Laminating film is widely used in printing, packaging, and archival preservation industries. Its core function is to provide protection, aesthetics, and durability for paper, printed materials, or packaging materials. However, many customers encounter problems such as delamination, peeling, or edge curling during use. This not only affects the product's appearance but can also lead to material waste and secondary processing costs.
As a professional laminating film manufacturer, YIDU, based on years of production experience, has summarized detailed methods and precautions for preventing laminating film delamination, helping buyers and end-users improve lamination effects and stability.
1. Main Causes of Delamination
1.1 Substrate Surface Contamination or Grease Residue
If the surface of printed materials or paper has undried ink, dust, fingerprint grease, or other contaminants, it will hinder the effective bonding of hot melt adhesive or pressure-sensitive adhesive to the substrate.
This problem is particularly common on digital printing, inkjet printing, or varnish-coated paper.
1.2 Inappropriate Hot-pressing Temperature
Too low a temperature will cause the hot melt adhesive to not melt fully, resulting in insufficient adhesion and delamination; too high a temperature may cause the adhesive layer to flow excessively, leading to shrinkage or delamination.
1.3 Uneven Pressure
Uneven pressure distribution or too low pressure will cause some areas of adhesive not to fully adhere to the substrate.
For large-format or thick paper, insufficient local pressure can easily form air bubbles and voids, leading to delamination.
1.4 High Substrate Moisture Content
Paper or cardboard absorbs moisture and expands, which will reduce the adhesion between the film layer and the substrate, especially under conditions of high humidity or significant seasonal changes.
1.5 Film Material Quality or Adhesive Layer Problems
Low-quality film, uneven adhesive layer, or aged film will result in insufficient adhesion.
Different brands of films have significantly different hot melt adhesive or pressure-sensitive adhesive properties; improper matching of temperature, pressure, and speed can easily lead to delamination.
2. Practical Methods to Prevent Delamination
2.1 Keep the Substrate Surface Clean
Operating Method
Before lamination, ensure the surface of paper, printed materials, or packaging materials is free of dust, grease, fingerprints, or loose particles.
For glossy coated paper or inkjet printed materials, clean the surface with a clean, soft cloth or compressed air.
2.2 Control the Hot Press Temperature
Operating Method
Set the optimal hot press temperature according to the film type:
BOPP film: 100–130℃
PET film: 110–150℃
For thick films or large-format materials, heat or preheat the substrate in sections to avoid localized overheating.
2.3 Adjust Pressure and Speed
Operating Method
The pressure of the rollers on the hot press or laminator should be evenly distributed. Too low a pressure will cause localized delamination, while too high a pressure may cause excessive film stretching.
Lamination speed should be matched with temperature: 0.5–1 m/min for small office paper, 0.3–0.7 m/min for large packaging.
2.4 Controlling Substrate Humidity and Environmental Conditions
Operating Method
The humidity of paper or cardboard should be controlled within the range of 4–6%.
In high humidity or seasonally damp environments, drying treatment can be performed before lamination.
Avoid storing laminated products for extended periods in high humidity environments.
2.5 Selecting High-Quality Film and Adhesive Layer
Operating Method
Select products with moderate film thickness, uniform adhesive layer, and good heat resistance.
2.6 Using Functional Films or Anti-Delamination Coated Films
Operating Method
For high-end printed materials or large-format packaging, select film materials with anti-delamination coatings.
Coated films maintain good adhesion under both hot and cold pressing conditions, while reducing the risk of wrinkling and bubbling.
Laminating film delamination is mainly caused by substrate contamination, improper temperature, uneven pressure, excessive humidity, and film quality issues. The following six methods can effectively prevent delamination:
Keep the substrate surface clean
Control hot-pressing temperature
Adjust pressure and speed
Control substrate humidity and environmental conditions
Select high-quality film materials and adhesive layers
Use functional films or anti-delamination coated films