JP2002145239A - Paper container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper container which can handle many different size retainers of a filling machine by changing heating conditions after molding the container, which results in the flexible change of the paper thickness of the container and in the change of the size under the flange of the container. SOLUTION: This relates to a paper container 10 with a flange 11 molded using a paper added with a heat foam type foaming agent in a paper making process. After molding, by heating the container for foaming, the size (W) under the flange of the container can be changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a paper container with a flange by heating after molding and foaming a part or the whole of the paper container to obtain a size under the flange of the container (outer diameter under the flange).
Related to paper containers that made it possible to change
The present invention relates to a paper container in which a lid or the like is sealed with sealing means such as an ultrasonic seal, a high-frequency seal, and a heat seal after filling the contents.

[0002]

2. Description of the Related Art Conventionally, after contents are stored in a storage portion of a paper container with a flange, the container and a lid material placed so as to cover an opening of the container are ultrasonically sealed at the peripheral edge of the flange, and high-frequency waves are applied. BACKGROUND ART Paper containers hermetically sealed by means such as sealing and heat sealing are known.

[0003] In the case where a hermetic seal is required after filling the contents, even if the size of the container is different even if it is 1 mm, the size of the retainer of the filling and sealing machine is also changed to a retainer size matching the size of the container. It is necessary to make a mold to deal with it, and this has bounced off the price of the packaging material in the form of depreciation, which is one of the causes of cost increase. Further, even if there is a mold having a retainer size that matches the container size, it takes a lot of time to switch the mold, which causes a reduction in the operation rate of the filling and sealing machine.

If the size below the flange of the paper container (the diameter of the opening of the paper container) does not match the retainer size, when the lid is sealed, pressure relief or the like occurs, resulting in poor sealing. Also, if the sizes are largely different, the paper container may fall off from the retainer. That is,
The size under the flange must be the size of the retainer.

[0005]

SUMMARY OF THE INVENTION The present invention focuses on the above-mentioned problems relating to a paper container having a flange, such as a paper cup, a paper tray, and a paper squeezing container, which hermetically seals a lid after filling the contents. By changing the heating conditions after forming the container, the thickness of the paper changes flexibly, and the size under the flange of the container changes. It is an object to provide a container.

[0006]

The above objects can be attained by the present invention described below. That is, claim 1
The invention described in is a paper container with a flange formed by using a paper to which a heat-foamable foaming agent or the like is added in a papermaking process, and after forming, the container is heated to expand the container. A paper container characterized in that the size under the flange can be changed.

As described above, a paper container with a flange formed by using a paper to which a foaming agent is added is formed, and after forming, the container is foamed by using a heating furnace, so that the molding die can be changed. Since the size under the flange of the container can be changed by changing the heating condition, paper containers having different sizes under the flange can be easily and inexpensively manufactured.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the paper container of the present invention will be described in detail below. Paper used as a paper for forming a paper container is formed by adding a foaming agent which foams by heat and a binder for connecting the paper pulp fiber and the foaming agent in a final residual amount of 1 to 50% by weight to the paper fiber pulp. Weight is 3
A mixed paper of 00 g / m ² was produced.

[0009] As the foaming agent, in addition to a thermally foamable foaming agent in which the outer surface of an internal foaming agent made of a chemical foaming agent such as carbonate is covered with a thermoplastic resin film such as polyurethane, a volatile gas is used. A microcapsule-type thermofoaming foaming agent in which the outer surface of an internal foaming agent composed of a physical foaming agent such as a hydrocarbon is covered with a thermoplastic resin film such as polyurethane, and a hydrocarbon such as a thermoplastic resin such as polyurethane A physical foaming agent obtained by kneading a volatile gas or a high-pressure gas such as carbon dioxide, nitrogen, and helium may be used.

The chemical foaming agents include, in addition to carbonates such as sodium hydrogencarbonate carbonate, azo compounds, nitroso compounds, hydrazine derivatives, semicarbazide compounds,
Known thermal decomposition type chemical blowing agents such as azide compounds and triazole compounds can be used.

Further, as the physical foaming agent, a thermal expansion type physical foaming agent comprising a hydrocarbon which is a volatile gas such as isobutylene, isobutane, pentane, hexane and petroleum ether can be used. At that time, the hydrocarbon is often used in a pressurized state, and the hydrocarbon may be liquefied to become a liquid hydrocarbon.

On the other hand, acrylonitrile, polyurethane, acrylic acid ester, methacrylic acid ester and the like can be used as the thermoplastic resin covering the outer surface as described above.

A printing layer was provided on the front surface of the mixed paper, and a low-density polyethylene resin was applied on the back surface by a melt extrusion method to provide a polyethylene coating layer having a thickness of 20 μm to obtain a processed paper for a paper container.

The processed paper for a paper container is cut into a blank sheet of a predetermined size, punched out, and then, by a molding machine, a paper tray with a flange, which is a paper container having a size below the flange (outer diameter under the flange) of 100 mm, is used. It was molded (see FIG. 1). As the paper container, in addition to the paper tray shown in FIG. 1, any container having a flange, such as a paper cup or a paper squeezing container, may be used.

A plurality of paper trays each having a size under the flange (outer diameter under the flange) of 100 mm were heated in an oven at 120 ° C. for 1 minute, 3 minutes, and 5 minutes, respectively, to heat and foam the entire paper tray. , The size under the flange (outer diameter under the flange) is 101 mm and 102 m, respectively.
m, 104 mm paper tray was obtained.

From these results, if a paper container made of paper to which a heat-expandable foaming agent is added is used, the container is heated and foamed after molding, so that containers having different diameters of about several mm can be used. It can be seen that this can be done without replacing the mold.

[0017]

As described above, in the conventional method, the size under the flange of the container is changed each time, for example, by changing the mold for forming the container or changing the basis weight of the paper. On the other hand, in the paper container of the present invention, if the size under the flange is changed to about 5 mm, it is possible to cope with foaming conditions when foaming after forming the container, and it is possible to reduce costs and shorten delivery time. .

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view showing one embodiment of a paper container according to the present invention, in which (a) is a cross section showing a state before heating and foaming;
(B) is a schematic explanatory view showing a cross section of a state after heating and foaming.

[Explanation of symbols]

 10 ‥‥ Paper container 11 ‥‥ Flange W ‥‥ Size under flange (outer diameter under flange) α ‥‥ Length (width) expanded by foaming

Claims (1)

[Claims] 1. A paper container with a flange formed by using a paper to which a heat-expandable foaming agent or the like is added in a paper making step, wherein the container is heated and foamed after molding.
A paper container characterized in that the size under the flange of the container can be changed.