Key points for adapting polyurethane laminating adhesives in the high-speed laminating process

With the upgrading of flexible packaging equipment, high-speed dry and solvent-free laminating processes have become the mainstream production mode. The conventional low-speed adapted polyurethane laminating adhesives are prone to problems such as poor leveling, uneven coating, bubbles, and unstable adhesion under high-speed conditions. The adaptation and process adjustment of dedicated high-speed adhesives are the core key to ensuring the yield rate of high-speed production.

 

High-speed laminating has extremely high requirements for the fluidity and wetting performance of adhesives. After the equipment speed is increased, the time for coating, leveling, and wetting of the adhesive solution is significantly shortened. Ordinary adhesives have high viscosity sensitivity and are prone to uneven coating thickness, orange peel texture, and strip-like drawing under high-speed shear. After curing, it causes appearance defects and uneven strength of the laminated film. The high-speed Polyurethane Adhesive has undergone rheological modification and has excellent shear fluidity. It can still quickly spread and wet the substrate under high-speed coating.

At the same time, the evaporation rhythm of the high-speed production drying tunnel is faster. Ordinary high-solid content adhesives are prone to surface dry skin and internal solvent residue problems. The formula of the high-speed adapted adhesive has a reasonable evaporation gradient and can be adapted to the segmented temperature rise drying process, effectively avoiding bubble, pinholes, and excessive residue defects. Its stable cross-linking reaction speed can also adapt to the requirements of high-speed winding and rapid curing, and prevent membrane layer slippage and misalignment caused by insufficient initial adhesion.

 

During production, it is necessary to match dedicated high-speed adhesives, reasonably control the working viscosity and drying tunnel temperature, and cooperate with high-precision coating mesh rollers. Through the adaptation of glue, equipment, and process, high-speed mass production can be achieved stably, taking into account production efficiency and product quality, and effectively reducing the rework loss in high-speed production.