JP2015151137A - Heat seal device and production method of sealed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat seal device capable of suppressing occurrence of white turbidness and pin hole, and being used in general purpose.SOLUTION: The heat seal device comprises a first bar member and a second bar member, which are disposed so as to face each other, and sandwich plural films for performing heat seal. The first bar member has a heating part, and the second bar member has an elastic layer having 40 or lower of Asker C hardness.

Description

  The present invention relates to a heat sealing apparatus for thermally welding a film and a method for manufacturing a sealed object using the same.

The heat sealing apparatus is generally used in the manufacturing process of plastic film packaging materials such as foods, daily necessities, and medical drugs.
There are various forms of the packaging material, and examples thereof include a gusset bag in which side surfaces on both sides of the packaging material are folded inward to form a folded portion.

  When heat-sealing a gusset bag, there is a problem in that it is difficult to heat-seal by applying uniform pressure because there is a difference in thickness between the folded portion and a portion other than the folded portion. Pressure is easily applied to the folded portion, and heat conduction is improved and heat dissipation efficiency is improved by the contact between the folded portion and the seal bar of the heat seal device. On the other hand, since it is difficult to apply pressure at the part other than the folded part, air tends to remain between the part other than the folded part and the seal bar of the heat seal device, the heat conduction is poor, and the heat dissipation efficiency is deteriorated. Heat tends to accumulate. Due to such heat unevenness, the amount of heat is excessive in portions other than the folded portion, and the film foams and becomes clouded during heat sealing. Further, in this case, particularly in the vicinity of the boundary between the folded portion and the portion other than the folded portion, the heat seal layer is locally thinned and pinholes are easily generated. Further, it is considered that due to the non-uniform pressure, the pressure is insufficient in the portion other than the folded portion, and the heat seal layers in the portion other than the folded portion are not sufficiently in contact with each other, so that pinholes may be generated.

  The problem as described above is not limited to the gusset bag, and may occur in a packaging material in which a difference in thickness occurs due to folding or folding of the film.

  Patent Document 1 discloses a first bar member and a second bar member that are sealed with a gusset bag between them for the purpose of providing a sealing device that reliably seals the gusset bag without clouding the heat seal portion of the gusset bag. The first bar member includes a convex portion that extends along the longitudinal direction and protrudes toward the second bar member at a central portion in the longitudinal direction of the first bar member. The length of the convex part along the direction is longer than the length of the central part excluding the gusset part in the cross section of the gusset bag, and the convex part is about twice the packaging material of the gusset bag toward the second bar member side. Has been proposed. It is also disclosed that a heat-resistant tape formed of a material such as silicon rubber is provided on the opposing surfaces of the first and second bar members for heat resistance and impact resistance.

  Further, in Patent Document 2, it is arranged so as to sandwich two films for the purpose of providing a heat seal device that does not cause a sealing failure without leaving contents or bubbles inside the seal. A heat seal device that heat seals films by pressing a pair of seal members together, and when at least one of the seal members presses the seal members together, the seal members touch each other through the film. There has been proposed a heat seal device that is deformed so as to gradually widen the contact surface that comes into contact with it and has a convex curved surface on the film side. Moreover, it is disclosed that a silicon rubber plate having flexibility and deformable by pressing from the front is used for one seal member.

  Patent Document 3 discloses that a contact surface with a plastic film is formed from a seal width for the purpose of providing a heat sealing method that eliminates the generation of bubbles in the heat seal portion and has excellent seal strength and appearance of the seal portion. When a seal bar having an arcuate surface having a larger diameter is used, the seal width of the seal bar is D, and the arcuate radius of the contact surface with the plastic film is R, the radius R is D ≦ R. A method of sealing a pouch with ≦ 15D has been proposed. Further, it is disclosed that a rubber such as silicon rubber is disposed as a buffering agent on one seal bar.

In order to reliably heat seal the packaging material in this manner, it is known to use a heat sealing device including a seal bar having a shape that matches the shape of the packaging material. It is also known to use a point seal device that locally heat seals the folded portion. However, these apparatuses are special-purpose heat seal apparatuses with low versatility.
Therefore, a highly versatile heat sealing apparatus that can heat seal packaging materials such as gusset bags having different dimensions in a small lot is required.

JP 2010-18300 A JP 2003-341624 A JP 2003-81216 A

  The present invention has been made in view of the above problems, and provides a versatile heat sealing apparatus that can suppress the occurrence of cloudiness and pinholes, and a method for manufacturing a sealed object using the same. The main purpose.

  In order to achieve the above object, the present invention provides a heat sealing apparatus having a first bar member and a second bar member that are arranged opposite to each other and heat-seal with a plurality of films interposed therebetween, wherein the first bar The member has a heat generating part, and the second bar member has an elastic layer having an Asker C hardness within a predetermined range.

  According to the present invention, since the elastic layer of the second bar member has a predetermined Asker C hardness and is easily deformed, the second bar can be used even when heat-sealing a plurality of films having partial thickness differences. The elastic layer of the member can be deformed by following the steps of the plurality of films, heat unevenness can be suppressed, and the occurrence of white turbidity and pinholes can be suppressed. Therefore, a plurality of films in various forms can be heat sealed well, and a versatile heat sealing apparatus can be obtained.

  In the said invention, it is preferable that the said elastic layer contains a porous elastic body. Since the porous elastic body is easily elastically deformed and the elastic layer including the porous elastic body is easily deformed following the steps of the plurality of films, the occurrence of white turbidity and pinholes can be effectively suppressed. Further, since the porous elastic body can be deformed by collapsing bubbles, the shear stress during deformation is small, lateral displacement due to the shear stress can be suppressed, and peeling of the elastic layer can be suppressed.

  Further, the present invention is a method for manufacturing a sealed object, wherein a plurality of films are sandwiched between a first bar member and a second bar member and heat sealed, wherein the first bar member has a heat generating portion, The two-bar member has an elastic layer having an Asker C hardness within a predetermined range, the plurality of films have a folded portion or a folded portion, and the folded portion or the folded portion is heat-sealed. A method for manufacturing a sealed object is provided.

  According to the present invention, since the elastic layer of the second bar member has a predetermined Asker C hardness and is easily deformed, the elastic layer is provided even when heat-sealing a plurality of films partially having different thicknesses. The film can be deformed by following the steps of the plurality of films, heat unevenness can be suppressed, and the occurrence of white turbidity and pinholes can be suppressed. Therefore, a plurality of films having various forms can be heat-sealed satisfactorily.

  In this invention, generation | occurrence | production of a cloudiness and a pinhole can be suppressed, and there exists an effect that a versatile heat seal apparatus can be provided.

It is a schematic diagram which shows an example of the heat seal apparatus of this invention. It is process drawing which shows an example of the manufacturing method of the to-be-sealed body of this invention. It is a schematic diagram which shows an example of the gusset bag used for this invention. It is a schematic diagram which shows the other example of the gusset bag used for this invention. It is a schematic diagram which shows an example of the joint bag used for this invention.

  Hereinafter, the manufacturing method of the heat sealing apparatus and the object to be sealed according to the present invention will be described in detail.

A. Heat Seal Device The heat seal device of the present invention is a device having a first bar member and a second bar member that are arranged to face each other and heat-seal with a plurality of films interposed therebetween, wherein the first bar member generates heat. And the second bar member has an elastic layer having Asker C hardness within a predetermined range.

  Here, the plurality of films is a concept including, for example, a cylindrical or bag-like film in which a film is folded or folded.

The heat sealing apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a heat sealing apparatus of the present invention. In the heat sealing apparatus 1, the first bar member 10 and the second bar member 20 are disposed to face each other and are provided so as to be close to and away from each other. In the first bar member 10, a first insulating layer 12, a second insulating layer 13, a heating part 14 such as a nichrome wire, and a release layer 15 are arranged in this order on the surface of the first bar body 11 facing the second bar member 20. In the second bar member 20, the elastic layer 22 having an Asker C hardness within a predetermined range is disposed on the surface of the second bar body 21 facing the first bar member 10. The heat sealing apparatus 1 is a single-sided heating type, and heat seals by sandwiching a plurality of films between a first bar member 10 and a second bar member 20 and applying pressure and heating.

  FIGS. 2A to 2B are schematic views showing an example of a method of using the heat sealing apparatus of the present invention, which is an example of heat-sealing a gusset bag. First, as shown in FIG. 2A, the gusset bag 30 is arranged as a plurality of films between the first bar member 10 and the second bar member 20. Next, as shown in FIG. 2B, the gusset bag 30 is sandwiched between the first bar member 10 and the second bar member 20, pressurized, and the heat generating portion 14 is energized and heated, thereby heating. Seal.

  Here, in the state where the gusset bag 30 is sandwiched between the first bar member 10 and the second bar member 20, four films are laminated in the folding part 31, while the other parts than the folding part 31. In this part, two films are laminated. Therefore, the thickness is different between the folding portion 31 and the portion other than the folding portion 31, and the folding portion 31 is approximately twice as thick as the portion other than the folding portion 31.

  The elastic layer 22 disposed on the surface of the second bar member 21 facing the first bar member 10 can be elastically deformed and has an Asker C hardness within a predetermined range, and thus is easily deformed. Therefore, as shown in FIG. 2 (b), when the gusset bag 30 is sandwiched between the first bar member 10 and the second bar member 20, the elastic layer 22 is moved to a portion other than the folding portion 31 and the folding portion 31. It can be deformed by following the level difference with the part. Thereby, parts other than the thin folding part 31 also come into contact with both the first bar member 10 and the second bar member 20, and the parts other than the folding part 31 and the folding part 31 are separated from the heat generating part 14. Heat can be conducted uniformly. Accordingly, it is possible to suppress heat unevenness, suppress the occurrence of white turbidity and pinholes, and heat seal well.

  Moreover, although the example which heat seals a gusset bag was shown in FIG. 2, not only in a gusset bag, but also in the case of heat-sealing a plurality of films having partial thickness differences, the elastic layer of the second bar member Can be deformed by following the steps of the plurality of films.

  As described above, in the present invention, by arranging the elastic layer having the Asker C hardness within a predetermined range on the second bar member, it is possible to reliably form a plurality of films of various forms without causing white turbidity and pinholes. It becomes possible to heat seal. Therefore, it can be set as a versatile heat seal device.

  Hereinafter, each structure in the heat seal apparatus of this invention is demonstrated.

1. 2nd bar member The 2nd bar member in this invention is arrange | positioned facing the 1st bar member, and has an elastic layer whose Asker C hardness is a predetermined range.

The Asker C hardness of the elastic layer is 40 or less. If the Asker C hardness is too high, the elastic layer may not be deformed so as to follow the steps of the plurality of films. Further, the Asker C hardness can be reduced to the limit at which the elastic layer has elasticity, but is usually preferably 20 or more.
Here, Asker C hardness is a value measured with an Asker C-type hardness meter by a measuring method defined in Japan Rubber Association Standard SRIS 0101.

  The elastic layer preferably has heat resistance. Here, heat resistance means that the apparent density, tensile strength, and elongation rate do not change before and after heating when heated at a temperature heated by the heat generating portion.

  The elastic layer is not particularly limited as long as it satisfies the above Asker C hardness, and may include an elastic body, but among them, a porous elastic body is preferably included. Conventionally, silicon rubber or the like has been used as an elastic body used in a heat sealing apparatus, and an elastic body that is not porous has been used. Since the porous elastic body contains bubbles, it is more easily elastically deformed than the non-porous elastic body, and the Asker C hardness is lowered. Therefore, the elastic layer including the porous elastic body easily deforms following the steps of the plurality of films, and can effectively suppress the occurrence of white turbidity and pinholes. Further, the non-porous elastic body may be laterally shifted due to shear stress when deformed, and the elastic layer may be peeled off from the second bar body. On the other hand, since the porous elastic body can be deformed by collapsing bubbles, the shear stress when deformed compared to the non-porous elastic body is small, and the lateral displacement due to the shear stress can be suppressed, Peeling from the second bar body can be suppressed.

  The porous elastic body is preferably a rubber sponge. The rubber sponge is also referred to as sponge rubber or foam rubber. Examples of the rubber sponge include silicon rubber sponge and fluororubber sponge from the viewpoint of heat resistance.

  The thickness of the elastic layer is not particularly limited as long as it is a general thickness as an elastic layer in a heat seal apparatus, and can be set within a range of 2 mm to 10 mm. If the elastic layer is too thick, lateral displacement due to shear stress when the elastic layer is deformed may increase, and the elastic layer may easily peel off from the second bar body. Further, if the elastic layer is too thick, when the plurality of films are sandwiched between the first bar member and the second bar member, the film is greatly sunk into the elastic layer, and the heat seal portion and the non-heat seal portion It becomes easy to make a crease at the boundary. On the other hand, if the thickness of the elastic layer is thin, it may be difficult to deform the elastic layer by following the steps of the plurality of films.

  The 2nd bar member should just have an elastic layer, for example, what has the 2nd bar main part and the elastic layer arrange | positioned in the opposing surface of the 1st bar member of a 2nd bar main body may be mentioned. it can. The elastic layer can be disposed on the second bar body via an adhesive layer.

  A release layer may be disposed on the surface of the elastic layer facing the first bar member. By forming the release layer, the peelability of the plurality of heat-sealed films from the second bar member can be enhanced. The release layer is not particularly limited as long as it has heat resistance applicable to a heat seal device, and for example, a heat resistant tape such as a Teflon (registered trademark) tape can be used.

2. 1st bar member The 1st bar member in this invention is arrange | positioned facing a 2nd bar member, and has a heat-emitting part.
As the heat generating portion, a general heat generating portion used in a heat sealing apparatus can be applied, and for example, a metal wire such as a nichrome wire, or a metal plate such as a nichrome plate can be used.

The 1st bar member should just have a heat generating part, for example, the 1st insulating layer and the 2nd insulating layer laminated | stacked in order on the opposing surface of the 1st bar main body and the 2nd bar member of a 1st bar main body, for example. And those having a heat generating portion and a release layer.
The first insulating layer and the second insulating layer may be any heat-resistant tape that can be applied to a heat seal device, and for example, a heat-resistant tape such as a glass tape or a Sarcon (registered trademark) sheet can be used.
The release layer may be any layer having releasability and heat resistance applicable to a heat seal device. For example, a heat-resistant tape such as a Teflon (registered trademark) tape can be used.

3. Heat Seal Device The heat seal device of the present invention is a single-sided heat seal device. As a kind of heat sealing apparatus, what is necessary is just a single-sided heating type, for example, an impulse sealer, a hot plate sealer, etc. can be mentioned. Among these, an impulse sealer is preferable.

4). Application The heat sealing apparatus of the present invention heat seals a plurality of films.
The plurality of films are appropriately selected according to the purpose, and examples thereof include a cylindrical or bag-like film. Especially, it is preferable that a some film has a folding part which folded the film, and a folding | turning part which folded the film. In this case, the plurality of films may have a folded portion, may have a folded portion, or may have a folded portion and a folded portion. Specifically, a gusset bag and a palm bag are exemplified.
In addition, a folding part may be called a gusset part or a gusset part.

When the plurality of films is a gusset bag 30 having a folded portion 31 as shown in FIG. 3A, for example, the opening 32 is heat sealed using a heat seal device. In this case, the folded portion 31 and the portion other than the folded portion 31 having different thicknesses are heat-sealed. At the time of heat sealing, the elastic layer of the heat sealing device is stepped between the folded portion 31 and the portion other than the folded portion 31. It can be made to follow and deform.
In the case where the plurality of films is a gusset bag 30 having a folded portion 31 as shown in FIG. 4A, for example, the oblique portion 32a of the opening 32 is heat-sealed using a heat seal device, and FIG. When forming the heat seal part 33 as shown in (b), most of the part to be heat sealed becomes the folded part 31, and a part becomes a part other than the folded part 31. Also in this case, at the time of heat sealing, the elastic layer of the heat sealing device can be deformed by following the step between the folded portion 31 and the portion other than the folded portion 31.
In addition, when the plurality of films is a palm bag 35 having a folded portion 36 as shown in FIG. 5A, for example, the opening 32 is heat sealed using a heat seal device. In this case, the folded portion 36 and the portion other than the folded portion 36 having different thicknesses are heat-sealed. At the time of heat sealing, the elastic layer of the heat seal device is formed at a level difference between the folded portion 36 and the portion other than the folded portion 36. It can be made to follow and deform.
As described above, in the present invention, the elastic layer can be deformed by following the steps formed by the folded and folded portions of the plurality of films during heat sealing, and heat sealing can be performed without generating white turbidity and pinholes. it can.

The thickness of the film may be any thickness that allows heat sealing, but is preferably in the range of 30 μm to 300 μm.
Moreover, as a level | step difference by a folding part or a folding | returning part, it should just be a heat sealable grade, However, It is preferable to exist in the range of 60 micrometers-600 micrometers.

  Any film can be used as long as it can be heat-sealed. For example, a laminated film in which a surface layer base material and a heat seal layer are laminated, or a laminated film in which a surface layer base material, an intermediate layer, and a heat seal layer are laminated is used. be able to. The material for the heat seal layer may be any material having heat seal properties, and examples thereof include olefin resins such as polyethylene and polypropylene. In addition, the material for the surface layer base material and the intermediate layer is appropriately selected according to the strength, application, and the like, and examples thereof include polyethylene terephthalate, nylon, and aluminum. The film may be transparent or opaque.

B. Manufacturing method of sealed object The manufacturing method of the sealed object of the present invention is a manufacturing method in which a plurality of films are sandwiched between a first bar member and a second bar member, and the first bar member is The second bar member has an elastic layer having an Asker C hardness within a predetermined range, the plurality of films have a folded portion or a folded portion, and the folded portion or the folded portion is It is characterized by heat sealing.

2 (a) to 2 (b) are process diagrams showing an example of a method for producing a sealed body of the present invention, which is an example of heat-sealing a gusset bag. 2 (a) and 2 (b) are described in the above "A. Heat seal device", description thereof is omitted here.
When heat-sealing the opening 32 of the gusset bag 30 having the folded portion 31 as illustrated in FIG. 3A, the heat-sealed portion 33 as illustrated in FIG. The gusset bag 30 can be obtained.

  When heat-sealing the opening 32 of the palm bag 35 having the folded portion 36 as illustrated in FIG. 5A, the heat-sealed portion 33 as illustrated in FIG. It is possible to obtain a palm bag 35 having

  In the present invention, as described in the above-mentioned “A. Heat sealing device”, the elastic layer of the second bar member is placed between the folded portion and the folded portion of the plurality of films and the portions other than the folded portion and the folded portion at the time of heat sealing. It can be deformed by following the step. Accordingly, it is possible to suppress heat unevenness, suppress the occurrence of white turbidity and pinholes, and heat seal well.

  Since the first bar member, the second bar member, and the plurality of films are described in the above “A. Heat seal device”, description thereof is omitted here. Hereinafter, the heat sealing method and the sealed body in the manufacturing method of the sealed body of the present invention will be described.

1. Heat Sealing Method In the present invention, when heat sealing a plurality of films, the pressure is appropriately selected according to the thickness of the film, the thickness of the folded portion or the folded portion, the material of the film, etc. It is preferably within the range of 1 MPa to 0.5 MPa. If the pressure is too high, the film may be damaged or become cloudy. Further, if the pressure is too low, there is a risk of poor sealing.

  The temperature is appropriately selected according to the film material and the like, but is preferably in the range of 140 ° C to 200 ° C. If the temperature is too high, the film may be damaged or become cloudy. Further, if the temperature is too low, there is a possibility that a sealing failure may occur.

  The time is appropriately selected according to the thickness of the film, the thickness of the folded portion or the folded portion, the material of the film, etc., but is preferably in the range of 1 second to 10 seconds. If the time is too long, the film may be damaged or become cloudy. Moreover, when time is too short, there exists a possibility of becoming a sealing failure.

  The number of heat seals may be one or two or more, and is appropriately selected as long as white turbidity does not occur. When heat sealing is performed twice or more, the conditions may be the same or different.

2. To-be-sealed body The to-be-sealed body obtained by the present invention has a heat-sealed part in which the folded part and the folded part are heat-sealed. The heat seal part should just have a folding part, a folding | returning part, and parts other than a folding part and a folding | returning part.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  The following examples illustrate the present invention in more detail.

[Example 1]
A biaxially stretched nylon (ONY) film, an ethylene vinyl alcohol copolymer (EVOH) film, and a polyethylene (PE) film are sequentially laminated on a PET film, and a gusset bag made up of a laminated film with a total thickness of 200 μm is prepared. did. This gusset bag was folded inward on both sides, and the width of the gusset bag was 50 cm and the width of the folded portion was 5 cm.
In addition, a single-side heating type heat sealing apparatus was prepared. The elastic layer shown in Table 1 below was used for this heat sealing apparatus. The measuring method of Asker C hardness is as described above. The type A hardness is a value measured with a type A durometer by a measuring method defined in JIS K6253. Further, the length of the nichrome wire constituting the heat generating part was 60 cm.

  The laminated film was heat-sealed under the conditions shown in Table 1 below using a heat-sealing device. The pressure is a set value of the heat seal device. The temperature is an actual measurement value measured in a state in which only a thermocouple is sandwiched and crimped without sandwiching a film in the heat seal apparatus. When heat sealing was performed twice, heat sealing was performed by reversing the upper surface and the lower surface of the laminated film between the first time and the second time. Moreover, the continuous use temperature of the silicon rubber sponge used for the elastic layer is −70 ° C. to 200 ° C., and the continuous use temperature of the fluororubber sponge is −20 ° C. to 230 ° C.

The heat seal portion was visually observed to check for the presence of cloudiness and pinholes, and evaluated according to the following criteria.
A: There is no cloudiness and no pinholes. B: There is cloudiness but no pinholes. C: There are cloudiness and pinholes.

[Example 2]
An unstretched nylon (CNy) film, an ethylene vinyl alcohol copolymer (EVOH) film, an adhesive layer, and a polyethylene (PE) film were sequentially laminated, and a gusset bag composed of a laminated film having a total thickness of 250 μm was prepared. This gusset bag was folded inward on both sides, and the width of the gusset bag was 50 cm and the width of the folded portion was 5 cm.
This laminated film was heat-sealed in the same manner as in Example 1 under the conditions shown in Table 2 below.
The heat seal part was evaluated in the same manner as in Example 1.

DESCRIPTION OF SYMBOLS 1 ... Heat seal apparatus 10 ... 1st bar member 11 ... 1st bar main body 12 ... 1st insulating layer 13 ... 2nd insulating layer 14 ... Heat generating part 15 ... Release layer 20 ... 2nd bar member 21 ... 2nd bar main body 22 ... Elastic layer 30 ... Gazette bag 31 ... Folding part

Claims (3)

A heat seal device having a first bar member and a second bar member that are arranged facing each other and heat-seal between a plurality of films,
The first bar member has a heat generating portion;
The heat sealing apparatus, wherein the second bar member has an elastic layer having an Asker C hardness of 40 or less.   The heat sealing apparatus according to claim 1, wherein the elastic layer includes a porous elastic body. A method for producing a sealed object in which a plurality of films are heat sealed by sandwiching between a first bar member and a second bar member,
The first bar member has a heat generating portion, and the second bar member has an elastic layer having an Asker C hardness of 40 or less,
The method of manufacturing a sealed object, wherein the plurality of films have a folded portion or a folded portion, and the folded portion or the folded portion is heat-sealed.

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