Polyurethane laminated adhesive will dominate the field of drug flexible packaging.

Bubble-cap packaging is made by placing the medicine in the pit of plastic hard sheet formed by plastic suction, and then bonding and heat sealing the plastic hard sheet with an aluminum foil printed by gravure and coated with protective agent and adhesive, so that the medicine can be safely protected. The main materials of blister packaging are medicinal FFP aluminum foil, plastic hard sheet (polyvinyl chloride PVC) and adhesive.

 

In the early days, single-component pressure-sensitive adhesive was used as the adhesive for blister packaging. The main components of pressure-sensitive adhesive include synthetic resin adhesive, adhesive, plasticizer, antioxidant, stabilizer, crosslinking agent, colorant and filler. In the earlier period, pressure-sensitive adhesives were mainly composed of natural rubber.

 

With the increasing demands on the hygienic performance of pharmaceutical packaging materials, the additives added to the natural rubber-based adhesives have peculiar smell and some are toxic, so they have not been used in the composite packaging of pharmaceuticals and foods. Because there are many kinds of materials in compound medicine packaging, enterprises have turned to two-component polyurethane laminating adhesive for compounding polar plastics and nonpolar materials.

 

At present, the laminated adhesive for soft packaging materials is developing towards solvent-free. The solvent-free adhesive is basically composed of two-component Polyurethane Adhesive, and its main agent and curing agent have high viscosity and fluidity at room temperature. When compounding, the main agent and curing agent are mixed in proportion and coated on the substrate after heating. Because no organic solvent is used, the cost is reduced, and there is no pollution to the environment caused by the volatilization of organic solvent, which saves huge drying, heating, blowing and waste gas discharge devices and reduces energy consumption. The product has no residual solvent damage, improved production speed, low maintenance cost and remarkable benefits, which is the future development direction in the field of drug flexible packaging.