JP2017197248A - Delamination container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a delamination container which improves crimping strength of a pinch-off part, prevents a bottom cracking phenomenon in which the pinch-off part is cracked due to a load applied, and prevents occurrence of bulging deformation of a bottom part at the time of heat filling or heating, thereby exhibiting excellent self-standing property.SOLUTION: In a delamination container, a cylindrical mouth cylindrical part 2 is erected and connected to an upper end of a cylindrical trunk part 4, whose lower end is closed with a bottom part 6, via a shoulder part 3, and an outer layer 5a and an inner layer 5b made of an inner bag incompatible with the outer layer are laminated. The delamination container has a central recess 8a on the bottom part 6, in which a central part of a bottom wall 8 is recessed inward. A bent part 10 which extends in a zigzag shape along a parting line PL formed during molding and is bent in a U shape is provided in the central recess 8a. A pinch-off part 9, in which a straight part having a straight part dimension W2 is arranged, is provided in the bent part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structure of a bottom seal portion of a synthetic resin blow container, particularly a blow-molded delamination container.

  Lamination which is a blow molded casing made of a synthetic resin, generally called a delamination bottle, which is constructed by laminating a flexible bag-like inner layer on an outer layer with a high self-shape-holding ability in a state where it can be easily peeled off. Peeling containers are known.

  This laminated peeling container is obtained by extruding an incompatible outer layer parison and an inner layer parison into a laminated parison, and blow molding this laminated parison, but it is crushed at the pinch-off part of the blow mold and cut into pieces. Since the bottom seal portion basically has a laminated structure of an incompatible outer layer portion and an inner layer portion, there is a problem that a bottom crack occurs when the pressure bonding strength is reduced.

  There are contents filled at high temperature for sterilization such as soft drinks such as tea, coffee and fruit juice, seasonings such as grilled meat sauce and dressing, etc. When filling them in a synthetic resin container, There is a risk of bottoming out due to an increase in internal pressure.

  In addition, a laminate peeling container having a form in which a body portion is squeezed and contents are discharged is known. For liquids that are poured out using squeeze deformation of the container body, a large bending force acts on the bottom when the body is squeezed, so the compression strength of the bottom seal (pinch-off) It is necessary to make it sufficiently large to withstand this bending force.

  As a shape of the pinch-off part, it is formed by extrusion blow molding (EBM) and has a bottom part formed with a rectangular cylindrical body part and a bent plug-shaped bite line made up of three straight parts by a parison pinch-off. Is disclosed (for example, see Patent Document 1).

  However, since the conventional pinch-off portion shape does not always withstand the bending force that repeatedly acts from the body side, further improvement in the pressure bonding strength at the bottom seal portion has been demanded.

  Furthermore, the blow container may be placed strongly or the blow container may fall, and an impact load may be applied to the bottom portion, which may cause a bottom crack that breaks the pinch-off portion.

Japanese Unexamined Patent Publication No. 2009-241947

  The object of the present invention is to eliminate the above-mentioned problems in the prior art, to improve the pressure-bonding strength of the pinch-off part in the delamination container, to prevent the bottom cracking phenomenon that the load is applied to the pinch-off part, and at the time of heat filling Another object of the present invention is to provide a delamination container excellent in self-supporting property by preventing the occurrence of bulging deformation at the bottom due to an increase in internal pressure during heating.

In order to solve the above problems, the main configuration of the present invention is:
An inner layer comprising an outer layer and an inner bag that is incompatible with the outer layer, with a cylindrical mouth tube portion standing upright via a shoulder at the upper end of a cylindrical body portion whose lower end is closed at the bottom. Is a delamination container formed by laminating
The delamination container includes a central recess in which the center of the bottom wall is recessed inwardly at the bottom,
A pinch-off in the central recess has a bent portion that extends in a zigzag manner along the parting line formed at the time of molding, and bends in a U-shape, and a linear portion having a linear portion dimension is disposed in the bent portion. Department.

  In the delamination container having the above main configuration, the bottom wall can be reinforced by alternately arranging pinch-off portions extending in a zigzag shape along the parting line. In addition, by providing a bent portion having a straight portion, it is possible to suppress a press-bonding failure due to the stacked body being folded at the pinch-off portion, thereby preventing a decrease in mechanical strength.

  In another configuration of the present invention, the zigzag pinch-off portion has an inclination angle θ with respect to the parting line of 5 ° to 30 °.

  If the inclination angle θ is less than 5 °, the bending angle of the bent portion to the straight portion becomes steep, and the laminate is easily folded, resulting in poor press bonding. If the inclination angle θ exceeds 30 °, a zigzag shape is formed. The number of pinch-off portions that can be formed is reduced, making it difficult to improve the mechanical strength of the entire bottom wall, and it is difficult to suppress the occurrence of the bottom cracking phenomenon. For this reason, the inclination angle θ with respect to the parting line at the pinch-off portion is preferably 5 ° or more and 30 ° or less.

  Furthermore, in another configuration of the present invention, a pitch dimension between adjacent bent portions is 5 mm or more and 20 mm or less.

  When the pitch dimension between adjacent bent parts is set to less than 5 mm, the moldability or formability of the bottom part is lowered. Moreover, when the pitch dimension between bending parts exceeds 20 mm, the space | interval becomes too long and there exists a tendency for the function of reinforcement of a bottom wall to fall. For this reason, the pitch dimension between adjacent bent parts is preferably in the range of 5 mm or more and 20 mm or less, and a more preferable pitch dimension is about 10 mm.

Since the present invention has the above-described configuration, the following effects can be obtained.
In the main configuration of the present invention, since the bottom wall can be effectively reinforced, a bottom crack phenomenon in which a load is applied to the pinch-off part, a bulging deformation of the bottom wall due to an increase in internal pressure during heating and heat filling, and the bottom It was possible to prevent cracking, thereby providing a blow container excellent in self-supporting property.

  Since the zigzag pinch-off portion has an inclination angle θ of 5 ° or more and 30 ° or less with respect to the parting line, it is possible to suppress a press-bonding failure in which the laminate is folded and to achieve an improvement in the mechanical strength of the entire bottom wall.

  When the pitch dimension between adjacent bent portions is 5 mm or more and 20 mm or less, the moldability or formability of the bottom portion is good, and the reinforcement of the bottom wall is exhibited.

It is a front view which shows one example of embodiment of the lamination peeling container of this invention. It is a bottom view of a lamination peeling container. It is the side view (a) which looked at the bottom part of the lamination peeling container from the direction orthogonal to a parting line, and the side view (b) seen from the parting line direction. It is sectional drawing of the lamination peeling container in the II line | wire of FIG. 2, and an expanded sectional view of a bottom part. It is sectional drawing of the lamination peeling container in the II-II line of FIG. 2, and an expanded sectional view of a bottom part.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a front view showing an embodiment of the delamination container of the present invention, FIG. 2 is a bottom view of the delamination container, and FIG. 3 (a) is a diagram illustrating the bottom of the delamination container orthogonal to the parting line. 3B is a side view seen from the direction of the parting line, and FIG. 4 is a cross-sectional view of the delamination container and an enlarged cross-sectional view of the bottom portion taken along the line II in FIG. FIG. 5 is a cross-sectional view of the delamination container and an enlarged cross-sectional view of the bottom along the line II-II in FIG.

  As shown in FIG. 1, the delamination container main body 1 shown in the present invention includes a cylindrical mouth tube portion 2, a shoulder portion 3, a body portion 4, and a body portion 4 that are formed in an enlarged shape from the mouth tube portion 2. It has a bottom portion 6 that closes the lower end.

  The container body 1 is formed of a laminate 5 formed by laminating a plurality of synthetic resin layers. More specifically, as shown in FIG. 1, FIG. 4 and FIG. 5, a part of the laminated body 5 is extracted and enlarged, and an outer layer 5a that forms an outer shell over the entire height range of the container body 1 and an inner side. A laminated peeling container formed by a laminated structure of the provided inner layer 5b, in which the inner layer 5b is formed to be peelable from the outer layer 5a, generally referred to as a delamination bottle. The inner layer 5b is flexible so that the contents are accommodated and squeezed and deformed as the contents are reduced, and the outer layer 5a includes the inner layer 5b and elastically deforms between the inner layer 5b and the inner layer 5b. An intake hole for inhaling outside air is formed in the mouth tube portion 2.

The outer layer 5a molded with the required self-shape holding ability is formed of, for example, a synthetic resin material such as polyethylene or polypropylene, and the inner layer 5b is a synthetic resin material that is incompatible with the outer layer 5a, for example, An inner layer 5b formed in a bag shape that can be freely deformed is laminated, such as polyamide, ethylene vinyl alcohol copolymer, polyethylene terephthalate, and the like.
The inner layer 5b does not need to be a single layer, and may be a multilayer as long as the layer in contact with the outer layer 5a is composed of an incompatible layer. For example, the inner layer 5b may be bent and deformable, such as polyamide / polyethylene, ethylene vinyl alcohol copolymer / polyethylene, or the like.

  The container body 1 has a bottle shape by sandwiching one end of a cylindrical parison obtained by coextrusion molding of an incompatible outer layer parison and inner layer parison with a mold and performing extrusion blow molding (EBM) by blowing compressed air. To be molded. At this time, the pinch-off blade of the mold cuts off the lower end portion of the co-extruded multilayer parison, whereby a vertical rib-shaped pinch-off portion 9 is formed on the bottom wall 8 of the bottom portion 6. Note that a parting line PL formed when the multilayer parison is sandwiched between molds is formed on the surface of the container body 1.

  As shown in FIG. 3, the bottom 6 includes a central recess 8a in which the bottom wall 8 is recessed in a dome shape toward the inside, and a grounding portion 7 provided in a ring around the central recess 8a. Have. The pinch-off portion 9 is formed in the central recess 8a along the parting line PL, and the pinch-off portion 9 is formed with a bent portion 10 that is bent in a zigzag shape and a U shape in a die during extrusion blow molding.

  In the delamination container shown in this embodiment, as shown in FIG. 2, the pinch-off portion 9 is configured in a zigzag shape and includes a bent portion 10 that is bent in a U shape. The mechanical strength of the entire bottom wall 8 can be improved by a configuration in which the pinch-off portions 9 extend in a zigzag shape, are alternately arranged on the left and right sides, and mesh with each other. That is, it is possible to more effectively prevent an increase in internal pressure during heating, a bulging deformation of the bottom wall 8 during heat filling, and a bottom crack where the bottom portion 6 is subjected to a shocking load and the pinch-off portion 9 breaks.

  Further, the straight portion of the bent portion 10 relaxes the zigzag bending angle at the bent portion 10, and suppresses poor crimping due to the stacked body 5 being folded at the pinch-off portion 9. In this embodiment, the linear part dimension W2 of the bent part 10 is set to 2 mm, which is in the range of 1 mm or more. In the V shape with the linear part dimension W2 of less than 1 mm, it becomes difficult to eliminate the folding of the laminated body 5, and the mechanical strength due to poor press bonding tends to be reduced.

  The pinch-off portions 9 extending in a zigzag shape have an inclination angle θ with respect to the parting line PL, and the adjacent zigzag pinch-off portions 9 form a groove angle 2θ as shown in FIG. In the present embodiment, the inclination angle θ is set to 10 ° within the range of 5 ° to 30 ° with respect to the parting line PL. A more preferable inclination angle θ is in the range of 8 ° to 20 °. If the inclination angle θ is less than 5 °, the bending angle of the bent portion 10 to the straight line portion becomes steep and the laminate 5 is folded and the pressure bonding failure is likely to occur, and if the inclination angle θ exceeds 30 °, the zigzag is formed. The number of pinch-off portions 9 that can be formed is reduced, and it is difficult to improve the mechanical strength of the entire bottom wall 8, and it is difficult to suppress the occurrence of the bottom cracking phenomenon.

  In the present invention, the pitch dimension W1 between the bent portions 10 adjacent to each other along the direction of the parting line PL in which the pinch-off portions 9 extend in a zigzag shape is set to 12 mm, which is in the range of 5 mm to 20 mm. Thereby, it becomes possible to improve the moldability or formability of the bottom portion 6 having the zigzag bent portion 10, and the function of the bent portion 10 formed on the bottom wall 8 can be sufficiently exhibited.

  That is, when the pitch dimension W1 between the adjacent bent portions 10 is less than 5 mm, the formability or formability of the entire bottom portion 6 provided with the plurality of bent portions 10 is deteriorated. Thus, the function of reinforcing the bottom wall 8 during this period is lowered. Therefore, by forming the bent portion 10 within the above range, a plurality of bent portions 10 can be formed and these functions can be fully exerted, and bulging deformation due to an increase in internal pressure during heating or heat filling can be achieved. It is possible to prevent the occurrence of a bottom crack phenomenon due to an impact load. Moreover, it can be set as the lamination peeling container excellent in stability at the time of self-supporting.

  As shown in FIGS. 4 and 5, the lower ends (protruding tips) of the pinch-off part 9 and the bent part 10 are located between the bottom wall 8 and the grounding part 7 so as not to project downward from the grounding part 7. It is formed in a state. With this configuration, the grounding portion 7 is surely grounded, and the stability when the container body 1 is self-supporting can be enhanced.

As mentioned above, although the structure of this invention and its effect were demonstrated along the Example, embodiment of this invention is not limited to the said Example.
For example, in the above embodiment, the laminated body 5 of the container body 1 has been described as having a two-layer structure of the outer layer 5a and the inner layer 5b, but is not limited thereto. For example, a layer having a gas barrier property, a colored resin layer having a light shielding property Further, a multilayer structure such as one or both of them may be laminated.
Moreover, although the example which arrange | positioned the bending part 10 in the pinch-off part 9 two in total on the left and three on the right was shown and demonstrated, the structure which increased / decreased the bending part 10 may be sufficient. It should be noted that the minimum number of the bent portions 10 is three in total, two on the left and one on the other and one on the other. Even in such a minimum number, the configuration does not have the bent portions 10 in a zigzag shape. In comparison, the bottom wall 8 can be strengthened while maintaining a left-right balance.

  As described above, the delamination container of the present invention has a zigzag shape at the bottom pinch-off portion, so that the occurrence of bottom cracking and bulging deformation can be prevented. Applications can be expanded in a wider area.

DESCRIPTION OF SYMBOLS 1; Container (lamination peeling container) main body 2; Mouth part 3; Shoulder part 4; Trunk part 4A; Waist part 5; Laminate body 5a; Outer layer 5b: Inner layer 6; Bottom part 7: Grounding part 8; Concave part 9; Pinch-off part 10; Bending part PL; Parting line W1; Bending part pitch dimension W2; Bending part linear part dimension θ; Inclination angle 2θ with respect to parting line;

Claims (3)

At the upper end of the cylindrical body (4) whose lower end is closed by the bottom (6), a cylindrical mouth tube (2) is provided upright via a shoulder (3), and the outer layer (5a). And an inner layer (5b) made of an inner bag that is incompatible with the outer layer (5a),
The delamination container includes a central recess (8a) in which the center of the bottom wall (8) is recessed inwardly at the bottom (6),
The central recess (8a) has a bent portion (10) that extends in a zigzag shape along a parting line (PL) formed during molding and bends in a U-shape, and a linear portion is formed in the bent portion. A delamination container having a pinch-off portion (9) in which a linear portion having a dimension (W2) is arranged.   2. The delamination container according to claim 1, wherein the zigzag pinch-off portion (9) has an inclination angle (θ) with respect to the parting line (PL) of 5 ° or more and 30 ° or less.   The lamination peeling container according to claim 1 or 2 whose pitch dimension (W1) between adjacent bent parts (10) is 5 mm or more and 20 mm or less.

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