JPH01157841A - Heat insulating packaging carton - Google Patents

Abstract

PURPOSE:To easily obtain a packaging carton having superior heat insulating property in packaging with required configuration and size by providing a weir so that the air in a corrugated medium of a card-board is prevented from entering a medium groove. CONSTITUTION:A weir 5 is formed at the opposite sides of a corrugated medium 4 of a cardboard so that the air present in the corrugated medium is prevented from moving, thus improving the heat insulating property. It is considerably advantageous from a viewpoint of saving of cost if a foaming plastic sheet is employed for the corrugated medium 4 in place of a conventional cardboard since the weir 5 is so easy and simple in working, moreover, the heat insulating property can be kept good. An aluminum layer is laminated onto the cardboard so as to improve the heat insulation. Although it is most effective to attach the aluminum layer to the outermost surface of the cardboard, it may happen with high possibilities that cartons when piled up slip to fall down or it costs much higher when some printing is performed on the surfaces of the cartons. Therefore, it is advantageous that the aluminum layer is pasted to the inner side of the outermost lining of the cardboard. It is more effective if a foaming plastic sheet is laminated on the outermost surface of the cardboard.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to a packaging surface with improved heat insulation properties used for packaging frozen foods.

However, the product of the present invention can also be suitably applied to packaging contents that require heat retention.

C. Prior Art] Conventionally, boxes made of foamed polystyrene resin have been injection molded in fields that require a high degree of heat insulation.

Although this product has excellent heat insulation properties, it is necessary to prepare separate molds for each of the nine dimensions of the box shape, and the cost of this is high, so it cannot be applied except for mass production. . Furthermore, foamed polystyrene boxes have the disadvantage that the container itself is thick and cannot be folded, requiring a large volume during transportation, storage, and storage. In addition, when the contents are filled inside the surface, the stacked bottom boxes may be damaged or deformed due to the insufficient strength of the surface material itself.

On the other hand, conventional cardboard boxes can be transported in sheet form,
Although it has the advantage of requiring a small volume, it has the disadvantage that it cannot be said to be sufficient in terms of heat insulation.

[Problem to be solved by the invention]

The present invention solves the above-mentioned drawbacks of the prior art, requires a small volume, can easily accommodate changes in shape and dimensions, and can be easily stacked in sheet form during transportation, storage, and storage. To provide a heat-insulating packaging box that can be easily assembled into a desired shape during use and has much better heat-insulating properties than conventional cardboard boxes.

[Means for Solving the Problems] The main component of the present invention is to improve the heat insulation property by blocking the movement of air surrounded by the corrugated core in conventional corrugated cardboard, and furthermore, By preventing air from penetrating through itself, further insulation was achieved.

Furthermore, aluminum layers are laminated to improve insulation.

The present invention will be further explained in detail below.

In order to fully utilize the heat insulating properties of the air present in the corrugated core of corrugated cardboard, the inventor has proposed a method to block the movement of air present in the corrugated core by providing a weir in the core groove. I thought about it. The heat insulation effect in this case was measured and confirmed using the following method.

-Using a test cardboard sheet with a side length of 20 cm, use synthetic rubber adhesive to make a pentahedron (only the - side is a box without a face plate) so that the dimensions of each side are 20 (21 x 20). (Fig. 1), and put cellophane tape on the joined ridgeline to prevent air leakage.The bottom surface has a thickness of about 10a1.
Using a foamed polystyrene block 1, dig a groove 2 with a depth of approximately 1 mark into which the pentahedral box described above fits, and make a groove 2 with a depth of about 1 mark in the center.
Install the bulb socket so that the filament part of the W incandescent bulb is about 7 cm above the top of the bottom plate (Figure 2). 6. Next, install a thermoelectric bulb for temperature measurement near the upper corner of the side inside the pentahedral box. A light shielding cover was installed to avoid the effects of direct radiant heat from the light bulb.

Next, place the test cardboard pentahedron box with the part without the face plate facing down in the groove provided in the bottom of the test box, and then adjust the DC stabilized power supply so that the power consumption of the incandescent light bulb is 25W. The temperature inside the box was measured every 2 seconds using a thermocouple, and the temperature after a longer period of time than the time required to reach constant temperature was taken as the temperature inside the box. During this time, the power consumption is of course continuously adjusted. .

A box with a high internal temperature measured as described above indicates good insulation, and a low box internal temperature indicates poor insulation.

Using the test equipment and test method as described above, first weirs were provided at different intervals in the grooves of the corrugated core, and the results were measured.

Fig. 3 is a perspective view of a corrugated core material showing the structure of the material of the insulating packaging box according to the present invention, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 3 used in the present invention. FIG. 5 is a cross-sectional view of the heat-insulating packaging material used in the present invention, taken along line B-B in FIG. 3, and FIG. 4 is a sectional view corresponding to FIG. 4. FIG. In the figure, 3 indicates a liner, 4 indicates a corrugated core liner, and 5 indicates a weir-like protrusion.

Weir spacing (all) 1 3 7 10 15
Temperature inside storage box ('C) 60.4 60.7
59,5 58.7 58,4 57.3 From the above measurement results, it was clearly recognized that the insulation effect was improved by providing a weir in the corrugated core groove.

Regarding the spacing between weirs, it was found that the smaller the spacing up to aaa, the slightly greater the effect on insulation. If the spacing between the weirs becomes too small, the heat insulation properties will decrease due to heat conduction in the weir portions. However, considering the increased cost of providing the weir and the degree of increase in the heat insulation effect, it is considered most practical to block the movement of air in the core groove at both ends of the packaging surface.

Although the above results were obtained when the weir was provided on only one side of the corrugated core, tests were also carried out when the weir was provided on both sides of the corrugated core. That is, weir spacing (am) 1
3 15 single side weir ('C) 60.4
60.7 58.4 Double-sided weir (”C) 61.3
61.8 58.9 From the above results, by providing weirs on both sides, the heat insulation properties are higher than in the case of one side, so double-sided base materials are used as a general rule, but depending on the circumstances, a single-sided base material can also be expected to have a considerable effect. However, when the thickness of the sheet is made as thin as possible and heat insulation properties are required, it is effective to use a double-sided base material. The weir may be formed integrally with the corrugated core, or
A weir may be installed later.

Replacing the corrugated core with a foamed plastic sheet instead of the conventional cardboard makes it extremely easy to process the groove weir, which is extremely advantageous in terms of cost, and also has good heat insulation properties. The matter was confirmed. 1 Paper core Foamed resin core 1 stage 5060 2 stages 5767 From the above measurement results, it was found that even if the thickness was the same, the heat insulation properties were significantly improved by using the base foam core.

Next, we conducted an experiment in which aluminum foil was laminated on one or both sides of a corrugated cardboard sheet to improve heat insulation. The results are general corrugated board (BF) 47 54 (both sides) general dub'' corrugated board 57 65 (single side) ball (AF + BF) foam core base material 60 78 (both sides) foam core base material + 648 □ (single side) general corrugated board (B
F) From the above results, even if an aluminum layer is laminated on conventional general corrugated board, the temperature rise is only 7 to 8℃, but when a core with a foam layer is used, a marked increase in insulation properties is observed. Ta. In other words, it was found that the combined use of a core with a foam layer and an aluminum layer greatly contributed to improving the heat insulation properties.

Furthermore, after considering the influence of the bonding position of the aluminum layer,
There is only a slight difference between the case where it is bonded to the outermost surface of the corrugated board and the case where it is bonded to the back side of the outermost layer liner, that is, the side that contacts the core, and it is considered that either is suitable for practical purposes. Therefore, the most effective position for laminating the aluminum layer is on the outermost surface of the cardboard, but in that case, there is a risk of the boxes slipping off when stacked, and there is a disadvantage that printing on one surface increases the cost. Therefore, it is advantageous to laminate an aluminum layer inside the outermost liner of the corrugated board.

Almost the same effect can be obtained by performing aluminum vapor deposition instead of aluminum foil, but similar results can also be obtained by thermal spraying a paint containing aluminum powder. Therefore, in the present invention, these are collectively referred to as the aluminum layer.

If a plastic film is laminated instead of the aluminum layer, the insulation effect will be inferior to that of the aluminum layer, but
It was observed that the heat insulation effect was improved compared to when no plastic film was used.

Next, measurements were taken when the cardboard was made into a two-tier structure (FIG. 3). In this case, it is sufficient that at least one of the corrugated boards uses a core with a foam layer.

General corrugated board (BF) 46.5°C General corrugated board (AF) 50°C General double corrugated board (AF + BF) 57°C foamed base material, OF corrugated board 64°C foamed base material,
AF cardboard 74°C The above results demonstrate the effectiveness of the two-tiered structure.

It is even more effective to laminate a foamed plastic sheet on the outermost surface of the cardboard. In this case, there is an advantage that even if the packaging surfaces are stacked, they do not slip off and they also have some cushioning properties, but the only disadvantage is that the printability is degraded.

No foamed plastic sheet 60.7°C Foamed plastic sheet double-sided layer 78°C The present invention is based on the idea as described above, and after confirming its effects through the above experiments, the following invention was completed.

(1) A heat-insulating packaging box characterized in that a barrier layer is provided in the core grooves for blocking the movement of air in the corrugated core of the corrugated board.

(2) The heat-insulating packaging box according to claim 1, wherein the corrugated core is processed from a plastic sheet or a foamed plastic sheet.

(3) Claim 1 or Claim 2 characterized in that an aluminum layer is laminated on at least one of the front and back surfaces of the flat liner on the surface of the corrugated cardboard sheet.
The insulating packaging box described in .

(4) The heat insulation properties according to claim 1 or 2, characterized in that a plastic film is laminated to at least one of the front and back surfaces of the flat liner on the surface of the corrugated cardboard sheet. packaging box.

(5) Any one of claims 1 to 4 having a two-tiered structure in which a core with a foam layer is used as the core of at least one of the corrugated cardboards.
The insulating packaging box described in section.

(6) The insulating packaging box according to any one of claims 1 to 5, characterized in that a foamed plastic sheet is laminated on at least one of the outermost surfaces of a corrugated cardboard sheet.

〔Effect of the invention〕

By implementing the present invention, it is possible to easily obtain a packaging box with a small volume required for storage and transportation, and with the desired shape and dimensions.
Moreover, a packaging box with excellent heat insulation properties can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the box of the thermal insulation measuring device, Fig. 2 is an explanatory diagram of the bottom part of the thermal insulation measuring device, and Fig. 3 shows the oval shape of the material of the thermal insulation packaging box according to the present invention. A perspective view of a corrugated core material shown in FIG.
Figure 4 is a sectional view of the heat insulating packaging material used in the present invention, taken along line A-A in Figure 3, and Figure 5 is taken along line B-B in Figure 3. FIG. 6 is a cross-sectional view of the heat-insulating packaging material used in the present invention, which corresponds to FIG. 4 of the conventional corrugated board. In the figure 1...Bottom part 2...Groove 3...Liner 4...Corrugated core liner 5...Weir-like convex part No. 15! I Figure 3 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A heat insulating property characterized in that a barrier weir into the core groove for blocking the movement of air in the corrugated core of corrugated board is provided on both sides or one side of the core. packaging box. 2. The insulating packaging box according to claim 1, wherein the corrugated core is processed from a plastic sheet or a foamed plastic sheet. 3. The heat-insulating packaging box according to claim 1 or claim 2, characterized in that an aluminum layer is laminated on at least one of the front and back sides of the flat liner on the surface of the corrugated cardboard sheet. . 4. The heat-insulating packaging box according to claim 1 or claim 2, characterized in that a plastic film is laminated to at least one of the front and back surfaces of the flat liner on the surface of the corrugated cardboard sheet. . 5. The heat-insulating packaging box according to any one of claims 1 to 4, which has a two-tiered structure in which a core with a foam dam is used as the core of at least one of the corrugated boxes. 6. The insulating packaging box according to any one of claims 1 to 5, characterized in that a foamed plastic sheet is laminated on at least one of the outermost surfaces of a corrugated cardboard sheet.