JPH10128888A - High strength double sided cardboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the vertical compression strength of a corrugated fiberboard sheet and improve its printability without increasing the weight per m<2> of a base paper by a method wherein the weight per m<2> of a corrugating medium, the height of a flute and the number of flutes of a flute near the inside of a box are specified and the flute structure of a flute near the outside of the box is specified. SOLUTION: In a double wall corrugated fiberboard, the weight per m<2> of the corrugating medium of a flute near the inside of a box is 160g/m<2> or more, its height of a flute is 5.5mm or higher and its number of flutes is 20 or more per 30cm while a flute near the outside of the box is an A-flute, C-flute or B-flute. The flute, the height of a flute of which is higher, is used as the flute near the inside of the box so as to play a roll for heighten the strength of the box, while the A-, B- or C-flute excellent in planeness is arranged near the outside of the box so as to coexist the strength and external appearance of the box with its printability. When the rear linerboard and the front linerboard having the weight per m<2> of 337g/m<2> or more are employed in this double wall corrugated fiberboard, the resistance to impact punching and printability of the box are further improved as well as the compression strength of the box, resulting in obtaining a double wall corrugated fiberboard suitable for transporting a heavier matter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cardboard for industrial and industrial use, and more particularly to a double-sided cardboard for packing heavy goods.

[0002]

2. Description of the Related Art Conventionally, as a flute configuration of a double-faced corrugated cardboard, there are an AB flute, an AC flute, and an AA flute. For example, the base paper composition of AB flute is K280 / SCP160 / K220 / SCP1.
60 / K280, and K440 / SCP160 / K220 / SCP160 /
K440 is an example. (K280 is K liner 280 g / m ² , SCP 160 is SCP core 160
g / m ² . same as below. )

Conventionally, the Kericut equation is known as an empirical equation for estimating the compressive strength of a cardboard box from the strength of the base paper, and this equation is based on the sum of the ring crush values of the liner and the core, the peripheral length of the box, and the flute configuration of the box. Has been calculated,
As the flute configuration, A, B, C, AB flute and the like are mentioned, but there is no description about a step higher than the A flute.

On the other hand, Wolf's equation is also famous as an empirical equation for estimating the compressive strength of a cardboard box. This formula estimates the strength of the box from the quality of the cardboard sheet, and estimates the strength of the box from the thickness of the cardboard sheet, peripheral length, box aspect ratio, box depth, and the like. In this equation, the box compression strength is proportional to the square root of the sheet thickness.

[0005]

As described above, it is known that the thickness of the base paper used or the number of layers should be increased in order to increase the strength of the corrugated cardboard. However, doing so increases the weight and the cost. So far, examples in which the core is strengthened are disclosed in JP-B-47-17354 and JP-A-51-131791, but have the disadvantage that the process becomes complicated and the price becomes high. An object of the present invention is to increase the vertical compressive strength of a corrugated cardboard sheet without increasing the base paper of the base paper, and to obtain a corrugated cardboard sheet excellent in appearance and printability of a corrugated cardboard box.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a middle rice tsubo having a height of at least 160 g / m ² and a height of 5.5 m is provided in a step adjacent to the inside of a box.
The present invention relates to a double-faced corrugated cardboard characterized in that the number of steps is not less than m, the number of steps is not less than 20 (per 30 cm), and the steps adjacent to the outside of the box are any of A flute, C flute and B flute. The present invention also provides the double-sided corrugated cardboard with a backing liner and a front liner of 337 g / m ^2.
The present invention relates to the double-faced cardboard described above.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have paid attention to the sheet thickness first, and have studied various steps having a step height higher than the A flute based on the step height and the step repetition rate. , 20 steps
It has been found that the use of a step (per 30 cm) or more improves the vertical compressive strength of the corrugated cardboard sheet, and the effect of the improvement is particularly remarkable when the central rice area is high.
Filed 55 applications.

[0008] The inventors have then more specifically examined the arrangement and appearance and printability of the cardboard sheet layer results, core rice basis in a stage close to the inside of the box is 160 g / m ² or more,
Double-sided corrugated cardboard with a step height of 5.5 mm or more, 20 steps (per 30 cm) or more, and the step adjacent to the outside of the box is A flute, C flute or B flute is economically high in compression strength and excellent sheet surface The present invention has been found to impart properties to the present invention.

When the number of peaks of a high step is to be suppressed to about 1.56 of the A flute, the number of peaks becomes 30 or less, and the pitch of the step becomes larger than that of the A flute, and the phenomenon is called a washboard. Occurs and the printability decreases. For this reason, the high step is used inside the box to play a role of increasing the strength, and by placing the A, B, C flutes with better flatness outside the box, strength, appearance, printing It has become possible to balance the nature.

In the present invention, when the backing liner and the front liner of the double-sided corrugated cardboard are set to 337 g / m ² or more, not only the box compressive strength but also the impact perforation resistance and printability are further improved, and the weight is reduced. A double-sided corrugated cardboard suitable for transporting goods is obtained.

[0011]

The present invention will be described in more detail with reference to the following examples.

[0012] Example 1 step High 7.1 mm, elevated portions 23 (per 30 cm), and with H ₂ stage creates a high-stage stage Repetitive rate 1.50, place it on the inside of the box, the outer stepped A stage having a height of 4.5 mm, a step repetition rate of 1.56, and 36 peaks was arranged. Base paper composition is K from the outside of the box
470 / SCP180 / RK180 / SCP180 / K
470. (K470 is K liner 470g /
m ² , SCP 180 is SCP core 180 g / m ² , RK1
80 refers to RK liner 180 g / m ² . same as below. ) The total of the ring crush values of the base paper is calculated as the total
C), length / width / depth (L / W / D) is 800mm / 700m
An m / 600 mm RSC box was prepared and the box compression strength was measured. Each measuring method followed the following. Ring Crush JIS P8126 Test method for compressive strength of paperboard. End crush It was expressed in kg / cm according to JIS Z0401 corrugated cardboard compression strength test. Box compression strength JIS Z0212 A compression test method for packaged cargo and containers.

Comparative Examples 1 and 2 Comparative Example 1 in which the same base paper structure was used and the AA flute was used, and Comparative Example _{2 in} which the H ₂ A flute was used from the outside of the box.
And the same measurement was performed.

[0014]

[Table 1]

[0015] From the above, the central rice tsubo of the step adjacent to the inside of the box is 160 g / m ² or more, the step height is 5.5 mm or more, and the number of steps is 20
(Per 30 cm) The double-sided corrugated cardboard is AA flute in which the step adjacent to the outside of the box is A flute, and the box compressive strength, appearance, and printability compared to H ₂ A flute in which H ₂ steps are arranged outside the box. It turns out that it has also.

[0016] In a similar base paper structure as in Example 1, step height 3.5 mm, stage Repetitive rate 1.45, creating double sided cardboard C flute and H _2-stage elevated portions 40, and H _2-stage The test was performed in the same manner as in Example 1 by disposing it inside the box (CH ₂ stage).

Comparative Examples 3 and 4 The same test as in Example 2 was performed, using the same base paper composition as in Example 2 except that the one using the CA flute was used as Comparative Example 3, and the one using the H ₂ C flute was used as Comparative Example 4. Was.

[0018]

[Table 2]

As described above, the core rice tsubo of the step adjacent to the inside of the box is 160 g / m ² or more, the step height is 5.5 mm or more, and the number of steps is 20.
(30 cm per) more than there box double sided cardboard CA flutes stage close to the outside is C flute, box compression strength compared to the H ₂ C flute arranged with H ₂ stages on the outside of the box and appearance, printability It turns out that it has also.

[0020] In a similar base paper structure as Example 3 Example 1, step height 2.5 mm, stage Repetitive rate 1.38, creating double sided cardboard B flute and H _2-stage elevated portions 50, and H _2-stage Arranged inside the box (BH ₂ tiers).

[0021] In a similar base paper structure as Comparative Examples 5 and 6 Example 3 was Comparative Example 6 that the Comparative Example 5, H ₂ B flute what was BA flute.

[0022]

[Table 3]

As described above, the core rice tsubo of the step adjacent to the inside of the box is 160 g / m ² or more, the step height is 5.5 mm or more, and the number of steps is 20.
(30 cm) or more, the double-sided corrugated cardboard in which the step close to the outside of the box is a B flute is a BA flute, and the box compressive strength, appearance, and printability are higher than those of an H ₂ B flute in which H ₂ steps are arranged outside the box. It turns out that it has also.

[0024]

According to the present invention, a cardboard box excellent in compressive strength, printability and appearance can be obtained even when the amount of the core base paper used is small (even when the step repetition rate is small).

Claims (2)

[Claims] 1. A medium rice tsubo of a step adjacent to the inside of a box is 16
0 g / m ² or more, the step height is 5.5 mm or more, and the number of steps is 20 (30
(per cm) or more, and the step close to the outside of the box is any one of A flute, C flute and B flute. 2. The backing liner and the front liner have a rice grain of 337.
The double-faced double-faced cardboard according to claim 1, which has a g / m ² or more.