What is the reason why traditional suitcases are heavy?

The hard box is mainly to protect your articles from too much impact, while the soft box is light in weight and can have some room for expansion. At present, the common hard box materials on the market are ABS, PP, PC, thermoplastic composites and so on. It has the characteristics of high temperature resistance, wear resistance, impact resistance, waterproof and compression resistance, but when choosing, you must choose the lighter one. The soft box is made of canvas, nylon, EVA and leather. It has the advantages of light weight, strong toughness and beautiful appearance, but it is not as waterproof, compressive and impact-resistant as a hard box.