EVA optical protective film performance application introduction
EVA film: Ethylene-
Vinyl acetate copolymer referred to as EVA, usually vinyl acetate (VA)The content is 5% ~ 40%.
Compared with polyethylene, EVA due to the introduction of vinyl acetate monomer in the molecular chain, and then reduce the high crystallinity, the progress of the soft resistance, impact resistance, filler compatibility and heat sealing function, it is widely used in foam shoes, functional greenhouse film, packaging film, Hot Melt Adhesive, wire and cable and toys.
EVA resin is characterized by outstanding softness, rubber-like elasticity, in-
It can still have good flexibility, good transparency and external gloss, excellent chemical stability, good anti-aging and ozone resistance, and no toxicity at 50℃.
Good blending with filler, good coloring and forming processability. EVA film use :(1)
Film, sheet and laminated products: with sealing, adhesion, softness, strong resistance, tightness, suitable elastic packaging film, heat shrink film, agricultural film, food packaging film, laminated film, can be used as an intermediate layer for polyolefin laminated films. (2)
Usually supplies: have the advantages of flexibility, resistance to environmental stress cracking, good weather resistance, suitable industrial materials include power wire insulated leather bags, household appliance accessories, window sealing materials, etc. (3)
Daily groceries include sporting goods, toys, cushions, belts, sealed container covers, EVA rubber football, etc. (4)
Auto parts include shock absorbers, fenders, interior decoration accessories, etc. (5)
Foaming finished products: pressurized foaming includes foam plastic slippers, sandals, building materials, etc.
Injection foaming has various industrial parts, female soles, hot melt adhesives, etc.
EVA film characteristics: water resistance: closed cell structure, no water absorption, moisture resistance, outstanding water resistance.
Corrosion resistance: resistance to seawater, grease, acid, alkali and other chemicals corrosion, antibacterial, non-toxic, tasteless, no pollution.
Processability: no joint, and easy to hot pressing, trade-offs, gluing, bonding and other processing.
Anti-sensation: high resilience and tensile strength, high patience, outstanding shockproof and buffering functions.
Thermal insulation: excellent thermal insulation, cold insulation and low temperature function, can withstand cold and exposure. Sound insulation: Sealed cells, good sound insulation.
When the content of vinyl acetate in EVA is less than 20%, it can only be used as plastic.
EVA has a good low temperature resistance function, and its thermal decomposition temperature is relatively low, which is about 230 ℃. With the increase of molecular weight, the softening point of EVA increases, the processability and the external gloss of plastic parts decrease, but the strength increases, the impact resistance and environmental stress cracking resistance are improved. EVA's chemical resistance and oil resistance are slightly worse than PE and PVC, and the change is more significant with the addition of vinyl acetate content.
The function improvement of EVA is better than that of PE, mainly in the aspects of elasticity, flexibility, gloss, air permeability and so on. In addition, its resistance to environmental stress cracking has been improved, and its tolerance to filler has increased, the method of participating in more reinforcing fillers can be adopted to prevent or reduce the reduction of EVA mechanical function compared with PE.
EVA can also be modified to obtain new applications. Its modification can be considered from two aspects: first, EVA can be used as the backbone of grafting other monomers; The second is to carry out some alcoholysis of EVA.