JPS6348706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a paper tube having a heat-shrinkable synthetic resin film tube attached to the circumferential surface.

A long strip of paper such as cardboard is wound spirally in one or more layers using a spiral tube winder to form a long tube, which is then cut to the required length and has openings at both ends. Paper tubes closed with lids made of synthetic resin plates, metal plates, cardboard, etc. can be used as packaging containers for snack foods, confectionery, etc., and can also be used as packaging containers for frozen foods, drinks, etc. with a waterproof lining on the inside. It is now widely used as a container for liquids.

This type of paper tube (composite tube) is cheaper in material cost than metal cans, has a simpler manufacturing process, is lighter and easier to handle, has advantages in transportation, and can be easily incinerated after use. It has advantages such as being able to be processed in various ways, and not having the problem of so-called can pollution like metal cans, etc. However, on the other hand (i) it is easily damaged and the outer paper strips peel off in a spiral pattern. (ii) It has poor water resistance and becomes soft due to dew condensation on the surface during cooling or frozen storage. (iii) The product name, picture, etc. displayed on the surface are printed in advance on the surface of the paper strip as a developed diagram. Therefore, in order to manufacture many types of paper tubes with different tube diameters, there are problems such as having to prepare many types of paper strips on which developed views corresponding to the respective tube diameters are printed. As a countermeasure for this,
A method has been proposed in which a tube of heat-shrinkable synthetic resin film is manufactured separately from the paper tube, the tube is placed over the paper tube, and the tube is brought into close contact with the outer circumferential surface of the paper tube through heat-shrinking treatment. By covering the circumferential surface of the paper tube with the tube, the tube acts as a protective film to prevent damage to the paper tube, and also blocks direct contact with moisture such as condensation. If a pattern is printed, the paper strip itself can be used as a plain color, so there is no need to print a developed diagram according to the pipe diameter. However, this manufacturing method requires tube forming equipment that is independent of the paper tube manufacturing process, and also requires a process for attaching the formed tube to the paper tube, making the manufacturing process complicated. It is extremely inefficient. Moreover, it is not possible to match the end face of the tube after heat shrinkage treatment with the end face of the paper tube, and the finished appearance is often impaired.

The present invention solves the above problem, and provides a paper that combines a paper tube forming process using a spiral tube winder, a heat-shrinkable synthetic resin film tube forming process, a heat-shrinking treatment process for the film tube, etc. as a series of processes. A method for manufacturing a tube is provided.

The paper tube manufacturing method of the present invention consists of a step of continuously forming a long paper tube using a spiral tube winder (paper tube forming step), and a heat-shrinkable synthetic resin film (hereinafter referred to as "shu") around the paper tube. A process of forming a tube surrounding a paper tube by overlapping both side edges of the film and gluing the overlapped surfaces while winding a "link film" (also called "link film"), and then heat-shrinking the tube. The step of bringing the paper tube into close contact with the outer circumferential surface of the paper tube (heat shrinking treatment step) and the step of cutting the paper tube together with the tube into a required length (cutting step) are successively performed.

To explain an embodiment of the present invention, in FIG. 1, A is a paper tube forming process using a spiral tube winder, 1 is a long paper strip having a predetermined width dimension, and 10 is a paper tube formed by winding the paper strip. 11 is the rotation of the mandrel 10 (arrow x
direction) drive motor; 12 is a roller for winding the paper strip wound around the mandrel; Reference numeral 2 denotes a paper tube, which moves forward in the direction of arrow y as the paper strip is wound around the shaft 10.

B is a tube forming process, 3 is a long paper tube 2
14 is a guide roll for winding the shrink film 4 around the paper tube 2, and 15 is a roll on both sides of the film. Edge 4
This is a heat roll for joining e and 4e by heat fusion.

C is a heat shrinking process, and 17 is a tunnel type heater having a heating source inside.

D is a cutting process. The paper cylinder 2 formed in the paper cylinder forming process A is fed as one continuous elongated body until it reaches the cutting process. Note that reference numerals 13 and 16 are holders which are appropriately arranged along the transition line of the paper cylinder in order to support the long paper cylinder 2.

The spiral tube winder and the forming operation thereof in the paper tube forming process A are not different from normal ones, and a predetermined plurality of paper strips 1 are shown on a mandrel 10 which is rotated by a motor 11 at a predetermined rotational speed. The paper strips are continuously unrolled from a roll of paper strips that do not overlap each other, and wound spirally around the mandrel 10 so that at least the side edges of each paper strip overlap each other. By appropriately adhering the surfaces, the paper cylinder 2 is continuously formed and moved forward along the mandrel 10.

In the tube forming process B, the film 4 unwound from the film roll 3 in accordance with the forward movement speed of the paper tube 2 is guided by the guide roll group 14, and is moved around the paper tube 2 so that both side edges 4e and 4e are aligned with each other. The tube 5 surrounding the paper cylinder 2 is formed by winding the paper so as to overlap and then heat-sealing the overlapping surfaces with a heat roll 15. That is, in this step, the paper tube 2 itself serves as a tubing plate in a normal tube forming apparatus, and the tube is formed and attached to the paper tube at the same time. The bonding of the polymerized surfaces of the film is not limited to thermal bonding, and may be performed using an adhesive, similar to the well-known tubing. Note that various labels may be inserted between the tube and the paper cylinder as desired.

The paper cylinder 2 with the tube 5 fitted thereon is then fed into the tunnel heater 17 in a heat shrinking process C, and the tube is tightly attached to the outer circumferential surface of the paper cylinder due to heat shrinkage, and then the paper cylinder 2 is moved to a cutting process D. Once there, the cutter 18 cuts it to a predetermined length. Heating of the tube in the heat shrinking process is of course not limited to the tunnel type heater, and any suitable heating method may be used.In the cutting process, the position of the tip of the paper tube is detected by a position detection device 19 made of, for example, a phototube. Therefore, cutting can be performed while automatically setting the cutting length.

In this way, a paper tube whose entire outer peripheral surface is covered with the tube is obtained. The tube is firmly integrated with the paper tube due to its thermal shrinkage force, but if you wish to further strengthen the engagement relationship, apply a suitable adhesive (pressure-sensitive adhesive,
use one coated with heat-sensitive adhesive (such as heat-sensitive adhesive), or
Alternatively, the adhesive may be interposed between the tube and the paper tube by applying an adhesive to the circumferential surface of the paper tube between the paper tube forming process and the tube forming process.

As shown in FIG. 2, the obtained paper tube is rolled up with the tube 5 at both open ends to form the seaming portion 6.1, so that both ends of the tube 5 are attached to the open end of the paper tube. It is firmly fixed, and by attaching the lid members 7, 7, the packaging container is completed. The lid material is a molded body made of a metal plate, synthetic resin, or cardboard, and depending on how the packaging container is used, one lid material may be fixed so that it does not come off.
The other lid material may be removably fitted to open and close the container. In addition, when using it as a substitute for cans filled with beverages or oils such as youth, for example, use a metal plate lid material and insert the periphery together with the end of the paper tube for a liquid-tight seal, as shown in Figure 3. , the container is provided with a pull-top spout that is broken by pulling the loop 7.1 defined by a shallow cut on the top surface of the lid material in the direction of the arrow with a knob ring 7.2. You can also do it.

According to the method of the present invention, (i) each process from paper tube forming to tube forming to cutting to the required length is performed continuously, so the process is extremely simple and tubes can be formed efficiently and inexpensively; A paper tube with an integrated paper tube can be obtained.

(ii) The paper tube and the tube, which are in close contact with each other due to heat shrinkage, are cut to the same length, and both ends of the tube and both ends of the paper tube coincide, so unlike conventional methods, both ends of the paper tube are cut due to insufficient tube length. It does not cause any unsightly appearance such as exposing the material of the part.

(iii) The tube completely covers the entire surface of the paper tube and is firmly integrated with the paper tube due to heat shrinkage and the seams formed at both ends, creating a protective film that prevents damage and is waterproof. It has excellent functions as

(iv) Since it has good water resistance, it will not become soft due to condensation even if it is stored under cooling conditions as a container for beverages, etc., and is therefore suitable for sales as a pull-top can container through vending machines, etc. be.

In addition, by covering the paper tube with a film tube, a high-quality image is added to the product compared to the base material of the paper tube, and product information (product name, usage, quality, etc.) and pictures are printed on the surface of the tube in advance. The product value and design effect can be enhanced by displaying the label or by sandwiching the label between the tube and the paper tube. Of course, there is no need to print on the paper strip itself and it can be left plain, so there is no need to use different paper strips for different pipe diameters.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of the paper tube manufacturing process according to the method of the present invention, Fig. 2 is a partially cutaway front view showing an example of a container made of a paper tube, and Fig. 3 is a lid of a container made of a paper tube. It is a perspective view of a material part. 1: paper strip, 2: paper tube, 4: shrink film, 5: tube, 6: paper tube, 10: paper tube forming bodyguard, 14: guide roll, 17: tunnel type heater, 18: cutter.

Claims (1)

[Claims] 1 The process of continuously forming a long paper cylinder using a spiral tube winder, and the process of winding a heat-shrinkable synthetic resin film around the formed paper cylinder, overlapping both sides of the film with each other, and folding the overlapped surface. The process of forming a tube surrounding the paper cylinder by gluing, the process of making the tube adhere to the outer circumferential surface of the paper cylinder by heat shrinking, and the process of cutting the paper cylinder together with the tube to the required length are successive. A method for manufacturing a paper tube coated with a heat-shrinkable synthetic resin film.