JPH06210767A - Fabrication of paper container for liquid - Google Patents

Abstract

(57) [Summary] [Purpose] In the method of heating both side regions of the blank by the flame of a gas burner to form a box, a blank for a liquid paper container whose surface material is modified polyester , To enable strong heat-bonding and make a box. [Structure] When the surface of the liquid paper container blank made of the modified polyester is heated by the flame of the gas burner to form a cylinder, the surface of the liquid paper container blank made of the modified polyester and the tip of the flame of the gas burner The surface of the modified polyester is heated with a mesh sheet interposed therebetween to form a box.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a liquid paper container in which at least one surface material is a modified polyester.

[0002]

2. Description of the Related Art Conventionally, as a material for a blank of a liquid paper container, a structure in which both surfaces are made of polyethylene is generally used, and when manufacturing the blank, both front and back end regions of the blank are exposed to a gas burner flame. The method of heating to make a box is used, and when making a box using a blank consisting of polyethylene on both the front and back sides, the above method also causes problems because the polyethylene on both sides is firmly heat-bonded. It was a long time ago.

Recently, due to the diversification of contents to be filled in liquid paper containers, there are problems such as citrus diuse, in which aromatic components are adsorbed by the polyethylene layer to impair the flavor and destroy vitamin C. For products that need to be prevented, blanks are often used in which the layer of modified polyester is used at least on the side of the liquid paper container that is in contact with the contents.

As described above, when a blank having a structure in which a layer made of modified polyester is used on at least the side of the liquid paper container that is in contact with the contents is boxed on both sides of the blank, as in the conventional case. When the method of heating by the flame of the above and making into a box is used, the layer of the modified polyester is directly heated by the flame of the gas burner, so that the surface of the modified polyester is oxidized and the box can be made without thermal adhesion. There is a problem of not having.

As a method for improving the above-mentioned drawbacks of the conventional method, in the case where a blank having a structure in which a layer made of modified polyester is used at least on the side in contact with the contents is box-made,
Although there is also a method of heating with hot air to make a box without using a flame of a gas burner, there is a disadvantage that the box speed cannot be increased due to insufficient heat capacity of the hot air.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the drawbacks of the above-mentioned conventional method and to directly heat the front and back side end regions of the blank by a flame of a gas burner to form a tubular box. In the case of, in the case of manufacturing a liquid paper container blank in which at least one surface material is composed of modified polyester, it is possible to perform strong heat bonding at both ends of the front and back sides of the blank so that the blank can be manufactured. Is.

[0007]

[Means for Solving the Problems] A method for heating a blank for a liquid paper container, at least the surface in contact with the contents of which is modified polyester, with both ends of the front and back by a flame of a gas burner to form a cylindrical box. The surface of the liquid paper container blank was heated by interposing a mesh sheet between the modified polyester surface of the paper container blank and the flame tip of the gas burner.

[0008]

When at least one surface of the blank for a liquid paper container of which the surface material on at least one side is made of modified polyester is heated by the flame of the gas burner on the surface made of modified polyester,
Instead of directly applying the flame of the gas burner to the surface of the modified polyester, the heat-resistant mesh sheet is interposed between the surface of the layer composed of the modified polyester and the tip of the flame of the gas burner to heat the modified polyester. Since the surface oxidation of the layer is prevented, the modified polyester layer can be thermally bonded.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a heating method of a liquid paper container blank of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, 1 is a liquid paper container blank, 2 is a gas burner, 3 is a gas burner. Flame, 4 is a mesh sheet, 5 is a modified polyester surface of a liquid paper container blank, and 6 is a polyethylene surface of a liquid paper container blank.

The laminated constitution of the blank 1 for liquid paper containers used for citrus juices, etc. is generally from the surface to polyethylene / paper / polyethylene / aluminum foil / adhesive / biaxially stretched polyethylene terephthalate / polyethylene / modified polyester. It is composed of. In view of cost and workability, it is usual to use the modified polyester only on the surface in contact with the contents, but it is acceptable to use the modified polyester on the opposite surface.

The box making machine and the gas burner 2 for heating are
What is conventionally used for box-making of a blank for liquid paper containers whose both sides are made of polyethylene can be used.

In the mesh sheet 4 used in the present application, corrugations are generated in the portion of the gas burner that is directly hit by the flame 3 and the uniform heating of the blank surface of the liquid paper container is hindered.
Made of material with excellent heat resistance and low coefficient of thermal expansion 50-
A mesh sheet 4 having a mesh size of 200 mesh is suitable. Even in the case of the mesh sheet 4 having a mesh larger than 50 mesh, it can be used by stacking two sheets, but the thermal efficiency is reduced. The material of the mesh sheet 4 is, for example, stainless steel, carbon fiber or the like, but carbon fiber is most suitable.

The mesh sheet 4 is a blank 1 for a liquid paper container.
It is optional to install the modified polyester surface 5 in the gas burner 2 for heating, and to install the mesh sheet 4 in the gas burner 2 for heating the polyethylene surface 6 of the liquid paper container blank.

The size and installation position of the mesh sheet 4 is such that the width of the gas burner 2 is such that the tip of the flame 3 of the gas burner is completely blocked and does not stick to the opposite side. , Placed at a position several mm below the tip of the flame so that the tip of the flame 3 of the gas burner contacts the mesh sheet 4 as close as possible to the modified polyester surface 5 of the blank 1 for liquid paper containers It is desirable to do.

Example 1 A blank for a liquid paper container having a constitution of polyethylene 30 / paper 400 g / polyethylene 30 / aluminum foil 9 / adhesive / biaxially oriented polyethylene terephthalate 12 / polyethylene 30 / modified polyester 30 (unit: micron) Using a 100 mesh mesh sheet made of carbon fiber, bring it as close as possible to the gas burner on the side that heats the modified polyester surface of the liquid paper container blank so as not to contact the modified polyester surface of the liquid paper container blank. And, with a box making machine installed 5 mm below the tip of the flame of the gas burner, line speed 100
The results obtained by carrying out box making at a speed of m / min were good, and sufficient thermal adhesive strength was obtained without oxidation of the modified polyester surface of the blank for liquid paper containers due to the flame of the gas burner.

[0016]

EFFECTS OF THE INVENTION In a method of heating a blank 1 for a liquid paper container, at least the surface of which is in contact with the contents, with a modified polyester, both ends of the front and back sides by a flame 3 of a gas burner to form a cylindrical box, The gas burner 2 for heating the modified polyester surface 5 of the blank 1 does not directly hit the flame 3 of the gas burner on the modified polyester surface 5 of the blank 1 for the liquid paper container.
Installing a heat-resistant mesh sheet 4 between the modified polyester surface 5 and the tip of the flame 3 of the gas burner, and heating the modified polyester surface 5 of the blank for the liquid paper container through the mesh sheet 4. As a result, the surface of the layer of the modified polyester of the blank 1 for liquid paper containers is prevented from being oxidized, and like the conventional case of the box for liquid paper container blanks of which both sides are made of polyethylene, at least one surface is modified polyester. It is possible to form the blank 1 for a liquid paper container having a layer consisting of.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method for heating a blank for liquid paper containers according to the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

[Explanation of symbols]

 1 Blank for liquid paper container 2 Gas burner 3 Flame of gas burner 4 Reticulated sheet 5 Modified polyester surface of blank for liquid paper container 6 Polyethylene surface of blank for liquid paper container

Claims (1)

[Claims] 1. A method for heating both sides of a blank for a liquid paper container, at least the surface of which is in contact with the contents, with a modified polyester, by a flame of a gas burner to form a cylindrical box, the blank for the liquid paper container. A method for making a box for a liquid paper container, comprising heating a surface of the blank for a liquid paper container by interposing a mesh sheet between the surface made of the modified polyester and the tip of the flame of the gas burner.