A Study on Bend Crease Technology of Honeycomb Paperboard III

4 The principle of realizing honeycomb cardboard creasing

This principle can be used to realize the creasing of honeycomb paperboard. By changing the stress state of the honeycomb paperboard, the honeycomb core is first crushed and then indented. According to the indentation of the honeycomb paperboard shown in Fig. 4, a section of the honeycomb paperboard is simultaneously subjected to a shear force and an M-bend, and a downward elastic deformation plastic deformation and a bending deformation of the honeycomb paperboard are generated in the compressed area and the adjacent area. The core will be bent and deformed to form an angled mouth with the direction of the pressure, so that the honeycomb core will also be subjected to the bending moment Mo.

Where: P is the pressure; θ is the angle between the honeycomb core and the pressure; T is the thickness of the honeycomb core.

The corners of each section are not the same as “2”, where θmax occurs on the mm section and Mθ is proportional to the θ corner. Therefore, Mmax occurs on the mm section. With the increase of the load P, the bending deformation becomes more serious and the Mmax also increases. As a result, the honeycomb core first decompresses and collapses in the mm cross section. Subsequently, due to the domino effect, all the instability in the pressed area and adjacent areas will be induced. Crush. After crushing, under the action of the shearing force of the mold, it is easy to press marks on the mm cross section to form a fold line.

Due to the mutual restraint of the adjacent honeycomb cores, the collapsed folding lines of the single honeycomb core alternately appear inwardly and outwardly. The resulting crushing shape resembles that of a butterfly spring and has certain elasticity both in the up and down direction and in the horizontal direction. Good bendability and folding resistance.

The upper part of the paper is deformed by bending the excess part, and it can make up the face paper required in the trapezoidal indentation area of ​​the figure. Therefore, indentation according to this method does not easily lead to tearing of the upper paper.

The above theory has been experimentally verified. The solution to the creasing and indentation problem of the honeycomb paperboard makes it possible for the honeycomb paperboard box to be produced by a stamping method like a corrugated paperboard box, which will completely change the hand-made status of the honeycomb paperboard box and realize an efficient and automated production of the honeycomb paperboard box.

(Wen/Li Qing Liu Guodong Chang Jianfeng Qi Mingsi)

Packaging Engineering