What are the differences between PE, EVA and PVC?

Soft films include polyvinyl chloride (PVC) shed film, polyethylene (PE) shed film, and ethylene vinyl acetate (EVA) agricultural film.

(1). Polyvinyl chloride (PVC) shed film: It is made by adding plasticizers, stabilizers, lubricants, functional additives and processing aids to polyvinyl chloride resin, and then rolling it into a film. Its characteristics are good light transmittance, blocking far-infrared rays, strong thermal insulation, soft and easy to shape, easy to bond, and good weather resistance. In Japan, about 80% of facility cultivation is covered with PVC greenhouse film. Its disadvantages are high density (1.3g/cm3), the coverage area of ??a certain weight shed film is 1/3 less than that of polyethylene film (PE), high cost, hardening and brittleness at low temperatures, and easy softening and loosening at high temperatures, which helps After the agent is precipitated, dust will easily stick to the film surface, affecting light transmission. The remaining film cannot be burned because toxic chlorine gas will be produced.

（2）． Polyethylene (PE) shed film: Polyethylene shed film is a film made of polyethylene resin by extrusion and blow molding. It is light, soft, easy to shape, has good light transmittance, and is non-toxic. It is suitable for various greenhouse films and mulch films. It is currently the main agricultural film variety in my country. Its disadvantages are: poor weather resistance, poor thermal insulation, and difficult to bond. If the greenhouse film is produced, it must be modified by adding anti-aging agents, drip-free agents, heat preservation agents and other additives to meet the production requirements. At present, the main raw materials of PE are high-pressure polyethylene (LDPE) and linear low-density polyethylene (L-LDPE).

（3）． Ethylene-vinyl acetate (EVA) agricultural film: EVA's infrared barrier properties are between those of PVC and PE. EVA has weak polarity and can be mixed with a variety of weather-resistant agents, thermal insulation agents, and anti-fogging agents to produce blown films. It has good compatibility and strong tolerance.

Different materials have different characteristics: EVA has particularly excellent low temperature resistance; followed by PE, PVC agricultural film containing 30% plasticizer hardens at 0°C, has tensile strength and impact resistance Extremely poor sex. EVA and PVC agricultural films are not suitable for use in hot summer weather. The initial light transmittance of both PVC and PE can reach 90%. As time goes by, PVC affects the light transmittance and causes the light transmittance to drop quickly. The transmittance of PE decreases slowly.