JPH024050Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a packaging box with a frame made of double-sided corrugated cardboard.

[Conventional technology]

BACKGROUND ART Conventionally, for packaging heavy items, a packaging box with a body frame is used, which is made by inserting a body frame made of double-sided corrugated cardboard for pressure-resistant reinforcement into an outer box made of double-sided corrugated cardboard.

As shown in the cross-sectional view of the main part shown in FIG. 3, the outer box X has a layer 1 with a low step height on the outer surface side from the viewpoint of surface smoothness or printing suitability. In addition, a layer 2 with a high step height is used on the inner surface of the barrel frame Y in order to softly contact the items to be placed inside and enhance the cushioning effect.

[Problem that the invention attempts to solve]

When evaluating the compressive strength of a box, it can be assumed that if the height of the box is sufficiently low, it will deform and fail due to compressive force alone.In this case, the compressive strength of the sheet determined by the end crush method (JISZ0401) It is considered that the strength of the box body can be evaluated.

However, the height of an actual box is much larger than the thickness of the sheet, and compression failure of a normal box is largely affected by deflection related to bending rigidity.
When a sheet bends, a bending moment acts on it, but if the inside of the sheet is made of a uniform material, there will be no directionality in which the sheet bends in one fixed direction.

However, in the case of double-sided corrugated board, it usually consists of a combination of a layer with a high flute height and a layer with a low flute height, and generally has a high flute layer called A flute and a high flute layer called B flute. It consists of a layer of low temperature. The deformation of the box in this case depends on the position of the neutral axis and the physical properties of the base paper, but in general, the edge stress is smaller on the side with lower step height, and the side with lower step height (B flute side) to the side with higher step height (A
It tends to bend toward the flute side).

For this reason, as in the conventional example, both the outer box and the trunk frame are made of double-sided corrugated cardboard with a layer with a low height (B flute) on the outside surface and a layer with a high height (A flute) on the inside surface. However, there was a problem in that each side wall was bent inward by the compressive force, and the deformation caused by this bending deteriorated the compressive strength, making it impossible to obtain the expected strength.

[Means for solving problems]

In order to solve the above problems, this idea uses a layer with a low height on the outside of the outer box,
In addition, the trunk frame is made of double-sided corrugated cardboard with a layer of high height on the outer surface. (See Figure 2) [Operation] According to this invention, when a compressive load is applied,
The outer box When the two abut against each other, deflection is prevented as a whole, and the overall compressive strength increases significantly.

〔Example〕

1 and 2 show an embodiment of this invention. The packaging box with a body frame of this invention consists of a double-sided corrugated board with a layer with a high height, ie, A flute, and a layer with a low height, ie, B flute. It consists of a rectangular cylindrical body frame Y with upper and lower openings that is tightly inserted and inscribed.

The outer box Two pairs of bottom flaps 4 are connected to the lower edge of the flap 3, and two pairs of lid flaps 5 are connected to the upper edge of the flap. Since the side wall 3 and lid flap 5 of this outer box X are made of B flutes with fine steps on the outer surface, the surface is smooth and the printing finish is beautiful, and the appearance is also beautiful.

Contrary to the outer box It is made into a cylindrical shape and its both ends are joined.

The packaging box with a body frame of this invention is often used to store heavy items and stack multiple boxes.
A large compressive force acts on the lower part, but the outer box X and the body frame Y deflect in opposite directions, and when they abut, the deflection is prevented as a whole, and a large overall compressive stress is generated.

〔effect〕

As described above, although the packaging box with a body frame according to this invention is formed from double-sided corrugated board, the outer box has a layer with a low height on the outside surface, and conversely, the body frame has a layer with a low height on the outside surface. Since high layers are used, when compressive force is applied, the forces tend to deflect in the direction of each other, and the mutual forces cancel each other out as a whole, preventing deflection and generating large compressive stress. Both have the effect of significantly increasing the overall compressive strength at the same material cost compared to conventional products that use a layer with a low step height on the outer surface side.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of this invention, FIG. 2 is a cross-sectional view of the main part of the same, and FIG. 3 is a cross-sectional view of the main part of the conventional example. 1... layer with low step height, 2... layer with high step height, X... outer box, Y... body frame.

Claims (1)

[Scope of utility model registration request] With a body frame consisting of an outer box made of double-sided corrugated cardboard that combines a layer with a high height and a layer with a low height, and a body frame inscribed in this outer box and made of the double-sided corrugated cardboard. 1. A packaging box with a body frame, characterized in that the outer box has a layer with a low step height on the outside surface, and the body frame has a layer with a high step height on the outside side.