JP5691340B2 - Water-resistant decorative carton manufacturing method - Google Patents

Description

  The present invention is used for containing various contents such as various beverages, liquid foods, fresh ingredients, etc., and it is necessary to form various decorative images such as printing on at least the surface thereof, and has excellent decorativeness. The present invention relates to a method for producing a carton substrate suitable for a functional carton, and improvement of a water-resistant decorative carton molded using the carton substrate.

  Various proposals have been made regarding water-resistant paper containers for containing beverages, liquid foods, fresh ingredients, and the like, and laminated materials suitable for their production.

  Although it is widely practiced to impregnate or apply a polyethylene resin to a paper substrate, high-density polyethylene (High Density) is focused on changes in properties depending on the crystallinity of the polyethylene resin. Patent Documents 1 and 2 are known as examples of reports referring to treatment with Polyethylene (HDPE) or low density polyethylene (Low Density Polyethylene; LDPE).

  In Patent Document 1, a high-density polyethylene film having a thickness of 20 μm or more is bonded to at least one surface of a paper via a low-density polyethylene extrusion coating layer, and a low-density polyethylene layer is further provided thereon. This is a polyethylene processed paper (claims), which realizes a polyethylene processed paper having a high tear strength by utilizing the fact that high-density polyethylene produced by the medium-low pressure method is stronger than low-density polyethylene.

  Patent Document 2 is a laminated material for paper containers in which a buffer layer, a barrier layer, and a sealant layer are sequentially laminated on one side of heat-resistant water-treated paper, and the buffer layer is made of nylon resin, medium density polyethylene resin, high density polyethylene resin. A laminated material for paper containers, which is a mixture of any resin selected from polypropylene resins, has a thickness of 10 to 70 μm, and has a tensile elastic modulus lower than that of the barrier layer The object of the present invention is to provide a laminated material for paper containers that can be retorted without generating pinholes.

Japanese Utility Model Publication No. 62-41803 Japanese Patent No. 4239821

  It is not required to be sealed as well as a container that directly stores liquid, and it does not require mechanical strength to accommodate large fish such as salmon and stacking during transportation, and it is relatively small such as vegetables and eggs. There is also a demand for cartons that are suitable for the storage of stored items and are required to be stored in a refrigerated or frozen state.

  Such a carton has a size limit of about 30 cm x 20 cm x 10 cm in length x width x height, and in order to use a corrugated cardboard having a structure in which the core portion is reinforced with liners on the front and back sides as a base material. A substrate made of paperboard having a thickness of 1 mm or less is sufficient because it is over-spec in terms of strength and cost.

The main object of the present invention is to provide a small and thin water-resistant carton excellent in decorativeness and its base material, and can easily form a clear printed image, and the obtained printed layer can be stored in a frozen or refrigerated state. It is intended to reduce the deterioration of decorativeness due to dropping or damage of the printed layer itself or surface processing due to the situation or the moisture or oil content of the contained material.

  In particular, when the printed layer is already dried during varnish application, moisture in the varnish enters between the ink dots, resulting in insufficient strength at the interface between the high-density polyethylene layer and the printed layer. That is, a phenomenon occurs in which the papers stick together when they are stacked, or a part of the layers peel and transfer to another paper.

In order to solve the above-mentioned problem, the present invention according to claim 1 provides a varnish layer that forms a low-density polyethylene layer , a high-density polyethylene layer , a decorative image printing ink layer, and a press coat layer on at least one surface of a paper substrate. the method of manufacturing a water-resistant decorative cartons made of waterproof paper that are laminated in this order,
The present invention provides a method for producing a water-resistant decorative carton, wherein only the crease line portion of the water-resistant decorative carton is subjected to water-resistant processing .
Moreover, the present invention according to claim 2 provides a method for producing a water-resistant decorative carton according to claim 1, further comprising a step of simultaneously drying the decorative image printing ink layer and the varnish layer. .

Further, the present invention according to claim 3 provides a method for producing a water-resistant decorative carton according to claim 1 or 2, wherein the further perform a smoothing process involving heating by specular roller from the press coat layer side Is.

Further, the present invention according to claim 4 provides the method for producing a water-resistant decorative carton according to claim 1 or 2 , further comprising performing matting treatment with heating by an embossing roller from the press coat layer side. Is.

Further, the present invention according to claim 5 is characterized in that the low-density polyethylene layer and the high-density polyethylene layer are formed by coextrusion molding, and the method for producing a water-resistant decorative carton according to any one of claims 1 to 4 Is to provide.

  According to the present invention, a substrate made of paperboard having a thickness of 1 mm or less is sufficient from the viewpoint of mechanical strength, and the size is about 30 cm × 20 cm × 10 cm or less in length × width × height. Even if it is a water resistant decorative carton, it may be necessary to have more thickness or liner reinforcement than necessary due to water resistance, oil resistance, refrigeration compatibility and refrigeration compatibility. Even if a water-resistant decorative carton having a size of about 30 cm × 20 cm × 10 cm or less in width × height is made of a base material made of paperboard having a thickness required from the viewpoint of mechanical strength, the decorative property can be improved. It is in providing an excellent small and thin water-resistant carton and its base material, and since the decorative image is in an undried state when varnish is applied, the moisture of the varnish does not enter between the halftone dots of the ink, and the density is high. Maintains the strength of the interface between the polyethylene layer and the printed layer It is easy to form a clear printed image without blocking phenomenon, ie, sticking when the paper is stacked or part of the layer is peeled off and transferred to other paper. A carton that can reduce the deterioration of decorativeness due to dropout or damage of the printed layer itself or surface processing due to the storage state of the printed layer frozen or refrigerated or the moisture or oil content of the contained material. A method for producing a substrate and a water-resistant decorative carton are provided.

It is a schematic diagram which shows an example of sectional drawing of the carton base material in this embodiment. It is a perspective view of the water-resistant decorative carton assembled with the carton substrate in the present embodiment. FIG. 3 is a development view of the water-resistant decorative carton of FIG. 2.

Hereinafter, a carton substrate according to an embodiment of the present invention and a method for producing a carton using the carton substrate will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing an example of the outer shape of a carton substrate in the present embodiment.

As shown in the figure, the water-resistant paper 1 has a 10 μm-thick low-density polyethylene layer 12 and a 10 μm-thick high-density polyethylene layer 13 laminated in this order on one side of a paperboard 11 having a basis weight of 370 g / m ² . On the other side of the paperboard 11, a 15 μm thick opposite low density polyethylene layer 14 is laminated. The low density polyethylene layer 12 and the high density polyethylene layer 13 are formed by coextrusion.

  In this case, the low density polyethylene layer on the opposite side is not necessarily required depending on the type of package contents, since it may not be necessary to consider penetration from the inside, and the thickness of each layer depends on the type of contents and machine It should be selected as appropriate depending on the type of liquid component such as moisture and moisture to be considered as penetration strength and the assumed generation amount.

  On this high-density polyethylene layer 13, six colors of offset printing were formed in a pattern with UV curable offset ink, and a decorative image 2 was provided.

  Further, immediately after the printing, a water-based varnish (manufactured by Dainippon Ink Co., Ltd .: product name HYDLITH P4036-S) was press-coated from above the decorative image 2 to provide a varnish 3. In this case, of course, the decorative image 2 is not yet dried.

  Therefore, the waterproof paper 1 is irradiated with UV lamp and near infrared light from the varnish 3 side, and the decorative image 2 and the varnish 3 are cured simultaneously with pressing by hot air blowing of 195 degrees to form a printing layer and a varnish layer. . Depending on the material and amount of the decorative image 2 and the varnish 3, conditions such as the temperature and time of the curing process are only given as an example, and the actual curing process is appropriately changed to appropriate conditions. Is common.

  In this case, the surface of the carton substrate is smoothed by a mirror roller for mirror finishing, the matte treatment by an embossing roller for roughening the surface, and the unevenness for embossing the surface. When treatment is required, it is efficient and preferable to carry out the curing simultaneously. As a result, the varnish is cured to become a press coat layer.

  In this case, the processing speed is 8000 sheets / hour (h).

  The carton substrate obtained as a result is punched as shown in FIG. 2, and the crease lines 61 to 73 are formed simultaneously with the punching process or separately. In this case, since the water resistance tends to be low at the crease lines 61 to 73, the crease line processing is preferred so that the water resistance is not as low as possible.

Further, a crease line 63 between the front piece 41 and the side piece 44, a crease line 62 between the rear piece 43 and the side piece 44, a crease line 61 between the rear piece 44 and the side piece 42, and the front piece 41. A crease line 64 between the adhesive strip 57, a crease line 65 between the rear piece 43 and the top piece 45, a crease line 66 between the rear piece 43 and the bottom piece 46, a side piece 42 and a folding tongue piece. 51, a crease line 71 between the side piece 42 and the folded tongue piece 53, a crease line 70 between the side piece 44 and the folded tongue piece 52, a side piece 44 and the folded tongue piece 54, The crease line 72 between the top surface piece 45 and the top surface insertion piece 55, the crease line 67 between the top surface piece 45 and the top surface insertion piece 55, and the crease line 68 between the bottom surface piece 46 and the bottom surface insertion piece 56 are subjected to folding processing. 64 is bonded to the side piece 42 and assembled as shown in FIG. 3 to complete a water-resistant decorative carton measuring 30 cm x 20 cm x 10 cm in length x width x height. That.

  Of course, a water-resistant decorative carton having a shape such as gluing the bottom surface, a shape other than a rectangular parallelepiped, or other shapes and structures may be used.

  The resulting water-resistant decorative carton has a clear image and satisfies the mechanical strength even in the case where the varnish is provided on the decorative image. Thickness according to the sufficient design thickness, the thickness of the paperboard is 1 mm, and even if it is frozen or refrigerated, the image will not deteriorate, even if moisture and oil ooze out from the inside or outside of the carton, Adhesiveness between the decorative image and water-resistant paper is good, and image degradation is small.

  In addition, although the water-resistant paper has purchased the commercially available thing, you may manufacture by application | coating or lamination. Moreover, although the low density polyethylene layer and the high density polyethylene layer were manufactured by co-extrusion, other lamination methods may be used. In addition, the low-density polyethylene layer and the high-density polyethylene layer showed an example of co-extrusion so that the problem of peeling due to the difference in heat shrinkage between the two layers did not occur. However, if there is no problem, another lamination method may be used.

  Various types of paperboard, such as Manila cardboard, can be used for strength and other reasons, and various thicknesses can be used, but the thickness depends on the mechanical strength of the carton. For example, in the case of 30 cm × 20 cm × 10 cm in length × width × height, about 1 mm is often sufficient in terms of performance.

  Further, in old JISK6748: 1995, high-density polyethylene is polyethylene having a density of 0.942 or more, and low-density polyethylene is polyethylene having a density of 0.910 to 0.930.

  In this water-resistant decorative carton, the contents are placed on the top side with the bottom insertion piece 56 inserted between the front piece 41 and the insertion tongue pieces 53 and 54 with the insertion tongue pieces 53 and 54 folded. The top surface insertion piece 55 can be used by closing it by inserting it between the front piece 41 and the folding tongue pieces 51, 52 in a state where the folding tongue pieces 51, 52 are folded.

  In this case, since the crease line portion tends to have lower water resistance than other portions, only the crease line portion may be additionally subjected to water resistance processing.

  INDUSTRIAL APPLICATION This invention can be utilized for the industry which concerns on the water-resistant carton excellent in the decorating property for accommodating various drinks, liquid food, fresh materials, etc.

DESCRIPTION OF SYMBOLS 1 ... Water resistant paper 11 ... Paper base material 12 ... Low density polyethylene layer 13 ... High density polyethylene layer 14 ... Opposite side low density polyethylene layer 15 ... Carrier detection part 2 ... Decoration image 3 ... Varnish 41 ... Front piece 42, 44 ... Side Piece 43 ... Rear piece 45 ... Top piece 46 ... Bottom piece 51, 52, 53, 54 ... Insert tongue piece 55 ... Top insert piece 56 ... Bottom insert piece 57 ... Paste allowance 61-73 ... Folded line

Claims (5)

Manufacture of a water-resistant decorative carton made of water- resistant paper in which a low-density polyethylene layer , a high-density polyethylene layer , a decorative image printing ink layer, and a varnish layer serving as a press coat layer are laminated in this order on at least one surface of a paper substrate A method,
A method for producing a water-resistant decorative carton, wherein only the crease line portion of the water-resistant decorative carton is subjected to water-resistant processing. The method for producing a water-resistant decorative carton according to claim 1, further comprising a step of simultaneously drying the decorative image printing ink layer and the varnish layer. The method for producing a water-resistant decorative carton according to claim 1 or 2 , further comprising performing a smoothing process accompanied by heating with a mirror roller from the press coat layer side. The method for producing a water-resistant decorative carton according to claim 1 or 2 , further comprising matting treatment with heating by an embossing roller from the press coat layer side. The method for producing a water-resistant decorative carton according to any one of claims 1 to 4 , wherein the low-density polyethylene layer and the high-density polyethylene layer are formed by coextrusion molding.

Images