JP4437313B2 - Synthetic resin housing - Google Patents

Description

  The present invention relates to a synthetic resin casing, and more particularly to a synthetic resin casing in which a plurality of panels for absorbing fluctuations in internal pressure are disposed in a body portion.

  2. Description of the Related Art Conventionally, a so-called high temperature filling method is used as a method for filling a synthetic resin casing such as a polyethylene terephthalate resin casing (hereinafter referred to as a PET bottle) with a liquid content such as fruit juice and tea that requires sterilization. The container is filled with the content liquid at a temperature of about 90 ° C., sealed with a cap and then cooled, and the inside of the casing is in a considerably reduced pressure state.

  For this reason, for applications involving high-temperature filling as described above, a so-called reduced pressure absorption panel, which is a region that can be easily deformed by depression, is formed in the body part, and this reduced pressure absorption panel is used during pressure reduction. By deforming into a depressed shape, it maintains a good appearance and secures rigidity as a casing in parts other than the vacuum absorption panel, so there are no troubles in the transport line of the chassis, stacked storage, vending machines, etc. I am doing so.

For example, Patent Document 1 describes a casing having a vacuum absorbing panel. FIG. 9 shows a casing shown in the embodiment of Patent Document 1. This casing 101 is a round PET bottle having a capacity of 500 ml, and includes a mouth tube portion 102, a shoulder portion 103, a trunk portion 104, and a bottom portion. An annular groove 106 is formed at a substantially central height position of the housing 1, and six vacuum absorbing panels 107 are formed below the annular groove 106. The reduced pressure absorption panel 107 has a substantially flat plate shape, and when the inside of the housing 1 is in a decompressed state, it can be easily deformed inwardly, so that the housing is deformed into an irregular shape. Thus, a function of absorbing (relaxing) the reduced pressure state (hereinafter referred to as a reduced pressure absorption function) can be exhibited without giving the feeling of being, that is, not conspicuous. Further, the rigidity as the casing is mainly borne by the column portion 109 formed between the adjacent vacuum absorbing panels 107.
Japanese Patent Laid-Open No. 10-58527

  In recent years, synthetic resin casings such as the PET bottles have been used for foods that require retort processing. In this case, the retort treatment is carried out by using pressurized heated water or steam in the retort kettle while filling the casing with food at a temperature of about room temperature to 80 ° C. and sealing the mouth tube with a cap. Heat sterilization is performed at a temperature of about 130 ° C. for a time of about 20 minutes.

  As described above, when a synthetic resin casing is used for retort food, the casing is sealed with a cap and then sterilized at a temperature of about 120 to 130 ° C. in the retort pot. In addition, the pressure inside the casing (internal pressure) increases due to the expansion of the contents. Here, when using pressurized heated water, the bulging deformation of the housing can be suppressed by adjusting the pressure of the hot water to balance with the internal pressure, but when using heated steam Needs to be heat-treated near the saturated water vapor pressure at that temperature, and cannot be balanced with the internal pressure of the housing.

  For this reason, especially when heated steam is used, the thin-walled body is bulged and deformed during the retort process. At this time, since the processing temperature is higher than the glass transition temperature in a general-purpose resin such as PET, the function of absorbing this pressurized state without causing local deformation (hereinafter referred to as a pressure absorbing function) is sufficient. Otherwise, permanent deformation will occur, and even if the normal pressure is applied, it will not return to its original shape, and it will be a casing product having an irregular appearance.

  Furthermore, when the product is returned to room temperature after completion of the retort process, the internal pressure decreases. In particular, when the contents are filled at a high temperature of about 70 to 80 ° C., the reduced pressure is obtained at the room temperature, so the reduced pressure absorption. It is necessary to have a configuration that also has functions. In other words, while ensuring a good appearance, the absorption function corresponding to the pressurized state and the decompressed state can be fully exhibited, and the deformation can occur smoothly in response to a large pressure fluctuation leading to the pressurized state and the decompressed state. Structure is required.

  Therefore, the present invention has been devised to solve the above-described problems, and both the pressure absorption function and the pressure reduction absorption function are fully exhibited, corresponding to the significant pressure fluctuations to the pressure state and the pressure reduction state. The objective is to create a panel structure that can be smoothly deformed, and to provide a synthetic resin casing that can be used with a good appearance even for retort foods.

The means of the invention according to claim 1 for solving the technical problem is as follows:
In a round frame with a panel for absorbing fluctuations in internal pressure in the body,
Each of the panels is formed by surrounding it with a recessed step,
Rights and sinking like inverted deformable convex portions Recessed and bulging shape inverted deformable concave portion as viewed in cross-section adjacent to the vertical through the boundary, the starting point of the convex portion is bulged like inversion deformation of the recessed portion And so that the concave part becomes the starting point of the inverted reversal deformation of the convex part,
It is possible to cope with both the pressurized state and the decompressed state inside the housing.

  In general, a PET bottle or the like is referred to as a round casing including a case where a panel is formed on a cylindrical tube wall of a body portion to absorb fluctuations in internal pressure. Also in the configuration, a round housing including the shape in which these panels are formed is used.

  The basic technical idea of the above-described configuration according to claim 1 is that, of the concave portion and the convex portion constituting the panel formed by surrounding the first step with a recessed step portion, the concave portion is bulged. The pressure-absorbing function is formed on the concave part, and the convex part is formed so as to be inverted and deformed so that the pressure-absorbing function is shared by the convex part. There is.

  Secondly, by arranging these two portions adjacent to each other in the vertical direction, when the concave portion is inverted and deformed into a bulging shape due to internal pressure, the bulging deformation of the convex portion is a boundary with the concave portion. On the contrary, when the convex portion reversely deforms into a depressed shape due to decompression so that it becomes the starting point of the bulging inversion deformation of the concave portion via a line, the concave shape of the concave portion is the boundary. In this configuration, the reverse deformation smoothly proceeds in any direction so as to be the starting point of the depression-like reverse deformation of the convex portion.

  That is, first, regarding the deformation of the panel wall in a pressurized state, when the concave portion is inverted and deformed in a bulging shape, the inner volume of the housing can be greatly increased, and the pressure absorbing function can be sufficiently exhibited. Can do. However, in general, when the volume increase due to inversion is increased, it becomes difficult to start the deformation particularly at the base point of inversion, and local distorted deformation occurs.

On the other hand, the pressure absorption function of the convex part is low, but since the force acts in an outwardly expanding manner on the wall surface from the initial state of pressurization, this force is a concave shape adjacent to the convex part via the boundary line. It also acts on the part and becomes a starting point for starting the reverse deformation of the concave part. Then, the bulging reversal deformation can smoothly proceed from the starting portion near the boundary line to the entire concave portion.

  Next, regarding the deformation of the panel wall in the reduced pressure state, when the convex portion is inverted in a depressed shape, the inner volume of the housing can be greatly reduced, and the reduced pressure absorption function can be sufficiently exhibited.

  On the other hand, although the concave portion has a low pressure absorption function, a force that pushes inwardly from the initial pressure state acts on the wall surface, so this force also acts on the convex portion adjacent to the concave portion via the boundary line. This is the starting point for starting the reverse deformation of the convex portion. Then, the inverted reversal deformation can be smoothly advanced from the starting point in the vicinity of the boundary line to the entire convex portion.

  In addition, when the panel is composed only of convex portions, an external pressure acts on the convex portions, and when depression deformation starts, a force that presses each other between adjacent convex portions acts. There is a problem that the concave deformation of the convex part of the part is obstructed, but since forces that pull each other reversely act between adjacent concave parts, this action acts on the convex part near the boundary line. In addition, it is possible to smoothly generate the depression and inversion deformation in all the convex portions.

  As described above, according to the configuration of the first aspect, by forming the panel by adjoining the concave and convex portions up and down, the bulging reversal deformation of the concave portion in the pressurized state can be performed. In addition, the concave reversal deformation of the convex part in the reduced pressure state can be smoothly achieved by the action of the concave part, and a sufficient pressure and reduced pressure absorption function can be exhibited by the both reverse deformation. .

  According to a second aspect of the present invention, in the first aspect of the invention, an inversion portion is formed along the stepped shape of the depression, and a panel is formed by using the inversion line as a base end.

  By forming the V-shaped or U-shaped reversal portion along the stepped portion by the above-described configuration according to claim 2, the reversal deformation of the concave portion and the convex portion in the progress of pressurization or the progress of pressure reduction, Alternatively, the reverse deformation of the reverse deformation can be progressed more smoothly.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a vertical center line is formed in a concave shape at the left and right central positions of the panel.

  According to the above-described configuration of the third aspect, it is possible to achieve the depression-like deformation more smoothly by the concave centerline forming portion particularly in the deformation at the time of decompression.

  According to a fourth aspect of the present invention, in the invention of the first, second or third aspect, the area of the concave portion is set to 50% or more with respect to the panel area, so that the retort treatment with heating steam is possible. That's it.

  According to the above configuration of the present invention, in the retort process, when the sterilization process is performed at a high temperature of 120 to 130 ° C., and particularly when heating steam is used, the thin barrel portion is bulged by adjusting the external pressure. However, by making the area of the concave portion 50% or more with respect to the panel area, the pressure absorption function is sufficiently exerted, so retort treatment is performed using thermal steam. It is possible to provide a housing that can be sufficiently used in applications.

  According to a fifth aspect of the present invention, in the first, second, third or fourth aspect of the invention, the invention is a biaxial stretch blow-molded product made of a PET resin.

  According to the above-described configuration of the fifth aspect, the biaxially stretched blow molded casing made of a PET resin can have heat resistance corresponding to the retort processing temperature. It can be used for a wide range of applications that require handling at high temperatures such as retort processing.

  As the polyethylene terephthalate resin used in the present invention, PET is mainly used. However, as long as the essence of the PET resin is not impaired, a copolymer polyester mainly containing ethylene terephthalate units and containing other polyester units is also used. In addition, for example, in order to improve heat resistance, a resin such as nylon resin and polyethylene terephthalate resin can be blended and used. Examples of the component for forming the copolyester include dicarboxylic acid components such as isophthalic acid, naphthalene 2,6 dicarboxylic acid, and adipic acid, propylene glycol, 1,4 butanediol, tetramethylene glycol, neopentyl glycol, cyclohexanedimethanol, Mention may be made of glycol components such as diethylene glycol.

  Furthermore, as long as the essence as a PET resin casing is not impaired, the PET resin casing of the present invention is, for example, PET resin / nylon resin / PET resin for improving heat resistance and gas barrier properties. It may have an intermediate layer such as nylon resin.

The present invention has the above-described configuration, and has the following effects.
In the first aspect of the invention, by forming the panel by adjoining the concave and convex portions on the upper and lower sides, the bulging reversal deformation of the concave portion in the pressurized state is caused by the action of the convex portion. In addition, the concave reversal deformation of the convex portion in the reduced pressure state can be smoothly achieved by the action of the concave portion, and sufficient pressure and reduced pressure absorption functions can be exhibited by the both reverse deformation.

  In the invention according to claim 2, by forming the reversal portion along the stepped portion, the reversal deformation of the concave portion and the convex portion or the reversal deformation in the progress of pressurization or depressurization. The return deformation can proceed more smoothly.

  In the invention according to the third aspect, particularly in the deformation at the time of decompression, the depression-shaped deformation can be achieved more smoothly by the concave center line forming portion.

  In the invention according to claim 4, by making the area of the concave portion 50% or more with respect to the panel area, the pressure absorption function is sufficiently exhibited. It is possible to provide a housing that can be used sufficiently in applications for retorting.

  In the invention described in claim 5, the biaxially stretched blow molded casing made of PET resin can be widely used for applications that require high temperature handling such as retorting.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 7 show an embodiment of the synthetic resin casing of the present invention. FIG. 1 is a front view of the housing 1, and FIG. 2 is an outline outline of a plane cross section along the lines AA and BB in FIG. 1. The casing 1 is a biaxially stretched blow molded product made of PET resin, and has a mouth tube portion 2, a shoulder portion 3, a trunk portion 4, and a bottom portion 5, and is a small 300 ml round bottle. Moreover, the mouth tube part 2 is in a state of being whitened by the thermal crystallization process, and the bottom part 5 is formed in a depressed shape. 2 (a) and 2 (b), the two-dot chain line indicates a circle inscribed by the outer outline of the cross section of the body 4 in plan view.

  Further, two peripheral step portions 6 are provided on the upper and lower sides, and the periphery of each of the peripheral step portions 6 is surrounded by a stepped portion 10 formed in a recessed shape, thereby forming six panels 7. Has been. In the present embodiment, a relatively small (300 ml) housing in which the influence of the pressurized state or the reduced pressure state due to temperature change appears severely was used.

  The panel 7 has a vertically long rectangular shape as a whole, and vertical rib-like pillar portions 9 are formed between the adjacent panels 7 so as not to be depressed. The six pillars 9 thus secured ensure the rigidity of the entire housing 1.

  3A is an enlarged front view of the panel 7 in FIG. 1, and FIG. 3B is a vertical cross-sectional outline diagram viewed longitudinally at the left and right center of the panel 7. The panel 7 surrounded by the step 10 is composed of a concave portion 7a located above and a convex portion 7b located below. A boundary line is formed between the concave portion 7a and the convex portion 7b. 11 is formed. Further, a center line 12 is formed in a concave shape in the vertical direction at the center position on the left and right over the entire height range of the panel 7, and a pair of side lines 13 are formed at positions symmetrical with respect to the center line 12. The area of the concave portion 7a is approximately 65% of the entire panel 7. Note that the two-dot chain line in FIG. 3B is an outer contour line corresponding to the circle shown by the two-dot chain line in FIGS. 2A and 2B.

  FIG. 4A shows an outline of a flat cross-sectional outline along the line CC in FIG. 3A, and shows a flat cross-sectional shape of the concave portion 7a formed symmetrically. The concave portion 7 a is formed in a concave shape with the inversion line 14 disposed at a position recessed from the column portion 9 through the stepped portion 10 as the left and right base ends, and has a shallow V shape in the center along the center line 12. A vertical line 8 is formed, and a side line 13 is formed between the center line 12 and the inversion line 14.

FIG. 4 (b) shows a flat cross-sectional outer contour line shape along the line DD in FIG. 3 (a), and shows the flat cross-sectional shape of the convex portion 7b formed symmetrically. is there. The convex portion 7b is formed in a convex shape with the inversion line 14 disposed at a position recessed from the column portion 9 via the step portion 10 as the left and right base ends, and the center line 12 and the center line 12 in the center. A side line 13 is formed between the first and second inversion lines 14.

  FIG. 5 is an explanatory view showing a deformed state of the wall of the panel 7 when the inside of the housing 1 changes from normal pressure to a pressurized state, and FIGS. 5 (a) and 5 (b) are FIGS. It corresponds to the portion (b), and in FIG. 5 (a), the bulging inverted deformation state 15a of the concave portion 7a is shown, and in FIG. 5 (b), the bulging deformation state 15b of the convex portion 7b is shown. Indicated by a two-dot chain line.

  In the pressurized state, the internal pressure acts on the concave portion 7a (see the white arrow in FIG. 5A) and tries to deform into the bulging and reversing deformation state 15a. Since a force (see the black arrow in FIG. 5 (a)) that pushes and spreads acts, the column portion 9 inhibits deformation. On the other hand, the internal pressure also acts on the convex portion 7b (see the white arrow in FIG. 5B), but since the shape is convex, the inversion line 14 is pulled toward the center of the panel 7 (FIG. 5B). ) (See the black arrow in the middle), there is no hindrance to deformation by the column part 9, and this convex part 7b easily deforms into the bulging deformation state 15b.

  By thus deforming the convex portion 7b into the bulging deformation state 15b, this deformation acts on the adjacent concave portion 7a through the boundary line 11, and the bulging with the left-right inversion line 14 as the base end. Outward reversal deformation starts, progresses upwards in sequence, and finally becomes a swollen reversal deformation state 15a over the entire area of the concave portion 7a, so that the pressure absorbing function is sufficient and smooth without local undue deformation. To be demonstrated.

  Here, since the panel 7 is surrounded by the step portion 10, the bulging deformation is limited to the region of the panel 7, and the portions other than the panel 7 are locally deformed and permanently deformed. Is preventing.

  FIG. 6 is an explanatory view showing a deformation state of the wall of the panel 7 when the inside of the housing 1 changes from the normal pressure to the reduced pressure state, and FIGS. 6 (a) and 6 (b) are FIGS. It corresponds to the part b). In the case of retort processing, the inside of the housing returns to normal pressure from the pressurized state by cooling (or cooling) after the processing, and the above bulging deformation returns to the original shape. In the case of filling at a high temperature of about 70 to 80 ° C., the pressure is reduced as the cooling proceeds.

  When the degree of depressurization becomes large, external pressure acts on the convex portion 7b (see the white arrow in FIG. 6B) and tries to deform into the depressed inverted deformation state 16b. Since a force (see the black arrow in FIG. 6B) that pushes outwards acts, the column portion 9 inhibits deformation. On the other hand, external pressure acts on the concave portion 7a (see the white arrow in FIG. 6A), but since the shape is concave, the inversion line 14 is pulled toward the center of the panel 7 (in FIG. 6A). And the deformation of the column portion 9 is not hindered, and the concave portion 7a is easily deformed into the depressed deformation state 16a.

  In this way, when the concave portion 7a is deformed into the depressed deformed state 16a, this deformation acts on the adjacent convex portion 7b via the boundary line 11, and the reversed inversion with the left-right reversal line 14 as the base end. Deformation begins, progresses downward sequentially, and finally becomes a depressed inverted deformation state 16b over the entire region of the convex portion 7b, and the reduced pressure absorption function is sufficiently exhibited without any local undue deformation. The

  FIG. 7 is an explanatory view showing a deformation mode of the panel 7 (concave portion 7a, convex portion 7b) in the pressurized and decompressed state in the outline profile of the longitudinal section similar to FIG. 3 (b). FIG. 7A shows a deformation state in a pressurized state (a bulging inversion deformation state 15a of the concave portion 7a and a bulging deformation state 15b of the convex portion 7b) by a two-dot chain line, and FIG. Deformation modes (a depression deformation state 16a of the recess 7a and a depression inversion deformation state 16b of the protrusion 7b) are indicated by a two-dot chain line.

  As described above, in the casing 1 of the present embodiment, the concave portion 7a and the convex portion 7b are adjacent to each other to form the panel 7, so that the concave portion 7a is deformed in an inverted state in a pressurized state. Can be smoothly achieved by the action of the convex part 7b, and the concave reversal deformation of the convex part 7b in the reduced pressure state can be achieved by the action of the concave part 7a. The function can be demonstrated.

  The arrangement of the concave portions 7a and the convex portions 7b in the panel 7 is not limited to this embodiment, and the effects of the present invention are generally exhibited by the arrangement in which both portions are adjacent to each other in the vertical direction. Is. For example, in this embodiment, the convex portion 7b can be disposed upward and the concave portion 7a can be disposed downward. FIG. 8 shows another embodiment of the panel 7. For example, the convex portions 7b can be arranged adjacently above and below the concave portion 7a, and the rigidity, appearance, etc. of the housing 1 and in the usage mode Considering the degree of pressurization or depressurization, the ratio of each part and its arrangement can be determined.

  Further, the shape of the casing is not limited to the present embodiment, and the type of the synthetic resin is not limited to the PET resin.

  The synthetic resin casing of the present invention can be used for steam heating type retort treatment, and can be expected to be used in a wide range of applications.

It is a whole front view which shows the Example of the synthetic resin casings of this invention. It is the plane sectional view along the (a) AA line of the housing of Drawing 1, and the plane sectional view along the (B) BB line. It is the (a) front view which shows the panel vicinity of the housing of FIG. 1, and (b) longitudinal cross-sectional view. FIG. 4 is a cross-sectional plan view along line CC in the vicinity of the panel in FIG. 3, and a cross-sectional plan view along line DD in FIG. FIG. 5 is an explanatory view showing a bulging deformation mode of the panel in a pressurized state in the same plane cross section as FIG. 4. FIG. 5 is an explanatory view showing a depressed deformation mode of the panel in a reduced pressure state in the same plane cross section as FIG. 4. FIG. 4 is an explanatory view showing a deformation mode of the panel in the (a) bulging state and (b) the depressed state in the same vertical cross section as FIG. 3 (b). It is the (a) front view and (b) longitudinal cross-sectional view which show the other Example of a panel similarly to FIG. It is a whole front view which shows the prior art example of a housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Housing 2; Mouth part 3; Shoulder part 4; Trunk part 5; Bottom part 6; Circumferential step part 7; Panel 7a; Concave part 7b: Convex part 8; Vertical groove 9; ; Boundary line 12; center line 13; side line 14; reversal line 15a; bulge reversal deformation state 15b; bulge deformation state 16a; depression deformation deformation 16b; depression reversal deformation state 101; housing 102; Shoulder 104; trunk 105; bottom 106; annular groove 107; vacuum absorbing panel 109; pillar

Claims (5)

In the round housing (1) in which the panel (7) for absorbing the fluctuation of the internal pressure is disposed in the body part (4), each of the panels (7) is a depressed step (10). vertically adjacent form surrounds, over a bulging shape inverted deformable recess as viewed in plan sectional (7a) and recessed sinking like inverted deformable convex portion (7b) the border (11) by Thus, the convex portion (7b) becomes the starting point of the bulging reversal deformation of the concave portion (7a), and the concave portion (7a) is the starting point of the concave reversal deformation of the convex portion (7b). A synthetic resin casing that is configured so as to be compatible with both the pressurized state and the decompressed state inside the casing (1).
The synthetic resin casing according to claim 1, wherein an inversion line (14) is formed along the stepped portion (10), and a panel (7) is formed with the inversion line (14) as a base end. The synthetic resin casing according to claim 1 or 2, wherein a vertical center line (12) is formed in a concave shape at a central position on the left and right of the panel (7). The synthetic resin casing according to claim 1, 2 or 3, wherein the area of the concave portion (7a) is 50% or more with respect to the area of the panel (7) and the retort treatment with heating steam is possible. The synthetic resin casing according to claim 1, 2, 3, or 4, which is a biaxially stretched blow molded product made of polyethylene terephthalate resin.

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