EP1414717A1

EP1414717A1 - Aerosol can

Info

Publication number: EP1414717A1
Application number: EP02774609A
Authority: EP
Inventors: Hartmut Schiefer
Original assignee: Fulmen Dispenser GmbH
Current assignee: Fulmen Dispenser GmbH
Priority date: 2001-09-12
Filing date: 2002-09-12
Publication date: 2004-05-06
Also published as: DE10144951A1; WO2003022711A1; RU2004107483A; US20060243741A1; JP2005502551A; CA2462373A1

Abstract

The invention relates to an aerosol can which comprises, as the energy accumulator, a reservoir for the substance to be filled, an expansion body that is firmly enclosed by said reservoir when the latter is empty, thereby widening the reservoir against its elastic force, an inlet for introducing a substance while further widening the reservoir into the space hereby created, and an outlet for discharging the substance during spraying.

Description

Spray can

The invention relates to a spray can for dispensing a good from a spray nozzle. The material can be released in the form of a fine mist, but also in the form of an atomized jet with larger drops. In any case, such spray cans comprise a filling material container which holds the filling material, furthermore a valve unit connected to the filling material container and having a spray head which in turn has a spray nozzle.

There are several options for dispensing the filling material from the filling material container, which are realized in different types of spray cans. So it is known to drive out the contents by means of a propellant gas. This principle is the worst because the propellant gas is known to be extremely harmful to the environment. In particular, the function of the spray system is only possible in a narrowly limited temperature range due to the large temperature dependence of the propellant gas.

Another possibility is to expel filling material from the filling material container by manual pressure on a displacement piston. However, this principle does not meet the comfort requirements. For example, the spray nozzle should generally be oriented in a certain direction; when pressure is applied by hand, there is often a deviation from this direction.

Another known type uses a container made of an elastomeric material as the filling material container. This material is stretchable. The filling container is stretched when the filling material is introduced ("loading"). Due to the inherent elastic force, it exerts pressure on the contents. When the valve is opened by applying slight pressure to the spray head, the product container itself drives one due to the elastic force mentioned

Portion of filling material through the spray nozzle. This principle has a disadvantage. This consists in the fact that the elastic force becomes smaller and smaller with increasing emptying of the product container. This means that the spray pressure and thus also the amount of the spray jet emerging from the spray nozzle diminishes over time. The work result thus changes over the life of a spray can, which is undesirable. In addition, at the end of the life of the spray can, that is, when the spray pressure of the filling material becomes very low, there is still a remainder in the filling container. This rest can no longer be driven out of the product container because the elastic force has practically dropped to zero.

The invention has for its object to design a spray can with a product container made of elastic material such that the elastic force of the product container remains at least approximately constant over most of the life of the spray can, and in particular in the last phase, that is, when only a small amount of product is left in the product container, is sufficient to drive out the last remainder or at least most of it from the product container. In addition, the residual amount in the product container should be as small as possible and the temperature dependence of the spray system should be minimal.

This object is achieved by the features of claim 1.

The inventors have broken new ground here. You have one in the product container made of elastic material, such as rubber

Expansion body introduced. Before the assembly of these two components, the product container has a smaller internal width than the outer diameter of the expansion body. The expansion body thus widens the product container during insertion. The product container thus encloses the expansion body tightly and under a certain tension.

The inventors have recognized that the stress-strain curve of the elastic material of the product container - when an optimal one is selected elastic material - runs at least approximately constant, so that the resilient force inherent in the product container remains the same regardless of its state of expansion, namely over a larger expansion range. This has two advantages: The quality of the spray jet in terms of pressure and throughput is largely preserved over the life of the spray can. Furthermore, even towards the end of the life of the spray can, that is, if only a small quantity of filling material is still contained in the filling material container, contain a sufficiently large force in the material of the filling material container, so that a remaining quantity is largely or completely expelled from the filling material container ,

There are numerous ways to implement the invention. This begins with the assembly of the expansion body and the product container. The expansion body can have the shape of a projectile and thus have a cylindrical shape on a large part of its outer surface. The contour of the

The inner wall of the product container can have the same shape. In any case, the expansion body can be pushed forcibly into the product container, with the product container widening. This is a covering of the product container over the expansion body.

Another possibility is to widen the contents container with other means than with the aid of the expansion body. For example, it is conceivable to introduce several rods into the filling container, which extend parallel to the longitudinal axis of the filling container and which are displaced in the radial direction in order to widen the filling container. The

Expansion body can then be easily inserted in the expanded state of the product container.

Another possibility is to apply a vacuum to the outer surface of the product container in order to widen it, then to insert the expansion body into the product container and finally to release the vacuum. Any type of spray nozzle must of course have an opening for introducing the filling material, but also an opening for dispensing. The valve mentioned is located in the opening for dispensing. This is opened by pressing the spray head - generally with the index finger.

The construction can be designed such that there is only a single valve. This serves both for filling the filling material container and for discharging filling material for the purpose of spraying. In such a case, the valve is a non-return valve which, during filling - without exerting pressure on the spray head - only allows the filling material to pass through in one direction, namely in the filling direction.

A particularly interesting embodiment consists in providing the expansion body with a channel which runs through the expansion body. The channel can be passed in the axial direction through the expansion body over the entire length. If one imagines the shape of the filling container as sack-shaped, the channel would open into the expansion body in the area of the sack bottom. But it is also conceivable to provide the channel with side outlets, so that several sub-channels open on the inner wall of the product container. It is also advantageous for

Assembly of the expansion body to install channels in the longitudinal direction of the expansion body and thus to create optimal conditions for the subsequent filling process.

There are a multitude of possibilities for designing the individual elements of the spray can according to the invention. The following options are possible:

^* The product container is made up of two or more layers. The outer layer consists of chemically cross-linked elastomer or

Natural rubber or from synthetic rubber or from mixtures between these two. * The inner layer can consist of an inert material that does not form a connection with the contents and does not impair its quality. For example, silicone or silicone rubber can be used here. One or more layers can also consist of thermoplastic elastomer (TPE).

* A barrier layer can also be provided between an inner and an outer layer, which prevents the contents or components of the contents from diffusing through the contents container.

* The outer layer need only partially enclose the inner layer or the inner layers.

* The partially closed layer can take the form of a cage

Rings or from longitudinal struts or from spirals or from nets.

^* Instead of a single expansion body, several expansion bodies can be provided. These can add up to a single expansion body, for example the shape of a

Projectile. It is also conceivable to use several expansion bodies with different external dimensions. For example, the expansion body can have ribs that run in the circumferential direction and that hinder a flat contact against the inner surface of the product container.

* The expansion body can have extensions at one or both ends, for example in the form of a spider, with which the expansion body is held in the product container.

There are several ways to expand the container. As mentioned above, this can be done by slipping the container over the expansion body with great effort. Keep coming forceps-like rods are considered, which are inserted into the product container in order to widen it and then to insert the expansion body. Furthermore, it is possible to insert the expansion body into the product container, the expansion body initially not having an excess compared to the product container, but then the

To enlarge the expansion body by other measures, for example by heating or foaming or - when using a hollow expansion body - by inflating with a liquid or gaseous medium. Another possibility is to insert the expansion body in the product container without oversize and then by the

To swell components added or contained therein, which increases its dimensions and creates the necessary tension.

The invention is explained in more detail with reference to the drawing. The following is shown in detail:

Figure 1 shows a schematic longitudinal section of the essential parts of a spray can.

Figure 2 shows a second embodiment of a spray can in a

View similar to that of Figure 1.

Figure 3 illustrates the stress-strain behavior of the elastic material from which an inventive

Product container is formed.

The spray can shown in FIG. 1 has a product container 1. In the present case, this is double-walled. It is namely assembled from an inner container 1.1 and an outer container 1.2. The inner container 1.1 consists of a material which is inert to the product in question. The outer container 1.2 consists of an elastic material that forms the energy store. The two containers lie with their corresponding ones Surfaces directly next to each other. You keep this contact in any operating condition. The inner container thus follows the movement of the outer container when it expands or contracts.

The outer container 1.2 is thickened in its upper region to form a flange 1.2.1. The flange is cylindrical.

A pot-like receptacle body 2 can also be seen. This tightly encloses the flange 1.2.1. The receiving body 2 has a cylindrical peripheral wall 2.1, a circular plate 2.2 and a collar 2.3.

The receiving body 2 is in turn enclosed by a receiving hollow body 3, namely by its neck 3.1. The receiving body 2 is secured against axial displacement.

The flange 1.2.1 of the outer container 1.2 encloses a valve 4. A filling and emptying nozzle 5 is connected to this. Filling material is introduced through the filling and emptying nozzle 5 and through the valve 4 for the purpose of filling, and is also let out again when the spray can is used in the opposite direction. This will be discussed further below.

The most important element according to the invention is an expansion body 6. This is enclosed by the inner container 1.1. It has a plurality of grooves evenly distributed over its circumference, so that a corresponding one

Number of longitudinal channels 6.1 is formed. The longitudinal channels 6.1 extend practically over the entire length of the expansion body 6. This creates a conductive connection between the valve 4 and the lower region of the product container 1.

The outside diameter of the product container 1 has an oversize compared to the inside width of the product container 1 in the non-assembled state. This means that the product container 1 during assembly - opening - on the Expansion body 6 is expanded and thus encloses it under tension.

For the purpose of filling, filling is through the filling and emptying nozzle 5 and further through the valve 4 under pressure in the upper region of the

Product container 1 initiated. It then flows down through the channels 6.1 of the expansion body 6. Since the introduction takes place under pressure, the product container 1 is expanded so that it is lifted off the expansion body 6. An annular space is thus created over the entire length of the product container and is filled with product. With this expansion the works

Filling pressure of the product against the elastic force that is inherent in the product container. The widening of the filling material container 1 can be carried out to such an extent that the outer lateral surface of the outer container 1.2 is largely in contact with the inner surface 3.1 of the receiving hollow body. The valve 4 can be designed as a check valve, so that there is initially only an inflow of the

Filled goods allowed, but not backflow. The valve 4 is also designed in such a way that the non-return function or blocking function of the valve 4 can be canceled, for example by finger pressure on a tappet, not shown here, which can be part of the fill and drain nozzle 5.

The receiving body 2 can be molded onto the filling material container 1, molded on or pushed onto it. It can be made of plastic, metal or a combination of these two.

In general, the connection between the receiving body 2 of the

Product container 1 and the surrounding hollow body 3 can be designed as a snap lock. One of these two elements can have hooks, and corresponding recesses or other counter-elements can be formed on the other. Receiving body 2 can also consist of glass fiber reinforced plastic, for example of glass fiber reinforced polyamide or

Polyester. The product container 1 can also be produced in different ways.

This means that it can have a non-constant cross-section over its length. The receiving hollow body 3 can consist of metal or plastic or any other material, for example also of cardboard.

An interesting variant is that the receptacle body 2 is firmly connected to the filling material container 1 during injection molding. An insert can also be inserted between these two. The insert can contain the valve and be firmly connected to it.

The spray can shown in FIG. 2 faces the one shown in FIG

The following differences:

The product container 1 is not double-walled, but only single-walled.

An elastomeric closure plate 7 is provided.

Between the elastomeric closure plate 7 and the lower end of the product container 1, a positive connection is made, namely in that the lower end of the product container 1 has a flange 1.2.2, which cooperates with a corresponding collar 7.1 of the closure plate 7. As can be seen, the lower end of the product container 1 is open in the unassembled state - in contrast to the embodiment according to FIG. 1.

The neck of the product container 1 has a bulge 1.2.3 which snaps into a corresponding annular groove in the receiving hollow body 3. Wuls 1.2.3 and the associated ring groove are concentric to the longitudinal axis of the spray can.

The closure plate 7 is also provided with a ring 7.2, which on the

Inner surface 3.1 of the hollow body 3 can rest and thus has a fixing function. The longitudinal channels 6.1 of the expansion body 6 can - seen in a cross section - be evenly distributed over the circumference of the expansion body 6. However, it is also sufficient to provide a single such longitudinal channel. In addition or instead of any longitudinal channels 6.1 arranged in the peripheral region, a central bore can also be provided, which

Strain body 6 penetrates along its entire length. In such a case, filling material is introduced from above into the central channel through valve 4 and exits at the lower end thereof. When exiting, it strikes the inner surface of the inner container 1.1 in the case of FIG. 1 and the surface 7.4 of the closure plate 7 in the case of FIG. 2.

However, it is also possible not to provide any longitudinal channels at all, thus neither the channels 6.1 shown, which are located in the peripheral region of the expansion body 6, nor the central channel mentioned. In such a case, the filling material is in turn filled by the filling and

Emptying nozzle 5 and introduced through the valve 4 under pressure. It then seeks its way between the outer circumferential surface of the expansion body 6 and the inner surface of the product container 1, whereby it removes the contact between these two surfaces and widens the product container 1 until it finally forms and at the same time fills an annular space of corresponding thickness.

The advantages of the invention become clear when considering the diagram according to FIG. 3. This shows the stress-strain behavior of the material of the filling container 1 - in the case of FIG. 1, the material of at least one of the partial containers, thus the inner container 1.1 and / or the

Outer container 1.2.

As can be seen from the diagram, there is an area in which the stress-strain behavior is at least approximated to a horizontal course.

The corresponding parameters are selected such that in the assembled but not filled state, the material of the product container 1 sets a bias voltage I, and a final voltage II when filled.

This means that the spray can - more precisely the product container 1 - works in the above-mentioned, approximately horizontal area. Even if there is only a small amount of filling material between the expansion body 6 and the filling material container 1, the material of the filling material container 1 still has a certain elastic force which is large enough to still generate a corresponding spray pressure when the spray can is used. This also ensures that no undesirable residue of filling material remains in the filling material container 1.

Claims

claims

1. spray can;

1.1 with an elastic filling material container (1) serving as an energy store;

1.2 with an expansion body (6), which is closely enclosed by the filling container (1) in the unfilled state and thereby expands the filling container (1) against its elastic force;

1.3 with an inlet for the introduction of filling material with further widening of the filling material container (1) into the resulting gap space;

1.4 with an outlet for dispensing filling material when spraying.

2. Spray can according to claim 1, characterized in that the product container (1) is at least double-walled at least in the area in contact with the product.

3. Spray can according to claim 2, characterized in that the product container (1) is constructed at least from an inner container and an outer container (1.1, 1.2), and that at least one of these containers consists of an elastic material.

4. Spray can according to one of claims 1 to 3, characterized in that in the material of the expansion body (6) and / or in the material of the product container (1) recesses to form longitudinal channels between the expansion body (6) and product container (1) are.

5. Spray can according to one of claims 1 to 4, characterized in that the expansion body has in a central region of its cross section at least one channel which extends over a substantial part of the length of the expansion body (6), and which is a conductive connection between the Inlet for introducing

Fills and the interface between the expansion body (6) and the inner surface of the product container (1).

6. Spray can according to one of claims 1 to 5, characterized in that the product container (1) has at its open end an annular flange (1.2.1) which is molded onto the product container (1) or pushed onto it or injected into it, and the fastening of the product container (1) to a receiving container

Hollow body (3) lies.

7. Spray can according to claim 6, characterized in that the ring flange is enclosed by a receiving body (2) made of plastic or metal or a combination of these two

Materials is built.

8. Spray can according to claim 6 or 7, characterized in that the connection between the receiving body (2) and the hollow body receiving it (3) is designed as a snap lock

9. Spray can according to claim 8, characterized in that the snap lock comprises hooks or projections (2.3).

10. Spray can according to one of claims 1 to 9, characterized in that. that at least one annular bead (1.2.3) in one of these two elements, and a corresponding recess in the other of these two elements, is provided to form a snap closure between the upper region of the product container (1) and the hollow body (3) receiving it.

11. Spray can according to one of claims 6 to 10, characterized in that the receiving body (1.2.1) consists of glass fiber reinforced polyamide or polyester.