Plastic flexible packaging film with high obstruction

Abstract

The invention provides a plastic flexible packaging film with high obstruction. The plastic flexible packaging film comprises a polyamide PA layer, an ethylene-vinyl alcohol copolymer EVOH barrier layer and a polyamide PA layer which are laminated in a coextrusion way, and a heat seal inner layer comprising an adhesive layer and a heat seal layer is prepared in the coextrusion way by taking one side surface of the plastic flexible packaging film as an inner side surface. The invention provides the plastic flexible packaging film which meets the requirements for high obstruction, moisture obstruction and gas obstruction and has high tenacity and strength and transparent appearance for foods, medicines, chemical products, and the like.

Description

technical field [0001] The patent application of the present invention relates to a multi-layer composite plastic flexible packaging film for food and medicine. Background technique [0002] At present, the manufacture of food and pharmaceutical packaging materials has begun to step into the high-tech industry field of worldwide concern. In my country, plastic flexible packaging materials for food and medicine and their manufacturing technology have also received considerable attention and development. As a plastic flexible packaging material for food and medicine, it has high technical standards for moisture resistance and barrier performance. In order to improve the barrier performance technical indicators of plastic flexible packaging materials, on the one hand, technicians start researching and developing new high-barrier performance plastic materials; Purpose. A variety of patented technologies are disclosed in Chinese patents, such as the name "High Barrier Aluminum...

AI Technical Summary

Problems solved by technology

A variety of patented technologies are disclosed in Chinese patents, such as the name "High Barrier Aluminum-plated Composite Film for Liquid Dairy Packaging", the patent number is CN200610050148.1, and its seven layers include various functional layers including barrier layers and aluminum-coated films. There are adhesive layers between them to be composited with each other. This packaging material can only be manufactured by dry composite method, which has a long production cycle and cannot meet the requirements of current professional technical standards. The packaging material film itself has technical problems of high cost and opacity; The Chinese patent also discloses a patent application number: CN200910247702.9, "Five-layer co-extruded high-barrier liquid packaging film and its preparation method" patent technology. The five-layer structure only includes one barrier layer, and the rest of the layers are high. Density polyethylene, low density polyethylene and linear low density polyethylene and other resins are mixed in a certain proportion. This structure has technical problems of high oxygen and water permeability, and the oxygen transmission rate is 12000cm 3 / m 2 , water vapor transmission is not more than 2 g / m 2 , the shelf life is short, and the air permeability leads to a decrease in the quality of the packaged product

[0003] In addition, on August 1, 2009, my country officially implemented the new national standard "Plastic Composite Films for Packaging, Bags, Dry Lamination, Extrusion Lamination" GB / T10004-2008 standard. Compared with the original standard, there are several important points in this standard. The difference is: 1. The requirements for the residual amount of solvent are increased, and the total residual amount of solvent is changed from 10mg / m 2 Adjusted to 5mg / m 2 , benzene residues from 3mg / m 2 Adjusted to not be detected; 2. Deleted the structure containing aluminum foil, which reflects that this professional technical standard was proposed due to a series of technical problems exposed by the dry composite production process. The dry composite manufacturing method of multilayer composite plastic flexible packaging film After coating a layer of solvent-based adhesive on the plastic film, the solvent is volatilized and dried in the drying tunnel of the composite machine, and then bonded with the adjacent composite material on one side by hot pressing to form a smooth composite material. The three-layer composite structure Just need to do the above operation again, the production cycle is very long, and the three-layer composite structure needs 96 hours to transfer to the next process. In addition, the thickness of the adhesive layer of the solvent-based adhesive in this production process is not easy to control, which often makes the solvent The residual amount of type adhesive increases, which leads to the peculiar smell of the laminated soft packaging material film and increases the probability of contaminating the packaged food or medicine. However, the plastic flexible packaging material containing the aluminum plating layer can only be produced by dry lamination. ; The above-mentioned technical standards also increase the requirements for hygiene indicators of raw materials and additives

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