JP2022061743A - Tray type paper container - Google Patents

Abstract

To provide a tray type paper container mainly composed of paper, having suitable stack pitch in stacking the containers and capable of smoothly separating them so that filling machine suitability is good.SOLUTION: In a tray type paper container 1 composed of one blank sheet comprising a laminate including a paper layer 3 and an inner resin layer 4, the blank sheet includes a bottom surface plate 5 having a shape of extending a regular octagon in horizontal and vertical directions, and rectangular corner plates 6 are continuously provided respectively via mountain-folding ruled lines at four non-extend sides of the bottom surface plate, inverted trapezoidal side face plates 7 are continuously provided at the other sides of the bottom surface plate respectively via mountain-folding ruled lines, flange parts 8 are continuously provided at the respective side face plates via valley-folding ruled lines, and a space (Sp) between the paper containers when stacking the paper containers is 6 mm<Sp<20 mm.SELECTED DRAWING: Figure 2

Description

The present invention relates to a tray-type paper container for storing foods and the like, and more particularly to a tray-type paper container having a flat flange portion, excellent sealing performance by a lid material, and excellent stacking suitability.

Due to the growing awareness of preserving the global environment, plastic containers that cause marine pollution will be replaced with paper containers that use biodegradable paper as a main material, which is a reproducible resource. Various attempts have been made. As for tray-type containers, attempts have been made to replace conventional plastic trays with paper containers.

The tray-type container is roughly classified into a use as a tray and a use as a storage container with an opening sealed with a lid material. In the latter case, it is common to provide a horizontal flange portion on the peripheral edge of the opening so that the lid material can be easily sealed.

In the case of a plastic container, it is easy to form a horizontal and flat flange part, but in the case of a paper container, seams, wrinkles and steps are likely to occur in the flange part, so a flat flange part can be stably formed. It was not easy to form.

The blank for a tray container described in Patent Document 1 which is the application of the applicant is a conventional tray pattern paper container, in which pinholes are easily formed at the base of the flange portion at the corner portion where the standing walls are connected to each other, and liquid leakage occurs. It is an improvement of what sometimes happened.

The blank for tray containers described in Patent Document 1 is effective as a countermeasure against pinholes in the conventional corner portion by providing a small protrusion in the corner portion where a problem may occur. Since there is a step due to the overlap of paper in the flange portion, there is a possibility that a gap based on the thickness of the paper is generated between the lid material and the flange portion.

On the other hand, in the filling machine, when filling the tray-type paper container with the contents, the blank containers are sequentially separated from the stack, one by one, taken out and filled. Trouble occurs in the machine.

The problem with stacking is that the stackability of containers is poor, and if the stack pitch (interval between stacked paper containers) is too wide, many paper containers cannot be stacked and the stack needs to be refilled frequently. There is. Also, if the stack pitch is too narrow, the probability of failure to retrieve is high. Also, if the force required for disconnection is too strong, the probability of failure in retrieval also increases.

Japanese Unexamined Patent Publication No. 2000-25546

The problem to be solved by the present invention is that in a tray-type paper container whose main material is paper, the stack pitch when stacked is appropriate and the separation can be smooth, so that a tray-type paper container having good suitability for a filling machine can be obtained. It is a suggestion.

As a means for solving the above problems, the invention according to claim 1 is a tray-type paper container formed from a single blank sheet composed of a laminate having a paper layer and an inner surface resin layer, and is a blank sheet. Is a paper layer in which an inner resin layer is formed on the entire surface after the necessary punching is performed, and then punched into a predetermined shape. The blank sheet is a shape obtained by stretching a regular octagon in the vertical and horizontal directions. A rectangular corner plate is connected to each of the four unstretched sides of the bottom plate via a mountain fold rule line, and a mountain fold rule line is provided on each of the other sides of the bottom plate. An inverted trapezoidal side plate is continuously provided via the side plate, and a flange portion is continuously provided on each side plate via a valley fold ruled line. A paper layer is provided between each corner plate and the side plate and the flange portion. Is punched out and there is only a part of the inner surface resin layer, and in molding, the tip and flange of each side plate are folded inside each corner plate and molded so that the tips do not overlap each other. The tray-type paper container is characterized in that the distance (Sp) between the tray-type paper containers when the tray-type paper containers are stacked is 6 mm <Sp <20 mm.

In the tray-type paper container according to the present invention, the space between the tray-type paper containers (stack pitch, Sp) when stacked is set to 6 mm <Sp <20 mm, so that the loading efficiency in the filling machine is improved.

The invention according to claim 2 is characterized in that C <25 mm and Hs <60 mm when the length of the bottom surface of the corner plate is C and the height of the side plate is Hs. Item 2. The tray pattern paper container according to Item 1.

In the tray pattern paper container according to the present invention, since the flange portions on the four sides do not overlap with each other by examining the shape of the blank sheet, the flange portions after molding do not have a step due to the overlap of the laminated body, and the lid is not formed. The sealing performance of the material is improved.

In addition, since a blank sheet is used in which an inner resin layer is formed on the entire surface of the paper layer and then punched into a predetermined shape, there is a concern about water leakage in the tray-shaped paper container after molding. There is no.

In the tray-type paper container according to the present invention, the spacing (stack pitch, Sp) between the tray-type paper containers when stacked is set to 6 mm <Sp <20 mm, so that the loading efficiency in the filling machine is improved. Further, when the paper containers are stacked, the paper containers do not come into point contact with each other and do not come into surface contact with each other, so that it is possible to prevent the paper containers from adhering to each other and causing a take-out error.

When the length C of the bottom surface of the corner plate is less than 25 mm and the height Hs of the side plate is less than 60 mm as in the invention described in claim 2, the features of the present invention can be fully utilized. It is a highly reliable tray-type paper container.

FIG. 1 is a perspective view of a tray-type paper container according to the present invention, showing a state in which the lid material is not sealed. FIG. 2 is a perspective explanatory view showing a state in which the tray pattern paper containers shown in FIG. 1 are stacked. FIG. 3 is a plan explanatory view of the tray pattern paper container shown in FIG. FIG. 4 is an enlarged view of a corner portion of FIG. 3, and is an explanatory view of points (Cp) that come into contact with each other when tray pattern paper containers are stacked. FIG. 5 is a plan explanatory view of a blank sheet of the tray pattern paper container shown in FIG. FIG. 6 is an enlarged view of a corner portion of the blank sheet shown in FIG. FIG. 7 is a cross-sectional explanatory view showing a cross section taken along the line AA of FIG. FIG. 8 is a cross-sectional explanatory view showing a cross section of FIG. 6 BB'. FIG. 9 is a blank sheet of the conventional tray pattern paper container used in Comparative Example 2. FIG. 10 is a perspective view of the conventional tray pattern paper container used in Comparative Example 2.

The tray pattern paper container according to the present invention will be described in detail with reference to the following drawings. FIG. 1 is a perspective view of the tray pattern paper container 1 according to the present invention, showing a state in which the lid material is not sealed. FIG. 2 is a perspective explanatory view showing a state in which the tray pattern paper containers 1 shown in FIG. 1 are stacked. FIG. 3 is a plan explanatory view of the tray pattern paper container 1 shown in FIG. FIG. 4 is an enlarged view of a corner portion of FIG. 3, and is an explanatory view of points (Cp) that come into contact with each other when the tray pattern paper containers 1 are stacked. Further, FIG. 5 is a plan explanatory view of the blank sheet BL of the tray pattern paper container 1 shown in FIG. 1, and FIG. 6 is an enlarged view of a corner portion thereof. Further, FIG. 7 is a cross-sectional explanatory view showing a cross section taken along the line AA of FIG. 3, and FIG. 8 is a cross-sectional explanatory view showing a cross section taken along the line BB'in FIG.

The tray pattern paper container 1 according to the present invention is a tray pattern paper container formed from one blank sheet (BL) composed of a laminate 2 having a paper layer 3 and an inner surface resin layer 4, as shown in FIG. be. In the blank sheet, the inner surface resin layer 4 is formed on the entire surface of the paper layer 3 after the necessary punching is performed, and then the blank sheet is punched into a predetermined shape. The blank sheet has a bottom plate 5 having a shape in which a regular octagon is stretched in the vertical and horizontal directions, and the four unstretched sides of the bottom plate 5 are routed via mountain fold ruled lines e, f, g, and h, respectively. Rectangular corner plates 6 are connected in series.

The paper layer, which usually corresponds to the outside of the container, is printed and displayed on the surface side of the laminate. Therefore, a fold ruled line having a mountain on the paper layer side is a mountain fold ruled line, and a fold ruled line having a valley on the paper layer side is a valley fold ruled line. In FIG. 5, the mountain fold ruled line is displayed as a dotted line, and the valley fold ruled line is displayed as a alternate long and short dash line. Note that FIG. 5 shows a state in which the blank sheet is viewed from the inner surface side.

Inverted trapezoidal side plates 7 are connected to the other sides of the bottom plate 5 via mountain fold ruled lines a, b, c, and d, respectively, and valley fold ruled lines i, j, k, l are connected to each side plate. Flange portions 8 are continuously provided via the above.

The paper layer 3 is punched out between each corner plate 6, the side plate 7 and the flange portion 8, and there is a portion of only the inner surface resin layer 4. In molding, the tip portion and the flange portion 8 of each side plate 7 are folded inside each corner plate 6 and molded so that the tips of the respective side plates do not overlap each other.

By preventing the flange portions 8 on the four sides from overlapping each other, the flange portions 8 after molding have a flat finish, and since there are no steps, pinholes do not occur when the lid material 10 is sealed, and the flange portions 8 are sealed. The sex has increased.

Further, since the blank sheet is formed by forming the inner surface resin layer 4 on the entire surface after the paper layer 3 is punched and then punched into a predetermined shape, the inner surface resin is used in the tray-shaped paper container after molding. Since the layer 4 exists continuously from the bottom surface to the flange portion, there is no concern that water leakage will occur.

FIG. 6 is an enlarged view of a corner portion of the blank sheet (BL), and is an explanatory view of a length C at the bottom of the corner plate 6 and a height Hs of the side plate 7. As shown in FIG. 2, the distance between the tray pattern paper containers (stack pitch Sp) when the tray pattern paper containers 1 are stacked is calculated from the formula shown in Equation 1, and is the length of the base of the corner plate 6. It is known that it is determined only by the height Hs of C and the side plate 7.

Table 1 is a calculation of the Sp value when the value of C is changed from 5 mm to 27.5 mm at intervals of 2.5 mm and the value of Hs is changed from 20 mm to 80 mm at intervals of 5 mm. The shaded area in the figure indicates that the Sp value is within the range of 6 mm to 20 mm.

It is empirically known that if the Sp value is in the range of 6 mm to 20 mm, the suitability in the filling machine is good, and if it is smaller than 6 mm, a take-out error may occur. On the contrary, if it is larger than 20 mm, the loading efficiency deteriorates, and it becomes necessary to replenish the container frequently. Further, in the relationship between the container height and the stack pitch, Sp <container height × 0.4 is preferable.

In the case of the tray-type paper container according to the present invention, when stacked, the paper containers come into contact with each other only at the Cp inside the corner plate side surface portion and the flange portion of the octagonal corner as shown in FIGS. Moreover, it is a point contact. Therefore, when the paper containers are stacked, the paper containers do not come into close contact with each other, and a take-out error does not occur.

The material of the paper layer 3 is not particularly limited, but various paperboards, coated cardboards, carton base papers, cup base papers, and the like generally used for paper containers can be used.

The material used for the inner resin layer 4 can be selected according to the intended use of the tray-type paper container. For example, if microwave heating is required, polypropylene (PP) resin or polyethylene terephthalate having high temperature resistance can be selected. (PET) resin, polybutylene terephthalate (PBT) resin and the like are used. If high temperature resistance is not required, low density polyethylene resin (LDPE), medium density polyethylene resin (MDPE), linear low density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene- Ethylene resins such as α-olefin copolymers and ethylene-methacrylic acid resin copolymers, blended resins of polyethylene and polybutene, propylene-ethylene random copolymers, propylene-ethylene block copolymers, and propylene-α-olefins. Synthetic resins generally used as sealants such as copolymers can be used alone or in combination.

Hereinafter, the stacking suitability when the length C of the bottom of the corner plate 6 and the height Hs of the side plate 7 were actually changed was confirmed.

<Example 1>
A blank sheet was punched out after removing a window from a cup base paper having a basis weight of 260 g / m ² and attaching an inner resin layer to the inner surface side of the paper. As the inner surface resin layer, a polyethylene resin film having a thickness of 40 μm was used. The length C of the bottom of the corner plate was 12.5 mm, and the height Hs of the side plate was 40 mm. At this time, the height of the container was 33.2 mm. When a blank sheet was made into a box to make a tray container and 40 pieces were stacked, the stack pitch Sp was 12.5 mm, the Sp value and the ratio of the Sp value to the container height were not high, and the loading efficiency was good. rice field. In addition, the stacked trays did not tilt. On the filling machine, the trays could be easily separated from the stacked state.

<Example 2>
A blank sheet was punched out after removing a window from a cup base paper having a basis weight of 260 g / m ² and attaching an inner resin layer to the inner surface side of the paper. As the inner surface resin layer, a three-layer film of polyethylene 15 μm / PET 12 μm / polyethylene 30 μm was used. The length C of the bottom of the corner plate was 15 mm, and the height Hs of the side plate was 50 mm. At this time, the height of the container was 41.0 mm. When a blank sheet was manufactured to prepare a tray container and 40 pieces were stacked, the stack pitch Sp was 16 mm, neither the Sp value nor the ratio of the Sp value to the container height was high, and the loading efficiency was good. In addition, the stacked trays did not tilt. On the filling machine, the trays could be easily separated from the stacked state.

<Comparative Example 1>
A blank sheet was punched out after removing a window from a cup base paper having a basis weight of 260 g / m ² and attaching an inner resin layer to the inner surface side of the paper. As the inner surface resin layer, a polyethylene resin film having a thickness of 40 μm was used. The length C of the bottom of the corner plate was 10 mm, and the height Hs of the side plate was 70 mm. When a blank sheet was manufactured to make a tray container and 40 pieces were stacked, the stack pitch Sp was 31 mm, the Sp value itself was high, and the loading efficiency was poor. The stacked trays did not tilt. Further, on the filling machine, the trays could be easily separated from the stacked state.

<Comparative Example 2>
After the inner surface resin layer was attached to the inner surface side of the cup base paper having a basis weight of 320 g / m ² , a blank sheet of a conventional paper tray as shown in FIG. 9 was punched out. A polypropylene resin having a thickness of 40 μm was used for the inner surface resin layer. The shape at the time of box making is as shown in FIG. The height of the side plate is Hs = 35.5 mm, whereas the height of the container is 35.0 mm. When 40 of these trays were stacked, the stack pitch was 20 mm, and the loading efficiency was poor. In addition, tilting was observed between the stacked trays, making it difficult to separate the trays on the filling machine.

1 ... Tray type paper container BL ... Blank sheet A ... Long side length B ... Short side length C ... Corner plate bottom base length Hs ... Side plate height Sp ... Stack pitch Cp ... Contact point 2 ... Laminated body 3 ... Paper layer 4 ... Inner surface resin layer 5 ... Bottom plate 6 ... Corner plate 7 ... Side plate 8 ... Flange portion 10 ... Lid material a to h ... Mountain fold ruled line i to l ... Valley fold ruled line

Claims (2)

A tray-type paper container formed from a single blank sheet composed of a laminate having a paper layer and an inner surface resin layer.
The blank sheet is obtained by forming an inner resin layer on the entire surface after punching the paper layer as necessary, and then punching it into a predetermined shape.
The blank sheet has a bottom plate having a shape in which a regular octagon is stretched in the vertical and horizontal directions, and rectangular corner plates are continuously provided on each of the four unstretched sides of the bottom plate via a mountain fold ruled line. And
On the other sides of the bottom plate, inverted trapezoidal side plates are connected via mountain fold ruled lines, and on each side plate, flanges are connected via valley fold ruled lines.
The paper layer is punched out between each corner plate and the side plate and the flange portion, and there is only a portion of the inner surface resin layer.
In molding, the tip and flange of each side plate are folded inside each corner plate so that the tips do not overlap each other.
The distance (Sp) between tray-type paper containers when stacking tray-type paper containers is
A tray pattern paper container characterized in that 6 mm <Sp <20 mm. When the length of the bottom of the corner plate is C and the height of the side plate is Hs,
The tray pattern paper container according to claim 1, wherein C <25 mm and Hs <60 mm.

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