JPH0455939B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of manufacturing a cardboard box for storing and transporting various products.

(b) Conventional technology Conventionally, cardboard boxes have been used to transport various products such as general goods, processed foods, and industrial products.
In order to reduce the cost and weight of corrugated cardboard while also preventing damage to the contents, the liner and core are impregnated with resin, a reinforced core is used, the liner and core are doubled, or pulp is used. It is already known to use multi-sided corrugated board or multi-sided corrugated board instead of multi-sided corrugated board or single-sided cardboard by changing the composition of the types.

In addition, in addition to improving the strength of cardboard boxes, adding resin etc. to the ruled lines to strengthen them has been proposed by Japanese Patent Laid-Open No.
It is already known from Publication No. 59-103737 or Japanese Utility Model Application Publication No. 51-75730, etc., and in addition, reinforcing tape made by aligning multiple threads and gluing them is pasted on the top and bottom of the hand hole for the purpose of increasing strength. It is already known that

(c) Problems to be solved by the invention If the strength of the previously known corrugated board is increased by increasing the number of laminated layers or using high-quality pulp, the cost becomes extremely high. The coating method requires a large amount of resin, which increases costs, and if the process of applying the resin and laminating the liner and core is run at high speed, the desired amount of additive cannot be obtained, resulting in low efficiency. When a problem occurred and the machine was stopped, the adhesive hardened, making it difficult to restart work. In addition, the resin must be flexible enough to be bent at the ruled lines, and in cases where the resin is applied from one side to every other groove in the center core, when tightened with a band for packaging, The resin deforms and crushes the empty space, making it easy to break.The method of applying resin to both sides of the core requires an extremely large amount of resin, resulting in a significant increase in cost.In general, the margins for cardboard box manufacturers are extremely thin, making it impossible to do so. It cannot be adopted.

In addition, if the reinforcing tape for the hand-holding holes is used as a reinforcing material for the ruled lines, the hand-holding holes will be cut out, so even if there are unbonded parts on both sides of the reinforcing tape, there may be no particular problem. In the ruled line area,
The strength of the unbonded portion is significantly lower than that of a normal unreinforced portion, and when the band is tightened, a serious problem arises in that the unbonded portions on both sides buckle or burst. Moreover, since the threads of the reinforcing tape are twisted threads, they will stretch when pressurized when banded, making it impossible to obtain a sufficient reinforcing effect.
The ruled line part is deformed, and as with the resin spraying method,
It was not suitable for fruits and vegetables such as peaches and cucumbers, perishable items such as sweets packed in cartons, and heavy items such as electrical appliances.

(D) Means for Solving the Problems The present invention involves aligning a plurality of bundled yarns consisting of a large number of thin, substantially untwisted yarns into a belt shape, adding a thermoplastic adhesive to the belt, and then creating a tape. This adhesive thread is formed into a shape and cured to form an adhesive thread, and this adhesive thread is introduced in the corrugated paper manufacturing process along the inner surface of the outer liner and at a position corresponding to the ruled line of the box.
Next, the cardboard is bonded under pressure in a heated state, the cardboard is cut, and the paper is bent at a portion close to the adhesive thread to form a box, thereby making it possible to manufacture cardboard with high efficiency using inexpensive materials. The above-mentioned problem has been solved by reducing the deformation of the ruled lines when a band or the like is hung on the box.

(E) Action: Thin threads such as fine-count monofilament, which are virtually untwisted, are made into assembled threads, which are tied together in a band shape, then thermoplastic adhesive is added and formed into a tape shape. At the same time, the adhesive thread is wound around the core as an adhesive thread, and in the process of polymerizing and bonding the liner and core in the corrugated paper manufacturing process, the adhesive thread is applied to a portion corresponding to the horizontal ruled line of the corrugated box between the liner and the core. The corrugated paperboard thus obtained is cut and bent along horizontal ruled lines near the adhesive threads to form a cardboard box.

When band binding is performed, the adhesive thread is located on one side of the thickness of the cardboard box in the vicinity of the ruled line and resists tensile force and bending force in a continuous state without elongation, The strength of the cardboard box itself can be increased, and the ruled lines can be prevented from deforming.

Even though yarn is the main material of the reinforcing material, the thermoplastic resin adhesive is melted by heating in the bonding process using heat and pressure, and each unit yarn of each aggregate yarn is oriented horizontally due to pressure. Since it spreads and becomes extremely thin, no protrusions corresponding to threads are formed on the surface, and no adhesion failure occurs on both sides of the adhesive thread between the liner and the core.

(F) Embodiments A part of embodiments of the present invention will be described with reference to the drawings.

Example The adhesive thread 1 is made of a large number of untwisted thin threads, which are arranged into a band shape, and then a thermoplastic adhesive such as EVA, nylon, or polyamide is applied to this. is added, molded into a tape shape, and cured, which is then wound onto a bobbin.

Next, the adhesive thread 1 is attached to the front liner 2 of the cardboard.
To explain the process of introducing and adhering between the core paper and the flute 3, the back liner 4 is supplied from one side to the press roll 5, and the core raw paper 6 is sequentially wound around a pair of interlocking corrugated rolls 7, 7. After applying the adhesive to the lower top part of the step with an applicator roll 8, the front liner 2 is applied.
Glue to.

The single-sided corrugated cardboard A thus obtained is guided to the liner roll 9, and the center core 3 of the single-sided corrugated cardboard A is guided to the liner roll 9.
Adhesive is applied to the protruding part of the lower surface with an applicator roll 10, a corrugating belt 11 is provided on the lower side thereof, a heating part 12 is placed in the front position, and a cooling part 13 is placed in the rear part, facing each other, When supplying the glued single-sided corrugated cardboard A to the starting end of the corrugating belt 11 and the starting end of the heating section 12, four bobbins 14 around which the adhesive thread 1 is wound are placed on the front side thereof. The front liner 2 and the single-sided corrugated cardboard A are supported in parallel with each other at approximately equal intervals to the horizontal ruled lines (vertical ruled lines) 16, 16 of the box 15, and the front liner 2 is pulled out from below.
Adhesive threads 1 drawn out from the bobbin 14 are introduced two by two in close proximity to both sides of the horizontal ruled lines 16, 16 between the single-sided cardboard A and the adhesive threads 1. ... and the front liner 2 pass over the heating section 12, the thermoplastic adhesive of the adhesive thread 1 melts, and the corrugating belt 11
By applying pressure, the adhesive thread 1... is attached to the center core (flute) 3 of the single-sided corrugated cardboard A and the front liner 2.
At the same time, the center core 3 and the front liner 2 are bonded by the adhesive applied by the applicator roll 10, and then cooled in the cooling section 13 to harden the thermoplastic adhesive and send it out. The double-sided corrugated cardboard B is cut into appropriate lengths by the cutter 17, thereby obtaining the double-sided corrugated cardboard B shown in FIGS. 2-4.

The double-sided cardboard B is cut into pieces of length necessary for one box, and horizontal ruled lines 16, 16 and vertical ruled lines 18, 18 are cut into pieces.
By folding the liner at the portion where it becomes , and joining the overlapped portion at the vertical ruled line portion, a cardboard box as shown in FIG. 5 is obtained. is 1
The books are glued together with each book interposed.

In the cardboard box, the adhesive threads 1, 1 running close to the horizontal ruled lines 16, 16 are integrated with the layered cardboard to perform the same function as reinforcing bars in reinforced concrete at the horizontal ruled lines 16, 16, thereby increasing the strength of the box. Moreover, in the manufacturing process, there is no reduction in efficiency due to intervening bonding of the adhesive thread 1.

Furthermore, when boxes containing products are tied together with a band as shown in FIG. 6, the horizontal ruled lines 16, 16 are extremely unlikely to be deformed by the tightening force of the band 20, and the stored items will not be damaged.

Example In the process of introducing the adhesive thread 1... between the single-sided corrugated board A and the front liner 2 in the above embodiment, eight bobbins were arranged, and the adhesive thread 1... pulled out from these bobbins was placed along the horizontal ruled line. By introducing two pieces on each side of the parts 16 and 16 and heat-pressing them, a corrugated board as shown in Fig. 7 is obtained.
The strength of a cardboard box manufactured using this cardboard is further improved.

Example This example is based on the horizontal ruled line 1 in the previous example.
Adhesive thread 1 is introduced and bonded to the parts corresponding to 6 and 16, and as shown in FIGS. 8 and 9, one adhesive thread 1 is placed on horizontal ruled lines 16 and 16, It is possible to obtain a cardboard with two pieces interposed on each side.

Further, adhesive threads 1, 1 may also be interposed and bonded to the parts corresponding to the horizontal ruled lines 16, 16 of the above embodiment.

Further, in each of the above-described embodiments, the adhesive threads 1... were interposed on the inner surface of the front liner 2, but they may be interposed and bonded on the inner surface of the back liner 4.

In addition, in FIG. 1, it is assumed that the bobbin 14 is wound with yarn, and this yarn is pulled out to form the front liner 2.
Even if an adhesive is applied and bonded during the process of sandwiching the box between the single-sided cardboard box A and the single-sided cardboard box A, the same reinforcing effect of the cardboard box as in the above-mentioned embodiment can be obtained.

(G) Effects of the Invention The present invention consists of aligning a plurality of bundled yarns consisting of a large number of thin substantially untwisted yarns into a band shape, adding a thermoplastic adhesive to the belt shape, and molding the yarn into a tape shape. This adhesive thread 1 is introduced into the inner surface of the outer liner in the corrugated paper bonding process along a position corresponding to the ruled line of the box, and is then bonded by applying pressure in a heated state. Since this corrugated paper is cut and bent at a portion close to the adhesive thread 1 and formed into a box, when it is bonded under pressure in an overheated state, the thermoplastic adhesive is melted and it is substantially melted. The thin threads that are not connected to each other spread out laterally and become extremely thin for each set of threads, and it goes without saying that it is possible to reliably bond even between the set threads, and especially on both sides, the thread layers becomes thinner and thinner, thereby preventing unbonded parts from forming on both sides. Therefore, when an external force is applied to the ruled line of the cardboard box 15, or when the cardboard box 15 is tied with the band 20, the area near the ruled line The adhesive threads 1 are integrated with the corrugated paperboard to resist the pressurizing force, and at this time, the corrugated paper does not burst or buckle on both sides of the adhesive threads 1, and the products housed in the cardboard box 15 are reliably protected. Can be done.

Moreover, since the adhesive thread is formed of a collection of thin threads that are not substantially twisted, it does not stretch like twisted threads even when subjected to tensile force, and the reinforcing effect can be further improved.

In this way, the strength of the ruled lines of the cardboard box can be increased, so the thickness of the cardboard can be increased,
An inexpensive adhesive thread that can prevent damage or breakage of stored items without using expensive pulp or reinforcing ruled lines with synthetic resin liquid, allowing heavy items to be transported safely. It is possible to manufacture corrugated cardboard with high efficiency even though it adopts this method.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention,
Figure 1 is a side view showing the process of manufacturing corrugated board in which adhesive thread is introduced and bonded, Figure 2 is a longitudinal cross-sectional view of the cardboard, Figure 3 is a partially cutaway plan view of the same, and Figure 4 shows the border of the box. Fig. 5 is a perspective view of a box, Fig. 6 is a perspective view of a box bound with a band, Fig. 7 is a cutaway of a part of cardboard glued with two adhesive threads interposed on both sides of the horizontal ruled line. The plan view shown in Figure 8 has one line on the horizontal ruled line,
FIG. 9 is a plan view of a corrugated board with two adhesive threads interposed and bonded on each side thereof, and a cross-sectional view of the ruled line portion of the same corrugated board. 1...Adhesive thread, 2...Front liner, 4...Back liner, A...Single-sided cardboard, 12...Heating part,
16...horizontal ruled line, 18...vertical ruled line.

Claims (1)

[Claims] 1. Adhesive thread 1 is formed by aligning multiple bundled threads consisting of a large number of thin substantially untwisted threads into a band shape, adding a thermoplastic adhesive to this, forming it into a tape shape, and curing it. None, this adhesive thread 1 is introduced in the corrugated paper manufacturing process along the inner surface of the outer layer liner and at a position corresponding to the ruled line of the box, and then adhered by applying pressure in a heated state, and this corrugated paper is cut, and the above-mentioned A method for manufacturing a corrugated box, characterized by forming the box into a box by bending it at a location close to the adhesive thread 1.