JP2005178822A - Plastic container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic container for which the strength of the arc-shape external contour section of the body section is increased, a deformation by decompression at the time of the discharging of a content can be prevented from occurring while reducing the weight amount of a using resin by making the thickness thinner, and of which the cross sectional shape of the body section becomes an approximately oval shape with corners. <P>SOLUTION: This plastic container is formed having a cross section of an approximately oval shape with corners for which spaces between linear external contours 5<SB>1</SB>and 5<SB>1</SB>at both ends of a major axis 6 are gently connected by the arc-shape external contour. In the plastic container, the radius of curvature of the arc when the spaces between the liner external contours 5<SB>1</SB>and 5<SB>1</SB>at both ends of the major axis 6 are connected by the arc-shape external contour 15<SB>2</SB>having only one radius of curvature is taken as R0, the central section of the arc which connects the space between the linear external contours 5<SB>1</SB>and 5<SB>1</SB>at both ends of the major axis 6 is constituted by a first external contour 5<SB>2</SB>comprising a radius of curvature R1 which is 80% or less of the radius of curvature R0. At the same time, sections on both sides of the central section are constituted of a second external contour 5<SB>3</SB>comprising a radius of curvature R2 which is twice or higher of the radius of curvature RO. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plastic container for storing liquid substances such as body soap, shampoo, and rinse.

  In general, liquid body soaps, shampoos, rinses, and the like are often filled and stored in a pump-type plastic container, and the contents are often discharged by pushing the pump during use. In the case of such a type of plastic container, when the pump is pushed and the contents are discharged, the pressure inside the container is abruptly lowered, and the body part may be dented and deformed under reduced pressure. Conventionally, in order to eliminate such problems, measures have been taken such as increasing the thickness of the container to such a level that it can withstand deformation under reduced pressure, or devising the cross-sectional shape of the container.

  As what devised the cross-sectional shape of a container, the plastic container as shown by patent document 1 (Unexamined-Japanese-Patent No. 2003-20022) is known, for example. This plastic container has a major axis and a minor axis whose outer contours of the trunk cross section are orthogonal to each other. A curve n1 having a curvature radius r1 and a curve n2 having a curvature radius r2 intersect at both ends of the major axis. The curves n3 and n4 having a large curvature radius r are connected between n2 gently, and at least one of the curvature radii r1 and r2 of the curves n1 and n2 is set as a minimum curvature radius.

JP 2003-20022 (all pages, all figures)

  The plastic container described in Patent Document 1 is configured to discharge the content liquid by forming all of the outer contours n1 to n4 of the body cross section with a curve having a predetermined radius of curvature and having a substantially oval or oval shape. This prevents deformation under reduced pressure. However, in the plastic container described in Patent Document 1, since the outer contour of the trunk portion is entirely configured by a curve, both long axis ends of the trunk cross section are configured by straight lines, and an arc between the straight lines at both ends is formed. It could not be applied to a container (see FIG. 10) having a so-called cross-sectionally substantially square elliptical shape that is gently connected. Therefore, in the case of a plastic container having a substantially rectangular elliptical cross section, the strength of the arc portion connecting the straight lines at both ends of the long axis is insufficient. This was dealt with by increasing the basis weight and increasing the thickness of the container.

  The present invention has been made in order to solve the above-described problem. The strength of the arc-shaped outer contour portion connecting the linear outer contours at both ends of the long axis is increased, the thickness is reduced, and the weight of the resin used is reduced. It is an object of the present invention to provide a plastic container having a trunk cross-sectional shape that can prevent deformation under reduced pressure during content liquid discharge while reducing the amount, and having a substantially rectangular elliptical shape.

  In order to achieve the above object, the plastic container according to claim 1 has a major axis and a minor axis whose outer contours of the trunk cross section are orthogonal to each other, and a linear shape perpendicular to the major axis is provided at both ends of the major axis. In a plastic container having an elliptical cross section in which the linear outer contours at both ends of the major axis are gently connected by an arc-shaped outer contour, the linear outer contours at both ends of the major axis are The arc-shaped outer contour connecting the two is composed of two or more outer contours having different curvature radii, and the outer contour located at the central portion is the arc having the smallest curvature radius, and each of the outer contours as it goes to the left and right ends. The curvature radius of the outer contour is set to be large.

  The plastic container according to claim 2 is the plastic container according to claim 1, wherein the linear outer contours at both ends of the major axis are connected by an arc-shaped outer contour having a single radius of curvature. When the radius of curvature of the arc is R0, the central portion of the arc connecting the linear outer contours at both ends of the major axis is constituted by the first outer contour having the curvature radius R1 of 80% or less of the curvature radius R0. In addition, the both side portions are formed by a second outer contour having a curvature radius R2 which is twice or more the curvature radius R0.

  The straight outer contour is not limited to a complete straight line in a mathematical sense, that is, a line connecting two points at the shortest distance, and is for extracting a molded product from a mold. An outer contour having a draft angle (taper, slight curve, etc.) applied to is also included in the linear outer contour referred to in the present invention. In general, the corner where the straight outer contour intersects with the arc is provided with a small radius for connecting the corner to round the corner in accordance with the requirements in the molding process. Is not included.

  According to the plastic container of the present invention having the above-described configuration, in the plastic container having a substantially rectangular elliptical cross-sectional shape, an outer contour having two or more curvature radii at the arc portion connecting the straight lines at both ends of the major axis Thus, the strength of the arc portion connecting the straight lines at both ends of the long axis can be increased. For this reason, compared with this kind of conventional plastic container, thickness can be made thin and the decompression deformation | transformation at the time of content liquid discharge can be prevented, reducing the amount of resin used. Moreover, since the basis weight of the resin can be reduced, resource saving can be achieved.

  Furthermore, in the case of a container whose body cross-sectional shape is substantially an elliptical shape, the vicinity of the central part of the arc part connecting the straight lines at both ends of the long axis tends to be thick at the time of injection molding of the container, and this part is easy to close, By adopting the configuration as in the present invention, it is possible to increase the strength near the center of the arc portion connecting the straight lines at both ends of the long axis, and to suppress the occurrence of sink marks during injection molding.

First, before describing the embodiment of the present invention, the conventional plastic container 11 shown in FIG. 10 will be briefly described. In FIG. 10, 12 is a barrel portion of the container, 13 is a spout portion formed at the upper end of the barrel portion, and 14 is a bottom portion of the container connected to the barrel portion 12. The conventional plastic container 11 has a major axis 16 and a minor axis 17 in which the outer contours of the cross section of the trunk portion 12 are orthogonal to each other, and linear outer contours 15 orthogonal to the major axis 16 are provided at both ends of the major axis 16. _{1 and the} left and right outer contours 15 ₁ , 15 ₁ are connected to _{each other} by one outer contour 15 ₂ made of an arc having a radius of curvature R 0, thereby forming a body portion 12 having an elliptical cross section as a whole. Is.

For conventional plastic container 11 described above, usually broad outer contour 15 ₂ parts of the area to be arcuate is used as a label attachment surface for displaying a product name and contents, on the appearance since most prominent label attachment surface is constituted only by a single arc-shaped outer contour 15 _2, the strength is not sufficient as a container, pressure reducing deformation is likely happening when the content liquid pouring. For this reason, it is common to prevent deformation under reduced pressure by increasing the basis weight of the resin to be used and increasing the wall thickness. In the present invention, the strength against decompression deformation can be remarkably increased when the wall thickness is the same as that of the prior art, and when the strength is the same as that of the prior art, the thickness is reduced and the basis weight of the resin is remarkably increased. A plastic container that can be reduced to a minimum is developed.

Next, an embodiment of the present invention will be described with reference to FIG.
Plastic container 1 according to this embodiment are those showing an example of a case where the arcuate portion connecting the straight line 5 _1, 5 ₁ of the long axis across the barrel cross-section by the two outer contour 5 _2, 5 ₃ It is. Incidentally, FIG. 1, for ease of features of the present invention, depicting in exaggerated the two ratios of the outer contour 5 _2, 5 of curvature of ₃ radii R1, R2 and practice are different.

In FIG. 1, 2 is a barrel portion of the container, 3 is a spout portion formed at the upper end of the barrel portion, and 4 is a bottom portion of the container connected to the barrel portion 2. The plastic container 1 of the present invention has a long axis 6 and a short axis 7 whose outer contours of the cross section of the body part 2 are orthogonal to each other. outer contour _{5 1} intersection, the left and right outer contour ₅ 1, _{5 1} between the knot by the radius of curvature R1, R2 2 two outer contour ₅ 2 consisting of, _{5 3,} a substantially square oval shape as a whole to become the straight line The body part 2 of FIG.

In the case of this embodiment, between the straight outer contour 5 _1, 5 _1, just as the radius of curvature when connecting outside contour 15 ₂ consisting of a single arc and R0 and conventional containers when, with an arc comprising a first outer contour 5 ₂ radius of curvature R1 located in central 80% or less of the radius of curvature of the curvature radius R0, the curvature radius R2 of the second outer profile 5 ₃ the It is constituted by an arc having a radius of curvature more than twice the radius of curvature R0.

When constituting the outer contour of the cross section of the body portion 2 by the radius of curvature of the two different outer contour 5 _2, 5 _3, as described above, a small first outer contour of the curvature radius of the front center of the body portion 2 5 ₂ Is formed in a state of projecting in a rib shape in the vertical direction, and becomes a form that reinforces the label attaching surface having a large area in front of the body portion. For this reason, the thickness of the container can be reduced by the increase in strength, and the basis weight of the resin used can be reduced. Moreover, when it is set as the same thickness as the conventional container, the intensity | strength of the label sticking surface with a large area can be improved significantly.

In the case of the embodiment is configured by a linear outer contour 5 _1, 5 ₁ Two outer contour different arcuate portion radius of curvature connecting the 5 _2, 5 ₃ in the major axis ends, two outer It is not limited to the contour, but may be composed of two or more outer contours. In this case, the first outer contour 5 ₂ and the second curvature of the outer contour ₃ radii R1, R2 are set to a ratio relationship described above, the third and later is further disposed on the outside of the second outer profile 5 ₃ For the outer contour, the radius of curvature may be set to be larger than the radius of curvature of the inner outer contour.

  In the case of the above-described embodiment, the cross-sectional shape that is line-symmetric with respect to the long axis 6, that is, in FIG. 1C, the upper half side arc portion and the lower half side arc portion have the same radius of curvature. The upper half and the lower half have the same cross-sectional shape, but as long as the relationship between the curvature radii R0, R1, and R2 satisfies the conditions of the present invention on each side, the upper half and the lower half A circular arc having a different curvature radius may be used on each of the part sides, and the cross-sectional shape may be asymmetrical with respect to the major axis 6.

  FIG. 2 is a first embodiment showing a specific example of the trunk cross-sectional shape of the plastic container according to the present invention. In the plastic container having the body cross-sectional shape of FIG. 2, a pressure-resistant characteristic test was performed when the curvature radii R1 and R2 were variously changed. The result is shown in FIG. In addition, the common specifications of each container used for the test are as follows.

(1) Common specifications Container material: High-density polyethylene Container height: 188.5 mm (see Fig. 1)
Body center width La: 91.0 mm
Body thickness Wa: 51.8mm
Arc part chord width L = 89.8mm
Arc height W = W / 2 + W / 2 = 21.3mm
L / W = 4.2
Curvature radius R0 = 100mm
Bottle surface decoration: Silk printing, 4 colors

(2) In the test method the common specification, a first outer contour 5 ₂ radius of curvature R1, create a second changed variously plastic containers curvature radius R2 of the outer contour _3, mouth for each container The internal pressure was lowered in a sealed state, and the reduced pressure value was obtained when the weakest strength of the central part of the body part was recessed 4 mm (= the size of the dent that impairs the appearance of the container visually). For comparison, the results are shown also conventional plastic containers constituting the outer contour 15 ₂ by only one arc consisting of curvature radius R0.

Test Results As apparent from FIG. 3, when configured by the outer contour 5 _2, 5 two arcs with different ₃ radius of curvature of the barrel cross-section, also in the curvature radius R1, the R2 is any value, only one It was found that the pressure-resistant characteristics are remarkably improved as compared with the conventional plastic container constituted by two arcs. Further, only the case of the conventional plastic container constituted by a single arc, when gradually increasing the curvature R0 of the outer contour 15 _2, anti-vacuum value decreases with it, the strength of the body is lowered when the outer profile is constituted by the radius of curvature of two different arcs as in the present invention, when gradually increasing the radius of curvature R2 of the second outer contour _3, anti-vacuum value becomes larger accordingly, cylinder It was found that the strength of the part increased.

  Furthermore, in the case of the present invention, if R1 = 0.8 × R0 = about 80 mm and R2 = 2 × R0 = about 200 mm, a strength comparable to that of a conventional container (decompression-proof value about 3.55 kPa) can be obtained. It was found that the wall thickness t of the container can be reduced from 1.0 mm to 0.8 mm. Accordingly, the basis weight of the resin used can be reduced by the amount that the thickness can be reduced. By the way, when R1 = 80 mm and R2 = 200 mm, the weight of the resin used was 54 g when the barrel thickness t = 1.0 mm, but when the barrel thickness t = 0.8 mm, the weight of the resin used was As a result, the amount of resin used was reduced by about 18.5%.

  FIG. 4 is a second embodiment showing a specific example of the trunk cross-sectional shape of the plastic container according to the present invention. In the plastic container having the cross-sectional shape of the trunk portion of FIG. 4, a pressure resistance characteristic test was performed when the curvature radii R1 and R2 were variously changed. The result is shown in FIG. In addition, the common specifications of each container used for the test are as follows.

(1) Common specifications Container material: High density polyethylene Container height: 188.5mm
Body center width La: 83.5mm
Body thickness Wa: 54.0 mm
Arc part chord width L = 82.3mm
Arc height W = W / 2 + W / 2 = 23.5mm
L / W = 3.5
Curvature radius R0 = 77.9mm
Bottle surface decoration: None

(2) In the test method the common specification, a first outer contour 5 ₂ radius of curvature R1, create a second changed variously plastic containers curvature radius R2 of the outer contour _3, mouth for each container The internal pressure was reduced in a sealed state, and the reduced pressure value was obtained when the weakest central part of the body was indented 4 mm. For comparison, the results are shown also conventional plastic containers constituting the outer contour 15 ₂ only by a single circular arc (R0 = 77.9mm).

  As is apparent from the test results of FIG. 5, the same results as in the case of the first example were obtained in the case of the second example.

  FIG. 6 is a second embodiment showing a specific example of the trunk cross-sectional shape of the plastic container according to the present invention. In the plastic container having the trunk cross-sectional shape of FIG. 6, a pressure resistance test was performed when R1 and R2 were variously changed. The result is shown in FIG. In addition, the common specifications of each container used for the test are as follows.

(1) Common specifications Container material: High-density polyethylene Container height: 188.5 mm (see Fig. 1)
Body center width La: 74.7 mm
Body thickness Wa: 54.0 mm
Arc part chord width L = 73.5mm
Arc height W = W / 2 + W / 2 = 24.5mm
L / W = 3.0
Curvature radius R0 = 61.3mm
Bottle surface decoration: In-mold label, thickness 90μm

(2) In the test method the common specification, a first outer contour 5 ₂ radius of curvature R1, create a second changed variously plastic containers curvature radius R2 of the outer contour _3, mouth for each container The internal pressure was lowered in a sealed state, and a reduced pressure value was obtained when the weakest central part of the body was recessed 4 mm. For comparison, the results are also shown for a conventional plastic container having an outer contour constituted by only one arc (R0 = 61.3 mm).

  As is apparent from the test results of FIG. 7, the same results as in the first example were obtained in the third example.

  FIG. 8 is a fourth embodiment showing a specific example of the trunk cross-sectional shape of the plastic container according to the present invention. With respect to the plastic container having the body cross-sectional shape of FIG. 8, a pressure resistance test was performed when the curvature radii R1 and R2 were variously changed. The result is shown in FIG. In addition, the common specifications of each container used for the test are as follows.

(1) Common specifications Container material: High density polyethylene Container height: 188.5mm
Body center width La: 68.9 mm
Body thickness Wa: 57.6 mm
Arc part chord width L = 67.8mm
Arc height W = W / 2 + W / 2 = 27.1 mm
L / W = 2.5
Curvature radius R0 = 49.1mm
Bottle surface decoration: None

(2) In the test method the common specification, a first outer contour 5 ₂ radius of curvature R1, create a second changed variously plastic containers curvature radius R2 of the outer contour _3, mouth for each container The internal pressure was lowered in a sealed state, and a reduced pressure value was obtained when the weakest strength of the central part of the body part was recessed by 4 mm. For comparison, the result is also shown for a conventional plastic container having an outer contour formed by only one arc (R0 = 49.1 mm).

  As is apparent from the test results of FIG. 9, the same results as in the first example were obtained in the fourth example.

The embodiment of the plastic container which concerns on this invention is shown, (a) is a typical front view, (b) is a typical side view, (c) is the trunk | drum in the II line position in (a). It is a typical outer outline figure of a cross section. It is a figure which shows the 1st Example of a trunk | drum cross-sectional shape. It is a graph which shows the decompression-proof characteristic test result of the plastic container which consists of a trunk | drum cross-sectional shape of a 1st Example. It is a figure which shows the 2nd Example of trunk | drum cross-sectional shape. It is a graph which shows the pressure-resistant characteristic test result of the plastic container which consists of a trunk | drum cross-sectional shape of a 2nd Example. It is a figure which shows the 3rd Example of a trunk | drum cross-sectional shape. It is a graph which shows the pressure-resistant characteristic test result of the plastic container which consists of a trunk | drum cross-sectional shape of a 3rd Example. It is a figure which shows the 4th Example of trunk | drum cross-sectional shape. It is a graph which shows the decompression-proof characteristic test result of the plastic container which consists of a trunk | drum cross-sectional shape of a 4th Example. The example of the conventional plastic container is shown, a) is a front view, (b) is a side view, (c) is an outer outline view of the trunk cross section at the position of II-II line in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic container 2 Body part 3 Outlet part 4 Container bottom part 5 ₁ Linear outer contour 5 1st outer contour which consists of ₂ circular arcs 5 _2nd outer contour which consists of ₃ circular arcs 6 Long axis 7 Short axis R0 Conventional container Radius of curvature of outer contour R1 radius of curvature of first outer contour R2 radius of curvature of second outer contour

Claims (2)

  The outer cross section of the trunk section has a major axis and a minor axis that are orthogonal to each other, and both ends of the major axis are provided with linear outer contours that are orthogonal to the major axis. Two or more arc-shaped outer contours connecting the linear outer contours at both ends of the major axis with two or more different radii of curvature in a plastic container having an elliptical cross section that is gently connected by an arc-shaped outer contour. The outer contour located in the center portion is an arc having the smallest curvature radius, and the curvature radius of each outer contour is set to increase toward the left and right ends. Plastic container.   The plastic container according to claim 1, wherein when the radius of curvature of the arc when the linear outer contours at both ends of the major axis are connected by an arc-shaped outer contour having only one curvature radius is R0, The central portion of the arc connecting the linear outer contours at both ends of the shaft is constituted by the first outer contour having the curvature radius R1 of 80% or less of the curvature radius R0, and the portions on both sides thereof are defined by the curvature radius R0. A plastic container characterized by comprising a second outer contour having a radius of curvature R2 that is at least twice as large as.

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