Water-soluble plastic film

With the support of the Ministry of Science and Technology of China National Packaging Corporation, Hunan University of Technology and Guangdong Zhaoqing Fangxing Packaging Materials Co., Ltd. have jointly researched and developed water-soluble films and production equipment that has passed provincial and ministerial level appraisal and is currently in production.

The main raw material of water-soluble packaging film is polyvinyl alcohol with low degree of alcoholysis, using polyvinyl alcohol film-forming, water-soluble and degradable, add various additives, such as surfactants, plasticizers, anti-sticking agents, etc. . Water-soluble film products are green packaging materials and have been recognized by the national environmental protection agencies in Europe, America, Japan and other countries.

The water-soluble film is packed in PE plastic to keep its specific moisture content constant. When the water-soluble film is removed from the PE package, its own moisture content changes with the ambient humidity, and its performance also changes. Water-soluble film is an anti-static film, unlike other plastic films, with good anti-static properties. In the process of using water-soluble film packaging products, it will not cause the decrease of its plasticity and electrostatic dust-carrying performance due to static electricity. Water-soluble films have strong permeability to moisture and ammonia, but have good barrier properties to oxygen, nitrogen, hydrogen, and carbon dioxide gas. These features make it possible to maintain the ingredients and original odor of the packaged product intact. Water-soluble packaging film also has a good heat seal, suitable for resistance heat sealing and high frequency heat sealing, heat sealing strength and temperature and humidity, pressure, time and other conditions, generally greater than 200g/cm. The mechanical properties of the water-soluble packaging film: elastic modulus 2 500-400 kg/cm 2, tensile strength 400-200 kg/cm 2, tear force 200-50 kg/cm, elongation 150%-220%. The water-soluble film can be clearly printed by ordinary printing methods, and the printability is good. Has good oil resistance (vegetable oil, animal oil, mineral oil), fat, organic solvents and carbohydrates, but strong alkalis, strong acids, chlorine radicals and other chemical reactions with PVA, such as borax, boric acid, certain Dyes, etc. These substances are recommended not to be packaged in water-soluble film. The water solubility of the water-soluble film is related to its thickness and temperature. Take a 25 μm thick film as an example, the dissolution time at 20°C is ≤300S, the dissolution time at 30°C is ≤50S, and the dissolution time at 40°C is ≤30S.

Reprinted from: China Food Industry Network