JPH07291339A - Manufacture of waterproof and reinforced paper - Google Patents

Abstract

PURPOSE:To obtain waterproof and reinforced paper with easy-to-work surfaces by providing curtain-shaped heated molten thermoplastic between No.1 and No.2 papers, and pressing the No.1 and No.2 papers to harden the resin. CONSTITUTION:A corrugated fiber board is made of a corrugated core 3 and two sheets of waterproof and reinforced paper 5 laminated and adhered to the front and back of the core 3. In the waterproof reinforced paper 5 manufacturing process, No.1 and No.2 papers 7, 11 unwound from No.1 and No.2 rolls 9, 13 are nippied between a pair of rolls 15, 15, and thermoplastic resin 19 is fed, in a shape of curtain through a slit in a synthetic resin feeder 17 located over the rolls 15, to between the papers 7 and 11 before being nipped. The thermoplastic resin 19 is hardened to a film thickness of 10 to 30mum while being rolled with the rolls 15, and adhered to the papers 7 and 11. The paper 5 thus obtained is wound on a winding roll 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing waterproof reinforced paper.

[0002]

2. Description of the Related Art For example, a conventional waterproof reinforced paper which is used as a liner paper for corrugated cardboard and enhances waterproof property and compressive strength is disclosed in, for example, Japanese Patent Publication No. 1-18.
As shown in Japanese Patent No. 349, a stretch-strengthening flexible synthetic resin film is laminated on the outer surface of the paper to manufacture it.

However, since the waterproof resin-reinforced paper produced by the above-mentioned conventional method has the synthetic resin layer exposed,
It was difficult to print or color the surface. This drawback can be solved by making the synthetic resin layer side the inner surface. For example, when corrugated paper is formed from this waterproof reinforced paper, the core is bonded to the surface of this synthetic resin layer. This made it difficult to construct corrugated paperboard.

In addition, when the synthetic resin layer is used as the outer surface, there is a problem in that the handling is slippery and the carrying process cannot be performed smoothly.

The present invention has been invented in order to solve the above-mentioned conventional drawbacks, and the object thereof is to easily process the surface while improving the waterproof property and the strength. It is to provide a method of manufacturing waterproof reinforced paper.

Another object of the present invention is to provide a method for producing waterproof reinforced paper which enables other paper to be adhered to any surface.

[0007]

In order to solve the above-mentioned problems, the invention of claim 1 forms a curtain shape of a thermoplastic resin heated and melted between first and second papers having a predetermined thickness. It is characterized in that the first and second papers are pressed together while being supplied to cure the thermoplastic resin to a film thickness of about 10 to 30 μm and adhered by its fusion force.

According to a second aspect of the present invention, the sheet-shaped thermoplastic resin is supplied between the first and second papers having a predetermined thickness, the sheet-shaped thermoplastic resin is melted by the heating member, and then the thermoplastic resin is melted by the cooling member. Is cured to a film thickness of about 10 to 30 μm, and the first and second papers are adhered to each other by the fusing force.

According to a third aspect of the present invention, the first to the third sheets of paper are applied to each other while the thermoplastic resin which has been heated and melted is supplied in a curtain shape between at least the first to the third sheets of a predetermined thickness. It is characterized in that the thermoplastic resin is pressed to cure it to a film thickness of about 10 to 30 μm and adhered by its fusion force.

According to a fourth aspect of the present invention, a sheet-shaped thermoplastic resin is supplied between at least the first to third papers having a predetermined thickness, the sheet-shaped thermoplastic resin is melted by the heating member, and then the thermoplastic resin is melted by the cooling member. It is characterized in that the resin is cured to a film thickness of about 10 to 30 μm, and the first to third papers are adhered to each other by the fusion force.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3, the corrugated paperboard 1 has a structure in which waterproof reinforcing papers 5 and 5 are laminated and adhered to the front and back surfaces of a corrugated core 3, respectively. The two-layer corrugated cardboard paper shown in FIG. 3 has waterproof reinforced paper 5 on the upper surface of the core 3 located above and between the two cores 3 and on the lower surface of the core 3 located below. It has a structure in which 5.5 are laminated and adhered.

The waterproof reinforcing paper 5 is manufactured as follows.

For example, when the waterproof reinforcing paper 5 having a thickness of 0.3 mm is manufactured, the first winding ball 9 on which the first paper 7 having a thickness of 0.18 mm is wound and the thickness of about 0.1. 11 mm second paper 1
The front end portions of the first paper 7 and the second paper 11, which are respectively fed from the second winding ball 13 on which 1 is wound up, are held by the pair of pressing rolls 15 and 15. One of the pressing rolls 15 is connected to an electric motor (not shown) to rotate and drive a driving roll, a driven roll that presses against the driving roll and is driven to rotate, or a drive that rotates in opposite directions. It is configured by rolls or driven rolls that are driven by each other.
The pressure rolls 15 and 15 are spaced apart from each other by a thermoplastic resin 19 (described later) interposed between the first paper 7 and the second paper 11.
The film thickness is appropriately adjusted according to the desired film thickness.

A synthetic resin supply device 17 is arranged above the intermediate portion of the pressing rolls 15. The synthetic resin is a thermoplastic resin 19 such as polyethylene, polypropylene, polybutylene, polyvinyl chloride, polyvinyl acetal or the like. The thermoplastic resin 19 is heated and melted by a heater (not shown) built in the synthetic resin supply device 17. The type of the thermoplastic resin 19 is appropriately determined depending on the type of the material to be formed from the waterproof reinforced paper 5. For example, when the thermoplastic resin 19 is used in a cardboard box containing food, it is non-toxic such as polypropylene. Stuff is required.

The heat-melted thermoplastic resin 19 is formed on the bottom surface of the synthetic resin supply device 17 in the longitudinal direction (first and second paper 7).
・ When flowing out from a slit (not shown) provided so as to extend in a direction orthogonal to the feeding direction of 11, the pressing rolls 15 and 15 become curtain-shaped due to the viscosity thereof.
It is supplied between the first paper 7 and the second paper 11 before being clamped by.

Then, the thermoplastic resin 19 supplied between the first and second papers 7 and 11 is hardened while being rolled by the pressing rolls 15 and 15 to have a film thickness of about 10 to 30 μm. The first paper 7 and the second paper 11 are adhered to each other by the fusing force at that time. The above film thickness is waterproof reinforced paper 5
In order to obtain the waterproof property and strength, it is necessary to set the thickness to 10 μm or more, and to reuse the waterproof reinforced paper 5 as a paper resource, the thickness must be set to 30 μm or less. That is, when the film thickness of the thermoplastic adhesive is 30 μm or more, the amount of resin contained is large, and it is difficult to reuse the waterproof reinforced paper 5 as a paper resource.

Since the molten thermoplastic resin 19 is hardened in a short time as the pressing rolls 15, 15, cold air is blown to the structure for circulating cooling water inside or to the outer peripheral surface of each pressing roll 15. A structure having a blower device (neither is shown) is suitable.

The waterproof reinforced paper 5 consisting of the first and second papers 7 and 11 adhered to each other by the fusion force of the thermoplastic resin 19 cured as described above is wound up on the winding roll 21. The take-up roll 21 is a pressing roll 15.
The waterproof reinforcing paper 5 is wound in a tensioned state by being rotated so as to be slightly higher than the peripheral speed of 15.

According to the first aspect, the thermoplastic resin 19 heated and melted between the first paper 7 and the second paper 11 is supplied in the flow coating method. Good.

That is, as shown in FIG. 4, a sheet-shaped thermoplastic resin 19 having a required film thickness is wound between the first winding ball 9 and the second winding ball 13 to form a winding ball. Place 23,
The thermoplastic resin 19 fed from the winding ball 23 is passed between a pair of heating rolls 25 serving as a heating member while being positioned between the first and second papers 7 and 11. Then, the sheet-shaped thermoplastic resin 19 located between the first and second papers 7 and 11 is melted by the heating and pressing by the heating rolls 25 and 25, and then is transferred to the lower side of the heating rolls 25 and 25. Cooling rolls 27, 27 as arranged cooling members
As the film passes, the film is cured while being pressed so that the film thickness becomes about 10 to 30 μm, and the mutual adhesion is caused by its fusion force.

The waterproof reinforced paper 5 consisting of the first and second papers 7 and 11 adhered to each other is wound up by the winding roll 21.

When the waterproof reinforced paper 5 is used as a liner paper for the corrugated cardboard paper 1, sufficient strength and waterproofness can be obtained by laminating and adhering two sheets of the first and second papers 7 and 11 to each other. Can be obtained,
When the waterproof reinforced paper is used alone after being shaped, as shown in FIG. 5, the first to third papers 7/11/33 fed out from the first to third roll balls 9/11/31 / With the thermoplastic resin sheets 39 and 41 unrolled from the winding balls 35 and 37 positioned respectively, the heating roll 25 and
It is sufficient if the waterproof reinforcing paper 43 is made by adhering and integrating three sheets of paper by passing the sheet of paper 25 and the cooling rolls 27, 27.

Next, the strength test results of a box formed of a corrugated cardboard paper 1 having a two-layer structure and using the waterproof reinforced paper 5 of claim 1 and having a thickness of 8 mm are shown below.

Structure: Top paper, bottom paper and middle paper Waterproof reinforced paper 280 g / m ² 1 layer thickness 5 mm 1 layer core core Reinforced core core 160 g / m ² 2 layer core medium center core 120 g / m ² 2 layer thickness 3 mm Sample A length (255 cm) x width (255 cm) x height (370 cm) B length (255 cm) x width (255 cm) x height (185 cm) Humidification condition 1 20 ° C-65% RH 2 20 ° C-80% RH 3 20 ° C.-90% RH Test method: JIS-Z-0212 (Compression test method for packaged cargo and container) Test result Sample A Humidity control condition 1: 543 Kgf (water content: 9.6%) Humidity control condition 2: 423 Kgf ( Humidity: 12.1%) Humidity control condition 3: 330 Kgf (water content: 15.4%) Sample B Humidity control condition 1: 497 Kgf (water content: 10.4%) Humidity control condition 2: 445 Kgf (water content: 11.7%) ) Humidity control condition 3: 300 Kgf ( Minutes: 15.3%)

[0026]

Therefore, the present invention can provide the following.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method of manufacturing waterproof reinforced paper.

FIG. 2 is a perspective view showing a corrugated paper board having a single-layer structure using waterproof reinforced paper.

FIG. 3 is a perspective view showing a two-layer corrugated paperboard using waterproof reinforced paper.

FIG. 4 is a perspective view showing an embodiment method according to claim 2;

FIG. 5 is a perspective view showing a method for manufacturing waterproof waterproof paper having a three-layer structure.

[Explanation of symbols]

 1 Corrugated Cardboard 3 Core 5 Waterproof Reinforced Paper 7 First Paper 11 Second Paper 15/15 Clamping Roll 19 Thermoplastic Resin 25/25 Heating Roll as Heating Member 27/27 Cooling Roll as Cooling Member 33th 3 paper 43 waterproof reinforced paper

Claims (4)

[Claims] Claim: What is claimed is: 1. A thermoplastic resin comprising a first and second papers each having a predetermined thickness, which is heated and melted in a curtain shape while being supplied in a curtain shape, while pressing the first and second papers together. Is cured to a film thickness of about 10 to 30 μm and adhered by the fusion force thereof. 2. A sheet-shaped thermoplastic resin is fed between first and second papers having a predetermined thickness, and is melted by a heating member, and then the thermoplastic resin is cooled to about 1 by a cooling member.
A method for producing waterproof reinforced paper, characterized in that it is cured to a film thickness of 0 to 30 μm and the first and second papers are adhered to each other by their fusing force. 3. A thermoplastic resin by pressurizing the first to third papers while supplying a thermoplastic resin which is heated and melted in a curtain shape between at least the first to third papers having a predetermined thickness. Is cured to a film thickness of about 10 to 30 μm and adhered by the fusion force thereof. 4. A sheet-shaped thermoplastic resin is fed between at least first to third papers having a predetermined thickness, and is melted by a heating member, and then the thermoplastic resin is cooled by about 10 to 10 by a cooling member. A method for producing waterproof reinforced paper, characterized in that it is cured to a film thickness of 30 μm and the first to third papers are adhered to each other by their fusing force.