PET/PE/EVOH/PE
EVOH can be regarded as EVA (ethylene—acetic acid ethylene ester copolymer) modified material. It has both ethylene polymer good process capability and vinyl alcohol polymer high gas obstruct capability. It is a new colorless, transparent obstruct material, with PVDC and PA, these three materials are the best barrier resin in the world. Its gas obstruct capability is 100 times higher than PA, 10000 times higher than PE,PP and ten times higher than PVDC which high obstruct material we used very often. In dry or relative humidity condition, its permeability is extremely low, but its gas barrier capability is 10 to 50 times or even more times higher than Nylon. EVOH has excellent transparency, glossiness, mechanical strength, retractility, abrasive resistance, freeze resistance and surface strength. It has the highest heat stability in all the barrier resins. It also has excellent oil resistance, organic solvent resistance and antistatic capability. It can regenerate and does not contain Chlorine and Dioxin,it is to be called green environmental production. According to the use of soft packaging, you must considered the material process capability and physics capability, to choose 10 to 20 times EVOH as the barrier layer, not only prevent oxygen and water vapor infiltrating into the content, but also chain up the aroma, fluid juice and the solvent of the content. Thus it solved the problem that the contents (liquid, gas) dissolved the compound water glue. In some areas, the EVOH has gradually replace the metallized film, aluminum foil and rigid container. It is being received various countries attention and shows the best potential growth trend in the market. Due to the oxhydryl in the molecular structure of EVOH resin, EVOH resin has the hydrophilia and hygroscopicity. When it adsorb the damp, its gas obstruct capability will be affected. So EVOH is used as the middle layer, usually coated with polyolefin. The damp quantity can be control aboratively, to use multilayers coated technic to packing EVOH resin (such as polyolefin).
After many years research, we discovered that if we select the international import raw materials, use the latest co-extruded process flow, the production which contains the EVOH high obstruct ability. Then compound many kinds of base materials like PE, PP, PVC, polystyrene, PET, PA and so on. The Oxygen transmission rate can be reduced to a small percentage even one thousandth. According the requirement of the obstruct effect, it can be coated on single side or double sides or even multilayer coated. The production of multilayer coated film for the automatic liquid filling machine, not only solved the moisture absorption problem, but also had a good economical efficiency. To each kind of active ingredient, the low adsorbability, high obstruct capability, it can prevent the loss of effective component; the excellent oxygen resistance, can prevent the oxidation and metamorphism of the effective component; the excellent transparency, can be applied to the oxygen sensitive goods. The packaging content can be solid granules, powdery products, fluid products.
Chemic and oil resistance capability
EVOH compound film has excellent oil resistance and organic solvent resistance. Put it in the liquor and oil in the 68 degree F. A year later, the increased percentage of the weight is : cyclohexane, xylene, petroleum ether, benzene and acetone is 0% ; glycol is 2.3% ; methanol is 12.2%; salad oil is 0.1%.
Thermal/ Mechanical Properties
EVOH compound film has high mechanical strength, flexibility, surface strength, abrasive resistant, weather resistance and strong antistatic capability. The material has high gloss and the low fog density, so it has a high degree of transparency.
