JP3765062B2 - Cardboard box and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a cardboard box mainly used for packaging and transporting canned beer and a method for producing the same.
[0002]
[Prior art]
Conventionally, a hexahedral cardboard box as shown in FIG. 1 is used as a cardboard box for packaging and transporting canned beer. Two weak lines 1 and 1 are provided in parallel to each other in the vicinity of the center of the two to four side surfaces of the cardboard box. A cut 2 is provided between the two weak lines 1 and 1 at an arbitrary position of the two weak lines 1 and 1. Then, by inserting a finger into the notch 2, gripping the edge of the notch 2, tearing in the direction of the weakening line 1, and removing the strip between the two weakening lines 1 and 1, this cardboard box Can be opened.
[0003]
After opening, the upper part 3a of the cardboard box is removed, the lower part 3b is left as it is, and it is placed in a store such as a supermarket for sale of canned beer. Then, as many cans as can be stored in the lower part 3b of the cardboard box are taken out and purchased by the final consumer. However, depending on the end consumer, there may be a desire for the total number of canned beers packaged in a cardboard box. That is, generally, 24 canned beers are stored and packaged in the cardboard box, and the final consumer may purchase all the 24 canned beers. In this case, it is not necessary to open the cardboard box, and the cardboard box can be sold together. Accordingly, the end consumer has to carry the sealed cardboard box with both hands, which is inconvenient to carry.
[0004]
On the other hand, mainly foreign-made canned beer is used in which a pair of grasping perforations 4 are provided on one side of the cardboard box so that the final consumer can easily purchase the canned beer together with the cardboard box (see FIG. 2). In this cardboard box, if a thumb and other fingers are put in the grasping hole 4 and grasped, the cardboard box can be carried with one hand, which is very convenient. In addition, on the back side of the side surface provided with the perforating holes 4, thick paperboard is bonded so that the side surface is not torn when the cardboard box is held with one hand. However, the corrugated cardboard box provided with the gripping perforations 4 is not provided with the weakening lines 1 and 1 as shown in FIG. 1, and the canned beer is stored in the lower part 3b of the cardboard box. It was not possible to sell only the number desired by consumers.
[0005]
For this reason, it is conceivable to provide the perforation 4 for gripping and the weakening lines 1 and 1 in the cardboard box. In this way, when selling canned beer together with the cardboard box, the final consumer can carry it with one hand and carry it out by opening the weakening lines 1 and 1 of the cardboard box. Can sell as many cans as desired by several end consumers. However, in the cardboard box provided with the gripping perforations 4, as described above, the reinforcing paperboard is bonded to the corrugated cardboard forming the side surface provided with the gripping perforations 4. This reinforcing paperboard improves the strength of the corrugated board near the perforation 4 for gripping, and prevents the cardboard paper near the perforation 4 for gripping from being torn when holding the perforation 4 for holding and providing a cardboard box. Is. Therefore, when such a reinforcing paperboard is bonded to the corrugated paper, not only when the weakening line is provided only on the corrugated paper, but also when the weakening line is provided between the reinforcing paperboard and the corrugated paper. The cardboard box cannot be easily opened by the wire.
[0006]
[Problems to be solved by the invention]
Therefore, in place of the reinforcing paperboard, the present invention uses a special reinforcing tape that exhibits high strength against the force applied when the cardboard box is hung, although it is easy to tear in the longitudinal direction. It is intended to provide a cardboard box that can be opened with a weak line or can be held with one hand by a perforating hole.
[0007]
[Means for Solving the Problems]
That is, according to the present invention, in a corrugated cardboard box composed of hexahedrons, at least two opposite side surfaces are formed with two parallel weakening lines for opening, and at least one side of the two side surfaces is formed. A pair of gripping perforations is formed, and a reinforcing tape is bonded to the back side of the side surface on which the gripping perforations are formed, and the reinforcing tape is wider than the width of the two weakening lines for opening. The ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction of the reinforcing tape is 3 or more. Yes, the material of the reinforcing tape is a laminate of a synthetic resin film uniaxially stretched in the longitudinal direction and a paper in which pulp is relatively oriented in the longitudinal direction , produced using a circular paper machine Also related to cardboard boxes characterized by the body It is. The present invention also relates to a corrugated cardboard sheet capable of suitably assembling such a corrugated cardboard box. Moreover, this invention relates to the backing tape which can be used conveniently when manufacturing such a cardboard box or a cardboard sheet. Furthermore, this invention relates to the method which can manufacture such a cardboard box or a cardboard sheet suitably.
[0008]
First, the backing tape 5 used when producing the cardboard box or cardboard sheet according to the present invention will be described. The backing tape 5 is composed of a reinforcing tape 6 and an adhesive 7 applied on one side. The reinforcing tape 6 has a ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction of 3 or more. That is, when the tensile strength (T ₁ ) in the width direction is X kg, the tensile strength (T ₂ ) in the longitudinal direction is 3X kg or more. In particular, the ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction is preferably 5 or more, and most preferably 6 or more. The tensile strength (T ₂ ) of the reinforcing tape 6 in the longitudinal direction is determined by using a tensile tester to grip both ends of the tape having a certain width with a pair of chucks, and the pair of chucks are relatively reversed in the longitudinal direction of the tape. It is measured by moving and reading the strength when the tape breaks. At this time, the width of the tape held by the chuck is the width of the reinforcing tape 6 in actual use. Generally, since the width of the reinforcing tape 6 is 30 mm or more, the tensile strength in the longitudinal direction of the tape having a width of 30 mm or more is measured by a tensile tester. On the other hand, the tensile strength (T ₁ ) in the width direction is determined when the tape breaks when both ends of the cut tape are gripped by a pair of chucks and the pair of chucks are moved relatively in the width direction of the tape. It is measured by reading the intensity. At this time, the length of the side edge of the tape gripped by the chuck is measured by cutting to the same length as the width of the reinforcing tape 6 instead of the length of the reinforcing tape 6 in actual use. The relative moving speed (tensile speed) of the pair of chucks at the time of measuring the tensile strengths (T ₁ ) and (T ₂ ) was measured at 300 mm / min.
[0009]
The specific numerical value of the tensile strength (T ₂ ) in the longitudinal direction of the reinforcing tape 6 is determined by the weight of the cardboard box in which canned beer or the like is packaged. Therefore, the specific numerical value of the tensile strength (T ₂ ) is arbitrary, but it is generally 20 kg or more, preferably 25 kg or more, and most preferably 30 kg or more. If the tensile strength (T ₂ ) in the longitudinal direction of the reinforcing tape 6 is less than 20 kg, the portion of the corrugated paper on which the reinforcing tape 6 is bonded tends not to be sufficiently reinforced, and a cardboard box containing canned beer can be held with one hand. When this occurs, there is a risk that the vicinity of the portion where the gripping hole is provided will break. In addition, when this reinforcing tape 6 is applied to a cardboard box containing a light product other than a cardboard box containing canned beer, the tensile strength (T ₂ ) may be further reduced. Of course. On the other hand, the tensile strength (T ₁ ) in the width direction of the reinforcing tape 5 is arbitrary as long as it is 1/3 or less of T ₂ , and is generally about 1 to 4 kg.
[0010]
Orientation as the material of the reinforcing tape 6, I material der is as described above _{(T 2 / T 1) ≧} 3, the longitudinal uniaxially stretched plastic film and pulp relatively longitudinally Use a laminate with the paper you are using. The synthetic resin film uniaxially stretched in the longitudinal direction is obtained by stretching a synthetic resin film such as a polyethylene film, a polypropylene film, a polyester film, or a polyamide film in the longitudinal direction. When stretched in the longitudinal direction, the polymer chains constituting the synthetic resin film are aligned in the longitudinal direction, and a synthetic resin film having a low strength in the width direction is obtained although the longitudinal direction is high in strength. It is done. Therefore, the synthetic resin film uniaxially stretched in the longitudinal direction has a low strength in the width direction and can be easily torn in the longitudinal direction. However, since it has high strength in the longitudinal direction, it is difficult to tear in the width direction.
[0011]
Further, as the paper, paper in which the pulp is relatively oriented in the longitudinal direction is used. The paper is used for the reason that it becomes easier to apply the adhesive 7 such as a re-wetting adhesive to the reinforcing tape 6. In this case, the paper is generally about 30 to 100 g / m ² , but is not limited to this, and any paper may be adopted. In addition, when using a heat sensitive adhesive or a pressure sensitive adhesive as an adhesive agent, an adhesive agent is not necessarily applied to a paper surface, and an adhesive agent may be applied to a synthetic resin film surface. In particular, when an adhesive is applied to the synthetic resin film surface, the paper surface is exposed on the back surface of the cardboard box, so that the entire back surface is composed of paper, which is preferable because the feeling of discomfort is reduced. Such paper can be easily manufactured using a circular paper machine and has high strength in the longitudinal direction and low strength in the width direction. Such a paper is employed for reasons such as making it easier to apply various adhesives 7 to the reinforcing tape 6 and further improving the strength of the reinforcing tape 6 in the longitudinal direction.
[0012]
Moreover, it is also possible to use the laminated body which pinched | interposed the thread | yarn arrange | positioned in a longitudinal direction with the synthetic resin film and paper as a raw material of the tape 6 for reinforcement. In this material, the tensile strength in the longitudinal direction is increased by the yarns arranged parallel to the longitudinal direction. In this case as well , it is a matter of course to employ a synthetic resin film uniaxially stretched in the longitudinal direction and paper in which the pulp is oriented in the longitudinal direction. The synthetic resin film and the paper are bonded to each other with an arbitrary adhesive such as a heat-sensitive adhesive, a pressure-sensitive adhesive, or a rewet-adhesive with the yarn sandwiched therebetween. As an adhesive used in this case, for example, when a polypropylene film is used as a synthetic resin film, it is preferable to use a polypropylene heat-sensitive adhesive. When a polyethylene film is used, a polyethylene-based film is used. It is preferred to use a heat sensitive adhesive. This is because the same kind of synthetic resin film and adhesive can be used to develop a strong adhesive force. In general, about 2 to 10 yarns are used in the reinforcing tape 6.
[0013]
An adhesive 7 selected from the group consisting of a heat-sensitive adhesive, a pressure-sensitive adhesive, and a rewet-adhesive is applied to one side of the reinforcing tape 6. The heat-sensitive adhesive is also referred to as a so-called hot melt adhesive, and preferably has a melting point and a softening point of 100 ° C or less, more preferably 80 ° C or less, and most preferably 60 ° C or less. . When the melting point of the heat-sensitive adhesive has a softening point exceeding 100 ° C., the sticking of the reinforcing tape 6 tends to be difficult due to the use of residual heat described later. The materials constituting the heat-sensitive adhesive include polyethylene, polypropylene, polyester, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylic acid copolymer, ethylene-methyl acrylic acid copolymer, ethylene-methyl methacrylic acid copolymer. A polymer etc. are used individually or in mixture. Moreover, what mixed terpene resin etc. in these materials is also used. The pressure-sensitive adhesive is a so-called pressure-sensitive adhesive, and a natural rubber-based or acrylic-based synthetic rubber-based adhesive is used. In addition, the re-wettable adhesive exhibits adhesive strength by applying water, such as starch paste, glue, gum arabic, polyvinyl alcohol adhesive, polyacrylic acid soda adhesive or acrylic amide adhesive, etc. Can be used. These adhesives 7 are applied to one side of the reinforcing tape 6 at an arbitrary application amount.
[0014]
A method for manufacturing a corrugated cardboard sheet and a corrugated cardboard box using the backing tape 5 will be described as follows. First, the flat cover 10, the corrugated core paper 11, and the flat backing paper 12 are fed out from the rolls. Desired printing may be given to the surface (surface which does not contact the core paper 11) of the cover 10, and the thing of non-printing may be sufficient as it. An adhesive solution 13 is applied to the surface of the crest of the corrugated core paper 11. As the adhesive solution 13, an arbitrary one is used. For example, an inorganic adhesive solution such as water glass mainly composed of sodium silicate, a natural adhesive solution in which starch paste or the like is dissolved in water, polyvinyl alcohol A synthetic adhesive solution or the like in which water is dissolved in water is used. Thereafter, the cover 10, the core paper 11 coated with the adhesive solution 13 on the surface of the crest, and the backing paper 12 are sequentially laminated and pressed by the pressure rolls 14 and 14, and then introduced into the dryer 15. The In the dryer 15, the adhesive solution 13 applied to the surface of the peak portion of the core paper 11 is dried (that is, the water in the adhesive solution 13 is evaporated), and the surface of the peak portion of the core paper 11 is The front cover 10 and the top surface of the core paper 11 and the backing paper 12 are bonded together.
[0015]
The backing tape 5 is adhered to a predetermined position on the backing paper 12 of the laminated body 16 coming out of the dryer 15. In addition, the predetermined position said here is a side surface in which a pair of perforations is provided. In order to bond the backing tape 5, the adhesive 7 provided on one side of the backing tape 5 may be laminated so as to abut on the backing paper 12 and pressed by the pressing roll 15. When a pressure sensitive adhesive is used as the adhesive 7, it can be easily bonded by simply pressing with the pressing roll 15. Moreover, when a heat sensitive adhesive is used, it can be easily bonded by heating the pressing roll 15 and applying this heat to the heat sensitive adhesive to develop an adhesive force. Furthermore, when a re-wettable adhesive is used, it can be easily bonded by applying moisture with a spray or watering roller (not shown) before pressing with the pressing roll 15. In addition, without using the backing tape 5, only the reinforcing tape 6 to which the adhesive 7 is not applied is used, and the adhesive is separately applied to the reinforcing tape 6 and then introduced into the pressing roll 15. Then, the reinforcing tape 6 can be bonded to the backing paper 12.
[0016]
When the backing tape 5 is coated with a heat-sensitive adhesive, the following advantageous bonding method can be employed. That is, the heat applied in the drying process remains as residual heat in the laminated body 16 that has come out of the drying process. Accordingly, residual heat remains on the backing paper 12. Using this residual heat, the heat-sensitive adhesive provided on the backing tape 5 can be softened or melted to develop an adhesive force. That is, if the backing tape 5 and the backing paper 12 are laminated so that the heat-sensitive adhesive of the backing tape 5 is in contact with the backing paper 12, the residual heat remaining on the backing paper 12 is reduced to the heat-sensitive adhesive. The heat sensitive adhesive softens or melts. The backing tape 5 and the backing paper 12 are bonded by this adhesive force. In this case, it is not necessary to heat the pressing roll 15, and it is only necessary to press the backing tape 5 and the backing paper 12 so that they are in close contact with each other. Of course, when the heat-sensitive adhesive is not sufficiently softened or melted only by the remaining heat, the pressing roll 15 may be heated to provide the heat-sensitive adhesive with a shortage of heat.
[0017]
As described above, the corrugated paper 17 having the backing tape 5 attached to a predetermined position of the laminate 16 is obtained. Then, two parallel weakening lines are formed at predetermined positions on the cardboard paper 17. As the weakening line, a perforation is generally adopted, but the weakening line may be formed by other means such as a groove. The positions where the weakening lines are formed are at least the side surface on which the backing tape 5 is adhered and the side surface facing this side surface. If desired, weak lines may be formed on the other two side surfaces. Thereafter, a pair of perforations is punched out at a predetermined position on the side surface to which the backing tape 5 is adhered. As the shape of the perforation, an arbitrary shape such as a circle, an ellipse, or a track shape is adopted. The cardboard sheet 18 can be obtained by cutting the cardboard box 19 into a predetermined shape that can be assembled.
[0018]
The configuration of the cardboard sheet 18 will be described with reference to FIG. The cardboard sheet 18 is a development view of the cardboard box 19. The cardboard box 19 has a hexahedron shape, and includes an upper surface A and a lower surface B facing each other, a side surface C and a side surface D facing each other, and a side surface E and a side surface F facing each other. As an example of the developed view, as shown in FIG. 6, rectangular portions for forming the upper surface A, the lower surface B, the side surface C, and the side surface D (in terms of arrangement, the side surface C, the upper surface A, the side surface D, and the lower surface B And an adhesive margin G is provided on the other edge of the side surface C.) and eight bent portions connected to two opposite sides of the rectangular portion. It is. The eight bent parts are two of the bent parts E _C and F _C connected to the two opposite sides of the side surface _C , and the bent parts E _A and F connected to the two opposite sides of the upper surface A. Two of _A , two folding parts E _D and F _D connected to two opposite sides of side _D, and one of bent parts E _B and F _B connected to two opposing sides of lower surface B It consists of two pieces. When this cardboard sheet 18 is assembled, the locations indicated by A, B, C, and D in the developed view are the upper surface, the lower surface, and the two opposite side surfaces of the cardboard box 19, respectively. _A side surface E is formed by the bent portions E _C , E _A , E _D , and E _B , and a side surface F that faces the side surface E is formed by the bent portions F _C , F _A , F _D , and F _B , and corrugated cardboard It becomes a box 19.
[0019]
Two parallel weakening lines C _W are continuously provided on the side surface C of the cardboard sheet 18 and the bent portions E _C and F _C connected to the side surface C. Further, the side surfaces D and site E _D and F _D bending are provided continuously to the side D, it is provided two parallel weakening lines D _W each other continuously. And the reinforcing tape 6 is bonded to at least one of the side surface C and the side surface D in a state of covering the weakening line C _W or D _W. The reinforcing tape 6 may be bonded only to the side surface C, or may be bonded over the side surface C and the bent portions E _C and F _C connected to the side surface C. . Similarly, the reinforcing tape 6 may also be stuck only on the side surfaces D, also have been stuck over the site E _D and F _D bending are provided continuously to the side D and the side Also good. Further, the reinforcing tape 6 is also provided with two parallel weakening lines C _W which are the same as those provided on the side surface C and the bent portions E _C and F _C connected to the side surface C. It may be done. Similarly, when the reinforcing tape 6 is bonded to the side surface D, the same two as those provided on the side surface _D and the bent portions E _D and F _D connected to the side surface D, A weak line D _W parallel to each other may be provided.
[0020]
In addition, a pair of perforations 4 is provided on at least one of the side surface C and the side surface D, and a cardboard box 19 can be held with one hand by inserting a finger into the perforations 4. The interval between the pair of perforations 4 is preferably about 30 to 35 mm so that it can be easily grasped with fingers. Further, a cut 2 serving as a starting end when breaking the weakening lines _CW and _DW is provided at an arbitrary position of the weakening lines _CW or _DW . The cardboard box 19 can be opened by putting a finger into the notch 2 and breaking along the weakening lines C _W and D _W. If the notch 2 is provided between the pair of perforations 4, the reinforcing tape 6 in the vicinity of the perforations 4 is also incised, the strength in the longitudinal direction is lowered, and when the cardboard box 19 is held with one hand, the corrugated cardboard is There is a risk of tearing. Therefore, it is not a good idea to provide the notch 2 between the pair of perforations 4 or in the vicinity of the perforations 4, and it is preferable to provide the notch 2 at a position slightly away from the perforations 4.
[0021]
When this cardboard sheet 18 is assembled, a hexahedral cardboard box 19 can be obtained. The two parallel weakening lines C _W and D _W provided on the corrugated cardboard sheet 18 are on the four side surfaces of the corrugated cardboard box 19 (strictly, not the four side surfaces, but about the two side surfaces and the other two side surfaces). The weak lines 1 and 1 are formed substantially continuously. In addition, gripping holes 4 are formed on at least one side surface. Further, a reinforcing tape 6 is bonded to the back side of the side surface on which the gripping holes 4 are formed. Accordingly, the cardboard box 19 can be provided with one hand by putting a finger into the grasping hole 4. Further, when the breakage is made along the weakening lines 1 and 1 with the edges of the notches 2 provided at arbitrary positions of the two weakening lines 1 and 1 parallel to each other, the cardboard box 19 is opened. It is also possible to remove the upper part 19a of the cardboard box 19 and sell canned beer stored in the lower part 19b of the cardboard box 19 in that state. In order to wrap canned beer in the cardboard box 19, it is common to wrap the canned beer simultaneously when assembling the cardboard sheet 18.
[0022]
Although the above description has mainly focused on the case where canned beer is packaged in the cardboard box according to the present invention, the cardboard box according to the present invention can be any of juice, soft drink, water, milk, lactic acid drink, etc. It can also be used when packaging such drinking water, and can be used not only in cans but also in any storage form such as bottles, paper packs, plastic bottles, etc. is there. Furthermore, it can be used not only for drinking water but also for packaging any product such as medicines, fruits, foodstuffs, and other household and industrial products. The “corrugated cardboard” referred to in the present invention is not limited to a cover, a core paper, and a backing paper, but is relatively thick and has a slight cushioning property, and is used for packaging various products. As long as there is any configuration, material, etc., it does not matter.
[0023]
[Action]
Since the reinforcing tape used in the present invention employs a special material, the tensile strength (T ₂ ) in the longitudinal direction is higher than the tensile strength (T ₁ ) in the width direction. In other words, it exhibits high strength with respect to tension in the longitudinal direction, but it is extremely easy to tear in the longitudinal direction because it has extremely low strength with respect to tension in the width direction.
[0024]
【The invention's effect】
Therefore, if this reinforcing tape is bonded to the back side of the side surface of the cardboard box provided with gripping perforations, the longitudinal direction of the side surface when the fingers are put in the gripping perforations Even if the total weight of the corrugated cardboard box is loaded, since the tensile strength (T ₂ ) in the longitudinal direction of the reinforcing tape is high, breakage of the side surface can be prevented. On the other hand, since this reinforcing tape is extremely easy to tear in the longitudinal direction, if a weakening line for opening is provided on the side surface, the reinforcing tape can be easily broken along with the corrugated paper along the weakening line. Can do.
[0025]
Therefore, if a corrugated cardboard box according to the present invention in which a punching hole for opening and a weakening line for opening are provided on the side surface of a corrugated cardboard box packed with canned beer and the like and a reinforcing tape is bonded to the back side of the side surface, When selling canned beer etc., the following two sales forms can be arbitrarily adopted. That is, if the final consumer wants all of the canned beer and the like packaged in a cardboard box, he / she sells the canned beer together with the cardboard box, and the final consumer puts his / her finger into the gripping perforation and uses one hand On the other hand, if the end consumer does not want all of the beer etc. packed in the cardboard box, but wants a few, the cardboard box is opened along the weakening line for opening, and the top of the cardboard box By removing this, the end consumer can purchase as many as desired.
[Brief description of the drawings]
FIG. 1 is a perspective view of a corrugated cardboard box according to a conventional example that is opened by a weak line.
FIG. 2 is a perspective view of a corrugated cardboard box according to a conventional example of a type that can be carried with one hand by a perforating hole.
FIG. 3 is a perspective view of a backing tape according to an example of the present invention.
4 is a cross-sectional view of the backing tape shown in FIG. 3. FIG.
FIG. 5 is a schematic view showing a part of a process for manufacturing a cardboard sheet according to an example of the present invention.
FIG. 6 is a back view of a cardboard sheet according to an example of the present invention.
FIG. 7 is a perspective view of a cardboard box according to an example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Weak line 2 Notch 3a Upper part 3b of a cardboard box Lower part 4 of a cardboard box 4 A pair of gripper holes 5 Backing tape 6 Reinforcing tape 7 Adhesive 10 Cover sheet 11 Core paper 12 Back paper 13 Adhesive solution 15 Dryer 16 Lamination Body 17 Corrugated paper 18 Corrugated sheet 19 Corrugated box A Upper surface B of corrugated box Lower surface C of corrugated box Side D of corrugated box Side of cardboard box facing side C Other side F of corrugated box F Corrugated box facing side E Side face C _W Weak line provided on the side face D _W Weak line provided on the side face

Claims (7)

In a cardboard box composed of hexahedrons,
At least two opposing side surfaces are formed with two parallel weakening lines for opening,
A pair of gripping perforations are formed on at least one of the two side surfaces,
A reinforcing tape is bonded to the back side of the side surface on which the perforating holes are formed,
The reinforcing tape is bonded to a position that is wider than the width of the two opening weakening lines and covers the two opening weakening lines,
The ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction of the reinforcing tape is 3 or more,
The material of the reinforcing tape is a laminate of a synthetic resin film uniaxially stretched in the longitudinal direction and a paper in which the pulp is relatively oriented in the longitudinal direction , which is manufactured using a circular paper machine. A cardboard box characterized by being. In a corrugated cardboard sheet capable of assembling a corrugated cardboard box having six faces of facing upper and lower surfaces A, B, facing side C and side D, facing side E and side F,
The corrugated cardboard sheet is connected to a rectangular portion for forming an upper surface A, a lower surface B, a side surface C and a side surface D, and two opposite sides of the rectangular portion, and the upper surface A, the lower surface B, and the side surface C and eight sides for forming the side surface E and the side surface F, which are connected to each of the side surfaces D independently,
Two parallel weakening lines are formed on the side surface C and the two bent portions connected to the side surface C, and the two bent portions connected to the side surface D and the side surface D. Formed continuously,
On the side C or the side D, a reinforcing tape is bonded in a state of covering the two weak lines, and a pair of perforations are formed,
The ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction of the reinforcing tape is 3 or more,
The material of the reinforcing tape is a laminate of a synthetic resin film uniaxially stretched in the longitudinal direction and a paper in which pulp is relatively oriented in the longitudinal direction , produced using a circular paper machine. A corrugated cardboard sheet characterized by that. The ratio of the tensile strength (T ₂ ) in the longitudinal direction to the tensile strength (T ₁ ) in the width direction is 3 or more, and a synthetic resin film whose material is uniaxially stretched in the longitudinal direction and a circular net paper machine Selected from the group consisting of a heat-sensitive adhesive, a pressure-sensitive adhesive, and a rewet-adhesive adhesive on one side of a reinforcing tape that is a laminate with a paper in which the pulp is relatively longitudinally oriented. The backing tape for cardboard boxes according to claim 1, wherein an adhesive is applied.   The backing tape for cardboard boxes according to claim 3, wherein a heat-sensitive adhesive is used as the adhesive. A laminating process in which a flat cover, corrugated core paper coated with an adhesive solution, and flat backing paper are laminated in this order;
Drying the adhesive solution, and bonding the cover and backing paper to the core paper; and
An adhesion step of adhering the backing tape according to claim 3 to a predetermined position of the backing paper to obtain corrugated paper;
Forming two parallel weakening lines at predetermined positions on the cardboard paper;
Forming a pair of perforations at predetermined positions on the cardboard paper;
Cutting the cardboard paper into a predetermined shape;
A method for producing a corrugated cardboard sheet, comprising: A laminating process in which a flat cover, corrugated core paper coated with an adhesive solution, and flat backing paper are laminated in this order;
Drying the adhesive solution, and bonding the cover and backing paper to the core paper; and
While the residual heat applied to the backing paper in the drying step remains, the backing tape according to claim 4 is brought into contact with the backing paper, and the heat-sensitive adhesive of the backing tape comes into contact with the backing paper. In this case, the heat-sensitive adhesive is softened or melted by the residual heat remaining on the backing paper, thereby bonding the backing tape to the backing paper to obtain a corrugated paper. Bonding process;
Forming two parallel weakening lines at predetermined positions on the cardboard paper;
Forming a pair of perforations at predetermined positions on the cardboard paper;
Cutting the cardboard paper into a predetermined shape;
A method for producing a corrugated cardboard sheet, comprising:   A method for manufacturing a cardboard box, wherein the corrugated cardboard sheet obtained by the method according to claim 5 or 6 is assembled into a hexahedral shape.

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