Rectangular lunch box

PP (polypropylene) is the most widely used material for lunch boxes due to its high stiffness, heat resistance up to 120°C, and excellent food-contact safety. PS offers a lower-cost alternative but is more brittle, while PET provides clarity but lower heat resistance. For reusable lunch boxes, PP is the recommended choice.

Proper sealing relies on precise die-cutting along the outer edges with no burrs or imperfections. In-mould trimming technology is recommended to achieve clean, smooth edges. Additionally, consistent material thickness and uniform forming pressure ensure the lid and base mate perfectly to create a reliable seal.

Common issues include warping or deformation, surface scratches, dimensional instability, and material breakage. These are addressed through strict temperature control during heating and cooling, proper material selection, regular mold maintenance, and careful handling of formed parts to prevent damage during stacking and packaging.

Yes, by changing molds, the same machine can produce various sizes and shapes, provided the production volume and specifications match the machine's forming area and depth capabilities. Quick-change mold systems can minimize downtime between production runs, making it feasible to switch between different lunch box designs efficiently.

Thin-gauge thermoforming under 1.5mm is standard for lunch boxes and similar food containers. The exact thickness depends on the product's strength requirements and the material used. PP boxes typically use 0.8-1.2mm sheet, while PS may require slightly thicker material to achieve sufficient rigidity.