JPS6213940Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention mainly relates to containers for contents that require high-temperature filling, and in particular to a heat-resistant container that is a composite of a container body made of saturated polyester and an exterior made of cardboard.

Packaging containers such as bottles made of saturated polyester are
Compared to conventional materials such as glass and metal, processing costs are lower, they are lighter and can be incinerated as they are after use, and they do not pose any social problems when it comes to recycling. It is becoming widely used instead of.

However, even though mechanical properties are increased by biaxial stretching, there is a drawback of poor thermal dimensional stability.Even if biaxial stretching is performed under the best conditions, the heat resistance is only around 75℃. It is said that if the filling temperature is higher than that, thermal shrinkage will occur. For this reason, for contents that require high-temperature filling, the filling temperature is lowered to an allowable range.

This idea attempts to eliminate the above-mentioned drawbacks of saturated polyester by combining it with cardboard. Even if the container body made of polyethylene terephthalate shrinks due to the filling temperature, the shrinkage is absorbed by the container body. The object of the present invention is to provide a composite packaging container with a new structure that can compensate for the high temperature and perform high-heat filling, which has been difficult in the past, without lowering the filling temperature.

This invention will be explained in detail below using illustrated examples.

In the figure, reference numeral 1 denotes a container body formed into a bottle shape, which is made of biaxially stretched polyethylene terephthalate. The bottom part 1a of this container body 1 is formed into a round bottom, and the body part 1b is formed by a large number of longitudinal protrusions 2, 2 formed by protruding outward from a thin side wall, so that the body part 1b extends in the circumferential direction. It is formed into a stretchable uneven wall A.

Reference numeral 3 denotes a bottomed exterior body made of cardboard formed into a cylindrical shape to match the cross-sectional shape of the container body 1, and a lid 5 having a hole 4 in the upper part through which the neck 1c of the container body 1 is inserted. is provided. Also, the exterior body 3
The inner wall 3a facing the body 1b is formed with an uneven surface B corresponding to the uneven wall A, and the uneven surface B and the uneven wall A are fitted together. , the respective convex surfaces a and b are formed to protrude from the side surfaces.

The uneven wall A and the uneven surface B of the container body 1 are fitted into each other by inserting the container body 1 or molding the container body 1, and are integrally joined in the circumferential direction. Insertion of the container body 1 involves press-fitting the container body 1, which has been biaxially stretched in advance, into the exterior body 3 in an empty state, and placing only the neck portion 1c on the exterior body 3 through the hole 4 of the lid 5. The injection port is exposed to the outside and can be closed with a cap screwed onto the neck portion 1c. Moreover, it is also possible to fit together the container body 1 at the same time as the molding. In this case, the exterior body 3 is inserted into a blow mold, and the preform is stretch blow-molded within the exterior body. In this case, the illustrated bottom plate 6 made of paper is placed in a blow mold together with the exterior body 3 as a member for forming a round bottom.

In the illustrated example, the upper periphery of the bottom of the container body 1 is formed into a bellows 7 that can be expanded and contracted in the vertical direction, so that when the contents filled with high heat are cooled, the internal depressurization generated causes the container body 1 to expand and contract. This prevents it from being partially deformed.

Further, a vertical hole 8 is provided below the side wall of the exterior body 3 so that the inside can be seen through the side wall of the transparent container body 1 through the vertical hole 8.

However, in the composite container having the above structure, when the contents are filled into the container body 1 at a temperature of around 85°C,
The container body 1 begins to contract due to the filling heat, but this is because the side wall of the body 1b is formed into an uneven wall A that is bent inward and outward, and the uneven wall A contracts more easily than other parts. , the contraction during filling is in the body part 1b.
It is absorbed by. Moreover, the uneven wall A also fits into the uneven surface B of the exterior body 3, and therefore, the contraction and deformation of the body portion 1b also involves the deformation of the inner wall of the exterior body 3. As a result, the concavo-convex wall A and the concave-convex surface B always maintain a fitted state, and since the exterior body 3 is made of cardboard, it does not exhibit large resistance during deformation and adapts to the thermal deformation of the container body.

As mentioned above, this invention forms the side wall of the body of the container body 1 made of saturated polyester into an uneven wall A that is expandable and contractible in the circumferential direction, and the inner surface of the exterior body 3 made of cardboard that faces the side wall of the body. is formed on the uneven surface B corresponding to the uneven wall A, and the uneven surface B
and the uneven wall A are fitted together to integrally join the container body 1 and the exterior body 3, thereby making the saturated polyester container, which has poor thermal dimensional stability, more stable than conventional containers. Because of this, it has excellent heat resistance,
It can be satisfactorily used as a packaging container for contents that require high-temperature filling.

In addition, the container body and exterior body are in a fitted state at the body, so even if deformation occurs due to heat contraction, it is difficult for the joint between the container body and exterior body to separate due to dimensional deviation, and the two The transmission of stress between the containers is not impaired, and the container has sufficient resistance not only to lateral pressure but also to compressive force, and because the injection port can be sealed with a cap, the container can be used repeatedly. It has features such as being possible.

[Brief explanation of the drawing]

The drawings show a heat-resistant saturated polyester composite container according to the invention, in which Fig. 1 is a longitudinal cross-sectional side view, Fig. 2 is a cross-sectional perspective view of the main parts showing the state in which the exterior body is joined to the container body, and Fig. 3 1 is a partial longitudinal sectional view of the upper part of the bottom of the container; FIG. 1... Container body, 1b... Body, 2... Protrusion,
3... Exterior body, A... Uneven wall, B... Uneven surface,
a, b... Convex surface.

Claims (1)

[Scope of utility model registration request] In a heat-resistant container that combines a container body made of saturated polyester formed by biaxial stretching molding and an exterior body made of cardboard, the body side wall of the container body is formed into an uneven wall that can be expanded and contracted in the circumferential direction, and the exterior The inner surface of the body facing the body side wall is formed into an uneven surface corresponding to the uneven wall, and the uneven surface and the uneven wall are fitted together to integrally integrate the container body and the exterior body. A heat-resistant saturated polyester composite container made by bonding.