The Influence of Affinity of Paper Plastic Composite Bag Packaging Materials

The paper plastic composite bag packaging material includes a paper layer and a sealed composite plastic film layer, with the plastic film layer coated with pearl pigment or plated with metal. The material has a pure white appearance and low requirements for paper, achieving offset printing of paper plastic composite materials on plastic surfaces, with a cost reduction of about 25% compared to existing paper offset printing materials; Reduce by about 40% compared to gravure paper plastic composite packaging materials and by about 50% compared to aluminum paper composite offset printing products; The offset printing surface of this material has full, bright, textured and metallic colors, and can also add printing patterns or anti-counterfeiting marks between the paper layer and the plastic film layer. Paper plastic composite products require strong bonding, clean, flat, smooth surface, no bubbles, curls, no loss of film, no peeling, etc. There are many factors that affect composite quality, including objective and subjective factors. It involves environmental factors of the operating site (indoor temperature, humidity, dust, etc.), as well as factors of the product itself (ink used, paper type, printing method, etc.), and is closely related to the adhesive, film, and process conditions used in paper plastic composite, operating methods, and the structure and technical performance of the laminating machine. The chemical structure of the composite polypropylene film itself does not have active genes and is a non-polar substance with poor affinity for glue, causing difficulties in surface adhesion. So, it is necessary to perform corona treatment on the film to make its surface product unsaturated with double bonds and carbon groups, so that its surface can have active genes. As a result, the surface roughness of the film increases, which is beneficial for adhesive coating. The change in the properties of the film surface after corona treatment, from non-polar substances to polar substances, is beneficial for improving the affinity between the adhesive and the film.