A 1.2kg Non Deformable French Fries Box: Structural Mechanics White Paper

In fast food packaging design, the French fries box needs to balance lightweight, cost-effectiveness, and structural strength to ensure no significant deformation when carrying a weight of 1.2kg. This article analyzes its implementation path from three aspects: material selection, structural design, and mechanical principles.

1. Material selection: balance between high strength and lightweight

Preferred 300-350gsm coated cardboard with PE film on the surface for waterproofing and oil resistance. The material needs to have high bending stiffness (EI value) and compressive strength, with a longitudinal compressive strength (ECT) of not less than 7kN/m, to ensure that the side walls do not buckle when vertically loaded.

2. Structural design: mechanical optimization of geometric shapes

Double layered composite wall structure: using hollow interlayers or corrugated liners to increase the moment of inertia (I value) of the section and effectively disperse local stress.

Bottom locking design: The staggered tongue structure forms a self-locking bottom plate, which evenly transfers the load to the side wall and avoids stress concentration.

Cone shaped sidewall optimization: The ladder platform with a wide upper and narrow lower shape reduces the center of gravity, utilizes geometric stability to resist overturning moments, and enhances lateral bending resistance.

3. Principles of Mechanics: Load Distribution and Stability

When bearing 1.2kg (approximately 11.8N), the bottom needs to withstand static loads and dynamic impacts (calculated at 1.5 times the safety factor). Verified through Finite Element Analysis (FEA):

The vertical load is transmitted to the four sides through the bottom plate, and is balanced by the bending moment of the side wall and the reaction force of the base;

The design of edge and fold lines forms natural reinforcement bars, enhances torsional modulus, and prevents mouth collapse;

The creep performance of the material must meet the requirement of plastic deformation<1% after 24 hours of load-bearing.

Conclusion

Successful design requires the integration of material mechanics and structural engineering: high ECT paper-based provides foundation strength, geometric optimization improves stiffness coefficient, and locking structure ensures load dispersion. The ultimate goal is to achieve a box body weight of less than 20g but a load-bearing capacity of 1.2kg without deformation, balancing environmental protection and commercial needs.

Zhejiang Dongou Printing Industry Co.,Ltd, the expert in French fried box production