JP2010269828A - Plastic bottle - Google Patents

Abstract

Disclosed is a plastic bottle capable of minimizing a decrease in appearance without affecting a label attaching position by specifying a portion where a bottle body is deformed by decompression.
A bottle body 2 is formed by blow molding, and the bottle body 2 includes a bottom portion and a body portion 4 formed by four side walls 4a to 4d standing from the outer periphery of the bottom portion. At least one corner portion in the horizontal section of the trunk portion 4, having a shoulder portion gradually reduced in diameter upward from the upper end of the trunk portion 4, and a mouth and neck portion standing in a cylindrical shape from the upper end of the shoulder portion Contour lines of two side walls 4a and 4b adjacent to each other across 4e form an arc shape outward, and one side wall 4a is configured with a surface having a larger curvature than the other side wall 4b.
[Selection] Figure 3

Description

  The present invention relates to improvements in plastic bottles.

  Plastic bottles are used as bottle containers for storing liquid products such as shampoos and rinses, body soaps, kitchen detergents, liquid clothing detergents, softeners, or mouthwashes and eyewashes. Alternatively, it is widely used for liquid products such as quasi drugs, beverages, and foods.

  A plastic bottle is generally formed by blow molding a synthetic resin material to form a bottle main body and covering the bottle main body with a cap. Specifically, the production of the bottle body of this plastic bottle includes a method in which a cylindrical molding material called a parison is melted, placed in a mold, blown into the interior and inflated, and simultaneously cooled and molded. Used.

  By the way, in such a plastic bottle, the liquid product described above is heated and filled in the bottle body, and after closing the cap, when stored at room temperature or low temperature, the pressure in the sealed bottle body decreases, A dent may arise in a bottle main part (for example, refer to patent documents 1).

  Although such a dent tends to occur in the body part of the bottle body, it is difficult to specify in which part of the body part the dent occurs. Moreover, since a label etc. are affixed on a trunk | drum, when a dent arises in the sticking position of the label of a trunk | drum, it not only will worsen the appearance of goods but will also cause a consumer's willingness to purchase. .

  In particular, in the case of a plastic bottle having a body having a horizontal cross section close to a square or rectangle, the surface to which a label or the like is attached is often the widest surface among the side surfaces of the body. However, since the widest surface is the surface that is most easily deformed when the inside of the bottle body is in a pressurized state or a depressurized state, there is a concern that the appearance of the appearance may be significantly impaired. Moreover, there is a similar concern in a plastic bottle having a surface with a large curvature at the body.

  Therefore, in the conventional plastic bottle, in order to prevent the bottle main body from being deformed due to a pressure change in the bottle main body, for example, the deformation of the bottle main body is suppressed by using a hard resin material, or the bottle main body is made spherical or hemispherical. A shape that can withstand pressure changes is used. Further, in the conventional plastic bottle, in order to make the deformation generated in the bottle body inconspicuous, for example, the body portion of the bottle body is formed with a smooth curved surface, or a rib or the like is provided on the surface of the body portion. ing.

  However, in order to prevent the deformation of the bottle body described above, measures were taken to increase the rigidity of the bottle body by increasing the amount of resin and forming the bottle body thick or using a highly rigid resin material. In this case, the production cost is increased.

  Moreover, when producing a container main body by the blow molding mentioned above, it is difficult to form a part of this container main body thicker than other parts. For this reason, it is technically difficult to form only the portion of the container body that is not desired to be deformed thick, and conversely, the portion of the container body that is not desired to be deformed is formed thin so that the bottle body can be easily deformed.

JP 2008-94491 A

  The present invention has been proposed in view of such a conventional situation, and the bottle main body is reduced in pressure or the like without forming the bottle main body thickly or using an expensive resin material having high rigidity. It is an object of the present invention to provide a plastic bottle capable of minimizing a decrease in appearance without affecting the label attaching position and the like by specifying a deformed portion.

  In order to achieve this object, the invention according to claim 1 is a plastic bottle in which a bottle body is formed by blow molding, and the bottle body is constituted by a bottom portion and four side walls standing from the outer periphery of the bottom portion. A torso, a shoulder that is gradually reduced in diameter upward from the upper end of the torso, and a mouth and neck that rises in a cylindrical shape from the upper end of the shoulder, and at least in a horizontal section of the torso, The outlines of two side walls adjacent to each other with one corner therebetween are arcuate outwardly, and one side wall is formed of a surface having a larger curvature than the other side wall. It is a plastic bottle.

The invention according to claim 2 satisfies the relationship of 1 <R ₂ / R ₁ ≦ 3 when the curvature of one side wall is 1 / R ₁ and the curvature of the other side wall is 1 / R _2. The plastic bottle according to claim 1.

  The invention according to claim 3 is the plastic bottle according to claim 1 or 2, characterized in that the bottom has a substantially square shape.

  Further, the invention according to claim 4 is characterized in that the container main body has a handle portion integrally formed with the trunk portion on the corner portion side facing one corner portion. The plastic bottle according to one item.

  As described above, in the plastic bottle according to the present invention, when the pressure in the bottle body decreases, one of the two side walls that are adjacent to each other with one corner interposed therebetween is configured with a surface having a large curvature. On the other hand, it is possible to selectively deform the other side wall composed of a surface having a small curvature.

  Therefore, in this plastic bottle, the label can be attached by specifying the portion where the bottle body is deformed by decompression or the like without forming the bottle body thick or using an expensive resin material with high rigidity. It is possible to minimize a decrease in appearance without affecting the position or the like.

FIG. 1 is a perspective view of a plastic bottle to which the present invention is applied as viewed from the upper surface side. FIG. 2 is a perspective view of the plastic bottle shown in FIG. 1 viewed from the bottom side. FIG. 3 is a top view of the plastic bottle shown in FIG. FIG. 4 is a characteristic diagram showing the results of the decompression analysis of the bottle body shown in the example.

Hereinafter, a plastic bottle to which the present invention is applied will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, a plastic bottle 1 to which the present invention is applied includes a bottle body 2, and the bottle body 2 includes a bottom portion 3 and a body portion 4 that rises in a cylindrical shape from the outer periphery of the bottom portion 3. The shoulder portion 5 is gradually reduced in diameter at the upper end of the torso portion 4 and the mouth and neck portion standing in a cylindrical shape from the upper end of the shoulder portion 5. The cap 6 is attached to the mouth and neck portion. ing. In addition, the bottle body 2 is provided with a handle portion 7 that is easy to hold during use and facilitates a dispensing operation.

  Such a bottle main body 2 consists of synthetic resin materials, such as a polyethylene resin, a polypropylene resin, and a polyester resin, for example. In manufacturing the bottle body 2, for example, a cylindrical molding material called a parison is melted, put into a mold, and air is blown into the interior, such as direct blow molding or biaxial stretch blow molding. A method of forming by cooling at the same time as inflating is used.

  The cap 6 attached to the bottle main body 2 is not particularly limited in its form. In addition to a cover cap that is detachably attached to the neck of the bottle main body 2 by screwing, for example, What provided the measuring cap which measures the content liquid poured out from the bottle main body 2 may be used.

  Examples of the liquid (content liquid) stored in the plastic bottle 1 include liquid products such as shampoo, rinse, body soap, kitchen detergent, liquid clothing detergent, and softener.

  The bottle main body 2 has four side walls 4a to 4d erected from the outer periphery of the bottom 3 having a substantially square shape, and four corners 4e to 4h positioned between the side walls 4a to 4d. Is formed in a substantially rectangular tube shape. That is, the body portion 4 of the bottle body 2 includes a first side wall 4a and a second side wall 4b that are adjacent to each other with the first corner portion 4e interposed therebetween, and a second corner portion that faces the first corner portion 4e. The third side wall 4c and the fourth side wall 4d adjacent to each other with 4f interposed therebetween, the third corner 4g between the first side wall 4a and the fourth side wall 4d, the second side wall 4b and the third side wall And a fourth corner 4h opposite to the third corner 4g.

  The handle portion 7 is located on the second corner portion 4 f side of the trunk portion 4. Specifically, the handle portion 7 is formed by forming the tunnel portion 8 so as to penetrate between the third side wall 4c and the fourth side wall 4d, leaving the second corner portion 4f. 4 and a single unit.

By the way, in the plastic bottle 1 to which the present invention is applied, as shown in FIG. 3, in the horizontal cross section of the body portion 4, the first side wall 4a and the second side wall 4b adjacent to each other with the first corner 4e interposed therebetween. Each of the contour lines forms an arc shape with predetermined curvature radii R ₁ and R ₂ toward the outer side, and the first side wall 4a is configured by a surface having a larger curvature than the second side wall 4b.

The “curvature” is a value representing the degree of curvature of a curve or curved surface. For example, the curvature of the circumference of the radius R is 1 / R, and the radius R at this time is called the “curvature radius”. Therefore, the curvature (1 / R) increases as the degree of bending becomes tight, and conversely the curvature radius (R) decreases. Further, the curvature of the first side wall 4a is represented by 1 / R ₁ , the curvature of the second side wall 4b is represented by 1 / R ₂ , and the radius of curvature is R ₁ <R ₂ .

  In the plastic bottle 1 having the structure as described above, when the liquid product (content liquid) described above is heated and filled in the bottle body 2 and the cap 7 is closed, the bottle body is sealed when stored at room temperature or low temperature. The pressure in 2 will fall.

  At this time, in the bottle main body 2, the first side wall 4 a configured by a surface having a large curvature among the first side wall 4 a and the second side wall 4 b adjacent to each other with the first corner 4 e interposed therebetween. The 2nd side wall 4b comprised by the surface with a small curvature can be selectively deformed.

  Therefore, in this plastic bottle 1, the surface of the bottle body 2 that is not to be deformed (the front surface on which the label or the like is attached) without forming the bottle body thickly or using an expensive resin material having high rigidity. The side) is configured with the first side wall 4a, and the surface that is not noticeable even when deformed (the back side) is configured with the second side wall 4b, so that the appearance of the label is not affected. It is possible to minimize the degradation.

In the plastic bottle 1 to which the present invention is applied, it is preferable that the relationship 1 <R ₂ / R ₁ ≦ 3 is satisfied. By satisfying such a relation, a large difference, that is, the first side wall 4a and the second between the curvature 1 / R ₁ of the first side wall 4a and the curvature 1 / R ₂ of the second side wall 4b The second side wall 4b can be selectively deformed with respect to the first side wall 4a without causing a difference in appearance (appearance) from the side wall 4b.

  Of the body 4 of the bottle body 2, the third side wall 4c and the fourth side wall 4d are portions in which the tunnel part 8 is formed integrally with the body 4 and therefore the first and Even if the rigidity is higher than that of the second side walls 4a and 4b and the contours thereof are arcuate with a predetermined radius of curvature toward the outside, the second side walls 4b with respect to the first side walls 4a. There is no particular influence on the selective deformation of.

  Further, the corners 4e to 4h located between the side walls 4a to 4d are also portions having a larger curvature and higher rigidity than the side walls 4a to 4d, although the outlines thereof are arcuate. There is no particular influence on the selective deformation of the second side wall 4b with respect to the first side wall 4a.

  Moreover, in the said plastic bottle 1, when sticking a label etc. on the 1st side wall 4a and the 2nd side wall 4b, the 1st side wall 4a side which does not want to make it deform | transform is more rigid than the 2nd side wall 4a side. It is preferable to stick a label or the like having a high thickness (for example, a large thickness or a high hardness).

  As a result, the second side wall 4b can be preferentially deformed with respect to the first side wall 4a. In addition, this also has an effect of preventing the occurrence of a dent due to a decrease in rigidity of the first side wall 4a when the second side wall 4b is formed thicker than the first side wall 4a.

  The plastic bottle 1 to which the present invention is applied is not necessarily limited to the above configuration, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the plastic bottle 1, the handle portion 7 is formed by forming the tunnel portion 8 so as to penetrate between the third side wall 4c and the fourth side wall 4d, leaving the second corner 4f. Is formed integrally with the body portion 4, but the handle portion 7 is formed integrally with the body portion 4 by recessing between the third side wall 4c and the fourth side wall 4d. It may be a configuration.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

In this example, a plastic bottle having the same shape as the plastic bottle 1 was actually produced. Specifically, the material of the bottle body of this plastic bottle, the molding method, and the dimensions of the body are as follows.
Material: High density polyethylene (HDPE) resin
Molding method: biaxial stretch blow molding
Body size: width 120mm x depth 120mm x height 160mm

  In this embodiment, as shown in FIG. 4, the thickness and curvature (curvature radius R) of the bottle body on the front side (first side wall 4a) side and the back side (second side wall 4b) side are changed. About the degree of deformation of the front side and the back side when it was made to perform the decompression analysis by computer simulation.

In FIG. 4, the vertical axis indicates the curvature radius R ₂ of the back surface and the curvature radius R ₁ of the front surface [unit: mm], and the horizontal axis indicates the thickness of the front surface and the back surface and the difference [unit: mm]. And the ratio (%). Moreover, the bottle main body shown in FIG. 4 shows the stress distribution at the time of pressure reduction on the front side (right side) and the back side (left side) in each condition, and shows that the stress increases toward the center. .

  As shown in FIG. 4, by making the curvature of the front side of the bottle body larger than the curvature of the back side, the influence due to the difference in thickness between the front and back sides is reduced, and the back side of the bottle body is easily deformed. It is possible.

  Therefore, according to the present invention, when the pressure in the bottle body is reduced, the back side can be selectively deformed with respect to the front side of the bottle body, so that the bottle body is formed thick, By specifying the location where the bottle body deforms due to decompression, etc. without using high-rigid and expensive resin materials, the deterioration of appearance is minimized without affecting the label attachment position. It is possible.

  DESCRIPTION OF SYMBOLS 1 ... Plastic bottle 2 ... Bottle main body 3 ... Bottom part 4 ... trunk | drum 4a ... 1st side wall 4b ... 2nd side wall 4c ... 3rd side wall 4d ... 4th side wall 4e ... 1st corner | angular part 4f ... 2nd Corner 4g ... third corner 4h ... fourth corner 5 ... shoulder 6 ... cap 7 ... grip 8 ... tunnel

Claims (4)

A plastic bottle in which the bottle body is molded by blow molding,
The bottle body includes a bottom part, a body part constituted by four side walls rising from an outer periphery of the bottom part, a shoulder part gradually reduced in diameter upward from an upper end of the body part, and an upper end of the shoulder part And a mouth-and-neck portion that rises in a cylindrical shape from
In the horizontal cross section of the body portion, the contour lines of two side walls adjacent to each other with at least one corner portion formed in an arc shape outward, and one side wall is a surface having a larger curvature than the other side wall. A plastic bottle characterized by being constructed. When the curvature of the one side wall is 1 / R1, and the curvature of the other side wall is 1 / R2,
1 <R2 / R1 ≦ 3
The plastic bottle according to claim 1, wherein the following relationship is satisfied.   The plastic bottle according to claim 1 or 2, wherein the bottom portion has a substantially square shape.   The plastic container according to any one of claims 1 to 3, wherein the container body has a handle portion formed integrally with the body portion on a corner portion facing the one corner portion. .

Images