JP4582273B2 - Paper container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper container that can change the size under the flange (outer diameter under the flange) of the container by heating the flanged paper container after molding and foaming a part or the whole. Thus, the present invention relates to a paper container that seals a lid or the like by sealing means such as ultrasonic sealing, high-frequency sealing, and heat sealing after filling the contents.
[0002]
[Prior art]
Conventionally, after the contents are stored in the storage portion of the flanged paper container, the container and the lid placed so as to cover the opening of the container are ultrasonically sealed, high-frequency seal, heat seal, etc. at the periphery of the flange A paper container hermetically sealed by the above means is known.
[0003]
When a hermetic seal is required after filling the contents, if the container size is different even by 1 mm, the retainer size of the filling and sealing machine will be the retainer size that matches the container size. It has to be made and dealt with, and this has bounced back to the price of the packaging material in the form of amortization, which is one of the causes of cost increase.
Moreover, even if there is a retainer-sized mold that matches the container size, it takes a lot of time to switch the mold, causing a reduction in the operating rate of the filling and sealing machine.
[0004]
If the size under the flange of the paper container (diameter of the opening of the paper container) does not match the retainer size, when the lid is sealed, pressure escape or the like is caused, which causes a sealing failure. In addition, if the size is significantly different, the paper container may fall off from the retainer. That is, the size under the flange = retainer size must be satisfied.
[0005]
[Problems to be solved by the invention]
The present invention has been made paying attention to the above-mentioned problems relating to a paper container with a flange such as a paper cup, a paper tray, and a paper squeeze container for sealing and sealing a lid material after filling the contents. It is an object of the present invention to provide a paper container that can respond to various retainer sizes of a filling machine by changing the heating condition to change the paper thickness flexibly and changing the size under the flange of the container. .
[0006]
[Means for Solving the Problems]
The above problems can be solved by the following present invention. That is, the invention described in claim 1 is a flanged paper container formed by using a paper to which a thermally foaming foaming agent or the like is added in the paper making process, and after forming, the container is heated and foamed. Accordingly, the paper container is characterized in that the size under the flange of the container can be changed.
[0007]
In this way, a flanged paper container molded using a paper to which a foaming agent has been added, and after molding, the container is foamed using a heating furnace, so that the heating conditions can be changed without changing the molding die. By changing the size, the size of the container under the flange can be changed, so that paper containers having different sizes under the flange can be easily and inexpensively manufactured.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the paper container of the present invention will be described in detail below.
As paper used for forming a paper container, paper is made by adding a foaming agent that is foamed by heat and a binder that connects the paper pulp fiber and the foaming agent to the paper fiber pulp in a final residual amount of 1 to 50% by weight. A mixed paper having a basis weight of 300 g / m ² was prepared.
[0009]
Examples of the foaming agent include a thermally foaming foaming agent in which the outer surface of an internal foaming agent composed of a chemical foaming agent such as carbonate is covered with a thermoplastic resin film such as polyurethane, and a hydrocarbon that is a volatile gas. Microcapsule type heat-foaming foaming agent whose outer surface of internal foaming agent composed of physical foaming agent is covered with a thermoplastic resin film such as polyurethane, and volatile such as hydrocarbons in thermoplastic resin such as polyurethane You may use the physical foaming agent which knead | mixes gas or high-pressure gas, such as a carbon dioxide, nitrogen, and helium.
[0010]
As the chemical foaming agent, in addition to carbonates such as sodium hydrogen carbonate, known pyrolytic chemical foaming agents such as azo compounds, nitroso compounds, hydrazine derivatives, semicarbazide compounds, azide compounds, triazole compounds are used. can do.
[0011]
In addition, as the physical foaming agent, a thermal expansion type physical foaming agent made of hydrocarbon which is a volatile gas such as isobutylene, isobutane, pentane, hexane, petroleum ether or the like can be used. In that case, it is often used in a pressurized state, and the hydrocarbon may be liquefied to become a liquid hydrocarbon.
[0012]
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.
[0013]
A printed layer was provided on the surface of the mixed paper, and a low-density polyethylene resin was applied to the back surface by a melt extrusion method, and a polyethylene coating layer having a thickness of 20 μm was provided to obtain a processed paper for paper containers.
[0014]
After cutting and punching the processed paper for paper containers into a blank sheet of a predetermined size, a flanged paper tray, which is a paper container having a flange undersize (outer diameter under flange) of 100 mm, was formed by a molding machine ( (See FIG. 1).
As the paper container, in addition to the paper tray shown in FIG. 1, a container having a flange such as a paper cup or a paper squeeze container may be used.
[0015]
When a plurality of paper trays with a flange undersize (outer diameter under flange) of 100 mm were heated in an oven at 120 ° C for 1 minute, 3 minutes and 5 minutes, respectively, the entire paper tray was heated and foamed. Paper trays having a size (outer diameter under the flange) of 101 mm, 102 mm, and 104 mm were obtained.
[0016]
From this result, if a paper container made using a paper to which a thermally foamable foaming agent is added is used, a mold for a container having a different diameter of about several millimeters can be obtained by heating and foaming the container after molding. It can be seen that it is possible to cope without exchanging
[0017]
【The invention's effect】
As described above, the change in the size under the flange of the container corresponds to the change in the conventional method such as changing the mold for forming the container or changing the basis weight of the paper. In the case of paper containers, if the size under the flange is changed to about 5 mm, it is possible to cope with the foaming conditions when foaming is performed after the container is formed, thereby reducing costs and shortening the delivery time.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows an embodiment of a paper container of the present invention, (a) is a schematic explanatory view showing a state before heating and foaming in a cross section, and (b) is a schematic diagram showing a state after heating and foaming in a cross section. It is explanatory drawing.
[Explanation of symbols]
10 ... Paper container 11 ... Flange W ... Under flange size (outer diameter under flange)
α ... Length spread by foaming (width)

Claims (1)

A flanged paper container formed using paper with a heat-foaming foaming agent added in the papermaking process, and after molding, the container can be heated and foamed to change the size under the flange of the container A paper container characterized by:

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