JP2521918Y2 - Synthetic resin bottle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a large-sized synthetic resin bottle, and particularly a biaxially stretch blow-molded polyethylene terephthalate resin (hereinafter simply referred to as PET) large square bottle. The present invention relates to a torso wall structure.

[Conventional technology]

PET large-sized biaxially stretch blow-molded bottles have many excellent properties and are therefore used in large quantities as various liquid storage bottles.

This large PET biaxially stretch blow-molded bottle has a thin body, which is the main part of the bottle, so that the mechanical strength such as the self-shape holding ability and the buckling strength of the body is never sufficiently large. Absent. In particular, in the case of a bottle having a square cylindrical shape, the buckling strength is naturally low, and the self-shape retention ability is low. There was an inconvenience that collapse deformation occurred.

In order to eliminate the inconvenience of this square PET bottle,
A central circumferential groove is provided around the center of the body to increase the buckling strength of the body against the pressing force applied from the outside to the bottle, and to maintain the shape of the body against the external force acting in the radial direction. At the center of a flat wall divided vertically by a central circumferential groove, a concave portion having a deformable panel wall as a bottom wall which is easily depressed and deformed is depressed and the negative pressure generated in the bottle is reduced by the deformed panel wall. Absorbed by constant depression deformation in
This prevents the body from being erroneously depressed and deformed, and enhances the ability of the flat wall portion to maintain its own shape.

[Problems to be solved by the invention]

The central peripheral groove and the concave part forming the deformed panel wall enhance the mechanical shape retention ability. The recessed central peripheral groove and the inclined groove side wall and concave side wall of the concave part are reinforced in the radial direction of the trunk. It is obtained by acting as a rib wall piece.

Therefore, conventionally, in order to enhance the function as a reinforcing rib wall piece by the inclined groove side wall and the concave side wall of the central peripheral groove and the concave portion, the inclination angle of the groove side wall and the concave side wall with respect to the bottle central axis direction is set to a large value. Was set to.

By setting the inclination angle of the groove side wall and the concave side wall to a large value, the self-shape retention ability near the bottle body, especially near the central circumferential groove gripped by hand, was remarkably enhanced. When a certain amount of pressing force is applied to the body of the bottle during handling of the body or transporting in a box, etc., a portion from the groove side wall portion and the concave portion side wall portion to the flat wall, and a part of the wall portion are formed. Beyond the elastic deformation range, it is locally inverted and bent and becomes permanent deformation. There was a problem that the commercial value of the bottle was lost.

The present invention has been devised in order to solve the above-mentioned problems in the prior art, and while the groove side wall of the central peripheral groove and the concave side wall of the concave portion function as a reinforcing rib wall piece, the concave side wall is not deformed at the time of collapse deformation. It is an object of the present invention to provide a self-returnable curved depression deformation in which the wall is inverted and bent in an arc shape within a range of elastic deformation, instead of a bent depression deformation.

[Means for solving the problem]

Means of the present invention for achieving the above-mentioned object relate to the wall structure of a biaxially stretch blow-molded PET large bottle, and the center of the rectangular cylindrical body is substantially centered in the height direction. The peripheral groove is provided in a depressed state, and the inclination angle of both the upper and lower groove side walls of the central peripheral groove with respect to the central axis direction of the bottle is set within a range of 21 ° to 28 °.

In addition, the inclination angle of the groove side wall with respect to the bottle central axis direction is:
The inclination angle of the upper groove side wall is not measured from the same direction with respect to the bottle center axis direction, but is measured from the acute angle side with respect to the bottle center axis direction. It is measured from the opposite direction.

In addition to the above-described means, a concave portion having a bottom wall as a deformed panel wall for absorbing decompression deformation is depressed at the center of each flat wall of the body portion divided vertically by a central peripheral groove. It is desirable to set the inclination angle of the side wall of the recess located close to the groove side wall with respect to the central axis direction of the bottle in the range of 21 ° to 28 ° similarly to both the groove side walls of the central circumferential groove.

The central peripheral groove may not be a special groove structure, but may be a normal groove structure, that is, a groove structure in which both groove side walls are connected by a groove bottom wall having a flat wall structure.

[Action]

Since the central circumferential groove is provided in a substantially depressed manner at the substantially central portion of the body, the continuous portion between the upper and lower groove side walls and the flat wall is in a state of being curved and projected on the bottle surface. For this reason, against the pressing force acting on the central peripheral groove portion, the groove side wall functions as a reinforcing rib wall piece, preventing the body wall portion to which the pressing force has been applied from being easily depressed and deformed. When the pressing force acts and the depression deformation occurs, the continuous portion between the groove side wall and the flat wall reverses its protruding posture and becomes the depression deformation.

As described above, in the bottle according to the present invention, similarly to the conventional bottle, the continuous portion between the groove side wall of the central circumferential groove and the flat wall is inverted and depressed, but in the case of the present invention, Since the inclined angle of the groove side wall is small, the continuous portion between the groove side wall and the flat wall is entirely curved and depressed and deformed, and the depressed deformation sufficiently reduces the inclination angle between the groove side wall and the flat wall, and While the amount does not increase, the central portion subjected to the pressing force is reversed and deforms into a curved shape within an elastic deformation range. At the time of the reverse bending deformation of the continuous portion between the groove side wall and the flat wall, the reverse deformation occurs when the inclination angle between the groove side wall and the flat wall is sufficiently reduced. The part does not bend locally beyond the elastic deformation range and becomes a permanent deformation due to the local deformation, but it becomes a curved deformation within the elastic deformation range of the wall, so that the self-return to the original shape surely with the disappearance of the pressing force I do.

That is, the upper and lower side walls of the central circumferential groove are set at an inclination angle that can function as a reinforcing rib wall piece as large as possible within a range where bending deformation does not occur when inverted. The setting of the inclination angle of the side wall is obtained from many experimental examples. According to this experimental example, when the inclination angle of the groove side wall is set to about 29 ° or more, the self-shape holding ability is increased, and the pressing force is applied. In this case, the entire curved portion of the continuous portion between the groove side wall and the flat wall is less likely to be bent and deformed. Therefore, the depressed deformation of the continuous portion is turned into an inverted bending deformation, which makes it difficult to self-return. On the other hand, if the inclination angle of the groove side wall is set to about 20 ° or less, a sufficient function as the reinforcing rib wall piece of the groove side wall cannot be obtained, and the self-shape holding ability is low, so that the bottle is grasped. Is difficult to handle.

Similarly to the groove side wall of the central circumferential groove, the concave side wall of the concave portion provided at the central portion of the flat wall and having the bottom wall as a deformed panel wall for absorbing reduced pressure deformation also effectively functions for maintaining the self-shape of the body. Of the concave side walls, the concave side wall portion located near the central peripheral groove has a flat wall portion between the central peripheral groove and a wall structure that protrudes horizontally and is curved. Although it is difficult for the entire part to be depressed and deformed in a curved form, similarly to the groove side wall of the central peripheral groove, the groove side wall is set by setting the inclination angle of the concave side wall part located near the central peripheral groove to 28 ° to 21 °. From the flat wall portion and the side wall of the concave portion can be easily caused to be entirely deformed, thereby reliably preventing the occurrence of local bending deformation when inverted.

In the case of the configuration in which the concave side wall is located close to the central peripheral groove, the length of the concave side wall is shorter than the length of the central peripheral groove side wall in the flat wall. This occurs mainly on the groove side wall side, and the concave side wall is naturally bent and deformed following the reverse bending deformation of the groove side wall.

By connecting the upper and lower side walls of the central peripheral groove with the groove bottom wall having a flat wall structure, the depth of the central peripheral groove is reduced, but the width of the central peripheral groove is made constant. Restricting the inclination angle of the groove side wall and the concave side wall under the certain size restriction similarly results in reducing the depth of the central peripheral groove and the concave portion. As described above, the depth of the central circumferential groove and the concave portion having the largest depressed dimension formed in the body can be reduced, so that a large difference in the amount of extension between the body, particularly each portion of the flat wall is prevented. Thus, this makes it possible to obtain good stretch forming of the body portion and greatly reduce the occurrence of local deformation after the stretch forming.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The body 2 of the bottle 1 has a ridgeline wall 13 in which each corner is an arc wall.
Is formed into a square quadrangular cylindrical shape composed of flat walls 6, and a central peripheral groove 3 is depressed at a slightly higher central height position. At the lower end of the body 2, a bottom 10 whose center is curved and depressed in the bottle 1 is continuously provided, and at the upper end of the body 2 whose diameter is gradually reduced, a shoulder having a substantially spherical arc wall structure is provided. A portion 11 is continuously provided, and a mouth portion 12 is provided upright at the upper end of the shoulder portion 11.

A concave portion 7 having a deformed panel wall 8 is provided at a central portion of each flat wall 6 vertically divided by the central peripheral groove 3. A concave side wall located near the central peripheral groove 3 of the concave portion 7 is provided. 9, ie, the upper concave side wall 9 portion in the case of the lower concave portion 7, and the lower concave side wall 9 in the case of the upper concave portion 7
The portion extends slightly linearly along the central circumferential groove 3,
The overall curved deformation of the flat wall 6 located between the central peripheral groove 3 and the concave portion 7 is easily caused.

Since the groove bottom wall 5 of the central peripheral groove 3 has a flat wall structure, and as shown in FIG. 2, the central peripheral groove 3 has a flat cross-sectional shape with a large radius of curvature. The depth of the portion facing the wall 6 is shallower than the depth of the portion facing the ridge wall 13, thereby making it difficult for the portion of the central circumferential groove 3 facing the ridge wall 13 to be deformed. 6 is likely to be curved and depressed. Therefore, the central circumferential groove 3 and the flat wall 6
When a curved deformation occurs in the portion, the ridge line wall 13 acts as a strong support portion, so that the curved deformation is performed in a stable form.

FIG. 3 shows a longitudinal section of a concrete wall structure near the central peripheral groove 3. The bottle 1 having this wall structure has an inner volume of 1.5 l, and The diameter of the lower body 2 is slightly larger than that of the upper body 2. In this wall structure, the inclination angle of the lower side wall 4 of the central peripheral groove 3 on which the pressing force by gripping is most likely to act when handling the bottle 1 is set to 28 °, which is the largest. The inclination angle of the groove side wall 4 above the central peripheral groove 3 is set to 24 °, and the inclination angle of the concave side wall 9 facing the central peripheral groove 3 of the concave part 7 forming the deformed panel wall 8 is 21 ° respectively. Is set.

The inclination angles of the groove side walls 4 and the concave side walls 9 and the combination thereof may be appropriately selected and set in the range of 21 ° to 28 °. The purpose of providing the central peripheral groove 3 is to enhance the self-shape holding ability. For this reason, it is preferable to maximize the inclination angle of the lower groove side wall 4 on which the pressing force acts during handling of the bottle 1, thereby increasing the ability of the central peripheral groove 3 to maintain the self-shape of the body 2.

According to the results of many experiments, when all of the groove side wall 4 and the concave side wall 9 are formed at 28 °, a higher self-shape holding ability is exhibited as compared with the example shown in FIG. The mode of self-recovery operation from deformation tends to be less smooth and awkward. In particular, as the inclination angle of the recess side wall 9 below the central circumferential groove 3 is increased, the above-described tendency is significantly increased. Since the experimental results and the main purpose of the concave portion 7 are to form the deformed panel wall 8, it is advantageous to make the inclination angle of the concave side wall 9 small.

[Effect of the invention]

Since the present invention has the above configuration, the following effects can be obtained.

By regulating the inclination angle of the groove side wall of the central circumferential groove,
It is possible to completely prevent the occurrence of a fold-deformation that cannot be self-returned at a continuous portion between the groove side wall and the flat wall portion. The inconvenience of loss of commercial value can be completely eliminated.

Curved depression deformation generated in the continuous portion between the groove side wall and the flat wall portion becomes elastic deformation within the entire range of the deformation, so that the fingertip of the hand that is applying the pressing force to generate the curved depression deformation Even when an elastic repulsive force is always applied, even if a curved depression deformation occurs, a stable gripping operation can be obtained.

Since the inclination angle of the groove side wall and the concave side wall is regulated to a relatively small value, the depth of the central circumferential groove and the concave portion can be reduced, and the degree of irregularity in the body can be reduced. The amount of stretching of the flat wall portion can be made uniform, so that a bottle having good moldability and less deformation can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall front view showing an embodiment of the present invention. FIG. 2 is a plan sectional view taken along the line II-II in FIG. FIG. 3 is an enlarged vertical sectional view of a circled portion in FIG. DESCRIPTION OF SYMBOLS 1; bottle, 2; trunk, 3; central circumferential groove, 4; groove side wall, 5; groove bottom wall, 6;
Flat wall, 7; concave, 8; deformed panel wall, 9; concave side wall, 13; ridge wall.

Claims (3)

(57) [Scope of request for utility model registration] 1. A large-sized bottle made of polyethylene terephthalate resin formed by biaxial stretching blow molding, wherein a central circumferential groove (3) is provided substantially at the center of a rectangular barrel-shaped body (2). (1) A synthetic resin bottle in which the inclination angle of both side walls (4) of the circumferential groove (3) with respect to the center axis direction is set within a range of 21 ° to 28 °. 2. A synthetic resin bottle according to claim 1, wherein the groove bottom wall (5) connecting between the groove side walls (4) of the central circumferential groove (3) has a flat wall structure. 3. A concave part having a bottom wall at the center of each flat wall (6) of a body part (2) divided into upper and lower parts by a central peripheral groove (3). (7) is depressed, and the inclination angle of the recess side wall (9) located near the groove side wall (4) of the recess (7) with respect to the central axis direction of the bottle is 21 °.
The synthetic resin bottle according to claim 1 or 2, which is set within the range of -28 °.