JP2005145516A - Biaxially drawn blow molded bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biaxially drawn blow molded bottle, whose bottom is not deformed to sag and keep unstable under gravity and heat from a content when the bottle as a plastic container is filled with a drink, heated with a hot warmer or the like, and is served to a consumer. <P>SOLUTION: The biaxially drawn blow molded bottle has a cave-in part, which caves in toward the bottle interior at the center of the bottom of the bottle, and consists of a tapered peripheral wall sloping toward the bottle interior and a top wall continuous with the upper end of the peripheral wall. The tapered peripheral wall consists of a plurality of peripheral wall portions, which are continuous with each other and slope against the ground surface of the bottle at respective different angles to give the peripheral wall a shape similar to that of the side wall of a wine glass. In the cave-in part, the distance between the ground surface of the bottle and the top wall is 25 to 40% of the trunk diameter of the bottle, and the diameter of a ground ring formed at the lower end of the cave-in part is 50 to 75% of the trunk diameter. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a biaxially-stretched blow-molded cage using a polyethylene terephthalate resin or the like, and more particularly to a biaxially-stretched blow-molded kit having a bottom structure that can withstand warming by a hot warmer or the like.

  In general, a beverage is filled in a plastic container, heated by a hot warmer device or the like, and provided to consumers.

In addition, in a biaxially stretched blow molded cage made of polyethylene terephthalate or the like, FIG. 13 shows a cross-sectional view of a conventional product, and FIG. 14 shows a bottom view thereof. 23 is depressed, and the independence is given to the bag. However, since the biaxially stretched blow-molded bowl 21 tends to be insufficiently stretched compared to the side wall 24 of the bowl, when the liquid content is heated to a high temperature, it is affected by gravity and heat from the contents. As the portion 25 reaches the ground contact surface of the heel, it hangs down and the heel sits more easily (see Patent Document 1).
JP-A-8-104313

  In a hot warmer device, a metal bowl containing a beverage heated to about 65 ° C. and a plastic bowl containing a beverage heated to about 55 ° C. are generally housed together and heated. The hot warmer device is operated so that the temperature of the heating plate is set to 100 to 120 ° C. and the heating plate is turned off when the ambient temperature reaches a predetermined temperature. When the product is sold and an additional product is put into the hot warmer device, the heating plate is turned on, and the temperature of the contents rises to about 70 to 75 ° C. For this reason, the plastic soot may be heated to 75 ° C. exceeding the glass transition point Tg = 67 ° C. of the polyethylene terephthalate resin.

  It is an object of the present invention to fill a beverage in a plastic container, heat it by a hot warmer device, etc., and provide it to a consumer, and the bottom part hangs down under the influence of gravity and heat from the heated contents. It is to provide a biaxially-stretched blow-molded cage that does not deteriorate sitting.

  The invention according to claim 1 solves the above-mentioned problem, and in the biaxially stretched blow-molded ridge, the bottom thereof is a tapered peripheral wall inclined toward the inside of the ridge at the center and a ceiling connected to the upper end thereof. The tapered peripheral wall is composed of a plurality of peripheral wall portions that are inclined at different angles with respect to the ground contact surface of the ridge that is connected to each other. The distance from the ground contact surface of the biaxially-stretched blow-molded cage to the top wall of the depression is 25 to 40% of the trunk diameter, and the annular ground contact diameter at the lower end of the depression is 50 of the trunk diameter. The gist is a biaxially-stretched blow-molded wrinkle characterized by being -75%.

  The biaxially-stretched blow molding ridge according to the present invention can be formed as a heating container having a body diameter of 55 to 70 mm.

  Further, the biaxially stretched blow molding rod of the present invention is formed so that the body portion is provided with a lateral rib for increasing the side wall strength below, and the top wall of the depressed portion is positioned above the lateral rib. Can do. By comprising in this way, the extending | stretching rate from a ceiling wall to a bottom part goes up, and it is thought that this led to the heat resistance improvement of a ridge.

  The biaxially-stretched blow molding ridge according to the present invention includes a tapered portion that is recessed toward the inside of the ridge that includes a tapered peripheral wall that is inclined toward the inside of the ridge and a top wall that is connected to an upper end of the tapered peripheral wall. The peripheral wall is composed of a plurality of peripheral wall portions inclined at different angles with respect to the ground contact surfaces of the ridges connected to each other, and is formed like a side wall shape of a wine glass. In the case of the conventional product, the distance from the contact surface to the ceiling wall is 23% or less of the trunk diameter (for example, 15 mm with respect to the trunk diameter of 66 mm), but is as high as 25 to 40% of the trunk diameter. By forming the ring-shaped ground contact diameter at the lower end of the depression part to be 50 to 75% of the trunk diameter and making the mountain shape of the depression part abrupt, the liquid content is heated to a high temperature, Under the influence of gravity and heat, the depression sags downward It is prevented that the saddle sits down and withstands long-term insulation at a temperature of 75 ° C. to 80 ° C., and the depressed portion of the bottom hangs down during the warm preservation by the hot warmer device, and the saddle sits badly. It can be utilized as a heating container having a trunk diameter of 55 to 70 mm.

  In the biaxially stretched blow-molded mold of the present invention, it is desirable to provide an inflection point between the annular tapered bottom wall at the bottom and the curved bottom wall on the outside. Due to the existence of such an inflection point, after filling the contents, the depressed portion at the bottom can be pushed up and capped, and then the contents can be sealed and packaged under reduced pressure by removing the bottom pushing force. As a result, even if the internal pressure rises due to heating by the hot warmer device, the internal pressure rise starts from the reduced pressure state, so that the gate portion at the center of the bottom portion is less protruded, and the effect of preventing the sagging of the depressed portion of the bottom portion of the present invention is prevented. It can be further increased.

  Moreover, since the biaxially-stretched blow molding cage of the present invention is used as a heating rod by a hot warmer device or the like, the plug portion (the region from the top surface of the basket to the bottom of the support ring) is crystallized. It is desirable that the cocoon is whitened. This is because, with a warming device such as a hot-warmer device, since the temperature above the glass transition point is applied to the product during the heating process, the mouthpiece of the product is deformed and the sealed part with the cap disappears. This is because it is desirable to crystallize the plug portion in order to eliminate the possibility of problems such as decay of the contents and liquid leakage.

  The biaxially-stretched blow molding ridge of the present invention includes a tapered portion that is recessed toward the inside of the ridge formed by a tapered peripheral wall that is inclined toward the inside of the ridge and a top wall that is connected to an upper end of the tapered peripheral wall. The peripheral wall is composed of a plurality of peripheral wall portions inclined at different angles with respect to the ground contact surfaces of the ridges connected to each other, and is formed like a side wall shape of a wine glass. The distance from the ground surface to the ceiling wall is 25 to 40% of the trunk diameter, and the annular ground diameter at the lower end of the depression is 50 to 75% of the trunk diameter. However, there is an advantage that the depression does not hang down under the influence of gravity and heat from the heated contents, and the sitting of the heel does not deteriorate.

  FIG. 1 shows a side view of a biaxially stretched blow-molded cage according to an embodiment of the present invention. FIG. 2 is a bottom view of the biaxially stretched blow-molded mold. FIG. 3 is a cross-sectional view of the bottom of the biaxially stretched blow-molded bowl. FIG. 4 is a perspective view of the biaxially stretched blow-molded cage.

  The biaxially stretched blow-molded kite 1 of the present invention shown in FIGS. 1 to 4 is a small kite (capacity 240 ml to 360 ml) made of polyethylene terephthalate or the like and having a body diameter of 55 to 70 mm, preferably 60 to 70 mm. This biaxially stretched blow-molded bowl has a wineglass-like shape that sinks toward the inside of the bowl comprising a tapered peripheral wall 4 inclined toward the inside of the bowl and a top wall 5 connected to the upper end thereof at the center of the bottom 3. A recessed portion 6 having a shape is provided. A gate portion (not shown) exists in the center of the top portion 5. Reference numeral 2 denotes the body of the heel. Reference numeral 3a denotes an annular tapered bottom wall surrounding the depressed portion 9, and an annular grounding portion is formed inside the tapered bottom wall. Further, the distance H from the ground contact surface of the biaxially stretched blow-molded bowl of the depressed portion 6 to the top wall 5 is 25 to 40%, preferably 25 to 35% of the trunk diameter, and the annular grounding at the lower end of the depressed portion 6 The diameter R is 50 to 75% of the body diameter, preferably 55 to 70%. Further, a lateral rib 11 for increasing the side wall strength is provided below the trunk of the heel.

  If the distance H is less than 25% of the body diameter, the depression will hang down under the influence of gravity and heat from the heated contents until the depression reaches the ground contact surface, and the saddle will not sit well. On the other hand, if the distance H exceeds 40% of the body diameter, the stability of the moldability is deteriorated and the shape of the bottom 3 is difficult to be obtained, which is not preferable.

  The tapered peripheral wall 4 is connected to the peripheral portion with a first peripheral wall portion 4a that is inclined with respect to the ground contact surface of the reed standing up from about 3 mm from the ground contact surface via the transition region 3b from the reed ground surface. The first peripheral wall portion 4a includes a second peripheral wall portion 4b that is inclined with respect to the ground contact surface of the bag at a different angle, and is formed like a side wall shape of a wine glass. The inclination angle of each peripheral wall portion is suitably 45 ° to 70 °. 7 represents a transition region between the peripheral wall portion 4a and the peripheral wall portion, and 8 represents a transition region between the peripheral wall portion 4b and the top wall 5.

  Moreover, it is not preferable that the ground contact diameter R is smaller than 50% of the trunk diameter because the heel tends to fall on a heating plate with an inclination such as a hot warmer. On the other hand, when the ground contact diameter R is larger than 75% of the body diameter, it is easy to hang down until the depressed portion reaches the ground contact surface due to the influence of gravity and heat from the heated contents.

  As a feature of the biaxially stretched blow molded cage of the present invention, a ceiling wall 5 having a small diameter is supported by a tapered peripheral wall 4, and the ceiling wall 5 is located above a lateral rib for increasing strength provided below the body side wall. It is mentioned that it is located. On the other hand, in the conventional container, the portion corresponding to the top wall 5 is located at a height equal to or lower than the lateral ribs 11. Further, since the bottom depression 6 has a high and simple shape, the stretch ratio of the portion from the top wall 5 to the bottom 3 can be increased, which is thought to have led to an increase in the heat resistance of the kite. It is done.

  The biaxially stretched blow-molded kite according to the present invention includes a taper-shaped peripheral wall 4 made up of peripheral wall portions 4a and 4b inclined toward the inside of the coffin at the center of the bottom portion 3, and a ceiling wall 5 connected to the upper end thereof. And the distance H from the ground contact surface of the biaxially stretched blow-molded bowl to the ceiling wall is 25 to 40% of the body diameter, preferably 25. Since the annular contact diameter R at the lower end of the depression 6 is 50 to 75%, preferably 55 to 70% of the trunk diameter, the mechanical strength of the bottom is ensured by the tapered wall. Not only that, the distance H from the ground contact surface of the biaxially stretched blow-molded bowl of the depressed portion 6 to the top wall is higher than 23% of the conventional trunk diameter, so that the liquid content is heated to a high temperature, Under the influence of gravity and heat, the depressed part hangs down, and the sitting of the eagle worsens Can withstand long-term heat retention at temperatures of 75 ° C. to 80 ° C., and the bottom depressions hang down, so that the sitting of the heel does not worsen, and it is used as a hot warmer heating container. be able to.

  Further, in the biaxially stretched blow-molded punch of the present invention, as shown in FIG. 5, it is desirable to provide an inflection point 3d between the annular tapered bottom wall 3a of the bottom portion 3 and the curved bottom wall 3c outside thereof. Due to the presence of such an inflection point, after filling the contents, a force is applied to the bottom 3 to push the bottom 3 toward the grounding surface 17, and the shape is changed to the shape indicated by the dashed-dotted line 18. The contents can be sealed and packaged in a reduced pressure state by removing the force that pushes the bottom portion 3 after capping with the depressed portion 6 pushed up. As a result, even if the internal pressure rises due to heating by the hot warmer device, the internal pressure rise starts from the reduced pressure state, so that the gate portion at the center of the bottom portion is less protruded, and the effect of preventing the sagging of the depressed portion of the bottom portion of the present invention is prevented. It can be further increased.

  FIG. 6 is a schematic cross-sectional view showing a state in which a parison is inserted into a blow mold in a method for producing a biaxially stretched blow mold.

  As shown in FIG. 6, the biaxially-stretched blow molded bag of the present invention can be manufactured by inserting an injection-molded parison 9 made of polyethylene terephthalate or the like into a mold 10 and blow-molding it. In that case, since the shape of the bottom part of the shaping | molding die 10 is comparatively simple, a housing can be shape | molded easily. The biaxially-stretched blow molding ridge of the present invention can be formed by a square ridge (square cylinder ridge), but a round ridge (a ridge or cylindrical cylinder having a multi-sided cylindrical body having six or more faces) The mold having a part has better formability.

  In addition, as a warming kite with a hot warmer device or the like, it is desirable to crystallize (whiten) the plug part (region from the top of the kite to the bottom of the support ring). This is because, with a warming device such as a hot-warmer device, since the temperature above the glass transition point is applied to the product during the heating process, the mouthpiece of the product is deformed and the sealed part with the cap disappears. This is because it is desirable to crystallize the plug portion in order to eliminate the possibility of problems such as decay of the contents and liquid leakage.

  The plug portion may be crystallized by a method of crystallizing the entire plug portion as in the conventional method. Preferably, the transition portion that follows the mouth portion and the rear portion other than the support ring is preferably crystallized. The support ring remains crystallized and the mouthpiece is crystallized, so the support ring remains amorphous. It has the advantage that it does not break.

  As a method of making the plug part crystallizing the mouth part other than the support ring and the rear part, (1) a method of subjecting the plug part to heat crystallization at the stage of parison, (2) after blow molding There are a method of subjecting the plug portion to heat crystallization treatment, and (3) a method of heat-treating only the inside of the plug portion at the parison stage, and then heat-treating the outside of the mouth portion other than the support ring after blow molding. Hereinafter, each method will be described.

(1) Method of Heating and Crystallizing the Mouth Portion at the Parison Stage First, as shown in FIG. 7, an injection mold 12 comprising a mouth mold 121, an injection cavity mold 122, and an injection core mold 123 is formed. Then, the parison 9 is formed by a normal injection molding method.

  When the molded parison 9 is cooled to a temperature lower than the glass transition temperature, the injection core mold 123 and the injection cavity mold 122 are released. At this time, as shown in FIG. 8, the mouth part mold 121 keeps holding the mouth part 91 of the parison 9.

  Next, as shown in FIG. 9, the parison 9 gripped by the mouth mold 121 is preferably placed in the cooling mold 13. At that time, it is preferable to cool not only the mouth mold 121 but also the body and bottom of the parison 9. The cooling temperature should just be lower than the crystallization temperature of resin, and specifically about 10-50 degreeC is preferable.

  With the parison cooled from the outside as described above, the rod heater 14 is inserted from the mouth portion 91 of the parison 9 as shown in FIG. By heating from the inside, only the inner part of the transition part 93 to the body part below the mouth part 91 and the support ring 92 is crystallized to form the crystallized part 19a. At this time, it is preferable to heat the parison so that the surface temperature becomes 100 to 190 ° C. It can carry out by heat-processing at 100-190 degreeC. In that case, when the temperature is lower than 100 ° C., the resin in the plug portion does not crystallize. Further, the heating time is set so that the resin causes partial crystallization, and specifically, about 0.5 to 3 minutes is preferable.

  Next, the mouth mold 121 is removed from the parison 9, and the support ring 92 is held by the support ring molds 16a and 16b as shown in FIG. In this state, the mouth portion 91 is heated from the outside by the ring heater 15. In that case, heating from the outside of the mouth may be performed using a hot air heater, an infrared heater or the like instead of the ring heater. The heating temperature may be about 100 to 190 ° C. as described above. Further, the time may be sufficient for the amorphous resin in the outer layer of the mouth to be crystallized, but specifically about 0.5 to 3 minutes is preferable. At this time, the support ring molds 16a and 16b are preferably cooled to a temperature lower than the crystallization temperature of the resin. Specifically, the cooling temperature of the support ring 91 is preferably about 10 to 40 ° C.

  By heating the mouth portion 91 by such a method, as shown in FIG. 11, the resin in the support ring 92 remains amorphous, and the other mouth portions 91 are crystallized. 19b shows a non-crystallized part.

  The support ring 92 is easily deformed by its own weight when heated, but as shown in FIG. 10, the support ring 92 is held by the support ring molds 16a and 16b in the course of the heat treatment, so that deformation is prevented.

  Subsequently, the parison 9 obtained in this way is blow-molded by a normal method, but at this time, a steep thickness difference does not occur from the transition portion 93 to the lower shoulder portion.

(2) Method of applying heat crystallization treatment to mouthpiece part after blow molding After blow molding of cocoons, the heel is taken out from the mold held by the mouth mold and subjected to the following heat crystallization treatment. In the heat crystallization treatment, the cocoon held in the mouth mold is placed in the cooling mold, and the heater and the transition part are heated from the inside by inserting a heater from the mouth of the jar in the same manner as in the method (1) described above. Then, the resin in that portion is crystallized. The heating crystallization condition may be the method (1).

  Next, after releasing the mouth mold from the heel, the support ring of the heel is gripped by the support ring mold. In this state, the mouth is heated from the outside to crystallize the amorphous resin in the outer layer of the mouth. The heat crystallization conditions may be the same as in the method (1).

(3) Method of crystallizing only the inside of the mouthpiece at the parison stage and then crystallizing the outside of the mouth other than the support ring after blow molding After injection of the parison, the injection core type with the parison held by the mouth mold Then, the injection cavity mold is removed, and the mouth portion and the transition portion are heated from the inside to crystallize the resin at that portion. The heat crystallization conditions may be the same as in the method (1).

  After blow molding using the parison, the support ring of the heel is gripped with a support ring mold. In this state, the mouth other than the support ring is heated from the outside to crystallize the amorphous resin in the outer layer of the mouth. The heating crystallization condition may be the method (1).

  As the molding resin for the biaxially stretched blow molded mold of the present invention, a polyester resin composed of a saturated dicarboxylic acid and a saturated dihydric alcohol can be applied. Examples of saturated dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-1,4- or 2,6 dicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid, diphenyldicarboxylic acids, diphenoxyethanediethanedicarboxylic acids, etc. Aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decane-1,10-dicarboxylic acid, and the like can be used. In addition, saturated dihydric alcohols include fats such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, dodecamethylene glycol, and neopentyl glycol. Group glycol, 2,2-bis (4′-β-hydroxyethoxyphenyl) propane, other aromatic diols, and the like can be used. As such a polyester resin comprising a saturated dicarboxylic acid and a saturated dihydric alcohol, it is preferable to use polyethylene terephthalate comprising terephthalic acid and ethylene glycol.

  In addition, the biaxially stretched blow molded cage of the present invention can also be formed as a two-layer or three-layer multilayer molded cage. That is, oxygen barrier such as polyethylene terephthalate / MXD6, MXD6 + cobalt salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer) or PEN (polyethylene naphthalate) is obtained by two-color extrusion molding or two-color injection molding. A multilayer bag having oxygen barrier properties and ultraviolet barrier properties may be formed by extrusion molding a three-layer parison of resin / polyethylene terephthalate having heat resistance and ultraviolet barrier properties, followed by blow molding.

  Alternatively, a hot-warmer container having a barrier property can be formed by attaching an in-mold label forming label to a blow mold and performing in-mold label biaxial stretching blow molding.

  The in-mold label forming label comprises a base material layer and an adhesive layer, and the adhesive layer is made of a heat-adhesive material that is softened at 130 ° C. or lower and adheres to the surface of the stretch blow molded article.

  Here, as a heat-adhesive material, (a) low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α olefin copolymer polymerized using a metallocene catalyst, polypropylene, ethylene- Vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, Polyolefin resins such as methylpentene polymer, polyethylene or polypropylene modified with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid or other unsaturated carboxylic acid, poly (meth) acrylic resin, thermoplastic Polyester tree One or a plurality of thermoplastic polyamide-based resins, (b) an unstretched or stretched plastic film such as polyethylene, polypropylene or polyethylene terephthalate having a heat seal layer, (c) an ethylene-vinyl acetate copolymer A hot-melt adhesive layer containing (d) a heat sealant layer containing ethylene-vinyl acetate copolymer or the like can be applied.

  The base material layer includes a barrier layer, an ultraviolet ray prevention layer, a light shielding layer, a printing base material layer, and the like.

  Next, the present invention will be described with reference to examples and comparative examples.

  As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. A recessed portion 6 of a wineglass shape that is recessed toward the inside of the ridge formed by the ceiling wall 5 that is formed, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the depressed portion 6 to the ceiling wall is 20 mm (body The ring-shaped ground contact diameter R at the lower end of the depressed portion 6 is 40 mm (60.6% of the body diameter), the inner capacity 350 ml (height 163 mm), and the inner capacity 280 ml ( A wrinkle with a height of 136 mm was formed. 350 ml of water was put into a tub with an internal volume of 350 ml, and 280 ml of water was put into a tub with an internal volume of 280 ml, and placed in a thermostatic bath at a temperature of 80 ° C. and left for 10 hours. However, under the influence of gravity and heat from the heated contents, the bottom part hangs down and the sitting does not worsen.

  As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. A recessed portion 6 having a wineglass-like shape that is recessed toward the interior of the ridge formed by the ceiling wall 5, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the recessed portion 6 to the ceiling wall is 17.5 mm (26.5% of the trunk diameter), the ring-shaped grounding diameter R at the lower end of the depression 6 is 40 mm (60.6% of the trunk diameter), the inner capacity 350 ml (height 163 mm), and the inner capacity A 280 ml (136 mm height) bag was formed. 350 ml of water was put into a tub with an inner volume of 350 ml, and 280 ml of water was put into a tub with an inner volume of 280 ml, placed in a thermostat at 78 ° C. and left for 10 hours. However, under the influence of gravity and heat from the heated contents, the bottom part hangs down and the sitting does not worsen.

  As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. A recessed portion 6 having a wineglass-like shape that is recessed toward the interior of the ridge formed by the ceiling wall 5, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the recessed portion 6 to the ceiling wall is 17.5 mm (26.5% of the trunk diameter), the ring-shaped ground contact diameter R at the lower end of the depression 6 is 45 mm (68.1% of the trunk diameter), the inner capacity 350 ml (height 163 mm), and the inner capacity A 280 ml (136 mm height) bag was formed. 350 ml of water was put into a tub with an inner volume of 350 ml, and 280 ml of water was put into a tub with an inner volume of 280 ml, placed in a thermostat at 75 ° C. and left for 10 hours. However, under the influence of gravity and heat from the heated contents, the bottom part hangs down and the sitting does not worsen.

  As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. The wine glass-like depression 6 is recessed toward the inside of the ridge, which is formed from the ceiling wall 5, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the depression 6 to the ceiling wall is 16.5 mm. The ring-shaped ground contact diameter R at the lower end of the depressed portion 6 is 50 mm (75.8% of the trunk diameter), the inner capacity 350 ml (height 163 mm) and the inner capacity 280 ml ( A wrinkle with a height of 136 mm was formed. 350 ml of water was put into a tub with an inner volume of 350 ml, and 280 ml of water was put into a tub with an inner volume of 280 ml, placed in a thermostat at 75 ° C. and left for 10 hours. However, under the influence of gravity and heat from the heated contents, the bottom part hangs down and the sitting does not worsen.

[Comparative Example 1]
As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. A recessed portion 6 having a wineglass shape that is recessed toward the interior of the ridge formed by the ceiling wall 5, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the depressed portion 6 to the ceiling wall is 15 mm (body A ring having an inner volume of 350 ml was formed, with an annular grounding diameter R of 50 mm (75.7% of the body diameter) at the lower end of the depressed portion 6. 350 ml of water was placed in this basket, placed in a constant temperature bath at 75 ° C. and left for 10 hours. As a result, under the influence of the gravitational force and heat from the heated contents, the bottom part hangs down until it reaches the ground contact surface, and the seating becomes worse.

[Comparative Example 2]
As shown in FIG. 1, using a polyethylene terephthalate resin, a tapered peripheral wall 4 having a body diameter of 66 mm and inclined toward the inside of the ridge is connected to the upper end thereof, as shown in FIG. The wine glass-like depression 6 is recessed toward the inside of the ridge, which is formed from the ceiling wall 5, and the distance H from the ground contact surface of the biaxially stretched blow molded ridge of the depression 6 to the ceiling wall is 16.5 mm. A collar having an inner capacity of 350 ml was formed, which was (25% of the trunk diameter) and the annular ground contact diameter R at the lower end of the depression 6 was 53 mm (80% of the trunk diameter). 350 ml of water was placed in this basket, placed in a constant temperature bath at 75 ° C. and left for 10 hours. As a result, under the influence of the gravitational force and heat from the heated contents, the bottom part hangs down until it reaches the ground contact surface, and the seating becomes worse.

  FIG. 12 shows the time when the contents of the soot are heated in a constant temperature layer (DN43 manufactured by Yamato Kagaku Co., Ltd.) maintained at 75 ° C. (warming) with respect to the gate portion depth change rate ((ground of the soot) Initial value of distance from gate part to gate part in the central part of the ridge (hereinafter referred to as gate part depth) −measured value of gate part depth of heel after heating) / initial value of gate part depth × 100 (% )) Graph. The gate depth was measured using a depth cage manufactured by Mitutoyo Corporation. In FIG. 12,-●-is Comparative Example 1, -O- is Comparative Example 2,-▲-is Example 1, -X- is Example 2,-◆-is Example 3,-■-is an Example. 4 is shown. As is clear from this figure, in Examples 1 to 4, the gate change rate after heating for 10 hours is 70% or less, and the bottom depression hangs down until it reaches the grounding surface, and the seating becomes worse. Absent. On the other hand, in the case of Comparative Examples 1 and 2, if the heating is continued for 10 hours, the gate change rate reaches 100% and the bottom depression hangs down until it reaches the ground contact surface, and the sitting of the heel becomes worse.

  The biaxially stretched blow-molded bowl according to the present invention can be effectively used as a sales container for heating and selling a beverage by a hot warmer device or the like.

It is a side view of the biaxial stretching blow-molding cage of an embodiment of the invention. It is a bottom view of the biaxially-stretched stretch blow molding punch of embodiment of this invention. It is sectional drawing of the bottom part of the biaxially-stretched blow molding cage | basket of embodiment of this invention. 1 is a perspective view of a biaxially stretched blow-molded cage of an embodiment of the present invention. It is the schematic which shows the shape of the bottom part which has an inflection point of the biaxially-stretched blow molding cage | basket of this invention. FIG. 6 is a schematic cross-sectional view showing a state in which a parison is inserted into a blow molding die in the molding process of the biaxially stretched blow molded punch. It is the schematic which shows the manufacturing process of the parison of the biaxially-stretched blow molding cage | basket of this invention. It is the schematic which shows the state hold | gripped with the mouth part type | mold of the shape | molded parison. 1 is a schematic diagram showing the process of crystallizing the inside of the mouth of a parison. 1 is a schematic diagram illustrating a process of crystallizing the outside of a parison mouth. It is an enlarged view of the mouth part of the bag which was blow-molded after crystallizing the mouth part. Elapsed time of heating of biaxially stretched blow molded mold vs. gate depth It is sectional drawing of the bottom part of the conventional biaxial stretching blower. It is a bottom view of the bottom part of the biaxially stretched blow-molded bowl shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biaxial stretch blow molding cage | basket 2 Trunk body 3 Bottom 3a Annular taper bottom wall 3b Transition area 3c Curved bottom wall 3d Inflection point 4 Tapered peripheral wall 4a Perimeter wall part 4b Perimeter wall part 5 Top wall 6 Depression part 7 Transition area DESCRIPTION OF SYMBOLS 8 Transition area | region 9 Parison 91 Mouth part 92 Support ring 93 Transition part to the trunk | drum under support ring 92 10 Blow-molding die 11 Horizontal rib 12 Injection molding die 121 Mouth type 122 Injection cavity type 123 Injection core type 13 Cooling type 14 Rod heater 15 Ring heater 16a Support ring type 16b Support ring type 17 Ground surface 18 Line indicating the outline of the bottom portion that is pressed and deformed toward the ground surface 19a Crystallized region 19b Non-crystallized region 21 Bottom 22 Peripheral wall 23 壜 Inside 24 壜Side wall of 25

Claims (5)

  In the biaxially stretched blow-molded ridge, the bottom portion is provided with a recessed portion that is recessed toward the interior of the ridge comprising a tapered peripheral wall that is inclined toward the interior of the ridge and a top wall that is connected to the upper end thereof, and is tapered. The peripheral wall is composed of a plurality of peripheral wall portions inclined at different angles with respect to the ground contact surfaces of the ridges connected to each other, and is formed like a side wall shape of a wine glass. A biaxially-stretched blow molded ridge, characterized in that the distance from the ground to the ceiling wall is 25 to 40% of the trunk diameter, and the annular ground contact diameter at the lower end of the depression is 50 to 75% of the trunk diameter.   The biaxially stretched blow-molded bowl according to claim 1, which is a heating container having a body diameter of 55 to 70 mm.   The biaxially-stretched blow molding according to claim 1 or 2, wherein the body portion is provided with a lateral rib for lowering the side wall strength, and the top wall of the depressed portion is located above the lateral rib.壜.   4. The biaxially stretched blow-molded bowl according to claim 1, wherein an inflection point exists between the tapered peripheral wall and the curved bottom wall on the outside thereof. 5. The biaxially stretched blow-molded bowl according to any one of claims 1 to 4, wherein the mouthpiece portion of the bowl is whitened.

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