Factors affecting the quality of the film lamination

01
Print ink layer condition
Refers to paper properties, ink properties, ink layer thickness, graphic area and printed graphic density. [ Film Lamination Machine ] When the printed ink layer is thick and the image area is large, many paper fiber capillary pores are blocked, which hinders the penetration and diffusion of the adhesive, making the printed matter and the plastic film difficult to adhere, and delamination, foaming and the like are prone to occur.



02
environment humidity
Between the adhesive and the plastic film and the printed matter, as the relative humidity of the air changes changed the water content. Humidity-sensitive prints can cause internal stresses due to dimensional changes. For example, the longitudinal expansion ratio of the printed matter is 0.5%, and the longitudinal heat shrinkage of the BOPP film is 4%. If the water absorption of the printed matter is too large and the elongation occurs, and the internal stress is caused between the heat shrinkage of the film, the film product may be curled, wrinkled, and bonded. [ Fully Automatic Lamination Machine ] Not strong. In addition, in a high humidity environment, the equilibrium moisture value of the printed matter will also change, and a large amount of moisture absorbed from the air medium will be released from the surface during the hot pressing compounding process, stagnating at the bonding interface, and partially forming a non-adhesive bond. phenomenon. Moreover, the change in the equilibrium moisture value of the printed matter (moisture from the air medium or dehumidification into the air medium) occurs mostly at the edge of the printed matter, so that it forms a ruffled edge or a tight edge, and is not easily formed well with the film in the hot press composite. [ Automatic Lamination Machine ] The wrinkles are caused by the bonding, so that the production cannot be carried out smoothly.



03
temperature control
Heating can soften the film and bond the paper to the plastic film. However, the temperature is too high, the film is easy to break, which seriously affects the quality of the product. Therefore, measures such as fan cooling and turning off the heating wire should be adopted.

Why air bubbles occurred during the lamination ?

The viscosity of the adhesive is also an important cause of air bubbles. 
[ water based lamination machine]


Generally speaking, the viscosity of the adhesive is related to the molecular weight of the adhesive, the plasticizer and the type of the diluent, and the adhesive generally has a high viscosity and a poor fluidity at normal temperature, so in order to lower the viscosity and improve the fluidity, it is required to be higher in the compounding. Insulation at temperature. The higher the temperature of the two-component adhesive, the shorter the mixing and storage time, and the larger the ratio of the main agent and the curing agent, the greater the viscosity of the adhesive, the more unfavorable the formation of bubbles, and the more easily the bubbles are formed. Bubbles of the same size, low-viscosity glue can be eliminated, and high-viscosity glue may not work because the high-viscosity gel has a large molecular weight and poor leveling.[sheet lamination machine]