US20100084360A1

US20100084360A1 - Plastic Bottle and Similar Containers Made Of Plastic

Info

Publication number: US20100084360A1
Application number: US12/516,342
Authority: US
Inventors: Christian Dornbach
Original assignee: Alpla Werke Alwin Lehner GmbH and Co KG
Current assignee: Alpla Werke Alwin Lehner GmbH and Co KG
Priority date: 2006-11-23
Filing date: 2007-10-15
Publication date: 2010-04-08
Also published as: BRPI0717222A2; WO2008061594A1; ES2382580T3; RU2457915C2; RU2009123842A; ATE545594T1; EP2091824A1; MX2009005436A; EP2091824B1; BRPI0717222B1

Abstract

A plastic bottle (1) and similar containers for receiving fluid substances have an elongated body (2), wherein the one longitudinal end is closed by a bottom (3) and the opposite end transitions into a neck section (4) having a pouring spout (5). A shoulder section (6) extends from the neck section (4) to a region (7) of the body (2), wherein the region has a larger diameter. The shoulder section (6) is equipped with structured regions (10) at least in a portion of the axial and circumferential extensions thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT/EP2007/008926 filed on Oct. 15, 2007, and CH1889/06 filed on Nov. 23, 2006, the entirety of each of which are incorporated by this reference.

BACKGROUND

1. Field of the Invention
The invention pertains to a plastic bottle and similar plastic containers for holding fluid substances with an elongated body, one longitudinal end of which is closed by a bottom and the opposite end of which transitions to a neck section with a pour opening, said body having a shoulder section that extends from the neck section to an enlarged diameter area of the body.
2. State of the Art
Containers used in the past, which were usually made of tin or non-ferrous metal sheeting, glass or ceramics, are being increasingly phased out by plastic containers. Particularly for the packaging of bulk media, such as cleaning utensils, body care products, cosmetics, automotive media, etc., plastic containers are usually used. The low weight and lower costs have certainly played a significant role in this substitution. The use of recyclable plastic materials and the more favorable overall energy balance in the manufacture of such materials have also contributed to promoting the acceptance of plastic containers, in particular plastic bottles, by consumers.
A very frequently used type of plastic container consists primarily of polyethylene terephthalate (PET). These plastic bottles are usually produced in a so-called injection stretch blow molding process, representing a combination of injection molding and blow molding. In this process, a PET pre-form is first produced in an injection mold in an injection molding process. Recently, cold extrusion methods have been proposed for the manufacture of pre-forms. The pre-form has a substantially elongated, cylindrical body and is closed at one longitudinal end. A support ring separates the body from a neck section that has an opening for pouring. The neck section usually already has the shape of the later shape of the neck of the bottle. On the outside of the neck section are pre-existing threaded sections or the like for the attaching of a closure part. The pre-form is de-molded after its manufacture and further processed right away or is intermediately stored for later processing at a blowing machine. Prior to further processing in a blowing machine, the pre-form is conditioned, if necessary; then, it is inserted into a blow mold of a blowing machine. In the blow mold, the pre-form is finally inflated according to the mold cavity by means of a pressurized gas that is blown in and is also stretched with a stretching mandrel. There is also a known injection blowing process in which the blowing takes placed directly following the injection of the pre-form. The pre-form remains on the injection core, which also constitutes the stretching mandrel. In this method, the pre-form is also inflated according to the mold cavity of a blow mold by means of pressurization and in the process stretched by the stretching mandrel that is placed on the injection core or vice versa. Then, the finished plastic bottle is de-molded.
Single or multi-layered plastic bottles and containers are often produced in so-called extrusion blowing processes, in particular in a tube blowing process. The extrusion blowing machines used for the extrusion blowing process generally include one or more extruders to feed the necessary plastic material. The outlet of the extruder is connected to an extruder head, with the extruded tube exiting from the discharge nozzle of the extruder head, said nozzle preferably having an opening width that can be regulated. The extruded plastic tube can be constructed in one or more layers. The tube exiting the discharge nozzle is continuously or quasi-continuously fed to a blow mold and inflated through pressurization using a blowing mandrel retracted into the mold cavity. Then, the blown plastic bottle is de-molded from the mold cavity.
Plastic bottles and similar plastic containers are produced in very high volumes and are therefore constantly subject to optimizations that save costs. Therefore, for reasons of cost, but also for ecological reasons, material savings is also sought. On the other hand, however, the required stiffness of the plastic bottles must be maintained in the process. This stiffness requirement places limits on engineering and design efforts for plastic bottles with a fill volume of 50 ml to 300 ml.
Therefore, the object of the present invention is to create a plastic bottle that exhibits the required stiffness. In the process, the required stiffness should be accomplished without the need for additional material. The existing manufacturing methods should not need to be modified.
The solution to this object is a plastic bottle and similar plastic containers having a shoulder section that is provided with structuring in at least a portion of its axial extent and along its circumference. Further developments and/or advantageous embodiments of the invention are set forth herein.

SUMMARY OF THE INVENTION

A plastic bottle and similar containers to hold fluid substances comprises an elongated body, one side of which is sealed by a bottom and the opposite side of which transitions to a neck section with an opening for pouring. A shoulder section extends from the neck section to an area of the body that is of a larger diameter. The shoulder section is provided with structuring in at least a part of its axial extent and circumference.
The structuring in the shoulder section of the plastic bottle provides the bottle with the desired stiffness. By further optimizing through material reduction in the shoulder section, the plastic bottle provided with the structuring exhibits at least the same stiffness as a similar plastic bottle with a greater wall thickness. With the same wall thickness, the stiffness is increased. This provides the plastic bottle with a higher storage longevity and it can also be used for filling systems operated at high temperatures.
The structuring is arranged evenly along the circumference of the shoulder section and is designed as repeating, annular geometric base structures. The repeating annular geometric base structures are easily created and directly result in an increased stiffness of the structured areas. The geometric base structures that repeat along the circumference of the shoulder section lead to an even strengthening of the wall are along the circumference.
In addition, it has been shown to be advantageous if two or more rings of geometrical base structures are located in the shoulder section separated from one another by transverse grooves. This permits the geometric base structures provided in the shoulder section to be tailored to the contour of the plastic bottle and to be designed according to this contour.
The advantageous embodiments listed below lead, alone or in combination with one another, to further improvements in the stiffness behavior of the plastic bottle:
One variation of the plastic bottle provides that the geometric structures are separate from one another by means of grooves that run essentially in the longitudinal direction of the body.
The grooves that run essentially in the longitudinal direction can be arranged parallel to the longitudinal axis or they can also form an included angle with the longitudinal axis of the body of up to 45°. The geometric base structures can thus comprise longitudinal sides that run in a projection parallel to the longitudinal axis of the body or that are tilted.
Good stiffness behavior results when the transverse and/or longitudinal grooves have a depth of about 0.5 mm up to about 1.5 mm. In the process, the transverse grooves and the longitudinal grooves can also have depths that differ from one another.
The stiffness is further increased by providing the transverse and/or longitudinal grooves with a notched base whose width measured perpendicular to the groove's length is about 0.2 mm to about 1.2 mm.
A practical variation of the plastic bottle provides that the walls of the transverse and/or longitudinal grooves form an opening angle (α) together that is about 50° to about 100°. The angle included by the walls of the transverse grooves and the longitudinal grooves can be designed to be different from one another.
It has been shown to be advantageous for the achievable stiffness of the plastic bottle for the annular structuring to have 9 to 15, preferably 10 to 14, geometric base structures in the shoulder section that are evenly arranged along the circumference.
A very practical embodiment of the invention provides that two or more rings of geometric base structures are located in the shoulder section. In the process, each ring has the same number of geometric base structures, each of which expeditiously having the number of base structures indicated above and being separated from one another through longitudinal grooves that extend across adjacent ring structures. The base structures of adjacent rings do not have to be identical, but can be different from one another according to the respective section of the shoulder section, such as to take into account different curvatures or different diameters.
For the geometric base structures, rectangular to trapezoidal shapes have proven to be useful. Here, trapezoidal base structures are advantageously placed in the section of the shoulder section near the neck.
The base structures have a height that is 1 to 1.5 times the width of the base structure. This results in advantageous strengths and at the same time the contour of the plastic bottle can be incorporated into the shape.
The design of the plastic bottle according to the invention, with structuring in the shoulder section, has proven to be useful in particular for plastic bottles with a fill volume of 50 ml to 330 ml.
The structuring in the shoulder section of the plastic bottle can be applied in plastic bottles that are produced in a stretch-blowing or extrusion blowing process. In the process, the structuring is produced inside the mold cavity of a blow mold during the blowing process. This is easily done by designing the walls of the mold cavity accordingly.
The pre-forms used in the stretch-blowing process remain unchanged here. Similarly, the extrusion process in extrusion blowing processes remains unchanged and no changes are required to be made to the extrusion nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features are given in the following description of an exemplary embodiment of the invention, with reference to the schematic drawings. Shown are (not to scale):

FIG. 1 A perspective view of a plastic bottle designed according to the invention;

FIG. 2 A side view of the plastic bottle in FIG. 1;

FIG. 3 An axial section of the plastic bottle; and

FIG. 4 A detail according to arrow IV in FIG. 3.

Elements common to all figures are provided with the same labels.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

A plastic bottle designed according to the invention is provided in general with the label 1 in FIG. 1-3. An example of a plastic bottle is one with a fill volume of 125 ml. The plastic bottle 1 has an elongated, rotationally symmetric body 2, one longitudinal end of which is closed off with a bottom 3. At the other end, the body transitions to a neck section 4 that comprises an opening for pouring 5. On the outside of the neck section 4 are threaded sections that enable a closure to be screwed on. A shoulder section 6 extends from the neck section 4 to an area of enlarged diameter 7 of the body 2. However, the area of enlarged diameter 7 does not necessarily have to be the area of enlarged diameter of the body 2 of the plastic bottle 1. These types of plastic bottles are usually produced in a stretch-blowing process. However, they can also be produced in an extrusion blowing process.
The shoulder section 6 of the body 2 is provided with structuring 10 along its axial length and its circumference. In the exemplary embodiment of the plastic bottle shown, the structuring consists of two rings 11, 12 of geometric base structures 13, 14 that are arranged evenly along the circumference of the shoulder section 6. The two rings 11, 12 of base structures 13, 14 are separated from one another by a transverse groove 15. Another transverse groove 15 forms the end of the shoulder section 6 that transitions to the enlarged diameter area 7 of the body 2. The geometric base structures 13, 14 are essentially rectangular or trapezoidal and are separated from one another through grooves 16 running in the longitudinal direction. In the exemplary embodiment shown, the longitudinal grooves 16 run in a side projection parallel to the longitudinal axis of the plastic bottle 1. In an exemplary embodiment not shown in more detail, the grooves that run in the longitudinal direction can also be set at an angle of up to 45° with respect to the longitudinal axis.
The geometric base structures 13, 14 have an axial height that is about one to one and a half times their width. It is understood that the height and the width are understood to mean the wound dimensions. FIGS. 1 and 2 show that the base structures 13 near the neck section 4 have an essentially trapezoidal shape with a larger height than width. The trapezoidal base structures 13 are directly adjacent to the neck section 4. The second ring 12 of base structures consists of approximately square base structures 14. The number of base structures 13, 14 is the same in the two rings 11, 12 and is typically about 9 to 15, preferably 10 to 14.
FIG. 4 shows the bottle wall section containing a transverse groove 15 identified with arrow IV in FIG. 3 at a greater scale. The transverse groove 15 is lined by walls 18, 19 that typically form an opening angle (α) together of 50°-100°. In the section IV shown, the opening angle α is about 90°. The two walls 18, 19 sit adjacent to a notched base 17 whose width measured perpendicular to the length of the groove is about 0.2 mm to about 1.2 mm. The groove 15 has a depth T of about 0.5 to 1.5 mm. The dimensions of the grooves have been explained through the example of a transverse groove 15. It is understood that the dimensions of the longitudinal grooves 16 are designed similarly and fall within the ranges indicated. In the process, the dimensions of the transverse grooves 15 and the longitudinal grooves can be different from one another. Usually, the longitudinal grooves have a narrower notched base than the transverse grooves. Also, their opening angle is typically smaller.
The invention has been explained through the example of a plastic bottle with a fill volume of 125 ml. Basically, the invention is not limited to these kinds of fill volumes. It has been shown that providing structuring 10 in the shoulder section 6, especially for plastic bottles with fill volumes of 50 ml to 330 ml, brings advantages with regard to achievable stiffnesses. Whereas in the exemplary embodiment shown the entire shoulder section 6 is provided with structuring 10, it is understood that they can also be provided only in part of the axial length and circumference of the shoulder section. The structuring can be applied to plastic bottles that are produced in the stretch-blowing process or in an extrusion blowing process. In the process, it has been shown to be particularly advantageous if the structuring is produced during the blowing process within the mold cavity of the blow mold.

Claims

1. A plastic bottle and similar containers to hold fluid substances, comprising:

an elongated body, one longitudinal end of which is closed by a bottom and the opposite end of which transitions to a neck section with a pour opening, said body having a shoulder section that extends from the neck section to an enlarged diameter area of the body, and the shoulder section being provided with structuring in at least a portion of its axial extent and along its circumference; and

two or more rings of geometric base structures located in the shoulder section, said rings being separated from one another by transverse or longitudinal grooves.

2. The plastic bottle according to claim 1, characterized in that the structuring is arranged evenly along the circumference of the shoulder section and comprises repeating, annular geometric base structures.

3. The plastic bottle according to claim 1, wherein the two or more rings of geometric base structures are separated from one another by grooves that run essentially in the longitudinal direction of the body.

4. The plastic bottle according to claim 3, wherein the grooves that run essentially in the longitudinal direction are located in a projection view parallel to the longitudinal axis of the body.

5. (canceled)

6. The plastic bottle according to claim 4, wherein the grooves that run in the longitudinal direction form an included angle of up to 45 degrees with the longitudinal axis of the body in a projection view.

7. A The plastic bottle according to claim 1, wherein the transverse and/or longitudinal grooves have a depth of about 0.5 mm to about 1.5 mm.

8. The plastic bottle according to claim 7, wherein the transverse and/or longitudinal grooves comprise a notched base whose width measured perpendicular to the groove's length is about 0.2 mm to about 1.2 mm.

9. The plastic bottle according to claim 1, wherein walls of the transverse and/or longitudinal grooves form an opening angle together of about 50° to about 100°.

10. The plastic bottle according to claim 9, wherein the structuring located in rings comprises 9 to 15 geometric base structures (13, 14) that are arranged evenly along the circumference.

11. The plastic bottle according to claim 10, wherein two or more rings of geometric base structures are arranged in the shoulder section, wherein each ring has the same number of geometric base structures separated from one another by longitudinal grooves that extend across adjacent ring structures.

12. The plastic bottle according to claim 1, wherein the geometric base structures are designed rectangular to trapezoidal.

13. The plastic bottle according to claim 12, wherein the base structures have a height that is 1 to 1.5 times their width.

14. The plastic bottle according to claim 1, wherein it has a fill volume of 50 ml to 330 ml.

15. A The plastic bottle according to claim 1, wherein the structuring in the shoulder section is produced in a stretch-blowing or extrusion blowing process within the mold cavity of a blow mold.