JPH0352678Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention is a sealing structure at the mouth and neck of a sealed container for packaging containing heat-sterilized high-temperature liquid or semi-liquid contents. Regarding improvements.

<Prior Art> Conventionally, as shown in Figure 3, in this type of container, the neck part b of a bottle-shaped glass container body a is often sealed with a cap c made of thermoplastic synthetic resin. It is being said. The cap c has a threaded part e screwed onto a threaded part d on the outer periphery of the mouth and neck part b, and its top part f.
The inner plug part g protrudes from the inner surface of the mouth and neck part b and fits into the inner surface of the mouth and neck part b. An example of such a structure is shown in Japanese Utility Model Application No. 101749/1983.

However, when this structure is applied to the container body a made of thermoplastic synthetic resin, which has recently become commonly used, when filling and sealing the contents such as liquids that have become hot for heat sterilization, There is a problem in the sealing between neck b and cap c.

That is, even if the mouth and neck part b and the cap c are made of the same synthetic resin material, the degree of heat shrinkage between the mouth and neck part b and the cap c is different, and the mouth and neck part b
There is an inconvenience that a gap is created between the screwing points d and e between the cap c and the inner peripheral surface of the mouth and neck part b and the inner plug part g, which deteriorates the sealing performance.

<Problems to be solved by the invention> The present invention solves these inconveniences by forming the mouth and neck part and the cap with thermoplastic synthetic resin, which ensures a secure seal between the two, and on the other hand, To provide a hot pack container that is easy to open.

<Means for Solving the Problems> As a means for solving the problems, the present invention is based on a thermoplastic synthetic resin that covers the mouth and neck of the container body and the cap that covers and seals the mouth and neck. The cap has a spiral part on the outer periphery of the mouth and neck, and an inner plug part that protrudes from the inner surface of the top surface and fits into the inner surface of the mouth and neck. It is characterized in that it is made of a synthetic resin with a lower thermal shrinkage rate, and a linear protrusion is formed on the inner plug part surrounding the outer peripheral surface of the inner plug part.

<Function> Since the above means are provided, the container body can be filled with a high temperature liquid and the cap screwed onto the mouth and neck to seal it, or after the container body is filled with room temperature liquid and the cap screwed on to seal it. When heated, the mouth and neck part has a higher heat shrinkage rate than the cap, so the mouth and neck part shrinks to reduce the inner diameter, while the inner plug part of the cap, which has a smaller heat shrinkage rate than the mouth and neck part, contracts. It comes into pressure contact with the inner surface of the mouth and neck, and the linear protrusion digs its tip into the inner surface of the mouth and neck, improving sealing performance.

<Example> A further detailed explanation will be given with reference to FIGS. 1 and 2 showing an example of implementation of the present invention.

In the illustrated container, reference numeral 1 denotes a bottle-shaped container body, and the entire body including the mouth and neck 2 is made of high-density polyethylene, which is commonly used these days. In the present invention, it is sufficient that the mouth and neck portion 2 is made of thermoplastic synthetic resin, and the other parts may be made of other materials. The mouth and neck 2
A threaded portion 5 is formed on the outer periphery of the cap 3 to be screwed into the threaded cylindrical portion 4 of the cap 3.

The cap 3 is made of polypropylene, which has a lower heat shrinkage rate than the mouth and neck part 2, and has a ring-shaped inner plug part 6 that fits into the inner surface of the mouth and neck part 2 and projects from the inner surface of the top part 7, as in the conventional product. Be prepared. The heat shrinkage rate of the cap 3 and the neck part 2 is arbitrarily selected depending on the material, pressure, temperature, time, and other conditions during the injection molding process.

In the present invention, a linear protrusion 8 is integrally formed surrounding the outer peripheral surface of the inner plug portion 6. The linear protrusion 7 preferably has an acute-angled tip and a triangular cross section. Furthermore, a similar linear protrusion 9 was formed on the inner surface of the top surface 5 of the cap 3 facing the top surface of the mouth and neck 2.

With the above structure, the container body 1 can be filled with high-temperature liquid and the cap 3 screwed onto the mouth and neck part 2 to seal it, or the container 1 can be filled with room-temperature liquid and the cap 3 can be sealed in the same way. After screwing and sealing the mouth and neck part 2, the mouth and neck part 2 is heated to about 95° in boiling water for sterilization.
Since the heat shrinkage rate is higher than that of the cap 3, the mouth and neck part 2 contracts to reduce the inner diameter, and on the other hand,
The inner plug part 6 of the cap 3, which has a smaller heat shrinkage rate than the mouth and neck part 2, is pressed against the inner surface of the mouth and neck part 2, and the linear protrusion 8 digs its tip into the inner face of the mouth and neck part 2. On the other hand, cap 3
When the cap 3 is firmly screwed onto the mouth and neck part 2, the linear protrusion 9 on the top surface 5 of the cap 3 is screwed onto the mouth and neck part 2 by the force.
It digs into the top surface, and therefore maintains the pressed state even if the mouth and neck portion 2 shrinks somewhat due to heat.

In this way, the linear protrusion 8 bites into the inner surface of the mouth and neck part 2, and the linear protrusion 9 comes into pressure contact with the top surface of the mouth and neck part 2, thereby improving sealing performance. On the other hand, since only the sharp tips of the linear protrusions 8 cut into the inner surface of the mouth and neck part 2 in order to improve their sealing performance, there is great resistance when the cap 3 is unscrewed and opened. Don't give power.

In the above embodiment, the inner plug part 6 of the cap 3
Although a ring-shaped one is shown, it is not limited to the ring shape and may be solid. In addition, when making a ring shape, it should be 1 mm to resist heat shrinkage of the mouth and neck part 2.
It is preferable to have a wall thickness greater than or equal to the above.

<Effects> As is clear from the above explanation, when the present invention is used, the cap is made of a synthetic resin with a lower heat shrinkage rate than the mouth and neck, and the cap is made of a synthetic resin that protrudes from the inner surface of the neck part of the cap and fits into the inner surface of the mouth and neck. Since linear protrusions are formed on the outer circumferential surface of the stopper to surround it, when used for hot packs, the linear protrusions dig into the inner surface of the mouth and neck as the mouth and neck shrink due to heat, improving sealing performance. In addition, since the area of this biting linear protrusion is small, it is effective to provide a sealed container for hot packs that does not require a large force to open the cap by unscrewing it.

[Brief explanation of the drawing]

1 and 2 show an example of the implementation of the present invention. FIG. 1 is a partially cutaway exploded view, and FIG.
The figure is a cutaway sectional view when sealed, and FIG. 3 is a cutaway sectional view similar to FIG. 2 of the conventional product. DESCRIPTION OF SYMBOLS 1... Container body, 2... Mouth and neck, 3... Cap, 4... Threaded part, 5... Threaded part, 6... Middle plug part, 7... Top surface part, 8... Linear part protrusion.

Claims (1)

[Scope of utility model registration request] The mouth and neck of the container body and the cap that covers and seals the mouth and neck are made of thermoplastic synthetic resin. In the cap, the cap is made of a synthetic resin having a lower heat shrinkage rate than the mouth and neck, and the cap is made of a synthetic resin that surrounds the outer peripheral surface of the middle plug. A sealed container for hot packs, characterized in that a linear protrusion is formed on the stopper.