JPS6360746A - Packaging material for tehrmoforming and manufacture thereof - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thermoformable packaging material suitable for distribution of fresh foods such as seafood, meat, fruits, vegetables, etc., and a method for producing the same. It is something.

[Background technology and its problems] Conventionally, packaging materials for fresh foods include trays made of thermoformed foamed sheets and resin sheets, and containers made of resin sheets to improve these materials to provide cushioning and water retention properties. Shredded foam sheets, paper, or sutra books are used as water-retaining materials on the bottom of the container, or extrusion laminates made of non-woven fabric, absorbent paper, foam materials, etc., and resin sheets are used. . However, in these conventional examples,
If a foam sheet or the like is laid or fixed on the bottom of the container, the workability is poor, and if extrusion lamination is used, the foam layer and sheet layer cannot be separated due to adhesive problems. Since it is limited to homogeneous resins, the types of water-retaining members that can be used and, by extension, the uses of the packaging material are limited.

Furthermore, in conventional examples, when a container having a predetermined shape is formed by thermoforming using a packaging material having a foam layer, the foam layer melts as the packaging material is heated, resulting in a cushioning effect and
The drawback is that it does not have a water retention effect. In addition, in the case of extrusion laminate, when the resin sheet is thin, laminates such as nonwoven fabric and blotting paper appear on the back side of the sheet, making thermoforming difficult, and even if thermoforming is possible, the commercial value of the thermoformed product is reduced. and becomes impractical. In particular, when laminating a resin sheet with a film made of a resin different from the sheet or a nonwoven fabric, it is necessary to perform a surface treatment such as oxidation treatment and then engage the resin sheet with an anchor effect, which is a complicated process. It is virtually impossible to laminate a thin sheet with a nonwoven fabric or the like. Furthermore, when laminating non-woven fabrics, absorbent paper, etc., these films and resin sheets are strongly engaged due to the anchor effect, so when thermoforming into a container-like object, the absorbent paper, etc. may crack or There is a problem that it breaks.

[Purpose of the invention]

An object of the present invention is to provide a packaging material for thermoforming that can be easily molded without causing cracks in the water-retaining member even when a resin sheet is laminated to the water-retaining member during thermoforming, and a method for manufacturing the same. It is in.

[Means and effects for solving the problems] The present invention has the following features:
For example, a water-retaining member made of multiple layers of paper bonded together by needle punching, and a film-like member made of a first resin that is bonded to this water-retaining member via an adhesive to form a composite film together with the water-retaining member. and a resin sheet laminated with this film-like member and made of a second resin that is compatible with the first resin. As a result, the water-retaining member is not engaged with the first resin film-like member due to the anchor effect, so it is highly flexible even when thermoforming trays, etc., and can be used for the purpose described above without impairing thermoformability. can be achieved.

The method for producing a thermoforming packaging material of the present invention includes laminating a water-retentive member and a film-like member made of a first resin with an adhesive, using dry lamination, sea urchin 7 laminate, etc. This film-like member is extrusion laminated with a resin sort made of a second resin that is compatible with the film-like member.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of a thermoformable packaging material according to the present invention.

In FIG. 1, a film-like member 1 made of a first resin is bonded to a water-retentive member 10 such as paper shown at the uppermost position by dry lamination or wet lamination via an adhesive 6, and thereby the composite material film 1
2 is formed. A resin sheet 20 made of a second resin that is compatible with this first resin is extrusion laminated onto the film-like member l made of a first resin of this composite film 12. A thermoformable packaging material 22 is formed.

Here, the water-retaining member 10 is a material having water-retaining properties such as paper such as absorbent paper, synthetic or natural nonwoven fabric, or open-cell foam sheet, and has a thickness of 50 μm to 5 μm.
cm is used. In this case, in the case of paper such as blotting paper, multiple layers may be needle-punched and partially locked or joined, and in the case of non-woven fabric,
Regardless of whether it is long or short fiber, it has more hydrophilic properties,
Alternatively, those subjected to hydrophilic treatment are preferable.

In addition, the film-like member 1 made of the first resin is made of polyolefin (PO), polystyrene (P
S), polyamide, polyethylene terephthalate (PE
T), polycarbonate (PC), etc. are used, and the thickness of the film is 10 to 1000 μm, preferably 10 to 1000 μm.
It is 500 μm, more preferably 10 to 100 μm. The adhesive 6 may be made of vinyl resins such as vinyl acetate or vinyl chloride, cellulose resins such as nitrocellulose or ethyl cellulose, copolymers of synthetic rubber and acrylic resins, urethane resins, epoxy resins, etc. is,
The type is not particularly limited, but urethane-based, acrylic-based, and other types used for food are preferred.

Further, the resin sheet 20 made of the second resin has a thickness of 100 μm to 3 fl, preferably 200 μm to 2 am.
Further, the type of resin can be appropriately selected depending on the application, such as PO, PET, PS, high impact polystyrene (HIPS), vinyl chloride, etc., and is said to be compatible with the first resin.

Note that the second resin may contain an inorganic filler or various additives.

Next, an embodiment of the manufacturing method according to the present invention will be described with reference to FIGS. 2 and 3.

FIG. 2 shows a schematic configuration of an apparatus for performing dry lamination among the apparatuses used to carry out the manufacturing method according to the present invention.

In FIG. 2, a rubber roll 3 and a gravure roll 4 are provided on one side of a roll 2 around which a film-like member l made of a first resin is wound, and this gravure roll 4 is housed in a pan 5. A part of the film-like member 1 is immersed in the adhesive 6, and the film-like member 1 is inserted between these rolls 3 and 4, and the adhesive 6 is applied to the first side of the film-like member.

A drying section 7 is provided downstream of the rolls 3.4, in which the adhesive 6 applied to the film-like member 1 inserted between the rolls 3.4 is dried.

On the downstream side of the drying section 7, a rubber roll 8 and a steel roll 9 are provided.On the other hand, on the upper right side of these rolls 8°9 in the figure, a roll 11 on which a water retaining member 10 is wound is provided. When the film-like member 1 and the water-retaining member 10 are inserted through the roll 8.9 with the adhesive 6 in between, the film-like member 1 and the water-retaining member 10 are pressed together to form a composite film 12. Further, this film 12 is wound to form a composite material roll 13.

FIG. 3 shows a schematic diagram of an apparatus for extrusion laminating a resin sheet 20 on the composite film 12 formed by the apparatus shown in FIG. 2, among the apparatuses used to carry out the manufacturing method of the present invention. The configuration is shown and the apparatus forms a thermoformable wrapper 22.

In FIG. 3, the feeding section 14 includes the composite material roll 1
An example of this composite roll 13 is provided with a pair of pressure rolls 15 and a cooling roll 16 at a temperature of 100°C to 250°C, and the composite film 12 unwound from the composite roll 13 is supported by a guide roll 17. It is inserted between both rolls 15 and 16 so that the water-retaining member 10 side faces the pressure roll 15 and the film-like member I side faces the cooling roll 16. Here, the cooling roll 16 also acts as a pressure roll.

On the other hand, an extrusion molding machine 30 is arranged above the pressure roll 15 and the cooling roll 16, and this extrusion molding machine 30
Hopper 18 into which the resin material is charged, this second resin
It is comprised of an extruder 19 that heats and melts at 90° C. to 280° C., and a die 21 that extrudes a resin sheet 20 made of a second resin between a pressure roll 15 and a cooling roll 16. The resin sheet 20 extruded from the die 21 is laminated onto the film-like member 1 side of the composite film 12, and is pressed and cooled between a pressure roll 15 and a cooling roll 16 to form a thermoforming packaging material 22. be done.

A packaging material 22 formed by laminating a composite film 12 and a resin sheet 20 is wound up by a winding section 24 via a guide roll 23 to become a packaging material roll 25. In addition, the packaging (packaging material 2 wound up on the roll 25)
2 is thermoformed by a molding device (not shown) to form a container of a predetermined shape.

According to this embodiment, when extrusion laminating the resin sheet 20 on the water-retaining member 10, the resin sheet 20 and the a-soluble film-like member l are laminated on the water-retaining member 10 in advance by a dry lamination method. Therefore, the material of the water retaining member 10 is not limited by the material of the resin sheet 20, and even if the resin sheet 2
Even if the water-retentive portion (OlO), such as a non-woven fabric or a foam layer made of a resin different from 0, can be laminated with this resin sheet 2o with sufficient adhesive strength. Therefore, the resin of the resin sheet 20 It is possible to select a water-retentive member lO suitable for the packaged item without changing the material.For this reason, for example, the resin sheet 20 can be used with a water-retaining member such as a foam material having a higher softening/!i!1 degree. 10 with resin sheet 20
By extrusion laminating the dry laminated film member 1 with Jl /8 properties, the air bubbles in the water retaining member 10 will not be melted and bonded by heat during thermoforming, so high water retaining and cushioning properties can be maintained. It becomes possible. Therefore, it has excellent water retention properties, which helps maintain the freshness of fresh foods.
It is possible to improve suitability for sale, and because it has excellent buffering properties, it is possible to improve protection of fresh foods, and by extension, to improve suitability for distribution. Moreover, in this embodiment, since the water-retaining member 10 is bonded to the film-like member 1 via the adhesive 6, it is highly flexible, and even during thermoforming, the water-retaining member 10 will not be damaged or cracked. Never,
Furthermore, since it has a so-called three-layer structure, the resin sheet 2
The appearance of the water-retentive member 10 on the back side of the product is good, and the product value can be improved. In addition, the water retaining member 10
If it is a double layer of needle-punched paper, even if it is a weak absorbent paper, the fibers can be entwined to achieve the desired strength.
It is possible to increase the thickness, and also to have excellent water retention and water absorption properties.

Next, a table of experimental results confirming the effects of this example is described below. Here, in each comparative example, other conditions were the same as in the experimental examples of the present invention, except that the film-like member 1 made of the first resin was not used.

In the present invention, the 'Xi Z for dry lamination and extrusion lamination is not limited to the one shown in FIGS. You can. Also,
When performing extrusion lamination, the temperatures of the pressure roll 15 and the extruder 18 are appropriately selected depending on the members to be laminated. For example, when laminating an impact-resistant polystyrene resin sheet to a composite film of needle-punched filter paper and a 50 μm polystyrene film, the temperature of the pressure roll 15 may be 50°C to 150°C. good.

〔Effect of the invention〕

According to the present invention as described above, even if a resin sheet is laminated to a water-retaining member, the water-retaining member can be easily molded without causing cracks or the like during thermoforming.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the thermoforming packaging material of the present invention;
FIG. 2 is a schematic diagram of a dry laminate used to implement an embodiment of the manufacturing method of the present invention, and FIG. 3 is a schematic diagram of an extrusion laminate used to implement the embodiment. be. 1... Film-like part consisting of the 1st m fat (E, 6...
Adhesive, 10... Water-retaining member, 12... Composite film, 15... Pressure roll, 16... Cooling roll acting as a pressure roll, 20... Resin sheet made of second resin, 22... Thermoforming packaging material, 30... Extrusion molding machine.

Claims (4)

[Claims] (1) A composite film is formed including a water-retaining member and a film-like member made of a first resin bonded to the water-retaining member via an adhesive, and a first
1. A packaging material for thermoforming, characterized in that the film-like member side of the resin is laminated to a resin sheet made of a second resin that is compatible with the first resin. (2) The thermoforming packaging material according to claim 1, wherein the water-retaining member is a plurality of layers of paper bonded to each other by needle punching. (3) A composite film is formed by laminating the water-retentive member and a film-like member made of a first resin via an adhesive, and the first resin is placed on the side of the film-like member made of the first resin of the composite film. 1. A method for producing a thermoforming packaging material, which comprises extrusion laminating a resin sheet made of a second resin that is compatible with . (4) In claim 3, the extrusion laminate is characterized in that a resin sheet of a second resin extruded from an extrusion molding machine and a composite film are combined together with a pressure roll.
A method for producing a thermoforming packaging material, characterized in that the method is carried out at a temperature of 00°C to 250°C.