(1) Hard intermediate parts
The hard intermediate part has good shapeability, which can make the structure of the bag firm, have a certain rigidity, and play a certain role in protecting the items in the bag. Common materials are cardboard, polyvinyl chloride plastic and so on. Among them, cardboard has steel sheet, fiberboard paper, white board paper and yellow board paper. The stiffness and toughness of steel sheet are the best.
(2) Soft intermediate parts
The purpose of the application of soft intermediate parts is mainly to increase the fullness of the bag body, improve the tactile effect of the hand feel, and also to give the bag body a better shape, mainly using foam, sponge, cotton, lining, non-woven fabrics and other materials , belonging to the padding material of the bag. Materials with high elasticity such as sponge can also be used in conjunction with cardboard to make the bag body with a hard structure, so that the bag body has a plump shape and a strong sense of concave and convex, and changes its rigid texture.
