JP6443712B2 - Blow molded plastic bottle - Google Patents

Description

  The present invention relates to a blow-molded plastic bottle for heating, and more particularly to a blow-molded plastic bottle for warming for beverages or the like heated in a hot warmer or a vending machine.

  Recently, plastic bottles for beverages and the like have become common, and such plastic bottles are also used for heated beverages.

  The performance required for such a plastic bottle for heating is that the bottle appearance is not impaired during heating.

  Such a plastic bottle has a mouth portion, a shoulder portion, a trunk portion, and a bottom portion, and the plastic bottle is formed by preparing a preform and performing blow molding on the preform. The Moreover, although the bottom part of a plastic bottle contains a peripheral part, depending on the shape of a bottom part, the plastic resin material of preform cannot wrap around, and it may be unable to shape | mold accurately. In this case, there may be a portion that cannot be reliably grounded at the peripheral edge of the bottom.

JP 2006-264721 A

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a blow-molded plastic bottle in which the peripheral edge of the bottom can be reliably grounded over the entire circumference.

  The present invention relates to a plastic bottle manufactured by blow molding, comprising a mouth portion, a shoulder portion, a trunk portion, and a bottom portion, the trunk portion having a substantially rectangular tube shape having four side surfaces, A boundary surface is formed between adjacent side surfaces, the bottom portion includes a peripheral edge portion, and four protrusions extending radially inward from the peripheral edge portion and projecting to the outside of the bottom portion. A concave portion that is drawn inwardly from the bottom is formed therebetween, and each protrusion is arranged at a position corresponding to each of the four side surfaces.

  The present invention is characterized in that a circumferential step portion is formed between the peripheral portion of the bottom portion, the protrusion and the concave portion, and the cross-sectional shape of the bottom portion has an inflection point in the circumferential step portion. It is a plastic bottle.

  The present invention is a non-heat-resistant molded plastic bottle in which a flat panel portion is formed on each side surface of the body portion.

  The present invention is a preform for molding the plastic bottle described above.

  According to the present invention, the plastic resin material of the preform can wrap around the entire bottom portion. Therefore, a portion that cannot be grounded does not occur at the peripheral portion of the bottom portion, and the plastic bottle can be grounded stably.

FIG. 1A is a front view showing a blow-molded plastic bottle according to the first embodiment of the present invention, and FIG. 1B is a bottom view showing the bottom thereof. 2A is a front view of the blow-molded plastic bottle as seen from an angle different from that of FIG. 1A, and FIG. 2B is a bottom view showing the bottom portion thereof. FIG. 3 is a cross-sectional view showing the bottom of the blow molded plastic bottle according to the first embodiment. FIG. 4A is a front view showing a blow-molded plastic bottle according to a second embodiment of the present invention, and FIG. 4B is a bottom view showing its bottom. FIG. 5A is a front view of the blow-molded plastic bottle as seen from an angle different from that of FIG. 4A, and FIG. 5B is a bottom view showing the bottom thereof. FIG. 6 is a cross-sectional view showing the bottom of a blow-molded plastic bottle according to the second embodiment. 7 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 1. FIG. 8 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 1. FIG. 9 is a cross-sectional view showing the bottom of a blow molded plastic bottle as Comparative Example 1. FIG. 10 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 2. FIG. 11 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 2. FIG. 12 is a cross-sectional view showing the bottom of a blow molded plastic bottle as Comparative Example 2. FIG. 13 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 3. FIG. 14 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 3. FIG. 15 is a cross-sectional view showing the bottom of a blow molded plastic bottle as Comparative Example 3. FIG. 16 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 4. FIG. 17 is a bottom view showing the bottom of a blow molded plastic bottle as Comparative Example 4. FIG. 18 is a cross-sectional view showing the bottom of a blow-molded plastic bottle as Comparative Example 4. FIG. FIG. 19 is a view showing a preform for producing a plastic bottle according to an embodiment of the present invention. 20A and 20B are diagrams in which ink is applied to the bottom of a blow-molded plastic bottle and the ink at the bottom is transferred to a white paper.

First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 3 are views showing a first embodiment of the present invention.

  First, an outline of a blow molded plastic bottle for heating according to the present embodiment will be described with reference to FIGS. 1 to 3.

The plastic bottle 10 shown in FIGS. 1 to 3 is obtained by injection molding, and a preform 10A having a mouth portion 11 is prepared (see FIG. 19), and biaxial stretch blow molding is performed on the preform 10A. It is produced by this.
Such a plastic bottle 10 is a lightweight bottle having a volume of 200 ml. The height of the plastic bottle 10 is 100 to 200 mm, and the body diameter is 50 to 70 mm. Moreover, the height of the bottom part 30 mentioned later is 5-30 mm.
Such a non-heat-resistant molded plastic bottle 10 for heating includes a mouth part 11, a shoulder part 12 provided below the mouth part 11, a body part 20 provided below the shoulder part 12, and a body part 20 below. And a bottom portion 30 provided on the bottom.

  Among these, the trunk | drum 20 has the four side surfaces 21 which become the mutually same shape, and consists of a square cylinder shape as a whole. Further, a flat boundary surface 22 is formed between the adjacent side surfaces 21.

  Moreover, the four side surfaces 21 of the trunk | drum 20 are divided into the upper area | region 21a and the lower area | region 21b through the side surface horizontal concave rib 24a drawn inward (inward of the bottle 10). Each boundary surface 22 is also divided into an upper region 22a and a lower region 22b via a boundary surface horizontal concave rib 24b that is drawn inward (inward of the bottle 10).

  Among these, the horizontal concave rib 24 is comprised by the side surface horizontal concave rib 24a and the boundary surface horizontal concave rib 24b.

  Further, a flat panel portion 23 is provided in each of the upper region 21a and the lower region 21b of each side surface 21 of the trunk portion 20, and the panel portion 23 allows the plastic bottle 10 to be inflated and decompressed. Absorbs the applied pressure.

  The bottom portion 30 has a peripheral edge portion 31 and a central portion 32 located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. The bottom portion 30 is radially inward from the peripheral edge portion 31. Four protrusions 33 extending in the direction are formed. The four protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33. Furthermore, a circumferential step 35 is formed between the peripheral portion 31 and the protrusion 33 and the recess 34, and the cross-sectional shape of the bottom 30 has an inflection point in the circumferential step 35. become.

  The four protrusions 33 are formed 90 ° apart from each other, and each protrusion 33 is disposed at a position corresponding to the side surface 21 of the body 20.

  Next, FIG. 3 shows a cross-sectional shape of the bottom. In FIG. 3, a curve A shows a cross section along line AA in FIG. 1B, and a curve B shows a cross section along line BB in FIG.

  As shown in FIG. 3, the curve A indicating the cross section between the opposing boundary surfaces 22 is greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform described later can be surely wound around the bottom 30 along the curve A.

  Further, the curve B indicating the cross section between the opposing side surfaces 21 also includes a protrusion 33 protruding outward in the cross section, and is thus greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform can be surely wrapped around the bottom 30 along the curve B, and the plastic resin material of the preform can be surely wrapped around the entire periphery of the peripheral edge 31 of the bottom 30. Can do. As a result, the peripheral edge 31 of the bottom 30 can be reliably grounded over the entire circumference, and a portion that cannot be grounded does not occur at the peripheral edge 31 of the bottom 30.

  Such a non-heat-resistant molded plastic bottle 10 for heating can be produced by biaxially stretching blow-molding a preform produced by injection molding a synthetic resin material (plastic resin material). As a material for the preform, that is, the plastic bottle 10, a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), a recycled resin, and a biodegradable resin should be used. Is preferred.

  The plastic bottle 10 can also be formed as a multilayer molded bottle having two or more layers. That is, by extrusion molding or injection molding, for example, the intermediate layer has gas barrier properties and light shielding properties such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer) or PEN (polyethylene naphthalate). A multilayer bottle having gas barrier properties and light shielding properties may be formed by extrusion molding a preform composed of three or more layers as the resin (intermediate layer), and then blow molding. Such an intermediate layer is preferably provided in at least the body 20 of the plastic bottle 10. Further, it is preferable to provide an intermediate layer in the region of the bottom 30 except for the central portion of the bottom 30. This is because this portion may cause delamination (delamination) when subjected to an impact such as a case dropping. Further, by mixing an inert gas (nitrogen gas, argon gas) with the thermoplastic resin melt, a foam preform having a foam cell diameter of 0.5 to 100 μm is formed, and this foam preform is blow-molded. As a result, the plastic bottle 10 may be manufactured. Since such a plastic bottle incorporates the foam cell, the light shielding property of the entire plastic bottle 10 can be improved. In order to have gas barrier properties and light shielding properties, a blend bottle in which thermoplastic resins are blended may be formed as well as multilayers.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, the above-described preform is prepared, and this preform is inserted into a blow mold (not shown). Next, the above-described plastic bottle 10 can be obtained by blow-molding the preform in a blow-molding die.

  In this case, the bottom 30 of the plastic bottle 10 is greatly open upward both in the cross section between the opposing boundary surfaces 22 (curve A) and in the cross section between the opposing side faces 21 (curve B). For this reason, the plastic resin material of the preform can be made to wrap around the entire periphery of the peripheral edge 31 of the bottom 30, and thereby the peripheral edge 31 of the bottom 30 can be reliably grounded over the entire periphery. A portion that cannot be grounded does not occur in the peripheral edge 31 of the bottom 30.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS.

  The second embodiment shown in FIGS. 4 to 6 is different only in the structure of the bottom portion 30, and the other configuration is substantially the same as that of the first embodiment shown in FIGS.

  4 to 6, the same parts as those of the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4 to 6, the bottom portion 30 includes a peripheral edge portion 31 and a central portion 32 that is located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. Four protrusions 33 extending from the portion 31 inward in the radial direction are formed. The four protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33.

  The four protrusions 33 are formed 90 ° apart from each other, and each protrusion 33 is disposed at a position corresponding to the side surface 21 of the body 20.

  In the second embodiment, no circumferential step is provided.

  Next, FIG. 6 shows the cross-sectional shape of the bottom. In FIG. 6, a curve A shows a cross section along line AA in FIG. 4B, and a curve B shows a cross section along line BB in FIG. 5B.

  As shown in FIG. 6, the curve A indicating the cross section between the opposing boundary surfaces 22 is greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform described later can be surely wound around the bottom 30 along the curve A.

  Further, the curve B indicating the cross section between the opposing side surfaces 21 also includes a protrusion 33 protruding outward in the cross section, and is thus greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform can be surely wrapped around the bottom 30 along the curve B, and the plastic resin material of the preform can be surely wrapped around the entire periphery of the peripheral edge 31 of the bottom 30. Can do. As a result, the peripheral edge 31 of the bottom 30 can be reliably grounded over the entire circumference, and a portion that cannot be grounded does not occur at the peripheral edge 31 of the bottom 30.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, the above-described preform is prepared, and this preform is inserted into a blow mold (not shown). Next, the above-described plastic bottle 10 can be obtained by blow-molding the preform in a blow-molding die.

  In this case, the bottom 30 of the plastic bottle 10 is greatly open upward both in the cross section between the opposing boundary surfaces 22 (curve A) and in the cross section between the opposing side faces 21 (curve B). For this reason, the plastic resin material of the preform can be made to wrap around the entire periphery of the peripheral edge 31 of the bottom 30, and thereby the peripheral edge 31 of the bottom 30 can be reliably grounded over the entire periphery. A portion that cannot be grounded does not occur in the peripheral edge 31 of the bottom 30.

(Comparative Example 1)
Next, a comparative example of the present invention will be described. 7 to 9 are views showing Comparative Example 1. FIG. Although the comparative example 1 shown in FIGS. 7 to 9 is different in the structure of the bottom 30, the other configuration is the same as that of the first embodiment shown in FIGS. 1 to 3.

  As shown in FIGS. 7 to 9, the bottom portion 30 has a peripheral edge portion 31 and a central portion 32 located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. Four protrusions 33 extending from the portion 31 inward in the radial direction are formed. The four protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33. Furthermore, a circumferential step 35 is formed between the peripheral portion 31 and the protrusion 33 and the recess 34, and the cross-sectional shape of the bottom 30 has an inflection point in the circumferential step 35. become.

  The four protrusions 33 are formed 90 degrees apart from each other, and each protrusion 33 is disposed at a position corresponding to the boundary surface 22 of the body 20.

  Next, FIG. 9 shows the cross-sectional shape of the bottom. In FIG. 9, a curve A shows a cross section along line AA in FIG. 7, and a curve B shows a cross section along line BB in FIG.

  As shown in FIG. 9, the curve A indicating the cross section between the opposing boundary surfaces 22 includes a protrusion 33 projecting outward in the cross section, and thus increases upward from the peripheral edge portion 31 along the central portion 32. It is open.

  For this reason, the plastic resin material of the preform described later can be surely wound around the bottom 30 along the curve A.

  In addition, the curve B indicating the cross section between the opposing side surfaces 21 includes a concave portion 34 in the cross section, and thus narrows from the peripheral edge portion 31 along the central portion 32.

  For this reason, it is difficult to make the plastic resin material of the preform wrap around the bottom portion 30 along the curve B. As a result, a portion that cannot be grounded remains on the peripheral edge 31 of the bottom 30.

(Comparative Example 2)
Next, Comparative Example 2 of the present invention will be described. 10 to 12 are diagrams showing Comparative Example 2. FIG. Although the structure of the bottom part 30 differs in the comparative example 2 shown in FIG. 10 thru | or FIG. 12, other structures are the same as 1st Embodiment shown in FIG. 1 thru | or FIG.

  As shown in FIGS. 10 to 12, the bottom portion 30 has a peripheral edge portion 31 and a central portion 32 located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. Four protrusions 33 extending from the portion 31 inward in the radial direction are formed. The four protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33.

  The four protrusions 33 are formed 90 degrees apart from each other, and each protrusion 33 is disposed at a position corresponding to the boundary surface 22 of the body 20.

  Next, FIG. 12 shows the cross-sectional shape of the bottom. In FIG. 12, a curve A shows a cross section along line AA in FIG. 10, and a curve B shows a cross section along line BB in FIG.

  As shown in FIG. 12, the curve A indicating the cross section between the opposing boundary surfaces 22 includes a protrusion 33 protruding outward in the cross section, so that the curve A greatly opens upward from the peripheral edge portion 31 along the central portion 32. doing.

  For this reason, the plastic resin material of the preform described later can be surely wound around the bottom 30 along the curve A.

  In addition, the curve B indicating the cross section between the opposing side surfaces 21 includes a concave portion 34 in the cross section, and thus narrows from the peripheral edge portion 31 along the central portion 32.

  For this reason, it is difficult to make the plastic resin material of the preform wrap around the bottom portion 30 along the curve B. As a result, a portion that cannot be grounded remains on the peripheral edge 31 of the bottom 30.

(Comparative Example 3)
Next, Comparative Example 3 of the present invention will be described. 13 to 15 are diagrams showing Comparative Example 3. Although the structure of the bottom part 30 differs in the comparative example 3 shown in FIG. 13 thru | or FIG. 15, other structures are the same as 1st Embodiment shown in FIG. 1 thru | or FIG.

  As shown in FIG. 13 to FIG. 15, the bottom portion 30 has a peripheral edge portion 31 and a central portion 32 located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. Five protrusions 33 that extend radially inward from the portion 31 are formed. The five protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33. Furthermore, a circumferential step 35 is formed between the peripheral portion 31 and the protrusion 33 and the recess 34, and the cross-sectional shape of the bottom 30 has an inflection point in the circumferential step 35. become.

  Further, the five protrusions 33 are formed so as to be separated from each other by 72 °, and one protrusion 33 is disposed at a position corresponding to the boundary surface 22 of the body part 20. The other four protrusions 33 are arranged so as to be shifted with respect to the side surface 21 and the boundary surface 22 of the body portion 20.

  Next, FIG. 15 shows the sectional shape of the bottom. In FIG. 15, a curve A shows a cross section along line AA in FIG. 13, and a curve B shows a cross section along line BB in FIG.

  As shown in FIG. 15, the curve A indicating the cross section between the opposing boundary surfaces 22 is greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform can be reliably wound around the bottom 30 along the curve A.

  In addition, a curve B indicating a cross section between the opposing side surfaces 21 narrows from the peripheral edge portion 31 along the central portion 32 on the side not including the protrusion 33.

  For this reason, it is difficult to make the plastic resin material of the preform wrap around the bottom portion 30 along the curve B. As a result, a portion that cannot be grounded remains on the peripheral edge 31 of the bottom 30.

(Comparative Example 4)
Next, Comparative Example 4 of the present invention will be described. 16 to 18 are diagrams showing a comparative example 4. FIG. Although Comparative Example 4 shown in FIGS. 16 to 18 is different in the structure of the bottom portion 30, the other configuration is the same as that of the first embodiment shown in FIGS.

  As shown in FIGS. 16 to 18, the bottom portion 30 has a peripheral edge portion 31 and a central portion 32 located at the center of the peripheral edge portion 31 and lifted upward from the peripheral edge portion 31. Five protrusions 33 that extend radially inward from the portion 31 are formed. The five protrusions 33 protrude toward the outside of the bottom 30, and a recess 34 is formed between the protrusions 33.

  Further, the five protrusions 33 are formed so as to be separated from each other by 72 °, and one protrusion 33 is disposed at a position corresponding to the boundary surface 22 of the body part 20. The other four protrusions 33 are arranged so as to be shifted with respect to the side surface 21 and the boundary surface 22 of the body portion 20.

  Next, FIG. 18 shows the cross-sectional shape of the bottom. In FIG. 18, a curve A shows a cross section along line AA in FIG. 16, and a curve B shows a cross section along line BB in FIG.

  As shown in FIG. 18, the curve A indicating the cross section between the opposing boundary surfaces 22 is greatly opened upward from the peripheral edge portion 31 along the central portion 32.

  For this reason, the plastic resin material of the preform can be reliably wound around the bottom 30 along the curve A.

  In addition, a curve B indicating a cross section between the opposing side surfaces 21 narrows from the peripheral edge portion 31 along the central portion 32 on the side not including the protrusion 33.

  For this reason, it is difficult to make the plastic resin material of the preform wrap around the bottom portion 30 along the curve B.

  As a result, a portion that cannot be grounded remains on the peripheral edge 31 of the bottom 30.

  Next, specific examples of the present invention will be described. A 18.3 g PET single layer preform was produced by injection molding. By performing biaxial stretch blow molding on this preform, a 350 ml plastic bottle 10 having the same shape as that of the first embodiment shown in FIGS. 1 to 3 was manufactured.

  Next, as a comparative example, a 18.3 g PET single layer preform was manufactured by injection molding. The preform was subjected to biaxial stretch blow molding to produce a 350 ml plastic bottle 10 having the same shape as that of Comparative Example 1 shown in FIGS.

  For the plastic bottles 10 of these examples and comparative examples, ink was applied to the bottom 30 with vermilion, the bottom 30 was placed on a white paper, and the ink was transferred onto the white paper.

The results are shown in Table 1 and FIGS. 20 (a) and 20 (b).

As can be seen from Table 1 and FIGS. 20A and 20B, in the case of the present invention, the ink 30A is transferred over the entire circumference of the peripheral edge portion 31 of the bottom portion 30 corresponding to the side surface 21 and the boundary surface 22, The part which is not left does not remain (refer Fig.20 (a) (b)). For this reason, the peripheral part 31 of the bottom part 30 was shaped according to the metal mold | die over the perimeter.
On the other hand, according to the comparative example, ink is transferred to the peripheral edge 31 of the bottom 30 corresponding to the boundary surface 22, but ink 30 </ b> A is transferred to the peripheral 31 of the bottom 30 corresponding to the side 21. The peripheral edge 31 of the bottom 30 corresponding to the side surface 21 was not shaped according to the mold (see FIG. 20B).

DESCRIPTION OF SYMBOLS 10 Plastic bottle 11 Mouth part 12 Shoulder part 20 Body part 21 Side 21a Upper area | region 21b Lower area 22 Boundary surface 23 Panel part 24 Horizontal concave rib 24a Side horizontal concave rib 24b Boundary horizontal concave rib 30 Bottom part 31 Peripheral part 32 Central part 33 Projection 34 Recess 35 Circumferential step

Claims (3)

In plastic bottles manufactured by blow molding,
The mouth,
Shoulder and
The torso,
With a bottom,
The trunk portion has a substantially rectangular tube shape having four side surfaces,
A boundary surface is formed between adjacent side surfaces of the body part,
The bottom part has a peripheral part, four protrusions extending radially inward from the peripheral part and projecting outside the bottom part, and a circular central part when viewed from the bottom, and the bottom part is between each protrusion. A recess that is pulled inward is formed,
The projections are arranged at positions corresponding to each of the four sides, bottom viewed from the projections are semicircular, and the projections will contact the center portion of the circular shape,
A circumferential step portion is formed between the peripheral portion of the bottom portion, the protrusion, and the concave portion, and the cross-sectional shape of the bottom portion has an inflection point that protrudes inward at the circumferential step portion. And plastic bottle.   The plastic bottle according to claim 1, wherein a flat panel portion is formed on each side surface of the body portion.   A preform for molding the plastic bottle according to claim 1.

Images