WO2012061885A1

WO2012061885A1 - Pressurised pet container

Info

Publication number: WO2012061885A1
Application number: PCT/AU2011/001445
Authority: WO
Inventors: Asim Salameh
Original assignee: SOUTHERN STAR Corp
Current assignee: SOUTHERN STAR Corp
Priority date: 2010-11-09
Filing date: 2011-11-09
Publication date: 2012-05-18
Anticipated expiration: 2013-05-09

Abstract

A container (1) for dispensing a pressurised product, said container including: a body (2), formed of PET or like plastics material, the body (2) including: a neck (7) about an opening, and a shoulder (9) depending from the neck (7); the neck (7) including a radially outwardly projecting flange dividing the neck (7) into an upper neck portion and a lower neck portion; and, the shoulder (9) depending from the neck (7) being of generally uniform convex shape.

Description

PRESSURISED PET CONTAINER

RELATED APPLICATIONS

Priority is claimed from US Patent Application No. 61/41 1,743 and Australian Patent Application No. 2010904964, the contents of which we incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a container for dispensing a pressurised product, and in particular, to such a container which is formed of PET or like material.

In particular, the present invention relates to the type of container described in the Applicant's earlier International Application Nos. PCT/AU2005/001474 and PCT/AU2006/001614, the disclosures of which should be considered to be fully incorporated herein by this reference thereto.

DESCRIPTION OF THE PRIOR ART

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge.

As described in the Applicant's earlier afore-mentioned Patent Applications, containers for dispensing pressurised products have been herebefore primarily constructed of metal. Such metal containers have a number of inherent shortcomings, which have resulted in some relatively unsuccessful efforts to replace such metal containers with containers formed of plastics.

The Applicant's earlier Patent applications provided significant advances in pressurised or aerosol containers, manufactured of plastics material, which overcame a number of deficiencies, by providing a container which included a plastics body, a shaped collar, and, a dispensing valve. The body was stretch blow moulded from polyethylene terephthalate (PET) or like plastics material, and had a shaped neck surrounding an opening. The collar was also injection moulded from plastics material and was shaped to be snap-fitted to the shaped neck of the body about the opening. The dispensing valve was thereafter able to be attached to the neck/collar, and, included an outer flange which was formed of malleable material, and which was shaped to be fitted about and be retained to the collar by being compressed therearound.

The Applicant's earlier Patent applications also provided an improved method of manufacturing the container, including the steps of, firstly, injection moulding a pre-form, wherein the pre-form included a shaped neck which was able to be thereafter supported in a stretch blow moulding apparatus, secondly, stretch blow moulding the preform, such that a container extended from the shaped neck, thirdly, cutting the extremity of the neck from the container, such that the neck surrounded an opening, fourthly, snap fitting an injection moulded plastics collar to the neck of the container in a position which surrounded the opening, and, finally, installing a dispensing valve to the neck/collar, the valve including an outer flange formed of malleable material which was able to be snap fitted and retained to the collar by being compressed therearound.

The Applicant's earlier Patent applications therefore provided an environmentally friendly aerosol container, which was able to be manufactured inexpensively, using simple steps, but without the inherent disadvantages of the prior art devices.

There are however some inherent disadvantages to utilising plastics material for pressurised products and aerosols. Plastic containers are prone to encounter changes in configuration when placed under pressure. In particular, the container is subject to deformation. The neck and shoulder portions in particular are prone to deformation as a result of stresses. This not only leads to the container being unsightly, but depending on the location of the deformation, the container could become unstable and rupture.

SUMMARY OF THE INVENTION

Whilst the Applicant's earlier Patent applications provided significant advantages over the prior art, the Applicant has now identified alternative versions of the PET aerosol container which have differences from the Applicant's earlier version, and which provides enhanced benefits thereover, including the ability of being able to contain higher pressures within the container. The Applicant has also invented improvements in relation to the container and has achieved a design which has comparable characteristics to prior art metal and aluminium containers, whilst having the advantages of using PET type plastics.

The present invention seeks to provide a plastics aerosol container which overcomes disadvantages of prior art aerosol containers. In one broad form, the present invention provides a container for dispensing a pressurised product, said container including:

a body, formed of PET or like plastics material, said body including:

a neck about an opening, and

a shoulder depending from said neck;

said neck including a radially outwardly projecting flange dividing said neck into an upper neck portion and a lower neck portion; and,

said shoulder depending from said neck being of generally uniform convex shape.

Preferably, said lower neck portion is within the range of about 1.5 mm to about 3.5mm in length, and preferably about 2.5mm in length.

Also preferably, said shoulder of generally uniform convex shape has a radius of about 69mm to about 77mm, and preferably about 73mm. Preferably, said container is capable of being pressurised to a pressure of up to about 140psi.

Also preferably, the container further includes a dispensing valve screw fitted or otherwise attached about said upper neck portion.

Preferably, the container is embodied having a wall thickness of between 0.4 and lmm, a height of between 60mm and 300mm, a diameter of between 40mm and 70mm, and, a capacity of between 125ml and 1.251.

In a preferred form, the angle at which the shoulder depends from the plane of the neck is between 56° and 58°, and most preferably 57.115°. (See Fig. 5)

In a further broad form, the present invention provides a method of manufacturing a^' container for dispensing a pressurised product, said method including the steps of:

injection moulding a preform from PET or like plastics material, said preform including a neck having a radially outwardly projecting flange dividing said neck into an upper neck portion and a lower neck portion; and,

stretch blow moulding, said preform to form said container, wherein said upper and lower neck portions are maintained to be of generally uniform cylindrical shape on either side of said flange, and, wherein a shoulder having a generally uniform convex shape depends from said neck.

Preferably, in said blow moulding step, said lower neck portion is heat shielded, for example by using a ring of metal or other material, to substantially maintain said generally uniform cylindrical neck shape.

Also preferably, said lower neck portion is within the range of about 1.5 mm to about 3.5mm in length, and preferably about 2.5mm in length.

Preferably, said shoulder of generally uniform convex shape has a radius of about 69mm to about 77mm, and preferably about 73mm.

Also preferably, said container is capable of being pressurised to a pressure of up to about 140psi. Preferably, the method of manufacturing the container further includes the step of installing a dispensing valve to the upper neck portion of said container by screw-fitting or other attachment, such as by crimping.

Preferably, the container is formed having a wall thickness of between 0.4 and lmm, a height of between 60mm and 300mm, a diameter of between 40mm and 70mm, and, a capacity of between 125ml and 1.251.

In a further broad form, the present invention provides a preform for manufacturing a container for dispensing a pressurised product, said preform being injection moulded from PET or like plastics material, said preform having a shaped neck which includes a radially outwardly projecting flange dividing said neck into an upper neck portion and a lower neck portion, such that it can be supported in a blow mould apparatus in a later stage of manufacture in a manner wherein said lower neck portion is capable of being heat shielded so that a generally uniform cylindrical shape is maintained over the entirety of said neck.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the following detailed description of preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings wherein:

Fig. 1 illustrates an exploded view of a prior art container;

Fig. 2 illustrates an assembled view of the prior art container of Fig. 1;

Fig. 3 illustrates a cross-sectional view of the prior art container of Figs. 1 and 2;

Fig. 4 illustrates the container in accordance with a preferred embodiment of the present invention;

Fig. 5 illustrates some variation of container dimensions in Fig. 5A to 5D respectively; and

Fig. 6 illustrates, in Fig. 6A, 6B and 6C, the steps of forming the container from a preform in Fig. 6A to the blow moulded form in Fig. 6B and 6C. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Throughout the drawings, like numerals will be used to identify similar features, expect where expressly otherwise indicated. As shown in Figs. 1 to 3, a prior art container, generally designated by the numeral

1 is formed of PET or other plastics material, and includes a body portion 2, a collar 3 and a dispensing valve mechanism 4.

The body portion 2 has a neck 7 at an upper end thereof, a shoulder portion 9 depending therefrom to a waist portion 10. A lower end of the container terminates in a base 6. The body 2, including its base, waist, shoulder and neck portions are integrally formed by stretch blow moulding plastics material, such as polyethylene, terephthalate (PET) from a preform, as described in the Applicant's earlier aforementioned patent applications, and as illustrated in Figs. 6A, 6B, and 6C.

An opening 10 is formed in the top of the neck 7 to receive the dispensing valve 4. The collar 3 is formed by injection moulding from plastics material and has the characteristics of being strong and rigid, with some degree of flexibility, such that it provides significant strength to the neck 7 of the body, which is important in housing a pressurised product, whilst having some degree of flexibility. Different arrangements of attaching the collar to the neck of the body have been previously proposed, including snap- fitting the collar to the neck, or screw fitting the collar to the neck.

In the Applicant's earlier patent applications, as observed from Figs. 1, 2 and 3, it will be noted that the shoulder portion 9 of the body depends directly from the lower portion of the neck 7.

Whilst the container shown in Figs. 1, 2 and 3 has proven reliable in the containment of pressurised or aerosol products, it will be appreciated by person skilled in the art that due to the high pressures of products in containers, the container experiences considerable pressures particularly in the shoulder and neck regions of the container. Considerable efforts have herebefore gone into improving the integrity of the container particularly in the shoulder and neck regions such that the container can withstand higher pressures.

Such earlier attempts have resulted in increasing at least the lower neck region thickness and the upper shoulder region thickness such that the risk of deformation is minimised. As shown in Fig. 4, the Applicant has identified that by differently designing the container such that an annular flange is provided intermediate the length of the neck, and that, by shielding and supporting the entire neck region both above and below the flange to thereby blow mould the shoulder and body portion of the container therefrom, significant increased pressures are capable of being withstood by the resulting container.

In particular, as will be seen in Fig. 4, the neck 7 includes an outwardly projecting flange 1 1 which divides the neck 7 into an upper neck portion 12 and a lower neck portion 13. The shoulder 9 depends from the lower extremity of the lower neck portion 13 and is generally of uniform convex shape. It should be noted that the term "convex" shape refers to any curved or rounded shape projecting in the manner shown in Fig. 4. Such shapes include a hemisphere, an ellipsoid, a hyperbola, a parabola, an arcuate shaped configuration or the like.

By configuring the neck and shoulder portions in the manner hereinbefore described and as shown in Fig. 4, the Applicant has been able to produce a container which can, without altering the dimensions or thicknesses of the neck or shoulder walls, permit the container to be filled to higher pressures without stress cracks of the like occurring in these sections of the container. In order to manufacture a container of the configuration shown in Fig. 4, reference is made to Figure 6 of the specification, which describes the prior art method of manufacturing the container illustrated in the Applicant's earlier International Application No. PCT/AU2005/001474.

In Fig. 6A is shown a preform. The preform incorporates an outwardly protruding flange extending in the neck region of the preform, labelled 21.

As shown in Fig. 6B, the flange is utilised during the manufacturing process to hold the container whilst the preform is blown into the shape of the container as shown in Fig. 6B. As then shown in Fig. 6C, the upper portion of the container, incorporating the flange 21 is thereafter cut from the rest of the container and discarded.

However, in the Applicant's invention to form the container in Fig. 4, this outwardly extending flange 21 need not be cut away from the remainder of the container but may be utilised to hold the container during the blow moulding manufacturing process and in other manufacturing processes thereafter, and then may be retained to form the neck of the container as shown in Fig. 4. It is important during the blow moulding process that the lower neck portion 13 is however heat shielded from the blow moulding process by utilising a metal ring or the like in the mould such that the lower neck portion 13 retains its shape as shown in Fig. 4 and is of consistent shape and dimension to the upper neck portion 12. The transition between the neck 13 and the shoulder 9 is then also of uniform thickness as is the wall thickness of shoulder 9.

It will therefore be appreciated by persons skilled in the art that by following this manufacturing process, the container may simply be formed by blow moulding from a preform similar to that shown in Fig. 6A, eliminating some of the manufacturing steps of the prior art. Whilst it is important to provide a neck as illustrated in Fig. 4, the different sized containers, the shoulder dimensions may be varied such as shown in Fig. 5. Fig. 5 shows containers of various diameter from 40mm to 66mm, with different radii of shoulder and height of shoulder all terminating in a similar neck shape, having the discrete upper neck portion 12 and lower neck portion 13 separated by the outwardly extending flange 11.

It should be noted that the angle of 57.115° between the plane of the neck and the shoulder is consistent in the drawings. Preferably, this angle is within 56° to 58°. It will be appreciated that the container described in the present invention has advantages over prior art PET type plastic containers described in the Applicant's aforementioned applications.

It will be appreciated that, whilst particular embodiments have been hereinbefore described, variations and modifications may be made to the shape and configuration of the container while still achieving the advantages of the invention. All such variations and modifications should be considered to fall within the spirit and scope of the invention as hereinbefore described.

Claims

CLAIMS:

1. A container for dispensing a pressurised product, said container including:

a body, formed of PET or like plastics material, said body including:

a neck about an opening, and

a shoulder depending from said neck;

said shoulder depending from said neck being of generally uniform convex shape.

2. A container as claimed in claim 1, wherein said lower neck portion is within the range of about 1.5 mm to about 3.5mm in length, and preferably about 2.5mm in length.

3. A container as claimed in claims 1 or 2, wherein said shoulder of generally uniform convex shape has a radius of about 69mm to about 77mm, and preferably about 73mm.

4. A container as claimed in any one of claims 1 to 3, wherein said container is capable of being pressurised to a pressure of up to about 140psi.

5. A container as claimed in any one of claims 1 to 4, further including a dispensing valve screw fitted or otherwise attached about said upper neck portion, such as by crimping.

6. A container as claimed in any one of claims 1 to 5, having a wall thickness of between 0.4 and 1mm, a height of between 60mm and 300mm, a diameter of between 40mm and 70mm, and, a capacity of between 125ml and 1.251.

7. A container as claimed in any one of claims 1 to 6, wherein the shoulder depends from a plane of the neck at an angle of between about 56° and 58°, and preferably substantially 57.115°.

8. A method of manufacturing a container for dispensing a pressurised product, said method including the steps of:

9. A method of manufacturing a container for dispensing a pressurised product as claimed in claim 8, wherein:

in said blow moulding step, said lower neck portion is heat shielded, for example by using a ring of metal or other material, to substantially maintain said generally uniform cylindrical neck shape.

10. A method of manufacturing a container as claimed in claims 8 or 9, wherein said lower neck portion is within the range of about 1.5 mm to about 3.5mm in length, and preferably about 2.5mm in length.

11. A method of manufacturing a container as claimed in any one of claims 8 to 10, wherein said shoulder of generally uniform convex shape has a radius of about 69mm to about 77mm, and preferably about 73mm.

12. A method of manufacturing a container as claimed in any one of claims 8 to 11, wherein said container is capable of being pressurised to a pressure of up to about 140psi.

13. A method of manufacturing a container as claimed in any one of claims 8 to 12, further including the step of:

installing a dispensing valve to the upper neck portion of said container by screw- fitting or other attachment.

14. A method of manufacturing a container as claimed in any one of claims 8 to 13, wherein a container is formed having a wall thickness of between 0.4 and 1mm, a height of between 60mm and 300mm, a diameter of between 40mm and 70mm, and, a capacity of between 125ml and 1.251.

15. A preform for manufacturing a container for dispensing a pressurised product, said preform being injection moulded from PET or like plastics material, said preform having a shaped neck which includes a radially outwardly projecting flange dividing said neck into an upper neck portion and a lower neck portion, such that it can be supported in a blow mould apparatus in a later stage of manufacture in a manner wherein said lower neck portion is capable of being heat shielded so that a generally uniform cylindrical shape is maintained over the entirety of said neck.