JPH0376819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing a shoulder of a laminate tube.

(Prior art) The shoulder of the conventional laminate tube is
As shown in the figure, a shoulder body 1 consisting of a cylindrical part 2 having an opening 4 and a shoulder part 3 extending in a cone shape from the cylindrical part 2 is molded from synthetic resin. As shown in the figure, a cone-shaped barrier disk 5 is molded from a synthetic resin with barrier properties, and this barrier disk 5 is fitted onto the shoulder portion 3 of the shoulder body 1 and bonded. The main body 1 is high-frequency welded to the tube main body B, and the cylindrical part 2 is
A synthetic resin cap (not shown) is fitted onto the cylindrical portion 2 with the opening 4 sealed with aluminum foil (not shown).

(Problems to be Solved by the Invention) In the shoulder as described above, the shoulder portion 3 of the shoulder body 1 is connected to the barrier disk 5.
Due to the two-layer structure of the cylinder part 2 and the cap,
The barrier properties of the openings 4 of the cylindrical portion 2 are ensured by aluminum foil, but the work of pasting aluminum foil to seal the openings 4 in this way is done after the molding work of each part is completed. Therefore, not only is there an increase in extra work, but it is also extremely complicated and time-consuming.

Moreover, since the shoulder main body 1, barrier disk 5, and cap are all made of synthetic resin, there is a risk that they will deteriorate over time, lose their barrier properties in a very short period of time, and cause the contents to deteriorate. It was hot.

Therefore, the inventor of the present invention designed the shoulder to have a three-layer structure consisting of an inner layer resin disk, an aluminum foil barrier disk, and an outer layer resin disk. A method for manufacturing a shoulder that does not impair its barrier properties even if the synthetic resin cap used for the product deteriorates, and that does not require extra and complicated work such as pasting aluminum foil on the opening end of the mouth after molding. However, in the shoulder manufactured by such a method, the contents enter between the inner layer resin disk and the barrier disk, and some of the contents also go around between the barrier disk and the outer layer resin disk. Some things were discovered. This seems to be due to the fact that the adhesion between the inner and outer resin disks and the barrier disk is not completed completely and some parts of the disk have peeled off. In comparison, the barrier properties are inferior, and the contents may deteriorate over a long period of time.

(Means for Solving the Problems) The present invention was invented in order to solve the above-mentioned problems as well as the problems of the conventional art. An aluminum foil barrier disk is formed by molding an inner resin disk having a shoulder extending in a cone shape, and is provided with a lid portion having substantially the same shape as the disk and closing the open end of its cylindrical portion. A method for manufacturing a shoulder, in which the outer resin disk is fitted and bonded together, and then an outer resin disk is integrally molded on the outside of the barrier disk, the cylindrical portion of the inner resin disk, and the shoulder portion of the outer resin disk. This method is characterized in that a thin film is simultaneously formed on the opening end to close the opening on the opposite side.

(Function) The shoulder manufactured by the above method has a barrier disk interposed between the inner layer resin disk and the outer layer resin disk, and this barrier disk is made of aluminum foil and does not change over time and can be used for a long period of time. It has a high barrier property, especially in the shoulder part as well as in the cylinder part, and exhibits high barrier property for a long period of time.Also, aluminum foil is provided at the opening end of the shoulder part, and it fits into this mouth part. Even if the synthetic resin cap deteriorates, its barrier properties will not be impaired, and there is no need for extra and complicated work such as pasting aluminum foil on the opening end of the mouth after the molding process.

Furthermore, a thin film can be used to prevent the contents from entering between the inner resin disk and the barrier disk, and this thin film can be easily opened at the same time as opening the aluminum foil lid. can.

(Example) The method of the present invention will be explained in detail below based on illustrative drawings.

First, use a piece of aluminum foil to make a cylindrical part 1.
1, a shoulder portion 12 extending in a cone shape from one open end of the cylindrical portion 11, and a lid portion 13 that closes the other open end of the cylindrical portion 11. A barrier disk 10 is formed by drawing.

Separately, a cylindrical tube portion 21 and a tube portion 2 are made of synthetic resin such as polyethylene resin.
An inner layer resin disk 20 having a shoulder portion 22 extending in a cone shape from one open end of the cylindrical portion 21 is molded, and when the disk 20 is molded, a thin film 23 is applied to the open end to close the other open end of the cylindrical portion 21. mold at the same time.

Next, the barrier disk 10 is fitted onto the inner layer resin disk 20 and bonded.

Thereafter, using synthetic resin such as polyethylene resin, an outer layer resin disk 30 having a cylindrical tube portion 31 and a cone-shaped shoulder portion 32 extending from one open end of the tube portion 31 is attached to the barrier disk 10. Molded integrally on the outside. In this outer layer resin disk 30, the other open end of the cylindrical portion 31 is left as an opening 33 through which the contents flow out, and a stepped recess 34 is simultaneously formed on the outer surface of the shoulder portion 32.

The shoulder A thus manufactured by the method described above is high-frequency welded to the tube body B.
That is, the outer resin disk 30 in shoulder A
The opening edge of the tube body B is fitted into the recess 34 on the outer surface and welded and joined by high frequency heating, and a synthetic resin cap is attached to the mouth of the shoulder A, which is essentially the cylindrical portion 31 of the outer resin disk 30. (not shown), and fill the tube body B with appropriate products from the rear end and seal it.

As shown in FIG. 7, the tube body B in the above-mentioned embodiments includes an inner tube 40 made of a soft synthetic resin such as polyethylene resin, which has high chemical resistance, an intermediate tube 41 made of aluminum foil, and a strong tube body B made of polypropylene resin or the like. It is formed in a three-layer structure with an outer cylinder 42 made of synthetic resin having high chemical resistance, and an adhesive layer 41a with high adhesiveness to the inner and outer cylinders 2 and 3 on both sides of the intermediate cylinder 3.
41b is provided.

Therefore, the tube body B first has an inner tube 40
is extruded, and then adhesive layers 41a,
41b is wrapped around the outer periphery of the inner tube 40, the edges on both sides are overlapped, and this overlapped portion is heated with high frequency while applying pressure from the outer surface, thereby forming an aluminum foil that fits around the inner tube 40. Intermediate cylinder 41
The inner cylinder 4
0 and the intermediate cylinder 41 are pressed and heated to fix them together, and then a synthetic resin is extruded between the inner periphery of the outer mold 50 placed outside the intermediate cylinder 41 and the outer surface of the intermediate cylinder 41. The outer cylinder 42 is formed by extrusion lamination.

In this manufacturing process, the synthetic resin inner cylinder 40
The order of forming the aluminum foil intermediate cylinder 41 may be reversed; that is, after forming the aluminum foil intermediate cylinder 41, an inner mold (not shown) is placed inside the intermediate cylinder 41.
The inner cylinder 40 may be formed by extrusion lamination by disposing a synthetic resin between the inner periphery and the inner surface of the intermediate cylinder 41.

By doing this, a gap is created by the synthetic resin layer between the side edges of the aluminum foil at the joint part of the tube body B, and the chemicals inside the tube will not ooze out from the synthetic resin layer in the gap or This eliminates the risk of deterioration in barrier properties due to heat transfer, and also allows printing on the outer surface without creating large irregularities at the bonded portion.

(Effects of the Invention) As explained above, when using the method of the present invention, a barrier disk is interposed between the resin disks of the inner and outer layers, and this barrier disk is made of aluminum foil, and does not change over time and can be used for a long period of time. It has high barrier properties, especially in the shoulder part as well as in the cylindrical part, for a long period of time, and can prevent the contents from deteriorating in quality.

In addition, the mouth of the shoulder, essentially the opening of the cylindrical part in the outer resin disk, is closed with the lid of the barrier disk made of aluminum foil. This eliminates the need for complicated work, simplifies the manufacturing process as a whole, and reduces costs.

Furthermore, the thin film at the open end of the cylindrical portion of the inner resin disk can reliably prevent the contents from entering between the disk and the barrier disk, and when in use, the thin film is attached to the aluminum foil lid. At the same time, it can be opened easily and easily.

[Brief explanation of drawings]

In the figures, FIGS. 1 to 3 are longitudinal sectional views showing the manufacturing process according to the method of the present invention, FIG. 4 is a partially enlarged sectional view of the tube body, and FIG. 5 is a longitudinal sectional view showing the manufacturing process of the tube body. 6 to 8 are longitudinal cross-sectional views showing the manufacturing process according to the conventional method. 10
... Barrier disk, 11 ... Cylinder part, 12 ...
Shoulder part, 13...Lid part, 20...Inner layer resin disk, 21...Cylinder part, 22...Shoulder part, 23...Thin film, 30...Outer layer resin disk.

Claims (1)

[Claims] 1. An inner resin disk having a cylindrical portion and a cone-shaped shoulder extending from one open end of the cylindrical portion is molded from synthetic resin, and a cylindrical portion having approximately the same shape as the disk is molded onto the inner resin disk. A method for manufacturing a shoulder, in which an aluminum foil barrier disk having a lid for closing an open end of the shoulder is fitted and bonded, and then an outer resin disk is integrally molded on the outside of the barrier disk. A method for producing a shoulder for a laminated tube, characterized in that a thin film is simultaneously molded on the open end of the inner resin disk in order to close the opening on the side opposite to the shoulder.