WO2023013472A1

WO2023013472A1 - Seal device

Info

Publication number: WO2023013472A1
Application number: PCT/JP2022/028752
Authority: WO
Inventors: 隆秋本庄
Original assignee: オリオン機械工業株式会社
Priority date: 2021-08-04
Filing date: 2022-07-26
Publication date: 2023-02-09
Also published as: TW202308909A; JP2023023122A

Abstract

[Problem] To provide a seal device capable of carrying out heat sealing favorably even if the thickness of a seal section is not uniform. [Solution] A seal device 1 comprises a pair of seal members 3, 3 which are disposed facing each other and sandwich to heat seal a seal section 22 of a gusset bag 20 which has a surface layer made out of paper, the pair of seal members 3, 3 having heat resistant elastic members 6, 6 on respective opposing surfaces 8, 8. Heat sealing can thus be carried out favorably even if the thickness of the seal section 22 of the gusset bag 20 is not uniform.

Description

sealing device

The present invention relates to a sealing device that sandwiches and heat-seals the sealing portion of a gusset bag whose surface layer is made of paper.

Generally, a gusset bag is known in which both sides of a packaging bag are folded inward to form a gusset. When the opening end (sealed portion) of the gusset bag is sandwiched between a pair of seal bars and heat-sealed, there is a difference in thickness between the pair of gusseted portions and the other central portion, so the thickness of these portions is evenly distributed. It becomes difficult to heat-seal by applying pressure. Specifically, pressure is easily applied to the pair of gussets, and the contact between the gussets and the seal bar of the heat sealing device improves heat conduction and heat radiation efficiency. On the other hand, since it is difficult to apply pressure to the central portion, air tends to remain between the central portion and the seal bar of the heat sealing device, resulting in poor heat conduction and poor heat radiation efficiency. It becomes easy to accumulate, and problems, such as a film becoming cloudy, arise. In this case, especially near the boundary between the pair of gusset portions and the central portion, the heat seal layer is locally thinned and pinholes are likely to occur. Furthermore, due to such uneven pressure, the pressure is insufficient in the central portion, and the heat-seal layers in the central portion do not sufficiently contact each other, which may cause pinholes.

A sealing device described in Patent Document 1 has been proposed in order to address the above-mentioned problems. The sealing device described in Patent Literature 1 is a sealing device having first and second bar members which are opposed to each other and provided so as to be close to or separated from each other and which seal a gusset bag by sandwiching the first bar member. The member has a convex portion extending along the longitudinal direction and protruding toward the second bar member at a substantially central portion in the longitudinal direction of the first bar member. A gusset formed by folding both side surfaces into the inside of the gusset bag is provided. The length of the convex portion along the direction is configured to be longer than the length of the central portion of the cross section of the gusset bag excluding the gusset portion.

Japanese Unexamined Patent Application Publication No. 2010-18300

In the sealing device described in Patent Document 1, it is necessary to replace the sealing bar based on the bag size, bag shape, thickness of the sealing portion, etc., which is inefficient.

The present invention has been made in view of this point, and it is an object of the present invention to provide a sealing device capable of excellent heat sealing even if the thickness of the sealing portion is uneven.

The present invention, as a means for solving the above problems, is a pair of sealing members arranged facing each other and heat-sealing the sealing portion of a gusset bag whose surface layer is made of paper. wherein the pair of sealing members has a heat-resistant elastic member on each opposing surface.
According to the first aspect of the invention, the pair of sealing members has an elastic member on each opposing surface. Each elastic member of the sealing member deforms according to the step (difference in thickness) of the sealing part, making it possible to heat-seal the sealing part by applying almost uniform pressure, suppressing the occurrence of pinholes. can do. Therefore, the sealed portion of the gusset bag can be heat-sealed satisfactorily, and the sealability can be improved. In addition, the sealing part of the gusset bag has a surface layer made of paper and an inner layer made of a synthetic resin film with excellent heat-sealing properties. Although there may be a large difference in thickness at the sealing portion compared to the configuration configured as follows, the elastic deformation of the elastic member can absorb the difference in thickness.

The invention recited in claim 2 is characterized in that, in the invention recited in claim 1, the material of the elastic member is fluororubber.
In the invention of claim 2, the fluororubber is excellent in heat resistance, and also excellent in releasability such that substances in contact with the resin surface hardly stick or adhere to each other, thereby improving the sealing action. can. In short, since the releasability is excellent, the releasability of the sealed portion of the heat-sealed gusset bag from the pair of seal members can be enhanced. Therefore, if the elastic modulus (or hardness) of the elastic member is large, it becomes easier to apply pressure to the sealing portion, but it becomes difficult to elastically deform due to the difference in thickness of the sealing portion, resulting in insufficient adhesiveness. There is a risk of becoming. On the other hand, if the elastic modulus (or hardness) is reduced, elastic deformation becomes easier with respect to the difference in thickness of the seal portion, but it becomes difficult to apply pressure, and there is a risk that the adhesiveness will be insufficient. In view of this situation, by adopting fluororubber as the material of the elastic member, its elastic modulus (or hardness) is appropriate, and even if there is a difference in thickness at the seal part of the gusset bag, there will be no adhesion failure. Good heat seal is possible without generating.

The invention recited in claim 3 is characterized in that, in the invention recited in claim 2, the elastic member is formed in a plate shape, and the thickness thereof is set within a range of 0.3 mm to 2.5 mm. It is.
Therefore, the thickness of the elastic member is appropriately set in consideration of the thickness of the sealing portion, the amount of heat, and the like. be. On the other hand, if the thickness is too thin, the amount of elastic deformation will be small, and there is a risk that the adhesion of seal portions with different thicknesses will become uneven. In view of such circumstances, in the third aspect of the invention, the elastic member is made of fluororubber, and the thickness of the elastic member is in the range of 0.3 to 2.5 mm while considering the thickness of the sealing portion and the amount of heat. Since it is appropriately formed inside, the sealing performance of the sealing portion can be improved.

With the sealing device according to the present invention, it is possible to perform good heat sealing even if the thickness of the sealing portion is uneven.

FIG. 1 is a front view showing how a pair of sealing members of a sealing device according to an embodiment of the present invention heat-seal a sealed portion of a gusset bag. FIG. 2 is a side view of the sealing member of the sealing device according to the embodiment of the invention. FIG. 3(a) is a perspective view of a gusset bag whose sealed portion is heat-sealed by a sealing device according to an embodiment of the present invention, and FIG. 3(b) is a plan view of the open end.

A sealing device 1 according to an embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 3. FIG.
First, a gusset bag 20 whose open end 21 is heat-sealed as a sheet portion 22 will be described using the sealing device 1 according to the embodiment of the present invention. The gusset bag 20 has a surface layer made of paper and an inner layer made of a synthetic resin film having excellent heat-sealing properties. The synthetic resin film may be one having excellent heat-sealing properties, and for example, an olefin resin such as polyethylene or polypropylene is used. As shown in FIGS. 1 and 3, the gusset bag 20 has an open end 21, and when the open end 21 is opened, a front surface 25, a back surface 26, and both side surfaces 27 in the width direction. 27 and a bottom portion 28 that is formed by folding the front surface 25 and the back surface 26 inward on the bottom side of the gusset bag 20 .

When the open end 21 of the gusset bag 20 is closed, the side surface 27 is folded inside the gusset bag 20 to form the gusset portion 30, and the gusset bag 20 is in a flat state. As a result, the opening end portion 21 of the gusset bag 20 is formed with a pair of

gusset portions

30, 30 positioned at both ends in the width direction, and a central portion 31 positioned between the pair of

gusset portions

30, 30. be. The opening end portion 21 of the gusset bag 20 becomes the sealing portion 22 heat-sealed by the sealing device 1 according to the embodiment of the present invention. In short, the pair of

gusset portions

30, 30 and the central portion 31 located along the width direction of the open end portion 21 of the gusset bag 20 are heat-sealed. In the following description, the open end 21 of the gusseted bag 20 will be referred to as the sealing portion 22 . When the seal portion 22 of the gusset bag 20 is closed, the gusset portions 30 overlap in four layers and the central portion 31 overlaps in two layers. As a result, a difference in thickness (step) occurs between the pair of gusset portions 30 and the center portion 31 in the seal portion 22 of the gusset bag 20 .

The sealing device 1 according to this embodiment is a double-sided heat sealing device. As shown in FIGS. 1 and 2, the sealing device 1 according to the present embodiment includes a pair of sealing

members

3, 3 which are arranged to face each other and heat-seal by sandwiching the sealing portion 22 of the gusset bag 20. there is The sealing member 3 is formed in a thin plate shape as a whole. A pair of

seal members

3, 3 are arranged to face each other. The pair of

seal members

3, 3 are configured to be movable so as to approach and separate from each other. The sealing member 3 includes a heating plate-shaped portion 5 in which the cartridge heater 9 is built, and an elastic member 6 provided on the facing surface 8 of the heating plate-shaped portion 5 .

A cartridge heater 9, which is a heat source, is built into the heating plate-shaped portion 5. The heating plate-like portion 5 is heated to a predetermined temperature, which will be described later, by the operation of the cartridge heater 9 . A thermocouple 10 is incorporated as a temperature sensor in the heating plate portion 5 on the facing surface 8 side of the cartridge heater 9 . The length dimension along the longitudinal direction of the heating plate-shaped portion 5 is longer than the width dimension of the seal portion 22 of the gusset bag 20 . The heat generating plate portion 5 is supported by the base 14 via a plurality of

support members

13 , 13 . The pair of

bases

14, 14 are connected to a power transmission member (not shown) to which power is transmitted from a drive source (not shown) such as a servomotor provided in the seal device 1 according to the present embodiment. By moving the pair of

bases

14, 14 toward and away from each other, the pair of

seal members

3, 3 move toward and away from each other.

The facing surface 8 of the heating plate-shaped portion 5 is flat and formed in a substantially rectangular shape in plan view. An elastic member 6 is attached to the facing surface 8 . The elastic member 6 has a substantially rectangular shape in plan view and is formed in a thin plate shape. The elastic member 6 is made of fluororubber, which has excellent heat resistance. The elastic member 6 is attached to the facing surface 8 of the heat generating plate portion 5 with an adhesive. The thickness of the elastic member 6 is appropriately set within the range of 0.3 to 2.5 mm, taking into account the thickness of the seal portion 22 (the thickness of the

gusset portions

30, 30 and the central portion 31), the amount of heat, and the like.

The sealing temperature of the heating plate portion 5 depends on the thickness of the sealing portion 22 (the thickness of the

gusset portions

30, 30 and the central portion 31), the material of the synthetic resin film arranged in the inner layer of the gusset bag 20, and the like. Although it is set appropriately, it is set appropriately within the range of 130 to 200°C. In addition, the pressing force when heat-sealing the sealing portion 22 of the gusset bag 20 by the pair of sealing

members

3, 3 also depends on the thickness of the sealing portion 22 (thicknesses of the

gusset portions

30, 30 and the central portion 31) and Although it is appropriately set according to the material of the synthetic resin film arranged in the inner layer of the gusset bag 20, it is appropriately set within the range of 0.1 to 0.5 MPa. Furthermore, the pressurization time for heat-sealing the sealed portion 22 of the gusset bag 20 also depends on the thickness of the sealed portion 22 (thicknesses of the

gusset portions

30, 30 and the central portion 31) and the inner layer of the gusset bag 20. The time is appropriately set in accordance with the material of the synthetic resin film, etc., and is set appropriately within the range of 1 to 10 seconds.

When the sealing device 1 according to the present embodiment heat-seals the sealing portion 22 of the gusset bag 20 having a surface layer made of paper and an inner layer made of a synthetic resin film, the pair of sealing

members

3 , 3 the sealing portion 22 of the gusset bag 20 is arranged. After that, the pair of

seal members

3, 3 move closer to each other, and the

elastic members

6, 6 of the pair of

seal members

3, 3 press the seal portion 22 of the gusset bag 20 so as to sandwich it. Then, the sealed portion 22 of the gusset bag 20 is heat-sealed based on a predetermined sealing temperature, pressing force, and pressing time set in advance.

At this time, since the

elastic members

6, 6 are respectively attached to the facing

surfaces

8, 8 of the pair of sealing members 3, 3 (heat generating plate-shaped portions 5, 5), the pair of sealing

members

3, 3 When pressing the seal portion 22 of the gusset bag 20 so as to sandwich it, even if there is a difference in thickness (between the pair of

gusset portions

30, 30 and the central portion 31) in the seal portion 22 of the gusset bag 20, The elastic member 6 elastically deforms following the step (difference in thickness) of the seal portion 22, so that substantially uniform pressure is applied to substantially the entire width direction of the seal portion 22 (the pair of

gusset portions

30, 30 and the central portion 31). can be applied and heat-sealed. As a result, the sealing portion 22 of the gusset bag 20 can be heat-sealed well, and the sealing performance can be improved.

As described above, in the sealing device 1 according to the present embodiment, the object to be heat-sealed is the gusset bag 20 whose surface layer is made of paper and whose inner layer is made of a synthetic resin film.

Elastic members

6, 6 excellent in heat resistance are provided on the facing

surfaces

8, 8 of the heating plate-shaped

portions

5, 5 of 3, 3, respectively. As a result, even if there is a difference in thickness in the sealing portion 22 of the gusset bag 20 whose surface layer is made of paper, the

elastic members

6, 6 of the pair of sealing

members

3, 3 follow the steps of the sealing portion 22. Since it can be elastically deformed, it is possible to heat-seal by applying substantially uniform pressure to substantially the entire width direction of the seal portion 22 (the pair of

gusset portions

30, 30 and the central portion 31), resulting in the generation of pinholes. can be suppressed.

In addition, in the sealing device 1 according to the present embodiment, the elastic member 6 is made of fluororubber, which is excellent in heat resistance and releasability. In addition, fluororubber has an appropriate modulus of elasticity (or hardness), and even if there is a difference in the thickness of the sealed portion 22 of the gusset bag 20, it is possible to perform good heat sealing.

Furthermore, in the sealing device 1 according to the present embodiment, the material of the elastic member 6 is fluororubber, and the thickness of the elastic member 6 is in the range of 0.3 to 2.5 mm while considering the thickness of the sealing portion 22, the amount of heat, etc. Since it is appropriately set inside, the sealing performance of the sealing portion 22 can be improved.

1 Seal device, 3 Seal member, 6 Elastic member, 8 Opposing surface, 20 Gusset bag, 22 Seal part

Claims

A sealing device comprising a pair of sealing members disposed facing each other and heat-sealing a sealing portion of a gusset bag whose surface layer is made of paper, the sealing member comprising:
A seal device, wherein the pair of seal members has a heat-resistant elastic member on each opposing surface.
The sealing device according to claim 1, wherein the elastic member is made of fluororubber.
The sealing device according to claim 2, wherein the elastic member is formed in a plate shape and has a thickness set within a range of 0.3 mm to 2.5 mm.