JPS5950502B2 - Manufacturing method of plastic squeeze tube - Google Patents

Description

[Detailed description of the invention] This invention has a head and a body both made of plastic,
This invention relates to an improved method for manufacturing a plastic squeezable tube whose head is fitted and secured within the upper end of a body.

For example, such a squeezed tube is
It is publicly known in Publication No. 3.

This is made of plastic and has an umbrella-shaped part, a mouth part that protrudes upward from the top, and a head part that has an annular part that projects downward from the outer periphery of the umbrella part and whose wall thickness gradually becomes thinner toward the bottom. Separately, a cylindrical tube base made of heat-shrinkable plastic is cut to the required length, one end (upper end) is heat-shrinked by at least 10% of the diameter to create a constricted part, a body is prepared, and the inside of the body is The head is fitted into the body, the constricted part of the body is engaged with the umbrella-shaped part of the head, and the body is thermally bonded to the umbrella-shaped part at the constricted part.
The annular portion is manufactured without heat bonding. However, with this method, after filling the inside of the torso with paste-like contents from the lower end, sealing the lower end of the torso and compressing the torso to squeeze out the contents from the mouth of the head, the outer periphery of the circular part of the head and the inside of the torso. Since there is no adhesive between the areas that touched this,
During this time, the contents seep in and swell abnormally, possibly causing the constricted part of the body and the umbrella-shaped part of the head, which are heat-bonded, to separate. Of course, the internal pressure generated by compressing the torso causes the contents to expand the annular part of the head in the direction of the outer periphery and bring the outer periphery into close contact with the inner surface of the torso. It is unlikely that the contents will infiltrate, but if the amount of contents in the body decreases, it is difficult to avoid the infiltration of the contents before sufficient internal pressure is generated to expand the circular part in the outer circumferential direction. be. The axial length of the annular portion is said to be approximately 2 to 8 mm, depending on the diameter of the head body, so if the length is long, the contents that have entered the ring cannot be squeezed out until the end, resulting in waste. become. In addition, in the case of this conventional method, since the annular part gradually becomes thinner toward the bottom, if the body is fused to the outer periphery of the annular part by heating to improve the attachment strength between the head body and the body, the body In addition to the drawback that the annular part is deformed by heat shrinkage, the upper end of the body is heat-shrinked by at least 10% in diameter to form a constricted part before the head is fitted. It requires a process and is time-consuming. Therefore, the present invention
The purpose is to provide an improved manufacturing method that solves the above-mentioned manufacturing problems of conventional plastic squeeze tubes and problems in using the manufactured tubes, and will be explained below with reference to the attached drawings. do.

Reference numeral 1 denotes a heat-shrinkable body, which is cut into required lengths from a base body formed into a long cylindrical shape by an inflation method using a thermoplastic plastic with a high expansion ratio as a raw material.

The raw material plastic may be, for example, polyethylene, polypropylene, vinyl chloride, vinylidene chloride, nylon, ionomer, or other appropriate materials, and the wall thickness of the cylinder wall is approximately 0.2
0 to 0.50 mm, expansion ratio is 1:2 or more, preferably 1
:2.0 to 3.0. 2 shows a plastic head made by injection molding.

The head body 2 has an umbrella-shaped part 3, which protrudes upward from the top of the umbrella-shaped part 3, and a mouth part 4 having a male screw on the outer periphery for attaching a lid, and which protrudes downward from the outer periphery of the umbrella-shaped part 3, as in the conventional one. However, the wall thickness of the annular portion 5 is the same as that of the umbrella-shaped portion 3 over the entire circumference and entire length. The head body 2 is molded from thermoplastic plastic that can be fused to the body 1 by heating, and the thickness of the umbrella-shaped part and the annular part depends on the type of raw material plastic used and the diameter of the outer periphery of the umbrella-shaped part or the annular part. However, the thickness is set at about 1.0 to 2.0 mm, with the aim of supporting the upper end of the fuselage from the inside without being deformed when the fuselage is heat-shrinked by heating, which will be described later.

The axial length of the annular portion 5 is approximately 6.0 to 10.0 mm, although it varies depending on its outer diameter. Of course, the outer diameter of the umbrella or annular portion is slightly smaller than the inner diameter of the body. To manufacture it, first, the head body 2 is fitted into the cylindrical body 1, and the upper end of the body is made to protrude a small amount forward from the outer periphery of the umbrella-shaped part 3. The amount of protrusion depends on the outer diameter of the umbrella or annular portion, but is approximately 5.
．． It is sufficient if it is about 0 to 10.0 mm. In the present invention, there is no need to heat-shrink one end of the torso to form a constricted part with a diameter reduced by 10% or more. Since it can be inserted into the body, it is not necessary to insert the figure from the lower end, which does not have the constricted part, with the mouth facing upward, and move it inside the body to the upper end, which saves time and effort. It doesn't take much time.
After fitting in this way, the outer periphery of the umbrella-shaped part 3 and the outer periphery of the annular part 5 of the head body are roasted with a gas flame.

As a result, the upper end protruding part 1a of the body that protrudes forward from the outer periphery of the umbrella-shaped part is thermally contracted and falls onto the outer periphery of the umbrella-shaped part while being fused to the outer periphery of the umbrella-shaped part. The annular region 1b of the body, which is in contact with the outer periphery of the annular portion 5 below 1a, is similarly heat-shrinked and fused to the outer periphery of the annular portion 5 of the head body. In this case, in order to prevent the part of the body below the annular region 1b from being deformed due to heat shrinkage, it should be wrapped in, for example, water-soaked cloth to prevent it from being heated until it shrinks. . Next, the region of the upper end protruding portion 1a of the body that has fallen down and fused onto the outer periphery of the umbrella-shaped portion 3 is notched by embossing by means such as high-frequency sealing, high-frequency induction heating sealing, ultrasonic sealing, impulse heat sealing, etc. 6 and bite into the outer periphery of the umbrella-shaped part 3.

This prevents the contents of the tube of the present invention from penetrating between the outer periphery of the annular portion of the head body and the annular region of the body under any circumstances.

Since the annular part 5 of the head body has a wall thickness equal to that of the umbrella part 3 over the entire length and circumference, it is not deformed by thermal contraction of the annular region 1b of the body.

Furthermore, as described above, the annular region 1b of the body and the outer periphery of the annular portion of the head body are fused together, leaving no room for the contents to infiltrate between them. Because it is fused to the outer periphery and is notched into the outer periphery of the umbrella-shaped part at the same time as it is sealed by embossing, the attachment strength between the head and body is extremely high, and the internal pressure is much lower than that of conventional ones. ,
Withstand external forces. In particular, in the process of notching by embossing with the sealing means, the upper end protruding part 1a of the body is heat-shrinked with a gas flame and collapsed onto the outer periphery of the umbrella-shaped part, and is fused. Completely eliminate the small percentage of products that are insufficient.

Also, when heating and fusing, a sealing piece 7 such as a sheet made of a material that can be welded to the head body 2 or aluminum foil laminated with the material is fitted inside the head body 2 and the sealing piece 7 is simultaneously fused. If you put it on the body, it will be filled from the bottom end of the body,
The contents sealed inside the body by sealing the lower end of the body are cut off from contact with the outside air until the mouth lid is removed and the sealing piece 7 is broken.

Therefore, the contents will not deteriorate over a long period of time, and the purchaser can confirm that the tube has never been used before and can use it with confidence.

[Brief Description of the Drawings] Figure 1 is a front view of the tube manufactured according to the present invention, Figure 2 is a front view of the tube manufactured according to the present invention;
The figure is an enlarged front view of a half of the main part of the same as above, Figure 3 is an enlarged cross-sectional view of the main part with the head body fitted into one end of the body, and Figure 4 is a heated and fused one. FIG. 5 is an enlarged sectional view of the main part in a state stamped with a sealing means. In the figure, 1 is the body, 2 is the head body, 3 is the umbrella-shaped part,
4 also shows the mouth part, 5 the same annular part, 1a the upper end region of the body, and 1b the same annular region.

Claims (1)

[Claims] 1. A mouth part and an umbrella-shaped part are placed in any end of the body obtained by cutting a heat-shrinkable base body formed into a tube shape by the inflation method from thermoplastic plastic with a high expansion ratio to the required length. and an annular part that protrudes downward from the outer periphery of the umbrella part with the same thickness as the umbrella part, and the outer diameters of the umbrella part and the annular part match the inner diameter of the body, and the thermoplastic material can be fused to the body. The head body molded from plastic is fitted, and the upper end of the body protrudes above the umbrella-shaped part of the head body to prevent the part of the body located below the annular part of the head body from being heated. A gas fire is directed at the outer periphery of the umbrella-shaped part and the outer periphery of the annular part, and the annular area in contact with the upper end protrusion of the body and the outer periphery of the annular part is thereby heat-shrinked, so that the upper end protrusion of the body becomes umbrella-shaped. At the same time, the outer periphery of the umbrella-shaped part and the outer periphery of the annular part are fused, and then the upper end protrusion of the body, which is collapsed and fused onto the outer periphery of the umbrella-shaped part, is subjected to high-frequency sealing. , high frequency induction seal,
A method for manufacturing a squeezed plastic tube, which is characterized in that it is bitten into the outer periphery of an umbrella-shaped portion while making indentations by embossing by means of ultrasonic sealing, impulse heat sealing, etc.