JP2014181056A - Heat seal method of container, heat seal head, and container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat seal method of a container which prevents pinholes from generating around an inner peripheral region of a flange of a lid member even the container is placed the lid member down, while keeping easiness of opening and sealability.SOLUTION: A heat seal method tight seals a container body 10 by heat-sealing a flange 12 of the container body 10 with a lid member 20, which is set to cover an opening 11, by pressing a seal area 111 of a heat seal head 100 to the lid member 20. A curvature radius of a first part 111a of a curved part curving downward from inner edge side of the seal area 111 is larger than a curvature radius of a second part 111b of the curved part continuing to said first part 111a and curving downward from outer edge side.

Description

  The present invention includes a sheet-like or film-like lid member that is made of a resin such as polyolefin resin and is set to cover the opening on a flange formed on the opening of a container body filled with contents. According to a heat sealing method of pressing the sealing surface of the heat seal head and heat-sealing the lid material and the flange portion to seal the container body, the seal head used in the heat seal method, and the heat seal method It relates to a manufactured container.

  Conventionally, as a packaging form for foods and drinks, after filling the container body with contents such as food, a flange formed on the opening of the container body is covered with a sheet-like or film-like lid material, and a heat seal head A method of maintaining a hermetic seal by heat-pressing (sealing) the lid member and the flange portion is widely adopted. In the case of such a packaging form, sufficient sealability is required to enhance the storage stability of the contents, while easy opening is required so that the lid can be easily opened in order to take out the contents. .

  For these problems, an easily openable container disclosed in Patent Document 1 is known. This container has a container main body having a flange portion formed in an opening, and a sheet-like or film-like lid member having a seal layer heat-sealed on the surface of the flange portion, and a sealing surface (pressing surface) An annular sealing plate (heat seal head) having an inclined surface portion is pressed against the lid member, and a seal layer is formed by thermally welding the sealing layer of the lid member and the resin of the flange portion, and the container body is sealed. ing. And this container is formed with a knob-like resin pool in the vicinity of the inner peripheral edge of the seal portion of the container main body (on the inner peripheral end side of the flange portion) by sealing by the above-described heat welding.

  Moreover, in such a container, since a cover material is opened from the flange part of a container main body by cohesive failure, initial opening strength is stabilized compared with interface peeling, and opening is performed smoothly. Further, the lumped resin reservoir formed on the inner peripheral end side of the flange portion of the container favorably causes the cohesive failure of the lid material and the flange portion of the container body in the resin reservoir portion, It is disclosed that the lid material can be prevented from being peeled off and the sealing property can be kept good.

JP 2006-206128 A

  However, such a container is normally labeled with a shrink label after filling the container body with the contents, sealing the lid material by heat sealing to the flange portion. At this time, since the flange portion of the container main body makes it difficult to attach the shrink label from above, the shrink label is attached in a state where the flange portion of the container and the lid member are down. For this reason, the container sealed with the lid material after filling the contents is inverted by a conveyor or the like so that the flange portion (cover material) of the container is placed downward, and is conveyed in the reverse direction to the shrink label mounting process. In addition, cardboard boxes containing a plurality of filled and sealed containers stacked in multiple layers via partition plates, or full shrinks, packages with half-shrinking the upper part of the cardboard half-tray, etc. are transported upside down. May be transported.

  In such a case, when the above-described resin reservoir is formed on the inner peripheral end side of the flange portion of the seal portion of the container, the sealing surface of the lid member on the inner peripheral end portion side of the flange portion is formed by the resin reservoir. Since the load acts on the inside in a concentrated manner, it becomes a factor in generating a hole in the lid member. And when the perforation on the inner peripheral end portion side of the flange portion of this lid material occurs, even if a seal portion is formed from the inner peripheral end portion side to the outer peripheral end portion side of the flange portion, it leaks from this portion. , Leakage of contents from inside the container cannot be prevented.

  Furthermore, when a lid member is thermally welded to the surface of the flange portion of the container main body and the container main body is sealed, when an annular sealing disk (heat seal head) having a sealing surface as an inclined portion is used, the sealing surface is particularly good. Is narrower than the flange width, the seal width of the seal portion between the flange portion of the container main body and the lid member is difficult to be constant, and the easy-openability and the sealing performance are not stable.

  The present invention has been made in view of such circumstances, and maintains the easy-openability and sealability of a filled and sealed container, and is placed under the condition that the container is placed with the flange portion and the lid facing down. However, the present invention provides a heat sealing method for a container and a heat sealing head in which perforation on the inner peripheral end side of the flange portion of the lid member is prevented.

  In addition, the present invention maintains the easy-openability and sealing performance of the filled and sealed container, and the inner peripheral end of the flange portion of the lid material even in a situation where the flange portion and the lid material of the container are down. A container in which perforation on the side is prevented is provided.

  In the heat sealing method according to the present invention, a lid member is set on the flange portion formed in the opening portion of the container body so as to cover the opening portion, and the sealing surface of the heat seal head is pressed against the lid member. A heat sealing method in which a lid member and the flange portion are heat-sealed to seal the container body, wherein the sealing surface is bent downward from the inner end side of the sealing surface. And a second portion of the curved portion that is curved downward from the outer end side of the sealing surface and is formed following the first portion, and the curvature radius of the first portion is the curvature radius of the second portion. A larger heat seal head is used.

  With such a configuration, when the seal member is formed by heat-sealing the lid member on the flange portion formed in the opening of the container body, the seal portion is provided with the first on the inner peripheral end side of the flange portion. A resin reservoir and a second resin reservoir on the outer peripheral end side of the flange are formed, and a protruding length of the first resin reservoir from the surface of the flange portion is a protruding length of the second resin reservoir from the surface of the flange portion. Smaller.

  In the heat sealing method according to the present invention, it is preferable that a radius of curvature of the first portion is 50 mm or more and a radius of curvature of the second portion is in a range of 4 mm to 20 mm.

  In the heat sealing method according to the present invention, a lid member is set on the flange portion formed in the opening of the container body so as to cover the opening, and the sealing surface of the heat seal head is pressed against the lid. A heat sealing method for heat-sealing the lid and the flange portion to seal the container body, wherein the sealing surface is formed on a flat surface from the inner end side of the sealing surface. A heat seal head comprising a first portion and a second portion of the curved portion curved downward from the outer end side of the sealing surface and formed following the first portion is used.

  With such a configuration, when the seal member is formed by heat-sealing the lid member on the flange portion formed in the opening of the container body, the seal portion is provided with the first on the inner peripheral end side of the flange portion. A resin reservoir and a second resin reservoir on the outer peripheral end side of the flange are formed, and the first resin reservoir is formed on the inner surface side of the container body toward the lower side of the inner peripheral end of the flange portion, Two resin reservoirs are formed protruding from the surface of the flange portion.

  In the seat sealing method according to the present invention, it is preferable that a curvature radius of the second portion is in a range of 4 mm to 20 mm.

  In the heat seal head according to the present invention, the sealing surface of the heat seal head is pressed against the flange portion formed in the opening portion of the container body so as to cover the opening portion. A heat seal head for heat-sealing a flange portion and sealing the container body, wherein the seal surface is bent downward from the inner end side of the seal surface, and the seal surface and the seal surface The second portion of the curved portion that is curved downward from the outer end side of the first portion and is formed to follow the first portion, and the radius of curvature of the first portion is larger than the radius of curvature of the second portion. Features.

  With such a configuration, when the seal member is formed by heat-sealing the lid member on the flange portion formed in the opening of the container body, the seal portion is provided with the first on the inner peripheral end side of the flange portion. A resin reservoir and a second resin reservoir on the outer peripheral end side of the flange are formed, and a protruding length of the first resin reservoir from the surface of the flange portion is a protruding length of the second resin reservoir from the surface of the flange portion. Smaller.

  In the heat seal head according to the present invention, it is preferable that a radius of curvature of the first portion is 50 mm or more and a radius of curvature of the second portion is in a range of 4 mm to 20 mm.

  In addition, the heat seal head according to the present invention presses the sealing surface of the heat seal head against a cover member set so as to cover the opening part on the flange part formed in the opening part of the container body. A heat seal head for heat-sealing the flange portion and sealing the container body, wherein the seal surface is formed as a flat surface from the inner end side of the seal surface, and the seal It is characterized by comprising a second portion of a curved portion that is curved downward from the outer end side of the surface and is formed so as to follow the first portion.

  With such a configuration, when the seal member is formed by heat-sealing the lid member on the flange portion formed in the opening of the container body, the seal portion is provided with the first on the inner peripheral end side of the flange portion. A resin reservoir and a second resin reservoir on the outer peripheral end side of the flange are formed, and the first resin reservoir is formed on the inner surface side of the container body toward the lower side of the inner peripheral end of the flange portion, Two resin reservoirs are formed protruding from the surface of the flange portion.

  In the heat seal head according to the present invention, it is preferable that a radius of curvature of the second portion is in a range of 4 mm to 20 mm.

  The container according to the present invention includes a container main body having a flange portion formed in an opening portion, and a lid material covering the opening portion of the container main body, and the lid material and the flange portion are thermally welded and sealed. A first resin reservoir formed on the inner peripheral end side of the flange portion and a second resin reservoir formed on the outer peripheral end side of the flange. And the protruding length of the first resin reservoir from the surface of the flange portion is smaller than the protruding length of the second resin reservoir from the surface of the flange portion.

  With such a configuration, in a state where the flange portion of the container and the lid member are placed downward, the load applied to the seal portion of the container is such that the first resin reservoir formed on the inner peripheral end side of the flange portion is It becomes smaller than the second resin reservoir formed on the outer peripheral end side of the flange.

  Further, the container according to the present invention has a container main body having a flange portion formed in an opening portion, and a lid material that covers the opening portion of the container main body, and the lid material and the flange portion are thermally welded. A first resin reservoir formed on the inner peripheral end side of the flange portion and a second resin reservoir formed on the outer peripheral end side of the flange. The first resin reservoir is formed on the inner surface side of the container main body toward the lower side of the inner peripheral end of the flange portion, and the second resin reservoir is formed to protrude from the surface of the flange portion. Features.

  With such a configuration, when the container is placed with the flange part and the lid facing down, the load applied to the seal part of the container is formed on the inner surface side of the container body toward the lower side of the inner peripheral end of the flange part. The first resin reservoir is smaller than the second resin reservoir formed on the outer peripheral end portion side of the flange. In addition, since the first partial resin reservoir composed of a flat seal surface is formed on the inner surface side of the container body toward the lower side of the inner peripheral end of the flange part of the container body, the seal width of the seal part of the container is constant. It becomes width.

  According to the heat sealing method and the heat sealing head according to the present invention, the easy-openability and sealing performance of the filled and sealed container are maintained, and the container is placed under the flange portion and the lid material. In addition, it is possible to easily manufacture a container in which perforation on the inner peripheral end side of the flange portion of the lid member is prevented.

  Further, according to the container according to the present invention, the easy-openability and sealability of the filled and sealed container are maintained, and the lid material is provided even under the situation where the flange part and the lid material of the container are placed downward. It can be set as the container by which the perforation in the inner peripheral end side of the flange portion is prevented.

It is a perspective view which shows the external appearance of the container main body in the container which concerns on embodiment of this invention. It is sectional drawing which shows the heat seal head which heat-welds a cover body to the container main body shown in FIG. It is a perspective view which shows the external appearance of the container which concerns on embodiment of this invention. It is sectional drawing which expands and shows a heat seal head. It is a figure which shows the relationship between the surface of a flange part, and the shape of the sealing surface of a heat seal head. It is sectional drawing which expands and shows the state in which the heat seal head is heat-sealing the cover material to a flange part. It is sectional drawing which expands and shows the sealing part of a cover material and a flange part. It is sectional drawing which expands and shows the state which the container shown in FIG. 7 set | placed with the flange part and the lid | cover material facing down. It is a figure which shows the relationship between a flange part and the other shape of the sealing surface of a heat seal head. It is sectional drawing which expands and shows the heat seal state of the cover material and flange part by the heat seal head which has a sealing surface shown in FIG. It is sectional drawing which expands and shows the seal | sticker part formed by heat-welding the cover material and flange part shown in FIG. It is a figure which shows an experimental result.

  Embodiments of the present invention will be described with reference to the drawings.

  The container main body in the container which concerns on one Embodiment of this invention is comprised as shown in FIG.

  In FIG. 1, a flange portion 12 projecting outward is formed on the peripheral edge 11 a of the opening 11 of the cup-shaped container body 10, and the container body 10 is formed of, for example, a thermoplastic resin such as sheet-like polypropylene. ing.

  As shown in FIG. 2, sealing of the container filled with the contents using the container body 10 is performed on the flange portion 12 formed in the opening portion 11 of the container body 10 filled with the contents. A sheet-like or film-like lid member 20 is set so as to cover. As the lid member 20, for example, a multilayer film composed of a seal layer: a polypropylene sealant, an intermediate layer: an aluminum foil, and an outer layer: a polyethylene terephthalate film is used.

  Subsequently, the heat sealing between the container body 10 and the lid member 20 is performed by heat sealing using the heat seal head 100 of the heat sealing device, with the lid member 20 set on the flange portion 12 of the container body 10. The heat seal head 100 includes an annular protrusion 110 having a lower end surface as a seal surface (pressing surface) 111 corresponding to the shape of the flange portion 12 formed in the opening 11 of the container body 10. Yes. Further, a heater (not shown) is embedded in the heat seal head 100, and the surface temperature of the seal surface 111 is maintained at a predetermined temperature suitable for heat sealing.

  In the heat sealing described above, the sealing surface 111 of the heat sealing head 100 is pressed against the flange portion of the lid member 20 and the container body 10 from above, and the lid member 20 is pressed against the flange portion 12 of the container body 10 by the heat seal head 100. It is heated under pressure and heat-sealed. Thereby, as shown in FIG. 3, the container by which the container main body 10 was sealed with the cover material 20 is manufactured. When the container has a rectangular cross-sectional shape, the lid 20 is opened from the container body 10 with the corners 20a of the lid 20, as shown in FIG. The seal portion between the material 20 seal layer and the flange portion 12 of the container body 10 is coherently broken and opened.

  Next, the shape of the seal surface 111 formed on the lower end surface of the annular protrusion 110 in the heat seal head 100 used for the heat seal described above will be described in detail with reference to FIG.

  In FIG. 4, the shape of the seal surface 111 formed on the lower end surface of the annular protrusion 110 in the heat seal head 100 is a direction Dout (outer end side) from the inner end side to the outer end side of the seal surface 111. Chamfered portions 112 and 113 are formed at both ends of the cross section in the direction Din toward the inner end portion from the same direction. The seal surface 111 has a first portion 111a composed of a curved portion that curves downward from the inner end portion side, and a curved portion that curves downward from the outer end portion side and continues to the first portion 111a. It is comprised from the 2nd part 111b which consists of a part. The curvature radius of the first portion 111a and the second portion 111b is set so that the curvature radius of the first portion 111a is larger than the curvature radius of the second portion 111b.

  The radius of curvature described above is determined by the size of the flange portion of the container body 10, but the typical filling capacity of the container body 10 is 60 to 300 ml, and the size of the flange portion in this case does not vary much. Therefore, the curvature radius R1 of the first portion 111a is preferably 50 mm or more, and the curvature radius R2 of the second portion 111b is preferably 4 mm to 20 mm. By setting the curvature radii R1 and R2 in the above range, the seal pressure is concentrated around the boundary 114 of the seal surface 111, so that the sealing performance can be further secured. Moreover, the curvature radius of each chamfered part 112,113 should just be a curvature radius in which the press by the sealing surface 111 of the heat seal head 100 does not relate when heat-sealing the cover material 20 to the flange part 12 of the container main body 10, For example, it may be about 1 mm. Further, in this embodiment, the width of the sealing surface 111 of the heat seal head 100 is made larger than the width of the flange portion 12 of the container body 10, so that the easy-openability and sealing performance of the container after heat sealing are more stable. This is preferable. A slight flat portion may exist between the first portion 111a and the second portion 111b of the heat sealing head 100 sealing surface 111 described above.

  When the heat seal head 100 having the sealing surface 111 having such a shape is used to heat-seal the flange portion 12 of the container body 10 and the lid member 20, the flange portion 12 to which the lid member 20 is thermally welded is formed. The relationship between the surface 12a (flat surface) and the seal surface 111 is as shown in FIG. That is, since the curvature of the curvature radius R1 on the sealing surface 111 of the heat seal head 100 is large and the curvature of the curvature radius R2 is small, the rising of the first portion 111a with respect to the surface 12a of the flange portion 12 of the container body 10 is the second portion. It becomes gentler than the rise of 111b with respect to the surface 12a of the flange portion 12.

  When the lid 20 is heat sealed to the flange portion 12 of the container main body 10 as shown in FIG. 6 with the heat seal head 100 having such a seal surface 111 formed, pressurization by the seal surface 111 of the heat seal head 100 is performed. Then, the sealing layer 30 is formed by heat-sealing the sealing layer of the lid member 20 and the resin of the flange portion 12. Then, on the inner peripheral end side of the flange portion 12 of the seal portion 30 of the container, a resin reservoir (hereinafter referred to as a first resin mass) that is softened and extruded by the first portion 111a of the seal surface 111 of the heat seal head 100 is used. 31a) is formed. On the other hand, on the outer peripheral end side of the flange portion 12 of the seal portion 30, a resin pool (hereinafter referred to as a second resin pool) 31 b that is a lump of resin that is softened and pushed out by the second portion 111 b of the seal surface 111. Is formed.

  At this time, as described above, in the shape of the seal surface 111 of the heat seal head 100 (see FIGS. 4 and 5), the first portion 111a formed from the inner end side (Din side) of the seal surface 111 The radius of curvature is formed so as to be larger than the radius of curvature of the second portion 111b formed from the outer end side (Dout side) of the sealing surface 111 continuously to the first portion 111a. For this reason, as shown in FIG. 7 in an enlarged manner, in the sealing portion 30 of the container described above, the protrusion length H1 (protrusion degree) of the first resin reservoir 31a from the surface 12a of the flange portion 12 is the second resin reservoir 31b. The protrusion length H2 (protrusion degree) from the surface 12a of the flange portion 12 becomes smaller.

  In a state where the container manufactured by heat sealing described above is placed with the flange portion 12 and the lid member 20 facing down, as shown in FIG. 8, the seal portion 30 of the container (including the contents) Further, the flange 12 is supported by the second resin reservoir 31b having a long protrusion length H2 (see FIG. 7) from the surface 12a. The load applied to the first resin reservoir 31a having a small protrusion length H1 (see FIG. 7) from the surface 12a of the flange portion 12 is smaller than the load applied to the second resin reservoir 31b. Therefore, in the container seal portion 30, the load applied to the inside of the seal surface of the lid member 20 by the first resin reservoir 31a formed on the inner peripheral end portion side of the flange portion 12 is reduced. In FIG. 8, the first resin reservoir 31a and the second resin reservoir 31b are expressed in a convex shape, but this is a sectional shape, and the first resin reservoir 31a and the second resin reservoir 31b are annular. It is a shape protruding.

  Therefore, according to the container, the easy-openability and the sealing performance of the container are maintained, and even when the container is placed with the flange portion 12 and the lid member 20 facing down, the flange portion 12 of the lid member 20 It is possible to prevent perforation on the inner peripheral end side. And the leakage of the content in the container main body 10 by this perforation can be prevented reliably.

  Further, the shape of the sealing surface 111 of the heat seal head 100 is not limited to the shape described above (see FIGS. 4 and 5). That is, the shape of the first portion 111a of the seal surface 111 from the inner end side to the outer end side (direction Din to direction Dout) of the seal surface 111 of the heat seal head 100 is defined with respect to the surface 12a of the flange portion 12. For example, it can be formed so as to have a relationship as shown in FIG.

  In this case, the first surface formed on the seal surface 111 of the heat seal head 100 from the inner end side of the seal surface 111 is a flat surface, and the outer surface of the seal surface 111 following the first portion 111a is viewed from the outer end side. The second portion 111b to be formed is a curved portion having a radius of curvature R2 similar to the shape described above (see FIGS. 4 and 5). As shown in FIG. 10, the cover member 20 is set between the heat seal head 100 and the surface 12 a of the flange portion 12, and the cover member 20 is pressed against the flange portion 12 by the seal surface 111. By the pressurization and heating of the heat seal head 100, the seal layer of the lid member 20 and the resin of the flange portion 12 are thermally welded, and the container is sealed.

  At the time of this sealing, as shown in FIG. 11 together with FIG. 10, the second end similar to the second resin reservoir 31b (see FIG. 7) is provided on the outer peripheral end portion side of the flange portion 12 of the seal portion 30. A resin reservoir 31b is formed. On the other hand, on the inner peripheral end portion side of the flange portion 12 of the seal portion 30, the first portion 111 a of the flat seal surface 111 that coincides with the surface 12 a of the flange portion 12, from the inner peripheral end portion side of the flange portion 12. A first resin reservoir 31 a is formed on the inner surface side of the container body 10 by being pushed out to the inner surface of the container body 10 and toward the lower side of the inner peripheral end of the flange portion 12 of the container body 10. And the protrusion length H2 from the surface 12a of the flange part 12 of the 2nd resin reservoir 31b of the seal | sticker part 30 is comparable as the protrusion length H2 (refer FIG. 7) mentioned above, On the other hand, the flange of the 1st resin reservoir 31a The protrusion length H1 from the surface 12a of the portion 12 can be substantially zero. Also in this embodiment, making the width of the sealing surface 111 of the heat seal head 100 larger than the width of the flange portion 12 of the container body 10 makes the easy-openability and sealing performance of the container after heat sealing more stable. This is preferable.

  Even in the container manufactured in this manner, the container seal portion 30 is supported by the second resin reservoir 31b (annular) in a state where the container flange portion 12 and the lid member 20 are placed downward. Therefore, the load applied to the seal portion 30 on the inner peripheral end side of the flange portion 12 of the seal portion 30 is reduced. Therefore, even when the container is placed with the flange portion 12 and the lid member 20 facing down, perforation on the inner peripheral end side of the flange portion 12 of the lid member 20 can be prevented. In addition, the first resin reservoir 31a described above is formed on the inner surface side of the container main body 10 toward the lower side of the inner peripheral end of the flange portion 12 of the container main body 10 by the first portion 111a of the flat seal surface 111. The seal width of the seal portion 30 between the flange portion 12 of the container body 10 and the lid member 20 becomes a constant width, and the easy-openability and the sealing performance are stabilized.

  On the other hand, when the container is placed with the lid member 20 facing down, a load is applied to the second resin reservoir 31b formed on the outer circumferential end portion side of the flange portion 12, and the outer circumference of the flange portion 12 of the lid member 20 is applied. There is concern about perforation at the end. However, this portion is sealed by the seal portion 30 which is located far from the opening portion 11 of the container body 10 and includes the first resin reservoir 31a formed by the first portion 111a of the seal surface 111 of the heat seal head 100. Therefore, leakage of contents from the container is prevented.

[Experimental example]
In order to confirm a preferable relationship (H1 <H2) between the protruding length H1 of the first resin reservoir 31a and the protruding length H2 of the second resin reservoir 31b in the seal portion 30 of the container, the first seal surface 111 of the heat seal head 100 The shape (curvature radius R1, flat surface) of the first portion 111a and the curvature radius R2 of the second portion were experimentally determined as follows.

<Conditions>
1. Structure and material of container body 10: 1.5 mm thick sheet made of polypropylene added with titanium-based white pigment. Shape of opening 11 (inner shape of flange 12): 49.0 mm × 66.6 mm
-Bottom shape: 34.4 mm x 52.0 mm
・ Height: 44mm
・ Width of flange portion 12: 6 mm
・ Thickness of the flange 12: 0.6 mm
-Thickness of the trunk of the container body 11: 0.4 mm
-Bottom thickness: 0.6mm
A cup-shaped container body 10 shown in FIG. 1 was prepared by plug assist molding.
2. Structure of cover material 20 / Outer layer: Polyethylene terephthalate (12 μm)
Intermediate layer: aluminum film (7 μm) / polyurethane adhesive / nylon (15 μm)
・ Inner layer: Polypropylene sealant (50μm)
A polyurethane adhesive was interposed between the resin layers, and the laminate was prepared by dry lamination.
3. The shape of the seal surface 111 of the heat seal head 100 and the width of the seal surface 111 (annular): 8 mm
-Shape of chamfered portions 112 and 113: radius of curvature 1 mm
-Width of the first portion 111a: 5.5mm
-Width of the second part 111b: 2.5 mm
-Curvature radius R1 of the first portion 111a: 50 mm, 70 mm, flat surface (R1 = ∞)
-Curvature radius R2 of the second portion 111b: 4 mm, 8 mm, 20 mm
4). Others The lid 20 is positioned and lowered so that the boundary 114 between the first portion 111a and the second portion 111b of the sealing surface 111 of the heat seal head 100 is positioned at the center in the width direction of the flange portion 12 of the container. The container body 10 was heat sealed to the flange portion 12.
In heat sealing, the temperature of the sealing surface 111 (first portion 111a, second portion 111b) of the heat sealing head 100 was set to 185 ° C., and heat sealing was performed for 1.2 seconds.
<Observation>
Next, after heat sealing, the sealed portion 30 (the flange portion 12 and the lid member 20) of the sealed container is longitudinally cut in the radial direction, and the inner peripheral end portion side and the outer peripheral end portion side of the flange portion 12 at the cut end surface thereof. The presence or absence of the first and second resin reservoirs, the protruding length (height (H1, H2)), and the form thereof were confirmed. The result is shown in FIG.
<Result>
According to this experiment, the shape of the first portion 111a on the inner end side of the seal surface 111 of the heat seal head 100 is in the range from the radius of curvature R1 = 50 mm to a flat surface, and the outer end portion of the seal surface 111. When the curved portion of the second portion 111b on the side has a radius of curvature R2 = 4 mm to 20 mm, the protruding length (height) H1 of the first resin reservoir 31a is the protruding length (height) H2 of the second resin reservoir 31b. A smaller and appropriate seal 30 was formed. In particular, heat sealing by the sealing surface 111 in which the first portion 111a is a curved portion having a radius of curvature R1 = 70 mm and the second portion 111b is a curved portion having a radius of curvature R2 = 8 mm is performed on the first resin reservoir 31a. The relationship between the protrusion length H1 and the protrusion length H2 of the second resin reservoir 31b was most preferable.

  A heat seal method for a container and a heat seal head according to the present invention include a heat sealing method in which a lid member covering the opening is heat-sealed to a flange formed in the opening of the container main body to seal the container main body. And a heat seal head used in the heat seal method. The container according to the present invention is useful as a container sealed by heat-sealing a lid material on a container body filled with the contents.

DESCRIPTION OF SYMBOLS 10 Container main body 11 Opening part 11a Periphery 12 Flange part 12a Surface 20 Lid 30 Seal part 31a 1st resin reservoir 31b 2nd resin reservoir 100 Heat seal head 110 Annular protrusion 111 Seal surface (pressing surface)
111a First part 111b Second part 112, 113 Chamfer 114 Boundary between first part 111a and second part 111b

Claims (10)

A lid is set on the flange formed in the opening of the container body so as to cover the opening, and the sealing surface of the heat seal head is pressed against the lid to heat the lid and the flange. A heat sealing method for fusing and sealing the container body,
The sealing surface is formed so as to bend downward from the outer end side of the sealing surface and to follow the first portion, the first portion of the bending portion bending downward from the inner end side of the sealing surface. A heat sealing method for a container, comprising: a heat sealing head comprising a second portion of a curved portion, wherein the curvature radius of the first portion is larger than the curvature radius of the second portion.   2. The heat sealing method for a container according to claim 1, wherein the radius of curvature of the first portion is 50 mm or more and the radius of curvature of the second portion is in a range of 4 mm to 20 mm. A lid member is set on the flange portion formed in the opening of the container body so as to cover the opening, the seal surface of the heat seal head is pressed against the lid member, and the lid member and the flange portion are A heat sealing method for heat-sealing and sealing the container body,
The sealing surface is formed so as to be curved from the inner end side of the sealing surface to a flat surface and curved downward from the outer end side of the sealing surface and to follow the first portion. A heat sealing method for a container, comprising using a heat sealing head comprising a second portion of a curved portion.   The heat sealing method according to claim 3, wherein the radius of curvature of the second portion is in the range of 4 mm to 20 mm. The flange part formed in the opening part of the container main body is pressed against the sealing material of the heat seal head against the cover material set so as to cover the opening part, and the lid material and the flange part are thermally welded, A heat seal head for sealing the container body,
The sealing surface is formed so as to bend downward from the outer end side of the sealing surface and to follow the first portion, the first portion of the bending portion bending downward from the inner end side of the sealing surface. A heat seal head comprising a second portion of a curved portion, wherein the radius of curvature of the first portion is larger than the radius of curvature of the second portion.   The heat seal head according to claim 5, wherein the radius of curvature of the first portion is 50 mm or more, and the radius of curvature of the second portion is in a range of 4 mm to 20 mm.   The flange portion formed in the opening of the container body is pressed against the sealing surface of the heat seal head against the lid set to cover the opening, and the lid and the flange are thermally welded, A heat seal head for sealing a container body, wherein the sealing surface is curved downward from a first portion formed on a flat surface from an inner end side of the sealing surface and from an outer end side of the sealing surface. A heat seal head comprising a second portion of a curved portion formed so as to follow the first portion.   The heat seal head according to claim 7, wherein a radius of curvature of the second portion is in a range of 4 mm to 20 mm. A container having a container body with a flange portion formed in the opening and a lid covering the opening of the container body, and the sealing member is formed by thermally welding the lid and the flange. And
The seal portion has a first resin reservoir formed on the inner peripheral end portion side of the flange portion and a second resin reservoir formed on the outer peripheral end portion side of the flange, and the first resin reservoir A container, wherein a protrusion length from the surface of the flange portion is smaller than a protrusion length from the surface of the flange portion of the second resin reservoir. A container having a container body with a flange portion formed in the opening and a lid covering the opening of the container body, and the sealing member is formed by thermally welding the lid and the flange. And
The seal portion has a first resin reservoir formed on the inner peripheral end side of the flange portion, and a second resin reservoir formed on the outer peripheral end portion side of the flange, and the first resin reservoir is A container formed on the inner surface side of the container body facing downward from an inner peripheral end of the flange part, wherein the second resin reservoir is formed to protrude from the surface of the flange part.

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