[China Packaging Network News] During the production of flexible packaging materials to be exposed to a variety of organic solvents, including toluene, ethyl acetate, acetone, methyl ethyl ketone, isopropyl alcohol, methanol, etc., these solvents from inks and adhesives.
For polyethylene and polypropylene films, toluene, ethyl acetate, etc. are all good solvents for polyolefins (similar solubility parameters), that is, the interaction between polyolefins and toluene, ethyl acetate is very large, even if After the printed film is in the drying tunnel, these organic solvents are also difficult to be desorbed from the inside of the polyolefin film, resulting in excessive toluene and ethyl acetate residues in the packaging material, resulting in food contamination and endangering people's health.
Shenzhen Huale Plastic Products Co., Ltd., in order to reduce the residual organic solvents such as toluene, when making flexible packaging bags, the commonly used method is to increase the drying tunnel temperature, increase the air volume and other means when preparing the composite membrane, and also to use the method of placing in the curing chamber. , sometimes even using multiple rewind methods. However, these means of reducing solvent residues are passive.
Foreign countries have developed soft packaging materials that have low adsorption properties to solvents, but research in this area in China is a blank. If we make some changes in the polarity of polyolefin resin, such as adding a small amount of high polarity additive (nano-modifier), the solubility parameter of polyolefin will be increased, and the solubility between the resin material and toluene and ethyl acetate solvent will be increased. The difference in degree parameter will reduce the interaction between the polyolefin and the solvent molecules. The organic solvent cannot enter the deep layer of the polyolefin film. The solvent adsorbed on the film surface can be easily removed in the drying tunnel.