Patent Application
20210284431
Multichamber applicator having a multichamber container for the storage of at least two subcomponents, having an apparatus for the removal of a mixture of the subcomponents.
A large number of containers having two or more chambers in which partial preparations can be stored prior to mixing and use are known to a person skilled in the art from the prior art.
These multichamber containers can be subdivided roughtly into two groups. Containers in which the content of several chambers is mixed fully in a large mixing chamber before dispensing and is then provided for use (multichamber container with batchwise mixing before removal). By way of example, U.S. Pat. Nos. 3,809,289 A, 4,682,689 A or 7,097,075 B are cited here.
A second group consists of multichamber containers in which the removal of the partial preparations from the chambers takes place simultaneously and the subcomponent streams are combined only during removal and continuously before being dispensed (multichamber container with continuous mixing directly before and/or during dispensing).
Continuous mixing during dispensing has the advantage that only as much of the subcomponents is mixed as is necessary for the required quantity of mixed preparation (referred to as “mixture” in the following).
The prior art provides a person skilled in the art with different container variants in which the precise dispensing of a mixture is possible.
US 2010091478 A and DE 1457439 B disclose arrangements of two aerosol containers which have an actuating device for opening the valves. In the actuating device, the subcomponent streams are mixed via a static mixer and then sprayed via a single nozzle. Following completion of the spraying operation, a residue of the mixture remains in the duct system, in particular in the static mixer and the nozzle.
U.S. Pat. No. 5,887,761 A discloses a trigger pump, which is capable, by means of two pumps coupled via a trigger, of delivering two subcomponents from separate chambers and dispensing them in a mixed form.
EP 2886625 A, EP 2204092 A and EP 2597055 A teach a person skilled in the art about multichamber containers, which separate chambers made of flexible bags that are pressurized from the outside (bag-in-can system/bag-on-valve system). These individual bags are connected via separate valves. Via a common actuating device, the dispensing of a mixture of the subcomponents from the chambers is possible.
In addition to the abovementioned multichamber packaging means in which each chamber has a separate valve or pump, a person skilled in the art is also familiar with systems in which the chambers are arranged such that they are emptied via a common multiway valve such that, upon actuation of only one multiway valve, two fluid streams can be directed into separate ducts located alongside one another or ducts located concentrically one inside the other. By way of example, U.S. Pat. Nos. 3,389,837 B, 3,598,292 B and EP 2634111 A may be mentioned here for concentrically constructed valves, and WO 2013130883 A and U.S. Pat. No. 3,478,933 B may be mentioned here for valves with ducts located alongside one another.
All of these multichamber containers with continuous mixing before or during dispensing have a major drawback. If the subcomponents react with one another in such a way that solids, gels or highly viscous pastes (referred to as “residue” in the following) are formed, the residual quantities of mixture that remain in the static mixtures and/or dispensing ducts after the emptying operation can solidify and clog the mixer or the ducts. As a rule, the system is then lost, since the residues (solids) usually cannot be pushed out upon recommencement of use.
Therefore, in the case of two-component adhesives (2K adhesives), following removal it is often necessary to clean off residue-forming mixture or to replace the mixing chamber and the dispensing duct.
The aim was to remedy the lack of unlimited further use without replacing and/or cleaning parts.
It was surprising for a person skilled in the art that a multichamber container comprising the features of claim 1 allows unlimited further use without additional cleaning or replacement of structural elements.
It is advantageous when the dispensing duct has a mixing chamber, the diameter of which is greater than the diameter of the dispensing opening.
In the rest state, in which there is no dispensing of a mixture, the piston in the dispensing duct or in the mixing chamber is in a forward position and as a result closes the openings in the mutually opposite inlet ducts in the side wall of the dispensing duct or mixing chamber. The piston is designed such that it completely fills the mixing chamber as far as the dispensing opening. The dispensing opening is completely closed by the corresponding design of the piston.
The dispensing duct is advantageously designed as a one-part or multipart assembly that is connected to the stem of the valve or to the outlet of one or more pumps. The dispensing duct can be vertically movable within the dispensing head in order for example to be able to follow the movement of a valve. In a preferred embodiment, the dispensing head has on its top side a button (actuating element). When the button on the top side of the dispensing head is depressed, the assembly with the dispensing duct is also depressed. This also causes the valve stem or a pump to move and thus the valve to open or the pump to pump. Actuating elements that allow dispensing via deflection mechanisms are already known from the prior art.
In particular embodiments, this simultaneous movement of piston and valve/pump can be supported by a lever mechanism.
It is particularly preferred for the button, while being depressed, to act on a resiliently mounted pull rod, which is connected at its other end to the piston, via one or more eccentric cams which form a control curve. Alternatively, a lever system with a transmission would be within the meaning of the invention. As a result of this suspension, when the button is pressed, the piston is moved horizontally away from the dispensing opening. The resultant movement of the piston causes first of all the dispensing opening to be opened and, as it continues to move, the piston opens the two openings in the inlet ducts that lead into the mixing chamber.
The mixing chamber within the meaning of the invention is that portion of the dispensing duct that is formed between the dispensing opening and the piston when the piston is not in its rest position. In the mixing chamber, the subcomponents are mixed before the resulting mixture emerges from the dispensing opening.
The subcomponents A and B can flow through the inlet ducts into the mixing chamber. Depending on the pressure, flow cross section and viscosity and on the miscibility of the two subcomponents with one another, more or less intensive mixing takes place. The mixture then emerges through the dispensing opening at the front side of the dispensing head. As a result of the ratio of the diameter of the inlet ducts to the size of the mixing chamber and to the diameter of the outlet opening, the flow rate upon passing through the outlet opening can be controlled and thus the intensity of mixing optimized. The mixing of the subcomponents can be improved when the inlet ducts are arranged such that a turbulent flow is formed, this being advantageous according to the invention.
When the pressure on the button on the top side is released, the spring force of the valve springs ensures that the assembly is moved up again. As a result, the piston moves back into its starting position via the suspension—in particular pull rod. This movement of the piston back in the direction of the dispensing opening causes the mixing chamber to be emptied via the dispensing opening and ultimately the inlet openings of the mixing chamber to be closed. In order to empty the mixing chamber in a residue-free manner, the piston has to fill the dispensing duct in a form-fitting manner. Within the meaning of the invention, form-fitting should be understood as meaning that, between the piston and dispensing duct inner wall, there are no gaps through which the preparation mixture can flow past the piston. Therefore, it is advantageous to provide the piston with a slight oversize. As a result of the elasticity of the piston and/or of the dispensing duct, effective sealing is achieved by the oversize.
If the piston and/or dispensing duct is made of such an inelastic material (for example metal) or too elastic material (for example silicone elastomer) that sealing cannot be achieved by an “oversize piston”, it is advantageous, for better sealing of the piston with respect to the dispensing duct inner wall and/or the mixing chamber, to provide the piston with piston rings, annular seals, finlike sealing lips, lamellar seals and/or equivalent sealing means.
As soon as the mixing chamber has been emptied and the piston is in its farthest forward position, the dispensing opening is also closed. This ensures that no subcomponents remain in the mixing chamber and react with one another and/or dry out and thus clog or stick the dispensing duct.
It is advantageous to implement a safety arrangement in the dispensing system, said safety arrangement preventing dispensing as soon as a subcomponent is no longer available.
It is particularly advantageous to arrange, in one or more dispensing ducts, a safety device that allows subcomponents to be mixed and the mixture of subcomponents to emerge only when at least one subcomponent is available for dispensing.
Thus, with such a safety device, for example when the multichamber applicator is used for cosmetic or dermatological preparations, it is possible to prevent subcomponents considered to be incompatible with the skin in a pure form from being applied in an unmixed form. The simplest situation is the application of a mixture made of a very acidic or very basic subcomponent with a subcomponent that equalizes the pH of the mixture to a skin-compatible pH (buffer system). If the buffering subcomponent has been used up, the acidic or basic subcomponent must not be applied on its own.
One technical example would be a reactive resin system (two-component adhesive made of resin and curing agent), in which the resin must not be dispensed without admixing curing agent.
This safety device comprises preferably a device that reacts to the hydraulic pressure of a component by moving a structural element. As long as this structural element is in its rest position, it blocks the dispensing of the other component. This can take place by the closure of the duct or by blocking the movement of the piston of the mixing chamber. As soon as the pressure in the duct of subcomponent A rises, the structural element is moved and as a result allows the mixing chamber piston to move or opens the cross section of the subcomponent B.
If both subcomponents are critical in a pure, unmixed state, the safety arrangement can be implemented in both ducts. As a result, the pistons of both subcomponents are blocked independently of one another. Only when the pressure has risen in both ducts on account of the subcomponents is the movement of the mixing chamber piston allowed. Only in this way can the subcomponents flow into the chamber and emerge as a mixture through the dispensing opening.
According to the invention, a safety device can be designed such that, in the connecting duct (duct that connects a storage chamber for a subcomponent to the mixing chamber), a safety piston is arranged. If a pressure builds up in the connecting duct, the safety piston moves from its rest position into an active position and as a result allows the piston to move in the mixing chamber. As a result of the withdrawal of the mixing chamber piston, the inlet openings of the mixing chamber are opened, with the result that the subcomponent can flow into the mixing chamber.
A multichamber applicator according to the invention is particularly suitable when one subcomponent contains very reactive preparation constituents, wherein these reactive preparation constituents by themselves are environmentally harmful or, upon contact with the skin or other parts of the body (for example eyes, mucous membranes), can have a corrosive or toxic effect or react very quickly with a further subcomponent and the reaction products are solid or highly viscous such that clogging can occur.
In particular, the multichamber applicator according to the invention is suitable when one subcomponent contains one or more substances from the group consisting of amines, peroxides, dicarboxylic anhydrides, silicon compounds (basic silicates or acidic silicas) or when one subcomponent has a pH that is very different from that of the second subcomponent.
Within the meaning of the invention, a very different pH should be understood as meaning an absolute pH difference of ≥4 (greater than or equal to 4), in particular ≥5, very particularly ≥7.
The multichamber applicator according to the invention has been found to be very particularly outstanding for producing a siliceous mixture from a basic, silicate-containing subcomponent A (for example Na/water glass solution) by mixing with an acidic subcomponent B (for example mineral acid such as hydrochloric acid or phosphoric acid). Or, for the reverse case, for producing a siliceous mixture that has a skin-compatible pH from a very acidic siliceous subcomponent A (pH<4) and a basic subcomponent B (for example alkali hydroxide solutions such as sodium hydroxide solution or potassium hydroxide solution).
Silicas are very unstable from a pH≥4 and polymerize within a short time (a few minutes at pH 5). Using the multichamber applicator according to the invention, silica mixtures can be repeatedly produced and dispensed without the applicator becoming unusable (clogging) because of the polymerization products.
The invention is explained in more detail with reference to the schematic drawings of two exemplary embodiments. For simplification, the structure and function are explained in each case using a multichamber container having only two chambers. However, this is not intended to have a limiting effect on the invention. Analogously to the arrangement of two chambers with two subcomponents, it is also possible for more than two chambers having more than two subcomponents to be realized in the multichamber applicator according to the invention.
The following reference signs are used for the six parts:
The dispensing head (3) has a cylindrical casing (14), via which it is held on the multichamber container (2).
When the valve is pressed vertically into the can by way of its stem, the openings in the valve are moved relative to rubber seals and the subcomponents flow out of the chambers, on account of the positive pressure, through the coaxially arranged ducts (7.1) and (7.2) and into the valve attachment (8). The valve is pressed in by means of the actuating element (13), which is anchored in the cylindrical casing (14) via the button holder (13.2). Via the film hinge (13.3), the button (13.1) is connected movably to the button holder (13.2). The button (13.1) bears on the valve attachment (8). As a result of the button being pressed, the valve attachment is pressed onto the valve (7), which opens and releases the subcomponents into the valve attachment.
For greater understanding, the dispensing head is reproduced in
The central part in the dispensing head is the valve attachment (8), into which the concentrically arranged ducts (7.1) and (7.2) of the valve (also referred to as stem) lead. The subcomponents A and B are conducted via a duct system formed from three concentrically arranged, cylindrical duct elements (9), (10) and (11). The inner duct element (9) has the mixing chamber (9.1) in its interior and the nozzle opening (9.2) at its end.
In the dispensing head, the two subcomponents are introduced into the interior of the inner duct element (9), which serves as mixing chamber, from the valve attachment (8) through the connecting ducts (9.4) and (10.2), formed by the duct elements (9), (10) and (11), and the passages (9.3), (9.5), (10.1), (10.3) and (11.1).
In order to orient the duct elements (9), (10) and (11) relative to one another and to the valve attachment (8), the valve attachment and duct elements have corresponding grooves and protrusions (8.1), (9.6), (10.4) and (11.2). (
The mixing chamber (9.1) transitions into the dispensing duct (9.2), which ends with its dispensing opening in the region of the lateral surface of the dispensing head.
In the interior of the inner duct element (9), a piston (12) is arranged such that it closes the mixing chamber in a sealed manner. The mixing chamber piston (12) has, on its side facing the dispensing duct, a protrusion (12.1) that has the dimensions of the dispensing duct (9.2).
In order to dispense the mixed subcomponents A and B, the button (13.1) is depressed, with the result that the valve (7) opens and releases the subcomponents into the valve attachment. Simultaneously with the opening of the valve, the mixing chamber piston (12) is retracted such that the eccentric cams (13.4) act on the bending spring (15) and the bending string is moved away from the dispensing duct in the direction (W). Via the pull rod (16), the mixing chamber piston (12) is connected to the bending spring (15) such that the mixing chamber piston follows the movement of the bending spring (15). If the mixing chamber piston is retracted, the dispensing duct becomes passable and the passages (9.3) and (9.5) are opened. The subcomponents A and B can flow into the mixing chamber, mix together and leave the mixing chamber as a mixture AB via the dispensing duct. This process is schematically illustrated in
If the pressure on the button (13.1) is released, the valve (7) pushes the valve attachment and the button into the starting position (
In the rest state, in which no dispensing of a mixture takes place, the piston is in a forward position in the dispensing duct or mixing chamber and as a result closes the openings of the mutually opposite inlet ducts in the side wall of the dispensing duct or mixing chamber. The piston is designed such that it completely fills the mixing chamber as far as the dispensing opening. In the example shown, the dispensing opening has a smaller diameter compared with the dispensing duct. The dispensing opening is completely closed by the corresponding design of the piston. Thus, no residues can form and clog the dispensing duct.
The present embodiment described by the figures is designed for a commercially available system made up of a valve with two coaxial ducts in a stem. Systems are also available in which the valves have two or more valve stems, or systems which consist of two or more separate cans that are connected together by a supporting structure. The duct routing in the dispensing head has to be accordingly adapted.
The whole can also be applied to a pressureless container with two or more chambers and two or more pumps or in an analogous manner to two or more separate containers that each have a pump. There are also further possibilities, known to a person skilled in the art, for feeding pressurized fluids into such a dispensing head.
According to the invention, the application direction does not have to be horizontal but can also point obliquely upwards or downwards or vertically upwards. The mechanism of the button and of the piston has to be adapted accordingly. By way of a corresponding design via deflections, the dispensing direction can also be decoupled from the direction of movement of the piston.
The dispensing head (103) has a cylindrical casing (114), via which it is held on the multichamber container (102).
The multichamber applicator reproduced in
The operating principle of the dispensing head is reproduced schematically in
If the pressure of the subcomponent A in the connecting duct (122) is enough to move the safety piston (121) out of a rest position, the piston is pushed out of the duct (active position) and the subcomponent A can flow as far as the mixing chamber (
In the application for a mass-consumption product, it is appropriate to produce the dispensing head from a plastics material. A large number of resins and thermoplastics which can be used depending on their compatibility with the subcomponents are known to a person skilled in the art from the prior art. PP, PE, PA, PS, SAN, ABS or PET have specific advantages and drawbacks, but are in principle suitable for the construction of a dispensing head and multichamber component according to the invention.
Injection-molded parts made of PP and PE are preferred.
Injection-molding is the first choice of manufacturing method for large quantities. However, this dispensing head can also be produced by drilling, milling, turning and a large number of additive manufacturing processes.
The mixing performance of the chamber can be increased by an appropriate design of the flow ducts. By way of an approximately tangential direction of inward flow, an additional rotational flow can be introduced into the mass to be mixed, resulting in more intensive blending.
In formulations which do not provide equal volume fractions (1:1), it is possible to achieve a different mixing ratio by way of different cross sections of the inflow ducts and valves/pumps. Likewise, with a different viscosity, a mixing ratio of 1:1 can be created by a corresponding design.
The mixing chamber does not have to be cylindrical in cross section, and other shapes, such as square, elliptical, inter alia, are possible.
The outlet opening does not have to lie on the axis of the mixing chamber. In particular in the case of mixing ratios other than 1:1, an off-center position is advantageous.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2016 012 651.5 | Oct 2016 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/075618 | 10/9/2017 | WO | 00 |
