Layered Paper Packaging Structure with Direct Polyamide Release Varnish

The patent removes the oPP layer from the layered structure, extracting the problematic intermediate layer that caused recycling difficulties and high production costs. The release layer is applied directly to the paper layer, eliminating the need for the oPP substrate while maintaining functional performance.

The patent replaces the expensive oPP layer with a thin polyamide-based release varnish coating that can be easily applied and removed. This disposable-like coating provides the necessary adhesion and release properties without the cost and recycling problems of the permanent oPP layer.

The patent modifies the chemical and physical parameters of the release layer by using a polyamide-based formulation with specific additives. This changes the coating's adhesion properties to ensure strong bonding to the paper layer while maintaining ease of separation, thus resolving the adhesion quality concern.

The patent creates a composite release layer by combining polyamide resin with specific additives and waxes. This composite formulation provides both strong adhesion to the paper layer and easy separability, achieving the desired balance between adhesion quality and recyclability.

The patent introduces dynamic characteristics to the adhesive layer through the polyamide-based formulation, which allows the bond strength to be context-dependent. The adhesive provides strong bonding during application and use, but enables easy separation when needed, due to the reversible nature of the adhesive mechanism.

The patent uses parameter changes in the adhesive layer formulation, particularly through the polyamide-based chemistry and additives, to create a bond that transitions from strong during application to easily separable during removal. This controlled parameter change allows both strong adhesion and easy separation to coexist.