JPH0199990A - Capping method - Google Patents

Abstract

PURPOSE: To obtain a high air-tightness by forming a depressed part on a cap, and strongly and tightly bringing a liner into contact with an upper edge of a cylindrical mouth inner peripheral face. CONSTITUTION: A cap 2 comprising a liner 3 made of a hard synthetic resin of ultrahigh molecular wt. on an inner peripheral edge part of an aluminium cap body 4, is fitted on a cylindrical mouth 1 of a bottle body made of a whitened crystallized PET resin, and a pressure body 6 is lowered. The liner 3 is kept into contact with an upper edge face and an outer peripheral face upper edge part of the cylindrical mouth 1. When the pressure body 6 is further lowered in this condition, a projecting part 7 presses a top wall 5 upper face downward, whereby the top wall 5 is depressed and deformed. When this depression and deformation are further advanced, the liner 3 mounted on the depressed part 8 of the top wall 5 inner face is elastically kept into contact with an upper edge part of the cylindrical mouth 1 inner peripheral face to be closely and strongly kept into contact therewith. Further the pressure body main part 9 presses the top wall 5 upper face peripheral part simultaneously, whereby the liner 3 positioned on the top wall 5 inner peripheral edge part is closely kept into contact with the upper edge face and the outer peripheral face upper edge part of the cylindrical mouth 1, whereby the high air-tightness can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to PET (polyethylene terephthalate) containing contents to be subjected to high-temperature filling or post-filling heat treatment.
In a method of assembling a cap to a weir body made of resin whose mouthpiece is whitened and crystallized.

The present invention relates to a capping method that increases airtightness between the two.

[Conventional technology]

Conventionally, PET resin bottle stands are biaxially stretched to enhance their mechanical strength and heat resistance, but most of them are not biaxially stretched, so the mechanical strength and heat resistance of other parts are Whitening and crystallization are often used to improve the strength of the mouth tube, which is inferior to the original.

Usually, a cap provided with a liner is attached to the inner surface of the top wall of such a PET resin bottle stand, and the liner is brought into close contact with the upper end surface of the mouth tube to provide airtightness. This liner is molded from a soft synthetic resin material so that it can be easily deformed into a shape that conforms to the upper end surface of the single-port cylinder and can come into close contact with the upper end surface of the single-port cylinder.

[Problem that the invention seeks to solve]

However, in the weir mouth tube and camp mentioned above.

The airtightness is not necessarily satisfactory.

This is because the mouthpiece of the weir body, the cap, and the liner on the inner surface of the cap each undergo different deformations due to heat (of course, the mouthpiece and cap deform in different ways).

Due to its material, it is smaller than that of the liner).

For example, since conventional liners are molded from soft materials, they are particularly susceptible to plastic deformation due to the heat generated when filling the contents at high temperatures, the heat from heat treatment performed after filling the contents, and the like. As a result, the liner, which has been elastically deformed and in elastic contact with the upper end surface of the mouth cylinder, is plastically deformed by the heat described above and loses its elasticity and loses its elastic contact with the upper end surface of the second mouth cylinder.

As a result, airtightness was reduced.

In order to solve the problem with this liner, the applicant has
First, I tried molding the liner from a hard material called ultra-high molecular weight polyethylene. the result.

Plastic deformation due to heat has been reduced, and the previous problem of the liner being plastically deformed and losing its elasticity, resulting in loss of airtightness, has been alleviated. However, when the liner is molded from a hard resin such as ultra-high molecular weight polyethylene, it tends to undergo large shrinkage deformation when heated and cooled. Therefore, after it is assembled into a two-neck cylinder, it will fit into the upper end surface of the two-neck cylinder,
A new problem arose in that the liner, which had previously exhibited high airtightness, contracted and deformed, causing a misalignment with the upper end surface of the mouthpiece, thereby reducing airtightness.

The present invention was conceived in view of the problem of airtightness between the cap and the two-shot cylinder including the liner.

Made of PET (polyethylene terephthalate) resin, it accommodates the contents to be filled at high temperature or subjected to heat treatment after filling.
An object of the present invention is to provide a capping method in which high airtightness is achieved between the weir body and the cap, the mouth of which is whitened and crystallized.

[Means for solving problems]

Therefore, first, the one-mouth cylinder 1 that houses the contents to be filled at high temperature or subjected to post-filling heat treatment is made of whitened and crystallized PET.
An aluminum cap body 4 is attached to a resin bottle weir body tube 1.
A cap 2 provided with a liner 3 made of an ultra-high molecular weight hard synthetic resin material is fitted to the inner circumferential edge of the top wall 5.

Then, the cap top wall 5 is pressed by the pressing body 6 having the protrusion 7 projecting from the lower surface, and the liner 3 and the upper end of the inner circumferential surface of the spout 1 are pressed by the recessed portion 8 which is the center portion of the cap top wall 5. Contact tightly and firmly. At the same time, at the peripheral end portion of the cap top wall 5, the liner 3 and the upper end surface and outer peripheral surface of the spout 1 are brought into close contact.

[Effect]

An embodiment will be explained with reference to FIGS. 1 to 3 showing one embodiment. Figure 1 shows a cap 2 in which a hard liner 3 made of ultra-high molecular weight polyethylene or the like is provided on the inner peripheral edge of the cap body 4.
This figure shows a state in which the press body 6 is fitted into the whitened crystallized PET resin bottle weir cylinder 1 and begins to be lowered. In this state.

The liner 3 is in contact with the upper end surface of the spout 1 and the upper end of the outer peripheral surface. From this state, if the pressing body 6 continues to descend, the second
As shown in the figure, the protruding portion 7 presses the top surface of the ceiling wall 5 downward, causing the ceiling wall 5 to be deformed.

(If the top wall 5 has been depressed in advance, it will naturally not be depressed due to the downward movement of the pressing body 6, and the protrusion 7 will press the depression 8 and press the liner 3 and the upper end of the inner peripheral surface of the spout 1. ), and as this depression deformation progresses further, as shown in Figure 3,
The liner 3 provided in the recessed part 8 on the inner surface of the ceiling wall 5 is 2
It comes into tight and firm contact with the upper end of the inner peripheral surface of the mouth tube 1.

At the same time, the pressing body part 9 presses the upper circumferential edge of the top wall 5, and as a result, the liner 3 located on the inner circumferential edge of the ceiling wall 5 is also tightly sealed against the upper edge of the single-port cylinder 1 and the upper edge of the outer circumferential surface. comes into contact with. As a result, the liner 3 comes into elastic contact with three surfaces of the nine-mouth cylinder 1, from the upper end of the inner peripheral surface to the upper end surface and the upper end of the outer peripheral surface, thereby achieving high airtightness.

After the cap 2 is assembled by the method described above, the weir mouth tube 1 is heated by the heat of the contents filled at high temperature or by the heat of heat treatment. Cap body 4. Since the liners 3 undergo different deformations, they are displaced from their original assembled positions.

For example, when the liner 3 is heated and then cooled, it shrinks and deforms and shifts inward. In the conventional case, the airtightness would be lost due to the displacement, but in the present invention, the cap 2 is provided with a recessed part 8, and the liner 3 is
By firmly and tightly contacting the upper end of the inner circumferential surface of the mouth tube 1, displacement of the liner 3 is prevented at that portion, and displacement of the liner 3 is suppressed. Therefore.

■ Due to the slight inward shift of the peripheral edge of the liner 3, the contact with the upper end of the outer peripheral surface of the single-port cylinder 1 becomes stronger, and at the same time, there is no large deviation from the initial close contact, so the height is high in that area. Airtightness can be maintained.

(2) As the outer circumferential end portion of the liner 3 contracts inward, the liner 3 located on the upper end surface of the one-mouth tube 1 becomes slightly thicker, thereby pressing the mouth tube 1 downward. This maintains high airtightness in that area.

Due to this action, the liner and the three surfaces of the inner circumferential upper end, upper end surface, and outer circumferential upper end of the 50 cylinders come into close contact with each other, thereby achieving high airtightness.

Also, due to the above three effects (especially the effect of ■).

When the spout 1 and the cap 2 are assembled by screwing.

An appropriate screwing force (opening torque of about 5 to 10 kg-cm) is maintained between the two. Incidentally, if the recessed portion 8 is not formed, looseness will occur in the assembly between the cap and the spout, and the opening torque will be close to zero, so that the container will not function as a container.

In this way, liner 3. Or even if the cap body 4 and mouthpiece 1 undergo different deformations.

Since the upper end of the inner circumferential surface, the upper end surface, or the upper end of the outer circumferential surface of the spout 1 closely contacts the liner 3, high airtightness is achieved.

[Example] An example is shown in FIGS. 1 to 3. This is equipped with a so-called pull-top type cap 2 that can be opened by pulling up. The PET resin bottle weir tube 1 is whitened and crystallized, the cap 2 attached to the mouth tube 1 is made of aluminum, and the liner 3 is molded from ultra-high molecular weight polyethylene resin. In this embodiment, the depressed portion 8 is formed by the pressing member protrusion 7, and after the cap 2 is assembled to the spout 1, the curling member 10 is formed.

A curled portion 12 that engages the mouth tube step portion 11 from below is formed at the lower end of the peripheral wall of the can 12.

FIG. 4 shows another embodiment. In this embodiment, a small protrusion 13 is provided on the circumferential edge of the lower surface of the pressing body body 9, and the small protrusion 13 presses the circumferential edge of the cap top wall 5 to move the liner 3 onto the outer circumferential surface of the mouthpiece 1. It makes strong contact with the upper end, making that part highly airtight.

FIG. 5 shows yet another embodiment.

This shows the assembly of the one-port cylinder 1 and the pilfer-proof cap 2, which is molded by a so-called roll-on method in which threads are formed on the two peripheral walls after the cap is assembled to the single-port cylinder 1. The pressing body 6 is composed of a central member 14 and a peripheral end member 15, and the central member 14 deforms the cap 2 so as to bring the liner 3 into close contact with the upper end and upper end surface of the inner peripheral surface of the spout l. The circumferential end member 15 achieves strong and tight contact between the liner 3 and the upper end of the outer circumferential surface of the spout 1. The central member 14 and the peripheral end member 15 are molded separately, and they can be moved down at the same time in an assembled state, or they can be moved down separately.

FIGS. 6 and 7 show an embodiment in which a liner 3 is previously formed into a shape that fits into the upper end of the mouthpiece 1 and is assembled to the two-portion cylinder 1. FIG. In this case, even if the amount of depression deformation of the depression part 8 is small, there is an advantage that the upper end of the inner circumferential surface of the single-port cylinder 1 and the liner 3 are in close and firm contact.

Incidentally, the depressed portion 8 may be formed by pressing with the protruding portion 7, as shown in the above-mentioned four embodiments, or may be formed in advance.

〔Effect of the invention〕

As described above, the present invention is a method for assembling a weir body and a cap 2, which are made of PET (polyethylene terephthalate) resin and which accommodates contents to be filled at high temperature or subjected to post-filling heat treatment, and whose spout 1 is whitened and crystallized. In this case, the recessed portion 8 makes the contact between the liner 3 and the upper end of the inner peripheral surface of the two-port cylinder 1 tight and strong, and also makes the contact with the upper end surface and the upper end of the outer peripheral surface of the single-port cylinder 1 tight and strong. Since I decided to use it, I included 2 caps, 3 liners. Alternatively, even if the spout 1 deforms differently, the liner 3 and the three surfaces mentioned above achieve close contact, resulting in high airtightness and appropriate assembly force (opening torque).
can be maintained.

As a result, in the weir body having the above-described structural requirements and the cap having a liner on the inner surface to be assembled thereto,
Even if they are deformed due to heat, they do not lose their airtightness, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a state in which a cap is assembled to a spout according to an embodiment of the present invention and before a recessed portion 8 is formed on the cap, and FIG. 2 is a partial sectional view showing a state in which the cap has been slightly recessed. FIG. 3 is also a partial sectional view showing a state in which the recessed portion 8 is formed. FIG. 4 is a partial sectional view showing another embodiment, and FIG. 5 is a partial sectional view showing still another embodiment. FIG. 6 is a partial sectional view showing the state before the depression 8 is formed in still another embodiment, and FIG. 7 is a partial sectional view showing the state after the depression 8 is formed. Explanation of symbols 1: Mouthpiece, 2: Cap, 3 Ni liner. 4: Cap body, 5: Top wall, 6: Pressing body. 7: Protruding portion, 8: Recessed portion, 9: Main body portion. 10: Curling body, 11: Stepped portion, 12: Curled portion. 13: small protrusion, 14 two central members, 15: peripheral end member. Chi A 1--Bite 2--Key/Sole 7° 3--Rye? −4−−−Key/Sole 7° each 5%−11,
6-7 No. 44 7--- t t 9 Procedure Amendment Form) 1. Display of the case 1986 Patent Application No. 254894 2, Name of the invention Camping method 3゜ Person making the amendment Relationship to the case Patent applicant name (690) Yoshino Kogyosho Co., Ltd. 4, Agent December 24, 1988 Date of delivery: January 26, 1988 6, Detailed description of the invention in the specification to be amended. 7. Between lines 17 and 18 of page 1 of the statement of contents of the amendment. F3, add Detailed Description of the Invention J. , /7− or more

Claims (1)

[Claims] An aluminum cap body (4
) Top wall (5) Cap (2) with a liner (3) molded from an ultra-high molecular weight hard synthetic resin material on the inner peripheral edge
and pressing the cap top wall (5) with a pressing body (6) having a protrusion (7) protruding from the lower surface,
The recessed portion (8), which is the central portion of the cap top wall (5), allows the liner (3) and the upper end of the inner circumferential surface of the spout (1) to tightly and firmly abut, and the cap top wall (5) 5), the liner (3) and the mouthpiece (1)
) A capping method in which the upper end surface and the upper end of the outer peripheral surface are brought into close contact.