JP3191848U - Mold used for manufacturing foamed resin trays - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold capable of transferring grain to a raised portion of a foamed resin tray with good reproducibility. SOLUTION: The mold is a mold used for manufacturing a foamed resin tray having a raised portion having a texture 26 formed on the surface from a foamed resin sheet, and corresponds to the foamed resin tray. It is composed of a pair of male molds 23 and female molds forming a cavity, and the male mold has a flat surface 25 on which a grain 26 is formed at a portion corresponding to a raised portion of the foamed resin tray. [Selection diagram] FIG. 8

Description

  The present invention relates to a mold used for manufacturing a foamed resin tray, and more particularly to a mold used to manufacture a foamed resin tray from a foamed resin sheet.

  Prior art related to this device is a mold for collectively molding a plurality of foamed resin trays from a foamed resin sheet, and individual molds corresponding to the plurality of foamed resin trays among the molds. By providing a point clamp to clamp and clamp the foamed resin sort to the minimum at the boundary part, and by allowing the foamed resin sheet to be drawn into individual molds at the time of molding, uniform wall thickness and There is known a mold that enables manufacture of a foamed resin tray having an outer shape (see, for example, Patent Document 1).

JP-A-6-226834

Conventionally, foamed resin trays made of foamed resin have been used as packaging containers for packaging and displaying foods at retail stores such as fresh food stores.
In recent years, the foamed resin trays are required not only to store foods but also to add value to store foods in an attractive manner, and foamed resin trays of various designs have been developed.
Under such circumstances, attempts have been made to enhance the sense of quality by applying a texture to the surface of the foamed resin tray.
However, foamed resin trays tend to shrink especially in the thickness direction during cooling after molding. Therefore, if the texture is simply formed on the surface of the mold, the texture transferred on the raised portion will shrink when cooled. There is a problem that it disappears, and this causes a restriction on the design.

  The present invention has been made in consideration of the above circumstances, and provides a mold capable of transferring a texture with good reproducibility to a raised portion of a foamed resin tray.

  This device is a mold used to manufacture a foamed resin tray having a raised portion with a textured surface formed from a foamed resin sheet, and is a pair that forms a cavity corresponding to the foamed resin tray. The male mold provides a mold characterized in that a portion corresponding to the raised portion of the foamed resin tray is a flat surface on which a texture is formed.

According to this device, since the portion corresponding to the raised portion of the foamed resin tray is a flat surface on which the embossing is formed, the thickness of the foamed resin sheet is extended by the portion corresponding to the raised portion. Reduction can be prevented, and the foamed resin sheet having an appropriate thickness can be sufficiently brought into close contact with the flat surface on which the texture is formed, so that the texture can be transferred to the surface of the raised portion with good reproducibility.
The wrinkles transferred to the ridges are deeply transferred in close contact with the mold so that they do not disappear from the surface of the ridges even when contracted during cooling.

  The finding that suppressing the expansion of the foamed resin sheet in the mold leads to improved reproducibility of the texture was first found by the inventors of the present application, and the inventors of the present application based on the above knowledge As a result of repeated contrivances, the above-mentioned problems have been solved by setting the portion where the texture is to be formed as a flat surface.

It is a perspective view of the tray made from foamed resin manufactured with the metal mold | die which concerns on embodiment of this invention. FIG. 2 is a plan view of the foamed resin tray shown in FIG. 1. It is AA arrow sectional drawing of FIG. It is explanatory drawing which shows the state which accommodated the foodstuff in the tray made from foamed resin manufactured with the metal mold | die which concerns on embodiment of this invention, and was wrapped. It is the B section enlarged view of FIG. It is explanatory drawing which shows the manufacturing method of the foam resin-made trays using the metal mold | die which concerns on embodiment of this invention. It is explanatory drawing which shows the structure of the metal mold | die which concerns on embodiment of this invention. It is the C section enlarged view of FIG.

  A mold according to the present invention is a mold used for manufacturing a foamed resin tray having a raised portion with a textured surface formed from a foamed resin sheet, and has a cavity corresponding to the foamed resin tray. It consists of a pair of male mold and female mold to be formed, and the male mold is characterized in that a portion corresponding to the raised portion of the foamed resin tray is a flat surface on which a wrinkle is formed.

  In the mold according to the present invention, the foamed resin sheet used as a processing material means a thermoplastic resin sheet containing a large number of bubbles. Examples of such foamed resin sheets include foamed resin sheets such as polystyrene-based foamed resin sheets, polyethylene-based foamed resin sheets, polypropylene-based foamed resin sheets, and polyethylene terephthalate (PET) -based foamed resin sheets. Among them, a polystyrene-based foamed resin sheet having a high expansion ratio, excellent heat insulation and strength, and good moldability is preferable.

  Examples of the polystyrene-based foamed resin sheet include conventionally known polystyrene-based resins such as polystyrene, rubber-modified polystyrene, styrene acrylic acid copolymer, styrene methacrylic acid copolymer, and styrene maleic anhydride copolymer. After a known foaming agent and an air conditioner are melted and kneaded with an extruder, extruded from a die adjusted to a temperature suitable for foaming and then foamed, or once extruded into a cylindrical shape and foamed In addition, it is possible to use an incision formed at an arbitrary line and formed into a long sheet shape.

  Moreover, in the metal mold | die by this invention, a wrinkle means the pattern formed by the unevenness | corrugation, and it does not ask | require whether the said pattern has regularity. Therefore, the wrinkles include various patterns such as leather patterns formed by unevenness, wood grain, rock grain, sand grain, plain fabric, and geometric patterns.

  In the mold according to the present invention, the flat surface on which the texture is formed is a surface that is substantially flat as a whole, although fine irregularities forming a predetermined pattern or pattern are formed on the surface. It does not mean a smooth surface without any unevenness.

In the mold according to the present invention, the raised portion of the foamed resin tray has a frame-like shape that rises with a certain width so as to surround the opening of the foamed resin tray, and corresponds to the male raised portion May be a flat surface having a width of about 5 mm or more.
According to such a configuration, the foamed resin sheet easily adheres to the flat surface of the male mold, and the reproducibility of the wrinkles is further improved.

In the mold according to the present invention, the embossing may be formed of unevenness imitating the skin of a casting.
According to such a configuration, a high-quality foamed resin tray having a texture like an iron plate can be provided.

  Hereinafter, a foamed resin tray according to an embodiment of the present invention, a manufacturing method thereof, and a mold used in the manufacturing method will be described with reference to the drawings.

  A foamed resin tray manufactured by a mold according to an embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view of a foamed resin tray manufactured by a mold according to an embodiment of the present invention, FIG. 2 is a plan view of the foamed resin tray shown in FIG. 1, and FIG. 3 is an AA arrow in FIG. 4 is an explanatory view showing a state in which food is contained in a foamed resin tray manufactured by the mold according to the embodiment of the present invention and wrapped and wrapped, and FIG. 5 is an enlarged view of part B of FIG. .

As shown in FIGS. 1 to 3, the foamed resin tray 1 manufactured by the mold according to the embodiment of the present invention is made of foamed polystyrene, and has a bottom 2 and an upper edge opening 3 a rising from the periphery of the bottom 2. The side wall part 3 to be formed and the flat flange part 4 extending outward from the upper edge opening 3a of the side wall part 3 are provided. Although not shown, the surface (inner surface) of the foamed resin tray 1 is covered with a thermoplastic resin film.
The flange portion 4 is formed with a raised portion 5 which is raised so as to surround the upper edge opening 3 a of the side wall portion 3.
Further, as shown in FIG. 3, an auxiliary flange portion 4b is formed at the end of the flange portion 4 through a bent portion 4a that gently bends downward once and projects outward again. The bent portion 4 a and the auxiliary flange portion 4 b improve the strength of the flange portion 4.

As shown in FIG. 1 and FIG. 2, a texture 6 is formed on the raised portion 5, the side wall portion 3, and the peripheral edge 2 a of the bottom portion 2. In the present embodiment, the texture 6 is formed by unevenness imitating the surface of a casting, and the foamed resin tray 1 has a high-grade feeling like an iron plate.
A plurality of bowl-shaped grooves 7 are formed in parallel in the region excluding the peripheral edge 2 a of the bottom portion 2. The plurality of bowl-shaped grooves 7 constitutes a placement portion 8 on which an article to be accommodated is placed.

As shown in FIG. 4, for example, food 10 such as meat is placed on the placement portion 8, and the foamed resin tray 1 is packaged with the wrap 11.
At this time, as shown in FIG. 5, the wrap 11 is folded back at the end of the flange portion 4, that is, the auxiliary flange portion 4b, and a strong force is applied to the opening 9 of the foamed resin tray 1 (see FIGS. 1 and 2). Will be added.

However, since the foamed resin tray 1 acts so that the flange portion 4 and the raised portion 5 reinforce the upper edge opening 3a of the side wall portion 3, the strength of the opening portion 9 is improved. It is possible to prevent wrinkles and the upper edge opening 3a from being bent. This leads to an improvement in appearance and a good sealed state.
Further, as shown in FIG. 5, since the wrap 11 is supported at the three portions of the raised portion 5, the bent portion 4a, and the auxiliary flange portion 4b, a strong sealed state can be created. In particular, the auxiliary flange portion 4b is formed thinner than the other portions, and since it is in close contact with the wrap 11 at a high pressure, it is easy to bend back, and acts advantageously in creating a strong sealed state.

In the case of wrap packaging, the wrap 11 is supported at the three locations of the raised portion 5, the bent portion 4a, and the auxiliary flange portion 4b as described above, and therefore does not contact the flat flange portion 4. That is, the wrap 11 is lifted by the raised portion 5.
For this reason, it is possible to prevent the wrap 11 from being unnecessarily stuck to the flange portion 4 which is flat and has a relatively large area during wrap packaging, thereby deteriorating the workability of the wrap packaging.
In addition, as described above, since the ridges 5 are formed with wrinkles 6 on the surface thereof, the wrap 11 is difficult to stick to the ridges 5 that are the starting points of folding, and a certain amount of slip is ensured. The workability of is very good. This is an unexpected and unexpected effect brought about by the texture 6 that gives the foamed resin tray 1 a high-class feeling.

In addition, as shown in FIG. 4, the food 10 is placed on the placement portion 8 in which the bowl-shaped grooves 7 are formed, and thus is partially supported on the placement portion 8.
For this reason, even if the soup oozes out of the food 10, the soup can flow to the peripheral edge 2a of the bottom 2 through the groove 7, and the food 10 can be prevented from being immersed in the soup. . This is hygienic and also suppresses deterioration of the food 10.

  A method for manufacturing the foamed resin tray 1 having the above-described configuration will be described with reference to FIG. FIG. 6 is an explanatory view showing a method for producing a foamed resin tray using a mold according to an embodiment of the present invention.

As shown in FIG. 6, the molding machine 20 includes a heating furnace 21 that heats the foamed resin sheet 30 before molding, and a pair of male mold 23 and female mold 24 that sandwich the heated foamed resin sheet 30 from above and below. And a cutter (not shown) that cuts out each foamed resin tray 1 from the molded foamed resin sheet 30.
Although not shown, each of the male mold 23 and the female mold 24 is connected to a vacuum pump and configured to be able to perform vacuuming from a number of fine vacuum holes formed on the surface. Further, the male mold 23 and the female mold 24 are configured to be moved up and down by cylinder mechanisms 27 and 28, respectively.

In the molding machine 20, a raw roll R1 obtained by winding a polystyrene-based foamed resin sheet (PSP sheet) as a raw material and a film roll R2 obtained by winding a thermoplastic resin film in a roll are set.
When the foamed resin sheet 30 and the thermoplastic resin film 40 respectively fed out from the raw roll R1 and the film roll R2 pass through a pair of thermal rolls 29a and 29b arranged to face each other and heated to a predetermined temperature. Heat welded together. The foamed resin sheet 30 integrated with the thermoplastic resin film 40 is passed through the heating furnace 21 and heated to begin plasticization and secondary foaming.

The thermoplastic resin film 40 and the foamed resin sheet 30 exiting from the heating furnace 21 are passed between a pair of male mold 23 and female mold 24 and sandwiched between the male mold 23 and female mold 24. At this time, evacuation is performed by the male mold 23 and the female mold 24, and the foamed resin sheet 30 integrated with the thermoplastic resin film 40 is rapidly molded into the male mold 23 and the female mold 24 in accordance with the shape. The
Thereafter, the male mold 23 and the female mold 24 are disengaged, the shape is stabilized by cooling, and then a series of steps is completed by cutting out each individual foamed resin tray 1 with a cutter (not shown).

  The metal mold | die 22 which concerns on embodiment of this invention used with the above-mentioned manufacturing method is demonstrated based on FIG. 7 and FIG. FIG. 7 is an explanatory view showing the structure of the mold according to the embodiment of the present invention, and FIG. 8 is an enlarged view of a C portion of the mold shown in FIG.

As shown in FIG. 7, the mold 22 used in the above-described manufacturing method includes a pair of male mold 23 and female mold 24.
As shown in FIG. 8, the male mold 23 has a flat surface 25 in which a portion 26 corresponding to the raised portion 5 (see FIG. 3) of the foamed resin tray 1 is formed.
For this reason, when the foamed resin sheet 30 (see FIG. 6) is sandwiched between the male mold 23 and the female mold 24, the foamed resin sheet 30 does not have to be stretched at the portion corresponding to the raised portion 5. A decrease in the thickness of the foamed resin sheet 30 can be suppressed.
Since the thickness of the foamed resin sheet 30 is properly maintained, the foamed resin sheet 30 is strongly pressure-bonded to the surface of the male mold 23 at a portion corresponding to the raised portion 5, and the texture 26 formed on the flat surface 25 is It is transferred with good reproducibility as the texture 6 of the foamed resin tray 1 (see FIGS. 1, 2 and 5).

The formation of the texture 26 can be performed using a chemical removal method typified by etching or a physical removal method typified by sandblasting. The chemical removal method is reproducible for obtaining a certain desired pattern. It is preferable from the viewpoint.
In the chemical removal method, a photosensitive chemical-resistant film is formed on the surface of the male mold 23 in layers, and then exposed through a desired pattern and developed to form a chemical-resistant film layer having a desired pattern.
Thereafter, a chemical or electrochemical erosion action by an acid or alkali solution is applied to the exposed portion of the male mold 23 to dissolve the exposed portion, and when the unnecessary chemical-resistant film layer is removed, the texture 26 having a desired pattern is formed. The formed male mold 23 can be obtained.

DESCRIPTION OF SYMBOLS 1 Foamed resin tray 2 Bottom part 2a Peripheral edge 3 Side wall part 3a Upper edge opening 4 Flange part 4a Bending part 4b Auxiliary flange part 5 Raised part 6, 26 Groove 7 Groove 8 Placement part 9 Opening part 10 Food 11 Wrap 20 Molding machine 21 Heating furnace 22 Mold 23 Male 24 Female 25 Flat surfaces 27, 28 Cylinder mechanisms 29a, 29b Heat roll 30 Foamed resin sheet 40 Thermoplastic resin film R1 Original roll R2 Film roll

Claims (3)

  A mold for use in manufacturing a foamed resin tray having a raised portion with a textured surface formed from a foamed resin sheet, a pair of male molds forming a cavity corresponding to the foamed resin tray; and A metal mold comprising a female mold, wherein the male mold has a flat surface on which a portion corresponding to the raised portion of the foamed resin tray is formed.   The raised portion of the foamed resin tray has a frame shape that rises with a certain width so as to surround the opening of the foamed resin tray, and the portion corresponding to the raised portion of the male mold has a width of 5 mm or more. The mold according to claim 1, which is a flat surface.   The metal mold according to claim 1 or 2, wherein the texture is formed of unevenness imitating a cast skin.