Paper-plastic detachment in packaging printing lamination phenomenon and treatment methods
We know that there are many factors that affect the quality of packaging box printing, there are many influencing factors, such as the printing paper, film, ink, adhesives, machinery and other objective factors used in printing, as well as temperature, pressure, speed, the amount of glue, customer use and other subjective factors caused.
The following is an overview of the packaging printing lamination when the phenomenon of paper-plastic separation and treatment. I hope to bring some technical learning for the use of composite process production enterprises.
Paper-plastic separation phenomenon when laminating
The essence of paper-plastic composite is to use adhesive as the central medium, in the laminating machine on the drum, under the action of external force of heating and pressure, the paper plant fiber and plastic non-polar polymer film and ink layer two-way moisture, immersion, oxidation film drying, and then an effective adsorption force, so that the paper-plastic bonding.
Paper-plastic detachment phenomenon when laminating the primary manifestation of the composite film peel strength lack of adhesive does not dry, paper printed materials and plastic film above the adhesive layer from. This phenomenon is mainly presented in the large field products, because the appearance of the ink layer is thick, the glue is difficult to wet, dispersion and penetration.
1、Cause of composition
There are many factors affecting the separation of paper and plastic in packaging printing, such as the smoothness of the paper, uniformity, water content, the functions of the plastic film, the thickness of the ink layer of the print, the amount of auxiliary materials, the temperature and pressure of the paper-plastic composite, the production environment health conditions and temperature, relative humidity, etc. will have a definite impact on the final results of the paper-plastic composite.
(1) when our ink ink layer is too thick, simply cause the adhesive penetration and dispersion, the occurrence of paper-plastic separation. Our packaging printers often take the treatment is to add the amount of adhesive coating and add pressure.
(2) the ink layer is not dry or not dry, the residual solvent components in the ink layer to weaken the adhesive force constitutes a paper-plastic detachment. Treatment is to wait for the product ink dry, then composite.
(3) the printed surface of the residual spray powder will also impede the paper and plastic film bonding constitutes a paper-plastic separation. Treatment is the use of mechanical and manual methods to erase the powder on the surface of the printed material and then composite.
(4) The operation process is not standard, the pressure is small, the machine speed is fast, resulting in paper-plastic separation. Treatment is strictly according to the process standard operation, appropriate to add the pressure of lamination, reduce the speed of the machine.
(5) adhesive is absorbed by the paper and printing ink, the lack of coating volume caused by paper-plastic detachment. Should be the adhesive from scratch formula and according to the manufacturer’s requirements to confirm the amount of glue.
(6) plastic film exterior corona treatment is not enough or more than the use period, so that the paper-plastic separation caused by the failure of the treatment surface. The corona standard of film lamination should be corona on the plastic substrate or update the plastic film.
(7) in the use of one-component adhesives, due to the lack of air humidity caused by the paper-plastic detachment, should be based on the humidity requirements of the one-component adhesive processing, artificial humidification.
(8) to ensure that the adhesive in the shelf life, and according to the manufacturer’s requirements for storage and use, such as automatic glue mixing machine in outstanding condition, to ensure the accuracy of the ratio, uniformity, adequate.