JPH06155644A - Corrugated cardboard and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide corrugated cardboard having excellent cushioning capacity whose curved face can be processed easily, and a manufacturing method thereof. CONSTITUTION:A corrugated cardboard 10 comprises a corrugated sheet 16, a composite sheet 12 which is stuck to one face of the corrugated sheet 16 and made of a plane sheet 18 having a flexibility higher than that of the corrugated sheet 16, and a backing sheet 14 stuck to one face of the composite sheet 12. The composite sheet 12 is bent in a direction almost rectangular with respect to the corrugating direction of the corrugated sheet 16. The backing sheet 14 whose flexibility is higher than that of the corrugated sheet 16 connects upper or lower ends of the bent parts alternately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cushioning material for packing, and more particularly,
The present invention relates to corrugated board that can be easily curved.

[0002]

2. Description of the Related Art Among typical cushioning materials for protecting medium-weight products, there are resin foam materials represented by Styrofoam and paper corrugated board.

[0003]

Since the resin foam material can be processed into various shapes at the time of manufacture, it can be easily adapted to the outer shape of the object to be packed. Therefore, it is particularly suitable for packaging of complicated shapes having many projections and curved surfaces. However, when the resin foam material is incinerated after use, it emits a harmful gas, which is problematic in terms of environmental pollution, and cannot be recycled due to its chemical nature.

On the other hand, corrugated board is not a problem in terms of environmental pollution or recycling, but in general, when a corrugated board consisting of a corrugated core material and flat paper stuck on one or both sides of the corrugated core material is used as a single item. Cannot absorb a large shock sufficiently. In order to enhance the impact suction ability, it is necessary to stack a plurality of corrugated boards, but if they are stacked, the flexibility is inevitably deteriorated (curved surface processing becomes difficult), and the range of use thereof is limited.

Therefore, an object of the present invention is to provide a corrugated board which has an excellent cushioning ability and can be easily curved, and a method for manufacturing the same.

[0006]

To achieve the above object, the present invention provides a composite sheet comprising a corrugated sheet and a flat sheet joined to at least one surface of the corrugated sheet and having higher flexibility than a corrugated sheet. Is bent in a wavy direction in a direction transverse to the wavy direction of the wavy sheet to form a large number of bent portions, and at least one surface of the composite sheet is joined with a backing sheet having higher flexibility than the corrugated sheet and the upper end of the bent portion and And / or a corrugated cardboard characterized in that lower ends thereof are connected to each other.

The present invention also comprises the step of joining a flat sheet to at least one surface of a corrugated sheet to produce a composite sheet,
A step of forming bending lines on the composite sheet at predetermined intervals in a direction transverse to the corrugation direction of the corrugated sheet; a step of bending the composite sheet from the bending lines to form a large number of bent portions; and a backing on at least one surface of the composite sheet. And a step of connecting sheets to each other to connect upper ends and / or lower ends of bent portions to each other.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. As shown in FIG. 1, a corrugated board 10 according to an embodiment of the present invention includes a long composite sheet 12 and
The backing sheet 14 is glued on one surface of the composite sheet 12. The composite sheet 12 is composed of a corrugated sheet 16 and a flat sheet 18 glued on one surface of the corrugated sheet 16. In the illustrated embodiment, reinforced core paper is used for the corrugated sheet 16, and kraft paper having higher flexibility than the corrugated sheet 16 is used for the flat sheet 18. Backing sheet 1
Although No. 4 was glued to the composite sheet 12 using an adhesive, other appropriate means such as stitching can be used. In addition, the composite sheet 12 has a flat sheet 18 on both sides of the corrugated sheet 16.
It is also possible to have a three-layer structure in which is attached. However, in that case, it is preferable that the basis weights of the two flat sheets 18 do not exceed the basis weight of the corrugated sheet 16.

In the embodiment shown in FIG. 1, the backing sheet 14 is glued to the flat sheet 18 side of the composite sheet 12, but the corrugated sheet 16 side or both sides of the composite sheet, that is, the flat sheet 18 side and the corrugated sheet are corrugated. You may stick one by one to the sheet 16 side. However, in the latter case, two backing sheets 14, 1
The sum of the grammage of 4 and the grammage of the flat sheet 18 is the corrugated sheet 16
It is preferable not to exceed the grammage.

The composite sheet 12 is continuously bent along its longitudinal direction so as to be corrugated also in a direction substantially orthogonal to the corrugated direction of the corrugated sheet 16 itself (direction along the short side in FIG. 1). is there. Each bent portion 20 is, as shown in FIG.
The triangular cross section is inclined from the upper end 20a to the lower end 20b, and the lower ends 20b are all interconnected by the backing sheet 14. In the embodiment shown in FIG. 2, the adjacent bent portions 20 share the lower ends 20b of each other, but as shown in FIG. 3, the lower ends 20b of the adjacent bent portions 20 are separated and the lower ends 20b are flattened. They may be connected to each other at different connecting portions 22. In the present invention, in order to facilitate bending, the bending line 24 which is a push groove along the lower end 20b of the composite sheet.
Has been formed. The bending line 24 may be a fold line, a cut line, a perforation line, or the like.

In the corrugated board 10 having such a structure, when an impact is applied from the upper end 20a of the bent portion 20 of the composite sheet 12 toward the lower end 20b, the bent portion of the corrugated sheet 16 of the composite sheet 12 is first deformed. Crush. As a result, the initial impact energy is absorbed to some extent. Then, the impact energy absorbed by the crush of the corrugated sheet 16 is absorbed again by the crush of the bent portion 20 of the composite sheet 12. The height of the bent portion 20 of the composite sheet 12 is higher than the height of the bent portion of the corrugated sheet 16 itself, and moreover, since the composite sheet 12 has appropriate rigidity, the collapse time is longer than that of the corrugated sheet 16. In other words, since the bending portion 20 of the composite sheet has a larger deformation amount than the bending portion of the corrugated sheet, the impact energy is absorbed more in the bending portion 20. The bending portion 20 of the composite sheet 16 tries to expand when an impact is received, but the backing sheet 14 connecting the lower end 20b and the lower end 20b prevents the expanding operation of the bending portion 20, so that the bending portion expands. Crush before opening to absorb shock.

As described above, in the present invention, the impact energy is absorbed in two stages by the two bent portions (which means the bent portion of the corrugated sheet itself and the bent portion of the entire composite sheet), and therefore, as a single item. Even if used, it exerts sufficient buffering capacity. From the viewpoint of cushioning capacity, the apex angle of the bend is 9
Most preferably, it is 0 ° or less and about 60 °. Further, it is preferable that the backing sheet is bonded to the composite sheet while being sufficiently stretched in the direction orthogonal to the corrugation direction of the corrugated sheet, because the resistance force is rapidly exhibited. However, the corrugated sheet needs to be somewhat loosened in the corrugating direction so that the corrugated board can be curved. The corrugated board 10 of the present invention is excellent in flexibility in the bending direction. Therefore, when the cardboard of FIG. 1 is rolled in the bending direction to first form a tube and then both ends thereof are closed, the corrugated board shown in FIG. 4 is obtained. At this time,
In the vicinity of both ends, the highly flexible flat sheet 18 and the backing sheet 14 are bent and enter the bent portion 20 as shown in FIG.

Next, the corrugated board manufacturing method according to the present invention will be described in detail.

First, on one surface of the corrugated sheet 16 which is a reinforced core paper having a basis weight of about 200 g / m ² (thickness of about 0.24 mm), a basis weight of about 80 g / m ² (thickness of about 0.2 mm). 09 m
The composite sheet 12 is prepared in advance by adhering the flat sheet 18 which is the kraft paper of m). When the production is completed, the composite sheet 12 is wound around the composite sheet supply roll 32 of the corrugated board manufacturing machine 30 shown in FIG. After winding, the composite sheet 12 is sent out from the composite sheet supply roll 32 in the direction of arrow F in the figure.

A plurality of rotary blades 34 are provided in the vicinity of the supply roll 32 in the width direction of the composite sheet 12 at equal intervals.
A plurality of push grooves 24 are engraved on the 2. Next, the composite sheet 12 is pushed inward in the width direction by a pair of guide plates 36 (which are tapered toward the downstream side) provided upright on both sides of the corrugated board manufacturing machine 30. The composite sheet 12 pushed toward the center is the die 3 provided near the downstream end of the guide plate 36.
Pass 8. A recess 40 having a shape corresponding to the shape of the bent portion 20 is formed at the lower end of the block-shaped die 38. When the composite sheet 12 passes through the recess 40,
A plurality of bent portions 20 as shown in FIG. 2 are formed on the surface.

On the downstream side of the die 38, a backing sheet supply roll 42 and a gluing roller 44 for gluing on one surface of the backing sheet supply roll are arranged in proximity to each other, and one surface of the backing sheet 14 fed from the backing sheet supply roll 42 is provided. After gluing with a gluing roller 44, the gluing backing sheet 14 is glued onto one surface of the composite sheet 12 that has passed through the die 38. A heat plate 46, which is a horizontal plate, is also provided on the downstream side of the die 38. While heat is applied to the cardboard by the heat plate 46, pressure is applied from the upper surface of the cardboard to the heat plate 46 side by a pressurizing machine (not shown). Promotes gluing of the backing sheet 14 to the composite sheet 12. By this step, the lower end of the bent portion is connected by the backing sheet 14, so that the shape becomes stable.

Finally, the completed corrugated board 10 is wound around the winding roller 50 while being fed in the direction of arrow F by the feed roller 48 provided on the downstream side of the heating plate 46. This completes the corrugated board manufacturing process. In addition, when changing the height and the inclination angle of the bent portion, it is sufficient to change the mounting interval of the rotary blades and the number and shape of the concave portions of the die.

Although the bent portion has a triangular cross section in the above embodiment, it may have a trapezoidal shape as shown in FIG. In this case, the flexibility is slightly inferior to that of the triangular cross section, but it is convenient when the corrugated cardboards are stacked and used because the stability is increased. Note that FIG. 8 is an example of a cushioning material for packing created using the corrugated board of FIG. 7.

[0019]

As described above, the corrugated board of the present invention is
Since the impact energy is absorbed twice by the corrugated sheet itself and the entire composite sheet, a sufficient cushioning ability can be exhibited even when used as a single item. Further, since the flat sheet and the backing sheet are more flexible than the corrugated sheet, the curved sheet can be easily processed by freely following the deformation along the bent portion. Therefore, even an object to be packed having a complicated shape such as a sphere can be easily adapted to its outer shape. Further, since it can be wound on a roll and stored, various advantages such as easy securing of a storage place can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a cardboard according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view similar to FIG. 2, showing a corrugated board according to another embodiment of the present invention.

FIG. 4 is a perspective view showing an example in which the corrugated board shown in FIG. 1 is curved.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a perspective view of a corrugated board manufacturing machine used for manufacturing the corrugated board of the present invention.

FIG. 7 is a sectional view similar to FIG. 2, showing a corrugated board according to another embodiment of the present invention.

8 is a perspective view showing an example in which the corrugated board shown in FIG. 7 is curved.

[Explanation of symbols]

 10 Corrugated Cardboard 12 Composite Sheet 14 Backing Sheet 16 Wavy Sheet 18 Flat Sheet 20 Bending Section 22 Connecting Section 24 Bending Line

Claims (9)

[Claims] 1. A composite sheet comprising a corrugated sheet and a flat sheet bonded to at least one surface of the corrugated sheet and having a higher flexibility than the corrugated sheet is corrugated in a direction transverse to the corrugation direction of the corrugated sheet. A plurality of bent portions are formed by bending, and a backing sheet having higher flexibility than the corrugated sheet is joined to at least one surface of the composite sheet to connect upper ends and / or lower ends of the bent portions to each other. Characteristic cardboard. 2. The backing sheet is bonded to both surfaces of the composite sheet, and the sum of the basis weights of the two backing sheets and the flat sheet does not exceed the basis weight of the corrugated sheet. Cardboard described in. 3. The corrugated board according to claim 1, wherein a bending line is provided between the adjacent bending portions, and the bending line is formed by a push groove, a fold, a cut, or a perforation. 4. Each bent portion has a triangular cross section and an apex angle of 6
The corrugated board according to claim 1, which is 0 to 90 degrees. 5. The corrugated board according to claim 1, wherein each bent portion has a trapezoidal cross section. 6. The corrugated board according to claim 4, further comprising a flat connecting portion that connects the lower ends of the adjacent bent portions to each other. 7. The corrugated board according to claim 1, wherein in the composite sheet, the flat sheet is joined to both surfaces of the corrugated sheet, and the sum of the basis weights of the flat sheet does not exceed the basis weight of the corrugated sheet. 8. A method for producing corrugated board, comprising the steps of joining a flat sheet to at least one surface of a corrugated sheet to form a composite sheet, and bending lines on the composite sheet in a direction transverse to the corrugation direction of the corrugated sheet. A step of forming a large number of bent portions by bending the composite sheet from the bending line, and joining a backing sheet to at least one surface of the composite sheet and / or an upper end of the bent portion. A method of manufacturing corrugated board, which comprises a step of connecting lower ends to each other. 9. The corrugated board manufacturing method according to claim 7, wherein an adhesive is applied to the backing sheet and the composite sheet is glued.