JPH022693B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] A tubular object made of a foamed plastic sheet is used as a packaging material for articles, and a net tube packaging bag with a foamed plastic string material is used for packaging fruits, etc. is often used, but if round objects such as fruit are to be placed in the cylinder and stacked, it is important to squeeze one end of the cylinder because the bottom needs to be shaped like a bowl, and the shape of this squeeze is an important issue. . The present invention relates to an improved method of manufacturing a net tube packaging bag.

[Conventional technology]

Currently seen in the market are net tubes folded in half and a rubber ring placed inside the fold, and net tubes with the lower part heat-shrinked.

[Problem that the invention seeks to solve]

However, since the former requires a lot of materials, improvements are desired in terms of resource saving and high cost, while the latter has the disadvantage that even the contracting part is a net, so it expands when you put something in it, causing the contents to fall out. There is also a limit to shrinkage, and since the bottom part is a contracted cylinder, it cannot completely wrap around the bottom of the package, so when stacked, the bottom of the package will not cover the top of the item underneath. The flaws that hurt him were unavoidable.

[Means for solving problems]

The present invention was completed as a result of various studies in order to manufacture a new type of net tube packaging bag that eliminates the above-mentioned drawbacks.As shown in Figures 1, 2, and 7, the bottom part This is a method for producing a net tube packaging bag having a structure never seen before, in which the bag is formed into a bottom shape and a circular or link-shaped film can also be formed in the center of the bottom. The basic technology of the method of the present invention will be described.

As shown in FIG. 1, a cylindrical net tube made of the above-mentioned material is cut into an appropriate unit length, and a receiving mold 10, which is a hollow conical body shown in FIG. 5, is prepared. A cylindrical net tube is fitted onto the outside so that the upper end of the net tube slightly protrudes from the upper end of the receiving mold. This state can be adjusted by moving the position of the regulating plate 13 shown in the figure up and down. In this state, the upper end of the net tube is focused inward in a direction substantially perpendicular to its length direction, and the focused upper end portion of the net tube, that is, the focusing portion 3 in FIG. 5 is held in the focused state. It will melt when heated, and once it melts, stop heating.

To explain more specifically, the method of the present invention can be performed automatically using an apparatus, so
As shown in the figure, after the unit cylindrical body 1 of the net tube is fitted onto the hollow conical receiving mold 10, a pair of diaphragms 12, 12 are moved horizontally to converge the upper end of the net tube that protrudes from the upper end of the receiving mold. ′ using
A method is adopted in which the protrusions 4 are focused at the inner curved part of the drawing tool, and in order to melt this focused part, it is preferable to use a heating device that moves up and down, and the lower end of the heating device, That is, the portion that directly contacts the convergence part is constituted by a suitable circular hot plate 4', and this hot plate contacts the convergence part 3 and melts the convergence part. In order to ensure the melting of the bundle part 3, improve the shape of the finished product, and increase the commercial value, the bundle part 3 is drawn into the hollow part 11 of the mold 10 in a U-turn shape (first step). Figure 6)
It is also effective.

The present invention uses elastic plastic string material as the material;
For example, a net tube made of foamed plastic string material or a foamed plastic cylindrical body with an appropriate number of short cuts in the longitudinal direction placed at predetermined intervals around the entire circumference of one end may be used, but the same effect as described above may be used. A packaging bag having a bowl-shaped bottom can be obtained.

[Effect]

By the means described above, the molten thermoplastic material is
A ring-shaped film 2 is formed on the ends of the string materials forming the net, and the end 6 of each string material (Fig. 7) and this ring-shaped film are integrally bonded to each other, as shown in Fig. 1A. A net packaging bag having a bowl-shaped bottom and a cylindrical main body is formed. Note that if the length of the converging part 3 of the net tube protruding from the upper end of the receiving mold 10 is long, the amount of the mucus that will be heated and melted will be large, and due to the surface strength, it will instantly form a circular film, and after cooling, it will become as shown in Figure 1 B. A thin film 2' is formed. In this case as well, the end portion of the string material is integrally joined to the outer peripheral edge of the circular film to form a net packaging bag having a bowl-shaped bottom and a cylindrical main body.

The present invention consists of a step of converging one end of a net tube in a direction perpendicular to the length direction, a step of heating this converged portion until it melts, and a step of immediately stopping the heating and cooling it (at room temperature). By doing this, a ring-shaped or circular film is formed at one end of the net tube in a direction perpendicular to the length direction, and this film is fused together with the end of the string material that makes up the net tube, and the tube is The first advantage is that it is formed as a packaging bag with one end shaped like a bowl bottom, and that the film is formed into a ring-shaped or circular film by itself due to the surface tension of the molten mucus, so no processing means is required. The second characteristic is recognized, and this is responsible for simplifying the apparatus for implementing the present invention and reducing the processing cost, which ultimately leads to the effect of lowering the price of the product.

〔Example〕

An example of implementing the present invention will be described with reference to the drawings. First, an example of the object produced by the present invention is shown in FIGS.
Reference numeral 2 denotes a film formed on one end of the net tube, which is formed by melting a focusing part 3, which focuses the end of the net tube from the periphery to the center in a conical shape, using a heater device 4, which will be described later, as shown in Fig. 3. The film is formed integrally with all ends of the string material 5 (Fig. 2). Further, depending on the structure of the heater, the film 2 can be formed as a single circular sheet-like film or as an annular film having a circular hole in the center of the sheet. The one shown in FIG. 1A is an annular coating 2, and the one shown in FIG. 1B is a circular coating 2'.

This tube-shaped packaging bag has the above-mentioned film 2 or 2' formed on one end, so even if you put quite heavy fruits etc. into this packaging bag, or even if the way to put it is inconvenient, There is no way that it will come off. This is because the end portions 6 of the string materials 5 are all integrally connected to the membrane 2, so even if a stretching force is applied to all of these cord materials, the membrane will not tear or break. , because it can withstand great force.

Therefore, glass vessels are heavier than fruits, etc.
In addition to ceramics, it is extremely convenient and inexpensive for packaging bags for lacquered utensils and large luxury fruits such as melons and watermelons. Needless to say, it is also used as a packaging material for other precision instruments, medical instruments, etc.

Next, an example of an apparatus used in the manufacturing method of the present invention will be described. In Figure 3, 4 is a circular heater, 7 is a spring, 8 is a small rod installed in the center of the heater, and 9 is a heater support cylinder. On the other hand, 10 is a net receiving type with a truncated conical tip, slightly longer than the length of the net, and a circular hole in the center 11
to do. As shown in FIG. 4, 12 and 12' are a pair of thin plates each having a semicircular bottom, with extensions of both ends of the semicircle opening outward.

In order to form the above-mentioned packaging bag using this device,
A net tube 1 of unit length is fitted into a receiving mold 10. In this case, adjust the regulating plate 13 so that the upper end of the net slightly protrudes above the receiving mold, and then use the squeezing tools 12, 12' (Fig. 4) to
When the upper part of the net tube is squeezed from the periphery, its upper end is focused and becomes a focusing part 3. Next, when the heater 4 is lowered to press this bundle, the bundle melts into a slimy state and then forms a film 2' or 2 depending on the amount of protrusion of the bundle.

If the heater device is adjusted so that the spring 7 of the heater device is compressed during film formation and the small rod 8 provided at the center of the heater advances, the spring 7 of the heater device will be compressed and the small rod 8 provided at the center of the heater will move forward. Small rods penetrate and form round holes in the film (not shown).

Next, add additional equipment to the above basic equipment,
A method for forming the bottom film more beautifully and accurately will be described. This uses the device shown in FIG.
A scraping device 18 is provided inside, and 19 is a piston with a scraping disk 20 attached to the top, and a drive mechanism (not shown) is used to move the piston up and down from the position shown in Figure 5 to the position shown in Figure 6. It is linked to.

Next, to describe the means for making a target object using this device, the upper end of the net tube 1 fitted in the receiving mold 10 is squeezed from the periphery to the center using squeeze tools 12, 12' in the same way as shown in FIG. When focused,
As shown in FIG. 5, the upper end of the net tube is focused around the upper part of the piston 19, and
When the piston 19 is lowered downward, the scraping disk 2 is formed as shown in FIG.
0, the focusing part 3 of the net tube is the receiving mold 10.
It is scraped into the hollow part of. In this state, the heater device 4 is lowered and the convergence part receiving mold 10 is
When it melts on the upper end surface, that part melts into a slimy state and then cools to form a film 2. In this case,
A hole 14' (not shown) may be drilled in the center of the membrane. The tube-shaped bag thus completed is removed from the receiving mold, and the bag manufacturing process is completed.
The film produced in this way is precise and beautiful, further increasing its commercial value.

Although the above is a case of a net tube, a similar type of membrane-covered tube-shaped packaging bag can be made using various other cylindrical materials.
For example, a foamed plastic cylinder with a short cut in the axial direction, or a tube with an axial cut in one end to form a tuft, etc. All you have to do is choose the material appropriately.

Now, as shown in FIG. 7, the membrane 2 or 2' is usually formed at a position that is raised from the lowermost end 15 of the bag formed by the string material 5 by the thickness of the string. Therefore, when fruits and the like are stacked inside the packaging bag, the upper and lower fruits are prevented from coming into contact with each other, making it even more effective. However, when stacking packages horizontally, there is no need to pay attention to film formation.
Any suitable position is fine.

〔Effect of the invention〕

The present invention has succeeded in producing an effective packaging bag using a small amount of material using the above-mentioned means, and the total number of man-hours involved is small, and even in the case of automatic production, the mechanical equipment is extremely simple, so it is ultimately inexpensive. This has a large effect in providing a packaging bag that is suitable for use in packaging, and it is also a great effect in saving materials.

[Brief explanation of drawings]

FIG. 1 is a net tube packaging bag obtained according to the present invention, FIG. 2 is a bottom view of the same, FIG. 3 is an example (partial cross section) of the device of the present invention, and FIG. 4 is a plan view of a squeezing tool.
Fig. 5 is an example (partially sectional) of the device of the present invention, Fig. 6 is a partially sectional explanatory view showing the action of the scraping device, and Fig. 7 is a sectional view of the packaging bag shown in Fig. 1B. . Explanation of symbols, 1... Net tube, 2... Ring-shaped film, 2'... Circular film, 3... Convergence part, 4... Heater device, 5... String material, 6... End of string material, 7... Spring, 8... Rod, 9 ... Cylinder, 10... Receiving mold, 11... Hollow part, 12, 12'... Squeezing tool, 13
...Regulation plate, 14...Round hole, 15...Bottom end of bag, 18
... scraping device, 19... piston, 20... disk.

[Claims]

1 comprises a back support layer 12, a foam polymer layer 18 adhered to the back support layer 12, and an adhesive layer 22 applied to the surface of the foam polymer layer 18 on the side opposite to the back support layer 12. The packaging sheet material is characterized in that the adhesive layer 22 has adhesive properties to itself and does not have adhesive properties to anything other than itself. 2. The packaging sheet material according to claim 1, wherein the adhesive layer 22 contains a volatile corrosion inhibitor and/or an antistatic agent. . 3. The packaging sheet material according to claim 1, wherein the back support layer 12 has a surface opposite to the foam polymer layer 18 covered with a hydrophobic polymer layer 20. A packaging sheet material characterized by: