Features and disadvantages of PVC film
Polyvinyl alcohol film (referred to as PVA), the density of the polyvinyl alcohol film is 1.26-1,29g/cm3, the refractive index is 1.52, and it emits white light after being irradiated by ultraviolet rays. It has high water absorption and can be dissolved when immersed in water. The moisture content of the fiber can reach 30%-50%, and the moisture content can reach 4.5% under the environment of 65% RH and 25 ℃. It can permeate water vapor, but it is difficult to permeate alcohol vapor, let alone organic solvent vapor, inert gas and hydrogen. The barrier properties of polyvinyl alcohol film are even better than vinylidene chloride film. PVA is the only vinyl polymer that can be used by bacteria as a carbon source and energy source. Under the action of bacteria and enzymes, it can degrade 75% in 46 days. It is a kind of biodegradable polymer material and can be produced on a large scale by non-petroleum routes. , Low price, excellent oil resistance, solvent resistance and gas barrier properties, and has unique advantages in food and pharmaceutical packaging.
The application of PVA is based on the solution method. Thin film materials are prepared by casting film. However, the solution processing and molding need to undergo dissolution and drying processes. It has disadvantages such as complex process, high cost, and low yield. It is difficult to prepare thick-walled and complex-shaped products. At the same time, it cannot be co-extruded and blown with other materials to prepare a multilayer composite film. Polyvinyl alcohol is non-toxic, tasteless and harmless to the human body, has good affinity with the natural environment, does not accumulate, and does not pollute.
The polyvinyl alcohol high-barrier composite film is a film with extremely high barrier properties formed by coating a modified polyvinyl alcohol water-soluble liquid on the substrate with polyethylene plastic as the base material. Because the polyvinyl alcohol high-barrier composite film has good barrier properties and meets environmental protection requirements, the market prospect of this type of packaging material is very bright, and there is a broad market space in the food industry.
pvc film
The application of PVA is based on the solution method. Thin film materials are prepared by casting film. However, the solution processing and molding need to undergo dissolution and drying processes. It has disadvantages such as complex process, high cost, and low yield. It is difficult to prepare thick-walled and complex-shaped products. At the same time, it cannot be co-extruded and blown with other materials to prepare a multilayer composite film. Polyvinyl alcohol is non-toxic, tasteless and harmless to the human body, has good affinity with the natural environment, does not accumulate, and does not pollute.
The polyvinyl alcohol high-barrier composite film is a film with extremely high barrier properties formed by coating a modified polyvinyl alcohol water-soluble liquid on the substrate with polyethylene plastic as the base material. Because the polyvinyl alcohol high-barrier composite film has good barrier properties and meets environmental protection requirements, the market prospect of this type of packaging material is very bright, and there is a broad market space in the food industry.
pvc film
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