Barrier and environmental protection of EVOH
The barrier performance is not only in blocking oxygen, but also in excellent aroma retention. The transmission rate of 15 u m EVOH was only 60 mg. EVOH not only has good barrier to aroma components, but also has much less adsorption capacity on its surface. The permeation rate and adsorption capacity of a certain flavor component are related to its chemical structure.
However, materials with excellent gas barrier properties usually have good barrier properties and low adsorption properties for general flavor components. In other words, it has good aroma retention. EVOH resin has strong oil resistance and organic solvent resistance. For example, when the solvent is immersed in various solvents, such as paraffine, paraffine, methanol and so on, the weight of the solvent is increased to 1210% by weight.
EVOH resin has high mechanical strength, elasticity, surface hardness, wear resistance and weather resistance. EVOH film has high gloss and haze, so it has high transparency. EVOH resin has high stability and processing waste can be recycled. Because EVOH has good gas barrier and aroma retention, it can greatly reduce the amount of packaging materials, which provides a good choice for plastic rice materials to replace glass and metal.
At the same time, EVOH contains only carbon, hydrogen and oxygen, and does not produce harmful substances such as hydrogen halide, hydrogen cyanide or dioxin during combustion. Moreover, the combustion heat is smaller than that of the general polyolefin, which can reduce the load of the incinerator. It is difficult for PDC with high barrier material to recycle leftover materials by using recycling layer. It can be seen that EVOH is a good material for environment protection and resource protection.