WO2004024583A1

WO2004024583A1 - Beaded thin wall aerosol container

Info

Publication number: WO2004024583A1
Application number: PCT/US2003/024647
Authority: WO
Inventors: Edward F. Kubacki
Original assignee: United States Can Company
Priority date: 2002-09-10
Filing date: 2003-08-07
Publication date: 2004-03-25
Also published as: JP2005538003A; MXPA05002598A; US6786370B1; EP1539601A1; CA2498117A1; AU2003261417A1; CA2498117C

Abstract

A non-barrier type aerosol container (10) dispensing a fluent material. A generally cylindrical can body (12) has a relatively thin sidewall thickness of between 0.004 and 0.010 depending upon the type of metal from which the container is made. The can body is a beaded body having beads (30) formed at uniform intervals substantially the length of the can body. The beading adds structural strength to the container so the container is not readily deformed when unpressurized. The aerosol container can withstand an externally applied force of at least 23 psi without collapsing. A valve assembly (14) includes a spray valve (20) for dispensing the fluent material stored in the container. The container is filled with the fluent material and a propellant which are stored in the container under pressure. The sidewall of the can body, when the container is pressurized, has a distortion of less than ten percent (10%) of the thickness of the container wall.

Description

BEADED THIN WALL AEROSOL CONTAINER Technical Field

This invention relates to aerosol containers, and more particularly to a 2 piece or 3 piece thin walled, non-barrier type aerosol container. Background Art

Thin wall non-barrier type aerosol containers are known in the art. See, for example, United States patent 5,211,317 to Diamond et al., and its reissue Re 35,843. It is a feature of containers built in accordance with the teachings of these patents that the sidewall of the container has a relatively thin thickness, h the Diamond et al. patent and its reissue, the container wall thickness is said to be on the order of 0.004-0.005 inches (0.102mm-0.127mm). hi unpressurized containers, it is often possible to distort the sidewall of the container. The Diamond et al. patents, for example, refer to the sidewall being deflected by as much as ^lA inch, if a force of as little as 5-10 pounds is applied to the can prior to filling. Additionally, the can is said to be easily crushable by hand pressure. However, the cans can be pressurized in a manner that at 130°F (54.4°C) the pressure does not exceed 120-130 psig, and will not burst at One and one-half times this pressure (180psig). However, the cans cannot be crimped to a spray valve because they collapse at under 18 inches of vacuum.

While there are a number of advantages to a container having thin sidewalls (lower material costs, for example), current can constructions have drawbacks as well. For example, during handling of the container prior to its being filled, even a moderate amount of force can distort or crush the container. This renders the container unusable and adds cost to the manufacturing process. Those skilled in the art will appreciate that moderate amounts of force can be inadvertently applied to the container at any number of different points to the handling and manufacturing process, even though the process is substantially automated.

It would be advantageous therefore to provide a thin wall aerosol container, but one which, when unfilled, is not readily distorted. The container would, when filled, withstand substantial forces without distorting, and would meet Department of Transportation (DOT) standards in this regard. Summary of the Invention

Among the objects of the invention, briefly stated, is a thin wall aerosol container for use in dispensing a fluent material. The container can be either of a 2- piece or 3-piece construction, and be either a barrier or non-barrier type container. The container includes a cylindrical can body having a beaded construction. The beading adds significant structural strength to the container and prevents distortion or crushing of the sidewall when the can is unpressurized. The container also includes a spray valve assembly for dispensing the fluent material. Because of the increased structural strength imposed by the beading on the can body, the container is less subject to damage during manufacture, while still allowing the manufacturer to reahze the savings of a thinner wall construction from conventional containers.

The can is filled both the fluent material and a propellant. The container can withstand at least 23 inches of vacuum without collapsing. This allows the can body to vacuum crimped to the spray valve assembly, which simplifies container construction.

Other objects and features will be in part apparent and in part pointed out hereinafter. Brief Description of Drawings

The objects of the invention are achieved as set forth in the illustrative embodiments shown in the drawings which form a part of the specification.

Fig. 1 is an elevational view of a container of the present invention;

Fig. 2 is a partial sectional view of the container; and,

Fig. 3 is an enlarged partial sectional view of the sidewall of the container body illustrating the amount of deflection which occurs when the container is subjected to pressure.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. Best Mode for Carrying out the Invention

The following detailed description illustrates the invention by way of example and not by way of liiTiitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a lhϊiiting sense.

Referring to the drawings, an aerosol container of the present invention is indicated generally 10 in Figs. 1 and 2. h Fig. 2, the container is shown to be a non- barrier type container (that is, it has no wall separating the fluent material discharged from the container with a propellant used for this purpose); although the contamer could be a barrier type container without departing from the scope of the invention. Container 10 includes a can body 12, a valve assembly 14 for dispensing the fluent material stored in the container, and a cap 16.

Can body is a generally cylindrical can body which has a relatively thin sidewall thickness. Preferably, can body 12 is made either of steel, or aluminum. If the can body is made of steel, this wall thickness is between 0.004 and 0.008 inches (0.102-0.205 mm). If made of aluminum, the wall thickness is between 0.004 and 0.010 inches (0.102-0.255 mm). It will be appreciated by those skilled in the art, that aerosol containers are manufactured in standard sizes. Can body 12 is available in all of these standard sizes, and custom size cans be manufactured as well. Next, the can body includes a dome shaped base 18 forming the bottom of the can. Base 18 is made of the same material as body 12. In a two-piece container construction, base 18 is integrally formed with the can body, h a three-piece container construction, the base is a separate piece which is attached to the lower end of the can body in the conventional manner. It is a feature of the invention that regardless of whether the container is of a two-piece or three-piece construction, the other pieces can be vacuum crimped to the can body. Naive assembly 14 includes a spray nozzle 20 of conventional design. The nozzle is mounted in a dome 22 forming the top of the can. Base 18 and dome 22 attach to can body 12 in a conventional manner. A hollow dip tube 24 extends from nozzle 20 down into the lower reaches of aerosol can as shown in Fig. 2. Fluent material flows through the dip tube to the spray nozzle. When the container is not in use, cap 16 is fitted over the nozzle portion of the container.

Unlike conventional thin wall aerosol containers, can body 12 of container 10 is a beaded can body. Preferably, the can has a series of spaced beads 30 formed at intervals along the length of the can body. As indicated in Fig. 1, the uppermost and lowermost beads are formed a predetermined distance X from the respective top and bottom of the can body. This distance is, for example, 0.75 inches (191 mm) for a two- piece container construction. Next, the beads are spaced so that the center of each bead is a predetermined distance Y from the center of the adjacent bead. This distance is, for example, 0.125 inches (31.8 mm). This spacing is uniform along the length of the can. Next, the beads, each of which extends completely about the can body, has a depth Z. This depth is, for example, 0.021 inches (5.3 mm). As described herein, having beads formed at spaced intervals substantially along the entire length of container body adds structural strength to the container. As a result, the container is not readily deformed when in its unpressurized state prior to being filled.

In fabricating the beads, they are made such that the outer surface of the can body has the same outer diameter (O.D.) as a can body for a standard, non-beaded container. The minimum diameter of the can, indicated W in Fig. 2 is given by the formula

Minimum diameter = O.D.- 2Z That is, the outer diameter of the can body minus twice the depth of the beads.

To determine the strength or rigidity of t e can in its unpressurized condition, containers made in accordance with the above dimensions were subjected to a series of tests. It was found that when subjected to forces in excess of 10 lbs., there was no discernible deflection in the sidewall of the can. Similarly, the can body could not be crushed by hand. This is important because in addition to the cost savings realized by a having a container requiring less material to make than conventional, thicker walled containers, the beaded thin wall container of the present invention is not susceptible to damage during the manufacturing operations performed prior to filling the container.

The fluent material dispended by aerosol container 10 and propellant used for this purpose are stored in the container under pressure. A two-piece aerosol container was constructed in accordance with the dimensions set forth above. When filled, it was found that the container could withstand a pressure in excess of 23 pounds exerted on the can body without collapsing. This is significant because it allows aerosol container 10 to be constructed with the spray valve assembly being crimped to the end of the can body instead of having to use other methods (welding, for example) of crimping. This can further lower manufacturing costs.

In pressurization tests, container 10 was subjected to pressures ranging from 0- 90 psi. Tests were performed to determine the amount of expansion which would occur (both longitudinally, and diametrically). It will be appreciated, that as shown in Fig. 3, the internal pressure would exert a hoop stress on the container sidewall which would tend to flatten the can. As shown by the dashed line in Fig. 3, the internal can pressure pushes the inner end or valley portion of a bead outwardly; which, in turn, tend to draw the outer or peak portion of the bead inwardly. For tests performed on a standard 202 size can, the maximum distortion measured (as indicated by N in Fig. 3) was less than 0.0003 inches (0.07 mm). This is less than 8% of the thickness of the sidewall, at the minimum sidewall thickness.

What has been described is a thin wall aerosol container having a beaded sidewall construction. The beading adds sufficient strength to the container that when unpressurized, the can body is not readily distorted or crushed making it less susceptible to damage during those manufacturing processes performed prior to filling the container. Further, when pressurized, the expansion of the can's sidewalls is minimal even at higher pressures. The can, when filled, can withstand pressures in excess of 23 psi without collapsing. Finally, aerosol containers made in accordance with the invention satisfy DOT regulations with respect to their ability not to distort when subjected to specified pressures at specified temperatures. hi view of the above, it will be seen that the several objects and advantages of the present invention have been achieved and other advantageous results have been obtained.

Claims

Claims:Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A non-barrier type aerosol container for dispensing a fluent material comprising: a generally cylindrical can body having a relatively thin sidewall thickness, the can body being a beaded can body having beads formed at spaced intervals substantially the entire length of thereof with the beading adding structural strength to the container so the container is not readily deformed when unpressurized; and, a valve assembly for dispensing the fluent material stored in the container, the container being filled with the fluent material and a propellant therefor, the fluent material and propellant being stored in the container under pressure.

2. The aerosol container of claim 1 wherein the valve assembly includes a spray valve for dispensing the fluent material, the valve assembly being attached to the can body at one end thereof.

3. The aerosol container of claim 2 further including a base attached to the other end of the can body.

4. The aerosol container of claim 1 which can withstand an externally applied force of at least 23 psi without collapsing.

5. The aerosol container of claim 4 in which the sidewall of the can body, when the container is pressurized, has a distortion of less than ten percent (10%) of the thickness of the container wall.

6. The aerosol container of claim 1 in which the can body is made of steel and has a sidewall thickness of between 0.004 inches (0.102 mm) and 0.008 inches (0.205 mm).

7. The aerosol container of claim 1 in which the can body is made of aluminum and has a sidewall thickness of between 0.004 inches (0.102 mm) and 0.010 inches (0.255 mm).

8. The aerosol container of claim 4 in which the propellant is a compressed gas and the container pressurize is between 90-140 psig (621-965 kPa) when filled.

9. The aerosol container of claim 4 in which the propellant is a liquefied gas and the container pressure between 30-50 psia (207-345 kPa) when filled.

10. The aerosol container of claim 1 in which the can body has a plurality of beads formed therein, the beads being uniformly spaced along the length of the can body.

11. The aerosol container of claim 10 in which the uppermost bead formed in the can body and the lowermost bead formed therein are each formed the same predetermined distance from the respective upper and lower ends of the can body.

12. The aerosol container of claim 1 in which the depth of each bead is approximately one-sixth the distance between the center of adjacent beads.

13. A non-barrier type aerosol container for dispensing a fluent material comprising: a generally cylindrical can body made of steel and having a sidewall thickness of between 0.004 inches (0.102 mm) and 0.008 inches (0.205 mm), the can body being a beaded can body having beads formed at uniform intervals substantially along the length of the can body, the beading adding structural strength to the container so the container is not readily deformed when unpressurized; and, a valve assembly for dispensing the fluent material stored in the container, the container being filled with the fluent material and a propellant therefor which are stored in the container under pressure.

14. The aerosol container of claim 13 which can withstand an externally applied force of at least 23 psi without collapsing.

15. The aerosol container of claim 14 in which the sidewall of the can body, when the container is pressurized, has a distortion of less than ten percent (10%) of the thickness of the container waU.

16. The aerosol container of claim 13 in which the propellant is a compressed gas and the container pressurize is between 90-140 psig (621-965 kPa) when filled.

17. The aerosol container of claim 13 in which the propellant is a liquefied gas and the container pressure between 30-50 psia (207-345 kPa) when filled.

18. The aerosol container of claim 13 in which the uppermost bead formed in the can body and the lowermost bead formed therein are each formed the same predetermined distance from the respective upper and lower ends of the can body.

19. A non-barrier type aerosol container for dispensing a fluent material comprising: a generally cylindrical can body made of aluminum and having a sidewall thickness of between 0.004 inches (0.102 mm) and 0.010 inches (0.255 mm), the can body being a beaded can body having beads formed at uniform intervals substantially along the length of the can body, the beading adding structural strength to the container so the container is not readily deformed when unpressurized; and, a valve assembly for dispensing the fluent material stored in the container, the container being filled with the fluent material and a propellant flierefor which are stored in the container under pressure.

20. The aerosol container of claim 19 which can withstand an externally applied force of at least 23 psi without collapsing.

21. The aerosol container of claim 20 in which the sidewall of the can body, when the container is pressurized, has a distortion of less than ten percent (10%) of the tliickness of the container wall.

22. The aerosol container of claim 19 in which the propellant is a compressed gas and the container pressurize is between 90-140 psig (621-965 kPa) when filled.

23. The aerosol container of claim 19 in which the propellant is a liquefied gas and the container pressure between 30-50 psia (207-345 kPa) when filled.

24. The aerosol container of claim 19 in which the uppermost bead formed in the can body and the lowermost bead formed therein are each fonned the same predetermined distance from the respective upper and lower ends of the can body.

25. A process for dispensing a fluent material from an aerosol container comprising: forming an aerosol container having a generally cylindrical can body of a relatively thin sidewall thickness, the can body being a beaded can body having a plurahty of beads formed at uniform intervals substantially the entire length of the can body, the beads adding structural strength to the container so the container does not readily deform when unpressurized; fitting a valve assembly to one end of the can body the other end of which is closed, the valve assembly including a spray valve for dispensing the fluent material; and, filling the container with the fluent material and a propellant for dispensing the fluent material, the fluent material and propellant being stored in the container under pressure.

26. The process of claim 25 in which the propellant is a compressed gas and the container pressurize is 90-140 psia when the container is filled.

27. The process of claim 25 in which the propellant is a liquefied gas and the container pressure is 30-50 psia (207-345 kPa) when the container is filled.

28. The process of claim 25 in which the can body is made of steel and has a sidewall thickness of between 0.004 inches (0.102 mm) and 0.008 inches (0.205 mm).

29. The process of claim 25 in which the can body is made of aluminum and has a sidewall thickness of between 0.004 inches (0.102 mm) and 0.010 inches (0.255 mm).

30. The process of claim 25 in which the aerosol container is capable of withstanding an externally applied force of at least 23 psi without collapsing.

31. The process of claim 30 in which the sidewall of the can body, when the aerosol container is pressurized, has a distortion of less than ten percent (10%) of the thickness of the container wall.

32. The process of claim 25 in which the uppermost bead formed in the can body and the lowermost bead formed therein are each formed the same predetermined distance from the respective upper and lower ends of the can body.