JP6101427B2 - Package and method for producing the same - Google Patents

Description

  The present invention relates to a package in which sheets having a foam layer and a heat seal layer are overlapped and joined by the heat seal layer, and a method for manufacturing the same.

Resin foams such as polystyrene and polyethylene are excellent in strength, shock-absorbing properties, and processability, so they are processed into bags and used in large quantities as packaging for electrical appliances such as TVs and refrigerators and other equipment. (For example, refer to Patent Document 1).
Conventionally, such a package is formed by folding a sheet in which a film having heat-sealability is attached to the surface of the foam, and sealing a portion corresponding to a side portion of the package by, for example, a known impulse sealing method in Patent Document 2 or the like Then, the sealed parts are cut into individual packages.

JP 2010-280072 A JP-A-9-142484

By the way, in the impulse sealing method, an opening of a synthetic resin sheet or film is sandwiched between a sealing base and a sealing bar, a high voltage current is instantaneously applied to a heater wire to melt the opening, This is a method in which the state of holding the opening is maintained until the temperature is lowered to a certain temperature, and the holding is released and sealed after the melted portion is solidified.
The impulse sealing method has an advantage that it can be sealed in a short time compared to other sealing methods such as a high frequency sealing method and an ultrasonic sealing method.
However, even in such an impulse sealing method, since it is necessary to wait for coagulation while maintaining the sandwiched state for a while after the application of the high-voltage current, it takes about several seconds to seal. is there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a package that can be sealed in a shorter time than the impulse seal method described above and a method for manufacturing the package.

  In the production of a package having a foam layer and a heat seal layer, the foam layer has elasticity, so that it is difficult to join unless the heat seal layer is sufficiently melted and solidified.

Then, the manufacturing method of the package of this invention WHEREIN: In the manufacturing method of the packaging body which overlap | superposes the sheet | seat which has a foam layer and a heat seal layer, and joins the peripheral part of the said sheet | seat with the said heat seal layer, the said foam Preparing the sheet having the heat-sealing layer on at least one surface of the packaging body of the layer, stacking the sheets with the foam layer facing each other, and surrounding the packaging body in a superposed state The portion to be heated is pressed to crush the foam layer to form a thin-walled portion, and while maintaining the pressurized state, the shape of the thin-walled portion is cooled and fixed, and then the pressure is released, and the heat The sealing layer is melted and joined together with the foam layer at the thin wall portion.
In this way, since the thin-walled portion is formed in the part to be joined with the heat seal layer in advance, the influence of the elasticity of the foam layer can be reduced, and in the process of separating the package by fusing in a short time Heat seal layer can be joined.
In order to increase the joint strength of the joint part, it is preferable that the heat seal layer has a higher melting point than the foam layer, and the thin part may be embossed.

The package manufactured by the manufacturing method of the present invention has a sheet having a foam layer and a heat seal layer, and a peripheral portion of the overlapping sheet, and the peripheral portion has a joint portion of the heat seal layer. In the package, the sheet includes the heat seal layer on at least one surface of the foam layer, and the peripheral portion where the foam layers overlap, and the peripheral portion is thick. Is provided with a thin-walled portion of the foam layer, and a joint portion of the heat-seal layer is provided at an overlapping portion of the edge of the thin-walled portion .
The melting point of the heat seal layer may be higher than that of the foam layer, and the thin portion may have an embossed portion.

  Since the present invention is configured as described above, heat sealing by fusing can be completed in a short time, and cost reduction can be achieved by shortening the manufacturing time of the package or omitting the manufacturing process. Can do.

A preferred embodiment of the package of the present invention will be described in detail with reference to the drawings.
[First embodiment]
Fig.1 (a) is a perspective view which shows one Embodiment of the package of this invention, FIG.1 (b) is an expanded view of the sheet | seat for producing the package of Fig.1 (a).
The packaging body 10 is for packaging electronic devices, parts, and the like. As shown in FIG. 1 (a), after a sheet is folded at a folding portion 11c, both sides of the front side sheet 11a and the back side sheet 11b are placed. By joining the portions 11d and 11d, a bag having an opening 12 on one side is formed.

In FIG. 1B, “′” is attached to portions corresponding to the front side sheet 11a, the back side sheet 11b, and the side portion 11d in FIG.
As shown in FIG. 1B, the package 10 is provided at intervals corresponding to the width of one package 10 after being folded by a folded portion 11 c formed in the longitudinal direction of the long sheet 11. It is formed by cutting at the cutting position (indicated by reference numeral 11d ') and joining the both side portions 11d and 11d of the front side sheet 11a and the back side sheet 11b at the cutting position.

FIG. 2 is a schematic diagram for explaining a procedure for manufacturing the package 10 of FIG. 1, and shows a process after the sheet 11 of FIG. 1 (b) is folded by the folded portion 11c.
As shown in FIG. 2, the sheet 11 forming the package 10 in this embodiment is configured by laminating a foam layer 111 and a heat seal layer 112. An intermediate layer may be interposed between the foam layer 111 and the heat seal layer 112.

As a material constituting the foam layer 111, a polyolefin-based foamed resin can be suitably used. Polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, poly (4-methylpentene- 1), polystyrene, polyamide, polyethylene terephthalate, partial hydrolyzate of ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer and salts thereof, vinylidene chloride copolymer such as vinyl chloride-vinylidene chloride copolymer, etc. And foams of these mixtures. Among these, polypropylene and polyethylene (low density or high density polyethylene) are preferable.
The thickness of the foam layer 111 is preferably in the range of 0.5 mm to 5.0 mm, and the foaming magnification is preferably about 30 to 40 times.

The material constituting the heat seal layer 112 may be any material that can be joined by fusing, such as ethylene / vinyl acetate copolymer, polyethylene, metal salt of ethylene / (meth) acrylic acid copolymer, so-called Surlyn, polypropylene, and the like. Available. Among these, polyethylene or polypropylene is preferable. The heat seal layer 112 is preferably a film having a thickness of about 0.01 to 0.03 mm.
The heat seal layer 112 is preferably formed of the same material as the foam layer 111 from the viewpoint of processing after disposal and recycling. For example, when the foam layer 111 is formed of a low density polyethylene foam, The heat seal layer 112 is preferably formed of high density polyethylene.
When the foam layer 111 and the heat seal layer 112 are formed of different materials such as polyethylene and polypropylene, it is difficult to adhere the foam layer 111 and the heat seal layer 112 with sufficient strength. For example, the same material as the foam layer 111 may be coated on the surface of the heat seal layer 112.

In this embodiment, the melting point of the heat seal layer 112 is preferably higher than that of the foam layer 111, and the temperature difference is preferably 10 ° C. or more.
For example, when the foam layer 111 is made of low density polyethylene (LDPE) having a melting point of about 100 ° C. and the heat seal layer 112 is made of high density polyethylene (HDPE) having a melting point of about 135 ° C., the temperature difference is about 35 ° C. For this reason, this combination is suitable for producing the package 10 of the present invention. The temperature difference when linear low density polyethylene (LLDPE) having a melting point of about 123 ° C. is used instead of the low density polyethylene (LDPE) is about 12 ° C., and the foam layer 111 has the low temperature difference. A combination of these can also be suitably used because the temperature difference is about 65 ° C. when density polyethylene is used and polypropylene having a melting point of about 165 ° C. is used as the heat seal layer 112.

  The intermediate layer interposed between the foam layer 111 and the heat seal layer 112 is any layer having functions such as buffering, coloring, waterproofing, UV absorption, antistatic, strength improvement, and adhesion (including primer and coating). Is included. For example, examples of a material that imparts buffering properties include highly elastic resins such as polyolefin resins, vinyl copolymer resins, polyurethane resins, and polyamide resins.

  In order to manufacture the package of the present invention, as shown in FIG. 2A, a sheet 11 having a heat seal layer 112 attached to one surface of a foam layer 111 is turned into a folded portion 11c (FIG. 1 ( In step b), the layers are folded so that the faces of the foam layer 111 face each other, and the heat seal layer 112 is positioned on the respective surfaces of the front side sheet 11a ′ and the back side sheet 11b ′.

Next, as shown in FIG. 2B, the heating / pressure punches 20 and 20 are pressed from above and below to the cutting position 11d 'to heat and press the foam layer 111 to form a thin portion. The shape of the thin portion is fixed by cooling while maintaining the pressurized state.
At this time, it is preferable to form a large number of irregularities and corrugations on the surfaces of the heating and pressure punches 20 and 20 and to emboss the thin-walled portion with a large number of irregularities and corrugations. By forming such an embossing on the thin portion, the bonding strength of the heat seal layer 112 after fusing can be increased.

  Next, a cutting die 22 and a heated cutter 21 are prepared as shown in FIG. 2C, and the sheet 11 is cut at a cutting position 11d ′ as shown in FIG. The cutting die 22 is preferably in the form of a roller as shown in the figure. By shifting the contact position with the cutter 21 while rotating, the resin die generated during fusing adheres to the cutting die 22. Can be suppressed.

  The cutter 21 is heated using a heater. The heating temperature of the cutter 21 varies depending on the type and melting point of the resin that forms the foam layer 111 and the heat seal layer 112. For example, the foam layer 111 is formed of low-density polyethylene, and the heat seal layer 112 is made of high-density polyethylene. When formed, the cutter 21 may be heated to about 250 ° C to 400 ° C.

  Then, the cutter 21 heated to a certain temperature is lowered and stopped for a certain period of time while being in contact with the cutting die 22. This time depends on the type of resin forming the foam layer 111 and the heat seal layer 112 and the temperature of the cutter 21. For example, the foam layer 111 is formed of low density polyethylene and the heat seal layer 112 is high density polyethylene. Is approximately 0.1 second to 0.2 second. After this fixed time has elapsed, the cutter 21 is raised to end the fusing, but the time from the fusing start to the fusing end is about 1 second to 2 seconds. Thereby, as shown in FIG.2 (e), the heat seal layer 112 of the front side sheet | seat 11a and the heat seal layer 112 of the back side sheet | seat 11b fuse | melt.

[Second Embodiment]
FIG. 3 is a schematic diagram illustrating a process according to the second embodiment of the procedure for manufacturing the package 10. FIG. 3 also shows a process after the sheet 11 of FIG. 1B is folded at the folding portion 11c.
In this embodiment, as shown to Fig.3 (a), the sheet | seat 11 is folded and overlap | superposed by the folding | returning part 11c so that the surface of the heat seal layer 112 may face each other. Therefore, in the package 10 manufactured by the manufacturing method of this embodiment, the foam layer 111 is positioned on the surface of each of the front sheet 11a ′ and the back sheet 11b ′.
In this embodiment, the foam layer 111 and the heat seal layer 112 can be the same as those in the previous embodiment, but the temperature difference between the melting points of the foam layer 111 and the heat seal layer 112 is 0. It is preferable that the temperature is close to ° C.
Examples of the foam layer 111 and the heat seal layer 112 include a combination of low density or high density polyethylene and a combination of polypropylene.

As shown in FIG. 3B, a cutting die 21 and a heated cutter 21 are prepared, and the sheet 11 is cut at a cutting position 11d ′ as shown in FIG.
In this embodiment, since there is almost no difference in melting point between the foam layer 111 and the heat seal layer 112, the foam layer 111 and the heat seal layer 112 are formed of the same material as the previous embodiment. In this case, the temperature is set lower than the set temperature of the previous embodiment. For example, when the foam layer 111 and the heat seal layer 112 are formed of low density polyethylene, the cutter 21 may be set to about 150 ° C to 300 ° C.

Also in this embodiment, the fusing is completed in about 1 second to 2 seconds, and the cutter 21 is stopped for a predetermined time in a state where the cutter 21 is in contact with the cutting die 22. Thereby, as shown in FIG.3 (d), the heat seal layer 112 of the front side sheet | seat 11a and the heat seal layer 112 of the back side sheet | seat 11b fuse | melt.
In the manufacturing method of this embodiment, the heat sealing layer 112 of the front side sheet 11a ′ and the heat sealing layer 112 of the back side sheet 11b ′ overlap in contact with each other, so that the cutting position is the same as the manufacturing method of the first embodiment. This eliminates the need for the portion 11d 'to be pressurized and heated to make it thin, which is advantageous in that the step of forming the thin portion can be omitted.

Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above description.
For example, in order to increase the strength of the package 10, a sheet 11 having a heat seal layer 112 on both sides of the foam layer 111 is prepared, and the sheets 11 are overlapped and joined in the same procedure as in FIG. Also good.
Furthermore, in the above description, the sheet 11 is folded back by the folding part 11c, but two sheets 11 may be overlapped and joined by fusing at the peripheral part.

  The package of the present invention can be widely applied to the protection of appliances such as home appliances and machine products that are required to have buffering properties, heat retention, etc., parts such as electronic parts and machine parts, furniture, food, and the like.

(A) is a perspective view which shows one Embodiment of the package of this invention, (b) is a development view of the sheet | seat for producing the package of (a). FIG. 3 shows a process for manufacturing the package of FIG. 1. The process concerning other embodiment of the method of manufacturing a package body is shown.

DESCRIPTION OF SYMBOLS 10 Package 11 Sheet | seat 11a, 11a 'Front side sheet | seat 11b, 11b' Back side sheet | seat 11c Folding part 11d, 11d 'Side part 12 Opening part 20 Heating / pressurization punch 21 Cutter 22 Cutting die

Claims (3)

In the method of manufacturing a package, in which a sheet having a foam layer and a heat seal layer is overlaid, and a peripheral portion of the sheet is joined by the heat seal layer,
Preparing the sheet having the heat-seal layer on at least one surface of the foam layer to be the surface of the package;
The sheets are stacked with the foam layer facing each other,
In a superposed state, the peripheral portion of the package body is heated and pressed to crush the foam layer to form a thin-walled portion, and cooled while maintaining the pressurized state to fix the shape of the thin-walled portion. After releasing the pressure,
Fusing and joining the heat seal layer together with the foam layer at the thin-walled portion,
A manufacturing method of a package characterized by the above. The method for manufacturing a package according to claim 1, wherein the heat seal layer having a higher melting point than the foam layer is attached to the foam layer. The method for manufacturing a package according to claim 1 or 2, wherein the thin-walled portion is embossed simultaneously with the formation of the thin-walled portion or after the thin-walled portion is formed.

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