JPS637145B2 - - Google Patents

Description

[Detailed Description of the Invention] Generally, the tensile strength of cardboard is low, so when a relatively heavy product is transported in a cardboard box, the cardboard box must be further packed in a wooden crate. In addition to significantly increasing transportation costs, there were drawbacks such as the handle part punched out at the top of the box being damaged when the cardboard box was carried.

In an attempt to improve the above-mentioned drawbacks, the present inventor introduced an ordinary mesh between the liner and the single-sided corrugated cardboard that is pulled out while applying adhesive, and then press-bonded these three members. However, since the net of the net has a rhombic shape, the net is deformed by the tensile force when introduced and the width becomes narrow, making it difficult to introduce the net with a predetermined width. Since there is only point contact with the core paper,
If only adhesive is used to bond the liner to the liner, the threads will easily peel off, and the knots will form protrusions on the surface of the cardboard, which will worsen printing compatibility and significantly reduce the product value. Occurred.

Therefore, as a result of further research, a large number of warp and weft yarns to which a thermoplastic adhesive was added were polymerized at intervals in the vertical and horizontal directions, and the intersections of these warp yarns and weft yarns were bonded with the thermoplastic adhesive. The net-like material is introduced between the liner paper side of the single-sided corrugated cardboard and the liner that is adhered thereto while being pulled out sequentially, and then the liner, the liner paper, and the reticulate material are polymerized and bonded under heat and pressure. All of the above-mentioned problems could be solved by adhering these three materials using an adhesive applied to the liner paper and a thermoplastic adhesive added to the net-like body.

The present invention will be described in more detail with reference to the embodiments shown in the drawings below.A liner 1 is supplied from one side to a press roll 2, and a corrugating base paper 3 is sequentially wound around a pair of interlocking corrugating rolls 4 and 5 to form corrugations. At the same time, an adhesive is applied to the top of the lower side using an applicator roll 6 and then adhered to the liner 1.

The single-sided corrugated cardboard A thus obtained is guided to a rider roll 7, and a top applicator roll 8 protrudes to the lower surface of the batting paper of the single-sided corrugated cardboard A.
After applying adhesive, a corrugating belt 9 is installed on the lower side of the corrugating belt 9, and a heating section 10 is placed at the front and a cooling section 11 is placed oppositely at the bottom of the corrugating belt 9. When supplying the starting end of the corrugating belt 9 and the starting end of the heating section 10, the net-like body 12 and the liner 13, to which a thermoplastic adhesive has been added in advance, are placed so that the net-like body 12 is on top. Supplied on the bottom surface of single-sided corrugated cardboard A.

Then, in the heating section 10, the top of the batting paper and the liner 13 are connected to the applicator roll 8.
At the same time, the thermoplastic adhesive of the net-like body 12 is melted and the three polymerized parts are bonded together by the adhesive applied by the reticular body 12. In the cooling section, the thermoplastic adhesive hardens and is firmly bonded. .

The double-sided corrugated cardboard B sent out from the corrugating belt 9 is cut to a fixed length by a cutter 14.

Next, the net-like body 12 will be explained.

3 to 7 untwisted or twisted yarns of 75 to 500 deniers are arranged in parallel, coated or impregnated with thermoplastic adhesive, sandwiched between a pair of rolls, made into a tape shape, and cured or without curing. When constructing a flat adhesive thread and sandwiching the net-like body 12 over a desired width, for example, the entire width of the cardboard, make the adhesive thread approximately the same width as the cardboard, and insert the adhesive thread at the center and/or both sides of the width of the cardboard. In case of reinforcing, a large number of warp yarns are pulled out at predetermined intervals within the width to be reinforced, and tape-shaped weft yarns with thermoplastic adhesive, which are constructed in the same way as the warp yarns, are stretched in a zigzag pattern and bonded under heat. A net-like body 12 is obtained.

Alternatively, the net-like body 12 may be constructed by plain weaving a thread that has been cured by adding a thermoplastic adhesive.

Furthermore, the mesh 12 may be placed over the entire width of the cardboard box as shown in FIG. 2, or in the center of the width of the cardboard box as shown in FIG. Thick threads may be inserted in the upper and lower portions of the area that will become the manual insertion hole 15 for reinforcement by increasing the number of threads, or the threads may be inserted in the center and both sides as shown in FIG.

As described above, the present inventor polymerized a large number of warp and weft yarns to which a thermoplastic adhesive was added at intervals in the vertical and horizontal directions, and then bonded the intersections of these warp yarns and weft yarns with the thermoplastic adhesive. The mesh is introduced between the liner side of the single-sided corrugated cardboard and the filling while being pulled out sequentially, and then the liner, the liner, and the mesh are polymerized and bonded under heat and pressure, thereby forming three parts. The material is bonded with an adhesive applied to the batting paper and a thermoplastic adhesive added to the mesh, so that the warp and weft threads that make up the mesh are attached to the protrusions of the batting paper of the single-sided corrugated board. Even in a point contact state, the thermoplastic adhesive added to the threads themselves and the adhesive that bonds the batting paper and liner ensure reliable adhesion without causing any peeling phenomenon, making it possible to bond with heat and pressure. Sometimes, the thermoplastic adhesive melts and adhesively connects the warp and weft threads, creating a state similar to a knot, and even if the intersection of these threads is located between the ridges of the batting paper, It is possible to obtain a corrugated paperboard that is strong and able to withstand tension.

In addition to obtaining great strength against the pressing force on the surface of the cardboard box, when carrying the carton by holding it, the handles are vertically and horizontally.
Even thin threads can provide sufficient tensile strength in the vertical and horizontal directions.

Furthermore, although it is a net-like material, it does not have any knots, so no convex portions are generated on the surface of the corrugated board, making it possible to improve printing adaptability and increase commercial value.

Moreover, no matter where in the cardboard box a long hole is drilled to serve as a hand hole, one thread runs approximately parallel to the hand hole, and at the end of the hand hole, the other thread runs in a direction perpendicular to the hand hole. Therefore, even if heavy mechanical parts are stored and carried, the cardboard will not break at the middle part above the handle hole or tear at the end.

Furthermore, since a thermoplastic adhesive is added to the net-like body before it is incorporated into the corrugated board, there is no need to add an adhesive applicator to each corrugated board manufacturing machine, and it is possible to add it to existing corrugated board manufacturing machines at low cost. It is easy to apply, does not cause problems such as hardening of the adhesive when the corrugated board manufacturing machine is stopped, and can continuously produce products of stable quality in the mesh manufacturing process with high efficiency. can.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention,
Figure 1 is a process diagram, Figures 2, 3, and 4 are plan views showing the position where the net-like body is inserted into the cardboard, and Figure 5 is another example of the position where the thread is inserted into the cardboard. FIG. 1, 13... Liner, 3... Medium paper,
4, 5... corrugated roll, 10... heating section, 12...
reticular formation.

Claims (1)

[Scope of Claims] 1. A network formed by polymerizing a large number of warps and wefts to which a thermoplastic adhesive has been added at intervals in the vertical and horizontal directions, and bonding the intersections of the warps and wefts with the thermoplastic adhesive. The body is introduced between the liner paper side of the single-sided corrugated cardboard and the liner adhered thereto while being pulled out one by one, and then the liner, the liner paper, and the net-like body are polymerized and bonded under heat and pressure.
Adhesive applied to the paperboard,
A method for manufacturing corrugated board characterized by bonding with a thermoplastic adhesive added to a mesh. 2. The method for manufacturing corrugated board according to claim 1, wherein the threads of the net-like body are formed by aligning a large number of threads in a tape shape. 3. The method for manufacturing corrugated board according to claim 1, wherein the net-like body is inserted approximately at the center of the width of the liner and the liner.