yangtze River is polypropylene plastic (PP), and the price is 60 yuan per meter, which is equivalent to 10 times that of metal bellows. The mechanical and mechanical performance test results are similar to the metal bellows of the same specification. According to the density polyethylene plastic pipes produced in China in recent years, due to the thin wall thickness and unevenness, the waveform structure is different and very irregular, so mechanical mechanics Performance varies greatly.
It is recommended to use high-density polyethylene (PE) for inner diameters below 95, and polypropylene plastic (PP) for inner diameters above 100. In addition, the additives should be cautious. Some manufacturers add calcium carbonate (lime), and found that the added plastic bellows are brittle, and they will crack after a little pressure.