Core Forming Processes
Liner Paper Lamination Process
Using a gluing machine and a flattening press as core equipment, the box board (with 12% moisture content) is bonded to the liner paper using an adhesive mixture of white PVA glue and water (3:1 ratio). The assembly is pressed flat at 20 MPa for 5 minutes to ensure a smooth surface free of wrinkles, glue overflow, or unwanted adhesion.
Box Body Assembly and Forming Process
Glue is applied to the edges of the die-cut box board, and the sides are folded up. The longer edges are pressed over the shorter edges, secured tightly with rubber bands, and stacked with a 45° offset to air-dry. This ensures the box corners are tight and seamless with flush edges, preventing misalignment issues during the subsequent outer wrap application.
Outer Wrap (Facing Paper) Application Process
After evenly applying glue to the outer wrap, it is precisely aligned with the box body. The four sides are folded down at 90° angles; a bamboo scraper is used to smooth the inner edges for full adhesion, followed by wiping with a soft cloth to expel air. This guarantees a smooth surface free of bubbles or glue stains, with no lifting or wrinkling at the edges.
Die-Cutting and Precision Trimming Process
Box components are cut using a high-precision die-cutting machine. Standard tolerances for finished dimensions (length and width) are controlled within 0.2 mm, and the fit tolerance between the lid and base is controlled within ±0.3 mm. This prevents mass-production issues such as loose fits with visible gaps or overly tight fits that cause the box to jam.
