EP1985555A1

EP1985555A1 - Aerosol container

Info

Publication number: EP1985555A1
Application number: EP07106707A
Authority: EP
Inventors: designation of the inventor has not yet been filed The
Original assignee: Crown Packaging Technology Inc
Current assignee: Crown Packaging Technology Inc
Priority date: 2007-04-23
Filing date: 2007-04-23
Publication date: 2008-10-29

Abstract

A combined bag 50 and spout 60 arrangement suitable for insertion into an aerosol can body 20,30,40. The spout 60 is composed of two sections, which are preferably integrally moulded. A tubular section 63 is adapted to accommodate a valve cup 70 and is thereby "clinched" in the aerosol can body 20,30,40. A fish-tail section 62 is provided to form a good seal with the bag 50. The bag 50 and spout 60 may be provided in a pre-charged aerosol can body 20,30,40 ready to be filled with a product. The relatively large pathway through the spout 60 means that a product may be filled into the bag 50 at higher speeds than is possible when the bag 50 has to be filled through the valve 5, which defines a relatively restricted pathway.

Description

Technical Field

The present invention relates to aerosol containers comprising an outer casing with a bag for a product encapsulated therein. Such containers are commonly referred to in the art as bag-in-can aerosols. In particular, the invention describes an arrangement comprising a bag whose opening is sealed to a bag, which may be fitted into an aerosol container separately from the dispensing valve.

Background Art

Bag-in-can aerosol dispensers have been known in the prior art since the 1960's. For example, GB 1030596 (ALLIED CHEM) 22.05.1966 describes the manufacturing method used for production of a nylon bag and its assembly into such a bag-in-can aerosol container.
A disadvantage of such nylon bags is that the nylon bag has to be soaked in water ("conditioned") to make it sufficiently flexible to insert into the casing of the aerosol container. Thus, the bag is permeable to moisture and compressed gases, which are often used as propellant in aerosol containers and in some cases this may adversely affect the product stored inside the bag. Alternative polymer bags have been tried to overcome this problem and whilst they may be designed so that they are impermeable to water and other gases, they are generally too stiff to fit into the casing of the aerosol container. Furthermore the applicants have found that such multilayer bags do not provide a good enough barrier against the ingress of gases, which is required by some products.
Bag-on-valve systems are also described in the prior art. For example, US 3823849 (COSTER TECNOLOGIE SPECIALI SPA) 16.07.1974 describes a system in which a flexible bag is sealed to the valve and valve housing of an aerosol valve. Likewise, US 7124788 (PRECISION VALVE CORPORATION) 10.07.2003 describes a similar bag-on-valve arrangement, where the valve has two filling position. One is used to fill the bag with a product and the other position directs propellant into the aerosol container outside the bag.
In a bag-in-can aerosol container the product to be dispensed is filled into the inside of the bag and a liquefied or compressed gas propellant is filled into the aerosol container outside the bag. When the aerosol valve is actuated, the pressure in the propellant chamber (between the bag and the outer casing of the aerosol container) forces compression of the bag, which drives the product contained in the bag through the aerosol valve.
Disadvantages of bag-on-valve systems include difficulty in filling products into the bag through the valve, which can be slow, and fragility of the bag / valve combination, which may result in damage to the valve stem or separation of the bag from the valve under the weight of loaded product.

Disclosure of Invention

The present invention seeks to overcome these difficulties by providing a bag-on-spout system, which can accommodate a valve cup and valve, but is not adhered to either of these components. The spout provides a larger orifice through which product may be filled into the bag at higher speeds and is of more rigid construction than many bag-on-valve systems in which the valve has a relatively fine valve stem onto which the bag is fitted. Furthermore, in bag-on-valve systems, the valve defines a relatively small pathway through which product must be filled into the bag and thus product filling through the valve is time consuming.
Charging of propellant into the propellant cavity (between the bag and the casing of the aerosol container) may be achieved by methods commonly used in the prior art. For example, propellant may be filled under the valve cup ("underbag gassing") of through a propellant charging port provided in the base of the container, which is sealed by a grommet after filling.
A further advantage of a bag-on-spout aerosol container according to the invention is that an aerosol container with bag and spout may be provided to a customer, who may then fit their preferred valve and assembly. The customer fills the bag with product through the spout, before fitting the valve and valve cup. The larger filling aperture provided by the spout allows a thicker (more viscous) product to be filled into the bag and reduces the time taken for product filling.

Brief Description of Figures in the Drawings

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 llustrates a section through a conventional bag-in-can aerosol according to the prior art and gives a detailed view of the upper portion of the can;
Figure 2 shows side sections of the evolution of the spout design from first generation (a), to second generation (b) and finally third generation (c);
Figure 3 shows a side section view of a bag and first generation spout with a tubular section, a frustoconical section and a fish-tail section;
Figure 4 shows a side section view of a bag and second generation spout with a tubular section only;
Figure 5 shows a side section view of a bag and third generation spout with a tubular section and a fish-tail section only;
Figure 6 illustrates a section through the upper section of an aerosol container incorporating a bag, third generation spout and an aerosol valve.

Figure 1 illustrates a conventional bag-in-can aerosol container 1. An outer casing comprises a sidewall 30 with a base 20 and top 40 seamed thereto. The top 40 defines an orifice through which a bag 50 is inserted into the outer casing 20,30,40. The bag 50 is held in place inside the outer casing 20,30,40 by a valve cup 70, which is adapted to accommodate an aerosol valve 5 in communication with the inside of the bag 50.
A product is filled into the bag 50 through the valve 5, but this process is difficult and slow because of the reduced diameter flow path through the valve 5.
Propellant is then inserted into the space between the bag 50 and the outer casing 20,30,40 through a propellant filling port 25. After propellant filling, the propellant filling port 25 is sealed by a plug or grommet 26. Other methods for filling the propellant are known in the prior art. For example propellant may be inserted into the container under the valve cup 70 or through a 2-position valve assembly.
Figure 2 shows the progression of the design of the spout 60. In its first generation (as shown in figures 2(a) and 3), the spout consisted of three co-joined parts, a tubular section 63, designed to accommodate the valve cup 70 (not shown), a frustoconical section 61, designed to direct the product into the bag 50 (not shown) during product filling and a fish-tail section 62 adapted for heat sealing the spout 60 to the bag 50 (not shown). The spout 60 was moulded from a relatively soft material, such as "special grade" polypropylene. The material is chosen for its elastomeric properties i.e. the stretch of the material, to minimise problems of splitting when "clinching" top 20 and the valve mounting cup 70 together. This process will stretch the spout 60, hence the need for a "stretchy" polymer.
The first generation of the spout 60 (as shown in Figures 2a and 3) had a frustoconical section 61 between the tubular section 63 and the sealing section 62. The purpose of the frustoconical section was to direct product into the bag 50 during filling. However, the inventors found that a problem with this design resulted from the use of "soft" material for the spout 60, which provided a poor barrier to air. Thus, the frustoconical section 61, which was not encapsulated by the bag 50 or mounting cup 70, allowed air to pass into the product in the bag 50. This had a negative effect on the product, for example products like shaving gels tend to pre-foam upon contact with air. The inventors tried manufacturing the spout from high-barrier materials, but these were found to be too stiff and split upon application of the valve mounting cup 70.
In the second generation (as shown in figures 2(b) and 4), the spout 60 consisted of only the tubular section 63 was retained and the inventors tried to heat seal the foil bag directly to the tubular section 63. The problem experienced with this second generation spout 60 was that the seal between the bag 50 and spout 60 leaked due the triple juncture between the two layers of foil (heat sealed together to form the bag 50) and the curved surface of the tubular section 63 of the spout 60.
The third generation of the spout 60 (as shown in figures 2(c) and 5) sought to overcome the problems described above. The third generation spout 60 retained the tubular section 63 for accommodating the valve cup 70 but this was connected directly to a fish-tail portion 61 for formation of a good seal between the spout 60 and the bag 50. The frustoconical section 62 was removed to reduce the surface area available for a leakage path between the valve mounting cup 70 and the bag 50.
Figure 6 illustrates the upper portion of an aerosol container according to the invention having an outer casing, comprising side-wall 30, top 40 and bottom (not shown) and a bag 50 sealed to a spout 60. The spout 60 includes a tubular section 63 designed to accommodate a valve cup 70 which accommodates a valve 5, such that it communicates with the inside of the bag 50.
The inventors have considered providing a bag-on-spout only (for insertion into an aerosol container), a bag-on-on spout assembled in an aerosol container for filling / insertion of valve and associated mounting cup by another or bag-on spout assembled in and aerosol can and secured by a mounting cup. The latter aerosol containers may be provided without propellant, in which case the filler of the product would fill the propellant or "pre-gassed" i.e. with propellant already filled into the empty aerosol container. The advantage of providing the aerosol container without propellant is that the cans are easier and quicker to fill, as there is no gas pressure to overcome. But the disadvantage is that the filler would need suitable equipment to supply the propellant under pressure. If the container is provided "pre-gassed", the filler will need to fill the product under increased pressure in order to overcome the gas pressure of the propellant.

Claims

A bag 50 and spout 60 combination, wherein the spout 60 comprises a tubular section 63 designed to accommodate a valve mounting cup 70 and a sealing section 62 adapted to form a leak-proof seal with a bag 50.
A bag 50 and spout 60 combination according to claim 1, wherein the sealing section 63 takes the form of a fish-tail adapted to form an airtight seal with the bag 50.
A bag 50 and spout 60 combination according to claim 1 or claim 2, wherein the tubular section 63 and sealing section 62 are integrally moulded.
A bag 50 and spout 60 combination according to any of the preceding claims, wherein the spout 60 is made from special grade polypropylene.
A bag 50 and spout 60 combination according to any of the preceding claims, wherein the bag 50 is made from foil or a foil laminate.
A bag 50 and spout 60 combination according to any of the preceding claims, wherein the bag 50 is rolled circumferentially around the spout 60 and taped in this rolled configuration for insertion into an aerosol container.
An aerosol container comprising a casing 20,30,40 encapsulating a bag 50 and spout 60 combination according to any of the preceding claims.
A method of making an aerosol container comprising the steps of
- taking a spout 60 having a fish-tail portion 62 and a tubular portion 63,

- sealing a bag 50 to the fish-tail portion 62

- inserting the bag 50 and spout 60 into a casing 20,30,40.
A method of making an aerosol container according to claim 8, comprising the additional step of
- securing the spout 60 in the casing 20,30,40 using a valve mounting cup 70.
A method of making an aerosol container according to claim 9, comprising the additional step of
- inserting propellant under pressure between the bag 50 and the casing 20,30,40.