Research On The Blow-molding Technology Of PEO Packaging Film

Polyethylene oxide(PEO) film is widely used for packaging film to pack agricultural products and toxic or harmful goods due to its excellent water-soluble, biodegradable and environmentally friendly. Extrusion blow molding has so many advantages, such as simple operation, high efficiency, wide range of raw materials and low use performance requirements of the processing products, which is one of the most common methods of molding plastic film. However, the report of using the method to blow PEO packaging film is rarely. Therefore, extrusion blow molding PEO raw material and the modified PEO blend have been used to blow PEO packaging film in this thesis. The main contents and conclusions are as follows.(1) Blow molding PEO raw material directly.(2) The plasticizer glycerin and stabilizing agent glycol have been selected to improve the PEO molding process ability and stability, and the packing starch and liquid paraffin flow modifier to improve the melt viscosity and flow performance of PEO.(3) The modification agent(plasticizer, stabilizer, packing and flow modifier) has been selected by the theoretical analysis. The best match quantity of the selected modifier is defined as 100% PEO, 20% glycerol,20% glycol, 15% starch and 0.4% liquid paraffin through the blend melt index and scanning electron microscope(SEM) test.(4) The influence of modifier content and process parameters on the blown film has been considered. It is found that the best blow molding temperature of modified PEO decreases with the increase of the plasticizer glycerin content. Starch and liquid paraffin can improve the processing flow properties of the PEO. In addition, the film can be blown best when the blowing ratio controlled in 2.5 ~ 3.0, traction ratio in 3 ~ 4.(5)The effects of different specific flow modifier on the mechanical properties and light transmittance of thin films have been identified through the mechanical performance and euphotic rate test. The results show that the tensile strength and the tears strength decrease of the film increase while the elongation increases with the increasing of the glycerol content in the film. In addition, the addition of starch decreases the PEOfilm’s light transmittance.(6)The thin films are characterized by SEM and Fourier transform infrared spectroscopy(FTIR) test.