JP4736769B2 - Paper tray - Google Patents

Description

  The present invention relates to a paper squeeze tray, and more particularly to a paper squeeze tray for preventing liquid leakage and liquid biting seal when sealing a lid.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. Also, “PET” is an abbreviation, functional expression, common name, or industry term for “biaxially stretched polyethylene terephthalate”, “ON” for “biaxially stretched polyamide”, and “PP” for “polypropylene”.

  (Main use) The main use of the paper squeeze tray of the present invention is as follows: foods such as fresh foods such as meat, vegetables, fresh fish, lunch boxes, prepared dishes, frozen foods, confectionery, noodles, soups, soup Is a tray for storing various processed foods such as foods and beverages, and is particularly suitable for contents containing moisture. However, there is no particular limitation as long as it is a use that requires prevention of liquid leakage or liquid biting seal when sealing the lid.

(Background Art) Conventionally, as a tray container used for foods, in particular, contents containing moisture, a tray made of various resins, for example, a molded tray of foamed PS beads or a foamed PS sheet is pressed. There are molded foamed PS trays, others, PS trays, PP trays, PET trays and the like, and there are also tray containers mainly made by press molding a thin metal such as aluminum. Further, a tray mainly composed of paper, for example, a paper squeeze tray, in which a ruled line is put in advance in four drawn portions at the corners on a processing base paper mainly made of paper, and the ruled line part is formed in the mold. It is press-molded in the shape of a folding tray, has an opening at the top, has an outward flange on the periphery of the opening, is inexpensive and lightweight, and is widely used for one-way applications. Specifically, there are in-store packs for prepared foods and take-outs, and manufacturer packs for frozen foods and chilled foods. However, in the paper squeeze tray, the ruled lines are continuous from the bottom of the tray to the peripheral edge of the flange, so that when the contents containing liquid such as water are filled, the liquid such as water is drawn. It is sucked up by the capillary phenomenon of the folded ruled line part and reaches the flange part. When liquid such as water in the flange portion leaks or the lid member is sealed to the flange portion by heat sealing or the like, it becomes a liquid biting seal and sealing performance cannot be obtained.
Therefore, the paper squeeze tray is required to prevent liquid leakage and liquid biting seal when sealing the lid while maintaining the conventional characteristics of easy formability, low cost, and light weight. Yes.

  (Prior art) Conventionally, there is a known base paper that is made of multi-layer papers with different densities, with a water-resistant layer laminated on at least one side. (For example, refer to Patent Document 1). However, the ruled line of the side wall part is a continuous ruled line from the bottom part to the flange part, and there is a drawback that liquid leakage easily occurs, and the division and position of the ruled line are neither described nor suggested.

JP 2002-326332 A

  Accordingly, the present invention has been made to solve such problems. The purpose is to provide a paper squeeze tray capable of preventing liquid leakage and liquid biting seals when sealing a lid while maintaining the conventional characteristics of easy formability, low cost, and light weight. is there.

In order to solve the above-mentioned problems, the paper drawing tray according to the invention of claim 1 is formed by press forming a ruled line in advance on a drawing base portion of paper or a processed base paper having a water-resistant layer laminated on at least one side of paper. The ruled line is divided into a side line ruled line and a flanged line ruled line in a paper drawing tray having a bottom part, a side wall part rising from the bottom part, and an outward flange part at the periphery of the side wall part, and having an open top. Then, the side wall ruled line from the bottom part toward the flange part is divided in front of the flange part, and the flange part ruled line is provided so as to be shifted laterally from the extended line of the side wall part ruled line.
The paper squeeze tray according to the invention of claim 2 is such that the dividing position on the flange side of the side wall ruled line and the position on the side wall side of the flange ruled line are substantially the same position.
The paper squeeze tray according to the invention of claim 3 is provided with a portion having no ruled line between the dividing position on the flange side of the side wall ruled line and the position on the side wall side of the flange ruled line, and a plurality of the side walls A ruled line for liquid retaining is provided at a position where the flange side dividing position of the part ruled line is connected.

According to the first aspect of the present invention, while maintaining the conventional characteristics of easy formability, low cost, and light weight, it is possible to prevent liquid leakage and liquid jam sealing when sealing the lid. A tray is provided.
According to the present invention of claim 2, in addition to the effect of claim 1, a paper squeeze tray having easier formability is provided.
According to the third aspect of the present invention, in addition to the effects of the first and second aspects, even if the liquid rises along the crease of the side wall ruled line, the liquid can be stopped and returned by the liquid retaining ruled line. A paper squeeze tray capable of preventing leakage and liquid biting when sealing a lid is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view and a cross-sectional view of a paper squeeze tray showing an embodiment of the present invention.
FIG. 2 is a plan view of a main part of a blank of a paper squeeze tray showing an embodiment of the present invention, and a perspective view of a main part of the paper squeeze tray.
FIG. 3 is a plan view of a main part of a blank of a paper squeeze tray showing an embodiment of the present invention, and a perspective view of a main part of the paper squeeze tray.
FIG. 4 is a plan view of a main part of a blank of a paper squeeze tray showing an embodiment of the present invention, and a perspective view of a main part of the paper squeeze tray.

  (Paper squeeze tray) The paper squeeze tray 10 of the present invention is formed by drawing as shown in FIG. The corner portion 17 is folded at a ruled line, rises to the flange portion, and has a tray shape or a dish shape. Although it is a rectangle in FIG. 1, a polygon such as a triangle, a circle, an ellipse, or the like may be arbitrary, and a depth or a flange shape may be arbitrary depending on the application. Further, even if the paper squeeze tray is used alone, although not shown, the lid covers the upper part of the paper squeeze tray 10 and is heat-sealed to the flange portion 15 to be used as a package. Also good.

  The lid material is produced by punching a laminated film, and covers the upper portion of the paper squeeze tray 10 and is heat-sealed to the flange portion 15. A knob portion may be provided at one end of the outer periphery of the lid member so as to protrude outward from the outer periphery of the flange portion 15 of the paper drawing tray 10. Moreover, you may punch, after heat-sealing a strip | belt-shaped laminated | multilayer film to the flange part 25, without punching a laminated | multilayer film.

  The laminated film used for the lid is simply laminated with a base film that has excellent mechanical strength such as tensile strength, heat resistance, and water resistance, and a heat-bondable sealant layer on the flange surface of the container body. A laminated film having the above structure can also be used. For example, a laminated film in which a base film / sealant layer is laminated in order from the outside can be applied. The base film is not particularly limited as long as the film has the above performance, but when considering economic performance as well as performance, a PET film, an ON film, an OPP film, etc. can be suitably used, and heat sealing Possible sealant layers include PP, propylene-ethylene copolymer (copolymer having an ethylene content of 10 mol% or less), or an unsaturated carboxylic acid, unsaturated carboxylic acid anhydride or ester monomer on polypropylene. Polypropylene resin, HDPE, polybutene-1, etc. obtained by graft polymerization or copolymerization of the above can be applied. As a preferable sealant layer, one having an easy open property is convenient for fully opening the opening when eating after heating.

As the material of the paper squeeze tray 10, paper or a laminated material in which a water-resistant layer such as a plastic film is laminated on at least one side of the paper can be applied. As paper, if necessary, fillers, pigments, dyes, sizing agents, yield improvers, paper strength enhancers, etc. can be added to the pulp raw material, or coated on the base paper surface after papermaking. Paper with enhanced water resistance may be used. Further, if necessary, a coating layer containing a pigment such as calcium carbonate, kaolin, clay, talc, titanium oxide, or plastic pigment may be provided on one side or both sides in order to impart good printability. . Furthermore, in order to obtain the required rigidity, multilayer laminated paper is preferable, and the density of the entire multilayer paper is preferably 0.4 to 0.7 g / m ³ .

As the laminate, for example, the above paper and PP, a propylene-ethylene copolymer (a copolymer having an ethylene content of 10 mol% or less), or an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride on polypropylene. Alternatively, a polypropylene resin obtained by graft polymerization or copolymerization of an ester monomer, HDPE, polybutene-1, or other heat resistant polyolefin resin may be laminated. Although it does not restrict | limit especially as paper, For example, the paperboard of about 100-300 g / m < ² > basic weight can be applied. The propylene-ethylene copolymer has an ethylene content of 10 mol% or less, for example, in the range of 5 to 10 mol%, and is suitable for extrusion without detracting from the advantages such as heat resistance and rigidity of polypropylene. Heat sealability and impact strength at low temperatures can be improved. In the case of graft polymerization of unsaturated carboxylic acid, unsaturated carboxylic acid anhydride or ester monomer to polypropylene with the polypropylene resin, specific examples of the graft component include acrylic acid, methacrylic acid, methacrylic acid. Glycidyl, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethyl maleate, monoethyl maleate, di-n-butyl maleate, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride , 5-norbornene-2,3-anhydride, citraconic acid, citraconic anhydride, crotonic acid, crotonic anhydride, acrylonitrile, methacrylonitrile, sodium acrylate, calcium acrylate, magnesium acrylate, and the like. Among these, a polypropylene resin obtained by graft polymerization of maleic anhydride onto polypropylene can be particularly preferably used because of cost and ease of graft polymerization. Moreover, you may laminate | stack other films which have piercing strength, tear strength, and a softness | flexibility as needed.

  (Rule line) FIG. 2 shows an example of a conventional paper squeeze tray. FIG. 2A shows a ruled line in a plan view of one corner (main part) of a blank before forming the paper squeeze tray. B) is a perspective view of a paper tray after molding. As shown in FIG. 2 (A), the flange ruled lines and the side wall ruled lines are arranged in a single line and are arranged in a radial pattern, and after drawing, they rise as shown in FIG. 2 (B). A side wall portion and a flange portion are formed to form a conventional paper drawing tray. The other corners are the same, and one corner is described. However, in the case of a circle, the whole may be considered as one corner.

  However, in the conventional paper squeeze tray, the ruled line is continuous from the bottom of the tray to the peripheral edge of the flange, so that when the contents containing liquid such as water are filled, the liquid such as water is squeezed. It is sucked up by the capillary phenomenon of the ruled line part that is molded and folded, and reaches the flange part. When liquid such as water in the flange portion leaks or the lid member is sealed to the flange portion by heat sealing or the like, it becomes a liquid biting seal and sealing performance cannot be obtained.

  (Rectification of Ruled Lines) Accordingly, as shown in FIG. 3A, the paper drawing tray 10 of the present invention divides the ruled line 21 in the blank into side wall ruled lines 31B and flanged ruled lines 31A, and from the bottom part 11 to the flange part. The ruled line toward 15 is divided in front of the flange part 15 so as to be independent as the side wall ruled line 31B, and the remaining flange part ruled line 31A is shifted from the extended line of the side wall ruled line 31B in the lateral direction. When the ruled line is drawn, the folded part may be slightly extended from the end of the ruled line, but the function is not affected and is within the scope of the present invention.

  When this is drawn, as shown in FIG. 3 (B), the side wall ruled line end 41B and the flange ruled line end 41A are not continuous with the lateral position shifted. Even if the liquid rises by capillary action through the folding line, it can be retained at the side wall ruled line end portion 41B to prevent liquid leakage and liquid biting seal when sealing the lid. There is no problem with the drawability, and the conventional characteristics of having good formability, low cost and light weight are maintained.

  3 (A) and 3 (B), as shown in FIGS. 3A and 3B, the dividing position on the flange side of the side wall ruled line (side wall part ruled line end 41B) and the side wall side position of the flange ruled line 31A (flange) The ruled line dividing position with the ruled line end part 41A) may be provided at a position where there is no ruled line between the ruled lines with a gap between them or substantially the same position. If a space is provided between the side wall ruled line end part 41B and the flange part ruled line end part 41A, the liquid that has risen to the side wall line ruled line end part 41B through the fold line due to capillary action may slightly shake the paper squeeze tray. However, it is difficult to move to the flange part ruled line end 41A, and it is possible to prevent liquid leakage and liquid biting seal when sealing the lid. Further, when the positions are substantially the same, the drawability can be further improved. From the viewpoint of formability, the dividing position a is preferably about 1 to 10 mm and 2 to 5 mm on the bottom side of the flange ruled line end 41 </ b> A from the flange line 33. However, it is preferable that the flange ruled line 31A extends to the side wall 13 side in terms of formability.

  (Liquid retaining ruled line) As shown in FIG. 4A, a portion having no ruled line is provided between the side wall ruled line end 41B and the flange ruled line end 41A, and a plurality of the side wall ruled lines 31B It is preferable to provide a liquid retaining ruled line 43 at a position connecting the flange side dividing positions. The interval b between the end portion on the side wall portion side of the flange ruled line 31A and the rule line 43 for liquid retaining may be 0 or more, but is preferably about 1 to 5 mm from the viewpoint of formability. When this is drawn, as shown in FIG. 4B, a liquid retaining ruled line 43 in which a plurality of side wall ruled line end portions 41B are connected in parallel to the bottom surface is formed. The liquid that has risen through the folding line to the side wall ruled line end 41B by capillary action can be dammed by the liquid retaining ruled line 43 and returned to the original state. Even if the paper squeeze tray is slightly shaken, it is possible to prevent liquid leakage and liquid biting seal when sealing the lid.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

(Example 1) (1) The paper squeeze tray 10 used PP resin 40 μm / paper as a laminate. Note that the paper is tray paper, the weight is 260 g / m ² , the density is 0.85 g / m ² due to the formability such as being hard to break the paper, the steak size is 1300 seconds or more to prevent water intrusion from the flange section, and the cup size A degree of 22 g / m ² or more was used, and a propylene-ethylene copolymer (ethylene content is 10 mol% or less) was used as the PP resin from the viewpoint of water resistance and oil resistance and easy openness.
3A, the ruled line is divided into a side wall ruled line 31B and a flange ruled line 31A, and the side wall ruled line 31B from the bottom 11 toward the flange part 15 is 3 mm before the flange part 15 as shown in FIG. The flange part ruled line 31A is shifted halfway in the horizontal direction from the extended line of the side wall part ruled line 31B so that the dividing position on the flange side of the side wall part ruled line and the position on the side wall side of the flange part ruled line are substantially the same position. Created a blank.
The blank was formed into a rectangular shape by using a paper drawing machine with PP resin on the inner surface, rounded corners on the top surface of the tray as shown in FIG. 3B, a flange width of 7 mm, and a full capacity of 946 cc. 1 paper squeeze tray was prepared.
(2) From the outside, the lid 13 is made of PET / print layer / adhesive / MXD6 biaxially stretched film / adhesive / easy peel sealant film having a thickness of 12 μm (propylene-ethylene copolymer (thickness)). 25 μm ethylene content 7 mol%) 13% by mass of polyethylene and a resin obtained by kneading 10% by mass of calcium carbonate as an inorganic filler) in order, a roll-shaped lid material cut and rolled up to a predetermined width Prepared. In addition, between each film, it bonded together by the dry lamination method using the two-pack hardening type polyurethane-type adhesive agent.
(Evaluation) The paper squeeze tray of Example 1 was filled with 220 g of oden with soup, and then the lid was pulled out and covered, and the flange 15 was heat-sealed with a ring sealer. A tray package was obtained by punching into a structure having an outer peripheral edge and a knob.
There was no oden soup on the flange of the paper squeeze tray, and there was no problem with heat sealing.

(Example 2) Using the laminate of Example 1, as shown in FIG. 4 (A), the ruled line is divided into side wall part ruled line 31B and flange part ruled line 31A, and the side wall part from the bottom part 11 toward the flange part 15 is used. The ruled line 31B is divided by 4 mm before the flange part 15 and 3 mm from the divided part, the flange part ruled line 31A is shifted halfway in the horizontal direction from the extended line of the side wall part ruled line 31B, and the flange part 15 of the side wall part ruled line 31B. A blank was prepared by pressing the liquid retaining ruled line 43 to the line connecting the end portions on the side and providing it with a ruled line. Except for this, a paper squeeze tray was obtained in the same manner as in Example 1.
(Evaluation) Using a self-sealing seal device having the shape of a ring sealer, a roll-shaped lid material is loaded, and the paper squeeze tray of Example 2 is filled with 220 g of oden with soup, and then the lid is placed on the lid. The material was pulled out and covered, heat sealed to the flange portion 15 with a ring sealer, and then punched into a configuration having an outer peripheral edge portion and a knob portion of the flange portion 15 to obtain a tray package.
Since the automatic filling and sealing device was used, the contents shook, but the oden juice did not rise to the flange portion of the paper squeeze tray, and there was no problem with heat sealing.

It is the top view and sectional drawing of a paper squeeze tray which show one Example of this invention. It is a top view of the principal part of the blank of the paper squeeze tray which shows one Example of this invention, and the perspective view of the principal part of a paper squeeze tray. It is a top view of the principal part of the blank of the paper squeeze tray which shows one Example of this invention, and the perspective view of the principal part of a paper squeeze tray. It is a top view of the principal part of the blank of the paper squeeze tray which shows one Example of this invention, and the perspective view of the principal part of a paper squeeze tray.

Explanation of symbols

10: Paper squeeze tray 11: Bottom part 13: Side wall part 15: Flange part 17: Corner part 21: Ruled line 31A: Flange part ruled line 31B: Side wall part ruled line 41A: Flange part ruled line end part 41B: Side wall part ruled line end part

Claims (3)

Paper or a processed base paper with a water-resistant layer laminated on at least one side of the paper is pre-molded with a ruled line in the draw-formed part in advance, and the bottom part, the side wall part rising from the bottom part, and the peripheral part of the side wall part. In a paper squeeze tray having an orientation flange portion and opened at the top, the ruled line is divided into a side wall ruled line and a flange ruled line, and the side wall ruled line from the bottom toward the flange is divided before the flange part, A paper squeeze tray, characterized in that a flange ruled line is provided so as to be shifted laterally from an extended line of the side wall ruled line. 2. The paper squeeze tray according to claim 1, wherein a dividing position on the flange side of the side wall ruled line and a position on the side wall side of the flange part ruled line are substantially the same position. To a position where a portion without a ruled line is provided between the flange side dividing position of the side wall ruled line and the side wall side position of the flange part ruled line, and the flange side dividing positions of the plurality of side wall ruled lines are connected The paper squeeze tray according to claim 1, further comprising a ruled line for liquid fixing.

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