Material Mismatch
Incorrect selection of hot stamping foil for the substrate material is the primary cause. For example, using standard paper-grade hot stamping foil on non-absorbent surfaces such as laminated films, UV-coated surfaces, or plastic films prevents the adhesive layer from forming an effective bond with the substrate surface. Additionally, low-quality hot stamping foil-characterized by an abnormal melting point or uneven thickness of the adhesive layer, or weak adhesion between the gold layer and the adhesive layer-directly leads to the peeling of both the adhesive and gold layers after golden hot stamping.
Improper Equipment Parameter Settings
Excessively low stamping temperature means the adhesive layer does not melt sufficiently, only adhering temporarily to the substrate under pressure and peeling off easily afterward. Insufficient or uneven pressure creates gaps between the molten adhesive layer and the substrate, causing weak local adhesion. Furthermore, an overly short stamping duration prevents the adhesive layer from completing full melting and bonding reactions, ultimately compromising overall adhesion strength.
Poor Substrate Surface Condition
Residual contaminants on the substrate surface, such as oil, dust, offset printing powder, or mold release agents, isolate the adhesive layer from contact with the substrate. This results in the adhesive layer bonding only to contaminants, making it highly prone to scratching and peeling. In addition, excessively low surface tension of UV-coated or laminated layers, or mismatched substrate surface roughness, also hinders effective adhesion of the adhesive layer and reduces the firmness of the gold layer.
Improper Process Operation and Post-Treatment
If products are stacked, die-cut, or laminated immediately after golden hot stamping without sufficient cooling, the uncured adhesive layer at high temperatures peels off due to external contact or pressure. Meanwhile, excessive die-cutting mold pressure, overly high lamination temperature, or chemical reactions between the lamination adhesive and the hot stamping foil's adhesive layer damage the bonding between the gold layer and the substrate, leading to peeling issues.
Inadequate Post-Stamping Handling
Rushing subsequent processes like stacking or secondary finishing right after golden hot stamping disrupts the adhesive layer's curing process. The unhardened adhesive cannot withstand external forces, resulting in the gold layer peeling off easily. Even minor impacts or friction during handling can damage the bond if the substrate and adhesive layer have not fully set.