Techniques for Using Flexible Packaging Polyurethane Laminating Adhesives

The flexible packaging polyurethane laminating adhesive, with its strong bonding strength, excellent flexibility, and excellent heat resistance and weather resistance, is widely used in the laminating process of food and daily necessities flexible packaging. The proper usage techniques are crucial for preventing problems such as delamination, blistering, and wrinkling, and ensuring the quality of the packaging. 

 

Base material pre-treatment is the foundation for a strong bond. Before the operation, it is necessary to thoroughly clean the dust, oil stains and moisture on the surface of the film, aluminum foil and other base materials, keeping the surface clean and dry. At the same time, the operation needs to be adjusted according to the characteristics of the base material. For soft films, they should be gently flattened to avoid stretching deformation, ensuring that the bonding surface is flat and free of defects, and creating conditions for the uniform adhesion of the glue. 

Precise glue dispensing and uniform coating are the core steps. For two-component adhesive, it is necessary to strictly follow the standard ratio for mixing, accurately weigh the ingredients, and thoroughly stir to avoid any deviation in the ratio that could lead to failure of curing or reduced adhesion. During coating, control the thickness of the glue layer to be uniform, avoiding uneven thickness that may cause local bubbling or detachment. Adapt the coating to the production line speed to ensure a continuous and stable coating process. 

 

Controlling the fixed temperature and humidity levels and the details of the curing process is of utmost importance. The working environment must be maintained at a constant temperature and humidity, with a suitable temperature and constant humidity. The environment should be dry, moist, well-ventilated and stable. After the adhesive layer is laminated, it needs to be dried according to the process requirements, allowing the solvents to completely evaporate, and then rolled up and left to stand still. The finished product needs to be left to cure for a sufficient period to achieve complete solidification. During this process, it is necessary to avoid squeezing and bending to maximize the peel strength and stability of the laminated film and extend the service life of the flexible packaging.