Blow molded plastic aerosol container

Abstract

A plastic container for holding aerosol contents under pressure includes a one-piece integrally molded plastic body having a base, a sidewall and a neck finish. The sidewall and the base are of oval cross-section, and the base has a contour and cross-section for maintaining the oval cross-section under aerosol pressure within the container body. The neck finish has an open mouth surrounded by a circumferentially continuous external bead for securing a dispensing closure. The bead has an undersurface that is perpendicular to an axis of the neck finish, and the neck finish has a chamferred inside edge around the open mouth to facilitate insertion of a dispensing closure.

Description

The present invention relates to aerosol packages in which the container is adapted to hold contents under pressure, and more particularly to a blow molded plastic container for such a package.

BACKGROUND AND SUMMARY OF THE INVENTION

Containers for aerosol packages typically are of glass or metal construction so as to possess sufficient strength to hold the package contents under pressure without distortion of the container. A general object of the present invention is to provide a blow molded plastic container for aerosol package applications in which the container body has an oval cross-section, in which the container base is contoured to retain the oval cross-section of the container body under aerosol pressure, and in which the neck finish is particularly well adapted to facilitate handling during manufacture.

A plastic container for holding aerosol contents under pressure in accordance with presently preferred embodiments of the invention includes a one-piece integrally molded plastic body having a base, a sidewall and a neck finish. The sidewall and the base are of oval cross-section, and the base has a contour and cross-section for maintaining the oval cross-section under aerosol pressure within the container body. The neck finish has an open mouth surrounded by a circumferentially continuous external bead for securing a dispensing closure. The bead has an undersurface that is perpendicular to an axis of the neck finish, and the neck finish has a chamferred inside edge around the open mouth to facilitate insertion of a dispensing closure. In the preferred embodiments of the invention, the neck finish includes a support flange spaced from the external bead. The support flange has a peripheral edge with at least one locating element for orienting the oval cross-section in automated equipment for assembling the dispensing closure to the container. The base preferably is a champagne base having a central outwardly oriented convex portion and a peripheral standing ring. The standing ring preferably has a thickness that is 2 to 2.5 times the thickness of the container sidewall.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with additional objects, features, advantages and aspects thereof, will best be understood from the following description, the appended claims and the accompanying drawings, in which:

FIG. 1 is a front elevational view of a container in accordance with one presently preferred embodiment of the invention;

FIG. 2 is a side elevational view of the container in FIG. 1;

FIG. 3 is a partially sectioned top plan view of the container in FIG. 1;

FIG. 4 is a fragmentary sectional view on an enlarged scale of the portion of FIG. 3 within the area 4;

FIG. 5 is a fragmentary sectional view on an enlarged scale of the portion of FIG. 2 within the area 5;

FIG. 6 is a fragmentary sectional view that illustrates the base of the container in FIGS. 1-3;

FIG. 7 is a front elevational view of a container in accordance with another embodiment of the invention;

FIG. 8 is a partially sectioned top plan view of the container in FIG. 7;

FIG. 9 is a fragmentary sectional view of the portion of FIG. 8 within the area 9; and

FIG. 10 is a sectional view of an aerosol dispensing closure that can be used with the container of FIGS. 1-6 or FIGS. 7-9.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1-6 illustrate a container 20 in accordance with one presently preferred embodiment of the invention. Container 20 is of one-piece integrally blow molded construction having a body 22 with a base 24, a sidewall 26 and a neck finish 28. Sidewall 26 and base 24 are of oval construction, as best seen in FIG. 3. Neck finish 28 is cylindrical and has a circumferentially continuous external bead 30 that surrounds the open mouth of the container. Bead 30 has an undersurface 32 that is flat and planar on an axis perpendicular to the axis of the neck finish. Flat undersurface 32 provides positive alignment with in-feed and out-feed jaws on two-stage reheat stretch blow molding equipment. Furthermore, undersurface 32 provides for secure crimping of an aerosol dispensing closure (FIG. 10). The inside diameter of the container mouth, at the open end of neck finish 28, is chamferred at 34 (FIG. 5) to facilitate placement and securement of the dispensing closure (e.g. FIG. 10).

Neck finish 28 preferably also includes an external support flange 36, sometimes termed a capping flange or a transfer flange, spaced from the open mouth of the container. Flange 36 is circumferentially continuous and perpendicular to the axis of the neck finish. Flange 36 has a peripheral edge that preferably includes at least one locating element 38 for orienting the oval cross-section of container 20. In the embodiment of FIGS. 1-6, the locating element 38 is a notch on the periphery of the flange aligned with the minor axis of the oval container cross-section, as best seen in FIG. 3. Notch 38 can be used by automated capping equipment for locating the dispensing closure angularly with respect to the container finish so that the closure dispenses product at a desired orientation with respect to the container cross-section, such as in the direction of the minor axis of the container.

The preferred construction of container base 24 is illustrated in FIG. 6. Base 24 preferably is a so-called champagne base, having an outwardly convex central portion or dome 40 and a peripheral standing ring 42. The thickness 44 of standing ring 42 preferably is 2 to 2.5 times the thickness 46 of container sidewall 26. Base 24 is designed to rigidify the container sidewall and maintain the oval contour of the container sidewall under pressure within the container. The thickness contour of base 24 can be designed either to have a constant thickness profile around the axis of the container, or to have two unique profiles at the major and minor axes of the container cross-section that are blended with each other between the major and minor axes.

FIGS. 7-9 illustrate a container 50 in accordance with a second embodiment of the invention. Container 50 is essentially the same as container 20 in FIGS. 1-6 except for the locating elements on the neck finish support flange 36. In the embodiment of FIGS. 7-9, the locating elements on the support flange comprise a pair of outwardly extending lugs 52 on diametrically opposed sides of neck finish 28 at the minor axis of the oval container cross-section.

FIG. 10 illustrates a conventional aerosol dispensing closure 60, which includes a metal ring 62 that is crimped over bead 30 for securing the dispensing closure to the aerosol container of the present invention.

The container of the present invention can be made employing any suitable manufacturing technique. The container preferably is made in a reheat blow molding process, in which a preform is first constructed such as by injection or compression molding, and the preform is then reheated and blow molded to form the container body. The container neck finish, including bead 30 and support flange 36, preferably are formed at the preform stage. The container can be of any suitable plastic material such as polyethylene terephthalate (PET), and can be of monolayer construction or multilayer construction that includes one or more internal barrier layers such as nylon or ethylene vinyl alcohol (EVOH). According to another feature of the invention, one of the layers of a multilayer sidewall construction can have a high glass transition temperature Tg, which helps resist deformation of the container body. For example, the container sidewall can have a two-layer construction: (1) PET having a thickness of 0.042 inch and a glass transition temperature of 70C, and (2) amorphous nylon having a thickness of 0.028 and a glass transition temperature of 115C.

There thus have been disclosed a plastic container and a method of making a plastic container, which are particularly well-suited for aerosol applications and which fully satisfy all of the objects and aims previously set forth. The invention has been disclosed in conjunction with two presently preferred embodiments, and a number of modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing disclosure. The invention is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.

Claims

1. A plastic container for holding aerosol contents under pressure, which includes: a one-piece integrally molded plastic body having a base, a sidewall and a neck finish, said sidewall and said base being of oval cross-section, and said base having a contour and cross-section for maintaining said oval cross-section under pressure within said body, said neck finish having an open mouth surrounded by a circumferentially continuous external bead for securing a dispensing closure, said bead having a flat undersurface perpendicular to an axis of said neck finish, said neck finish having a chamferred inside edge around said open mouth to facilitate attachment of a dispensing closure.

2. The container set forth in claim 1 wherein said neck finish includes a support flange spaced from said external bead.

3. The container set forth in claim 2 wherein said support flange has a peripheral edge with at least one locating element for orienting said oval cross-section.

4. The container set forth in claim 3 wherein said at least one locating element is positioned on a minor axis of said oval cross-section.

5. The container set forth in claim 4 wherein said at least one locating element includes a pair of locating elements on opposed sides of said neck finish along said minor axis.

6. The closure set forth in claim 4 wherein said at least one locating element is a notch or a lug.

7. The container set forth in claim 1 wherein said base is a champagne base having a central outwardly convex portion and a peripheral standing ring.

8. The container set forth in claim 7 wherein said standing ring has a thickness that is 2 to 2.5 times the thickness of said sidewall.

9. The container set forth in claim 1 wherein said body is of multilayer construction including at least one relatively thick layer of a first material, and at least one relatively thin layer of a second material having a higher glass transition temperature than said first material for retaining the oval cross-section of the container body.

10. A method of making a plastic container that includes the step of blow molding a one-piece plastic body having a base, a sidewall and a neck finish, said sidewall and said base being of oval cross-section, and said base having a contour and cross-section for maintaining said oval cross-section under pressure within said body, said neck finish having an open mouth surrounded by a circumferentially continuous external bead for securing a dispensing closure, said bead having a flat undersurface perpendicular to an axis of said neck finish, said neck finish having a chamferred inside edge around said open mouth to facilitate attachment of a dispensing closure.