Bag-on-valve

Abstract

A bag-on-valve for a pressure vessel, more particularly pressurized canisters (40), for dispensing viscous to pasty products, comprising a valve plate (3), a valve body (6) arranged on the valve plate (3), a stem (5), which is guided in a central hole in the valve body (6), at least one inlet opening (9) for the product contained in the bag (30), which inlet opening can be opened by actuation of the stem, at least one outlet opening (10), an elastic element (8) acting on the stem (5), sealing elements (12) acting between the valve plate (3) and the valve body (6) and between the valve body (6) and the stem (5), and a bag (30) for the product to be dispensed by the valve (1), which bag is arranged on the valve (1), wherein the bag (30) is fastened to a retaining element (2), which has a central passage (23), wherein the retaining element (2) has a laterally extending retaining plate (22), which is sealingly connected to a collar (7) of the valve body , which collar extends vertically on the canister side.

Description

[0001] The invention relates to a bag valve for a pressure container, in particular pressure cans, for dispensing viscous to pasty products, comprising a valve plate, a valve body arranged on the valve plate, a stem guided in a central recess of the valve body with at least one inlet opening for the product contained in the bag that can be opened by actuating the stem, at least one outlet opening, an elastic element acting on the stem, sealing elements acting between the valve plate and valve body and between the valve body and stem, and a bag arranged on the valve for the product to be dispensed through the valve, wherein the bag is fixed to a holding element that has a central passage, wherein the holding element has a laterally extending holding plate that is sealingly connected to a collar of the valve body that extends vertically on the can side.The problem is further solved by a pressure canister equipped with such a bag valve. The invention further relates to a pressure canister with such a bag valve.

[0002] Pressurised cans for dispensing viscous to pasty substances have been known and in use for a long time. They are used, for example, in the food sector (cake decorations), in hygiene products (toothpaste) and in cosmetics. Piston cans are often used for this purpose. In these cans, a piston divides the pressurised can into an upper and a lower part. The upper part, below the valve, contains the product to be dispensed and the lower part, below the piston and above the base, contains a propellant. With such pressurised cans, the often inadequate separation of product and propellant is problematic, and the introduction of both the product and the propellant is complex. In particular, a second valve in the base of the can is required to fill the propellant. The second valve and the piston, as well as the filling equipment, make the cans and the product considerably more expensive.

[0003] Pouch cans offer an alternative. Such pouch cans contain the product separately from the propellant gas. If the pouch is attached to the can body, the same problems arise when filling with propellant gas as with the piston can described above. If the pouch is arranged on the valve, the product must be filled through the valve, which is time-consuming and labor-intensive and also contaminates the valve. Due to the design of the valve systems, the filling speed is limited. The introduction of the propellant gas requires either a special design of the main valve or a second valve in the base of the can. Such pouch cans are not suitable for products with a viscosity of more than 50 Pas. They are used, for example, for shaving gels.

[0004] Bag valves of the type mentioned above are known from US 2010 / 320 230 A1, US 2010 / 001020 A1, EP 2 634 111 A1, EP 0 471 503 A2 and JP 563 281 977 A.

[0005] The object of the invention is therefore to provide a pressurized container with which viscous and pasty substances stored in a bag can be dispensed using a propellant. Such a bag container should be inexpensive to manufacture, easy to fill, and safe to handle.

[0006] This object is achieved with a bag valve according to claim 1. a pressure can which is equipped with such a bag valve.

[0007] The bag valve according to the invention avoids the disadvantages of the prior art. Firstly, the product and propellant are safely separated from each other, as desired. The special design of the valve with a retaining element allows the bag to be filled with a product, even inside the pressurized container, before the valve is installed and the pressurized container is pressurized with propellant. Conventional pressurized containers can be used; they simply need to be equipped with the bag valve according to the invention.

[0008] The terms "valve-side" and "can-side" used here refer to an orientation toward the valve or the can interior, vertically. Similarly, "can-inward" and "can-outward" refer to an orientation toward the can edge or the can axis, horizontally.

[0009] The bag valve according to the invention is derived from a conventional solid valve for the application of polyurethane-based assembly foams, as described, for example, in EP 2 028 131 A1 and EP 3 044 123 A1.

[0010] The bag valve according to the invention is intended and suitable for dispensing viscous to pasty products from a pressurized can using a propellant. It is based on a conventional solids valve that has been modified for this purpose. Such a solids valve is usually manufactured from a polyalkylene, such as polypropylene, using an injection molding process. The conventional part of the valve consists of a valve disk and a valve body arranged on the valve disk, which has a central recess in which a stem is guided, wherein the valve has an inlet opening for the bag contents that can be opened by actuating the stem. Actuation occurs in particular by pressing in the stem. An elastic element connected to the stem causes the valve to return to the closed state after actuation. Sealing elements are arranged between the valve disk and valve body and between the valve body and stem.

[0011] The product bag is mounted on the can-side end of the valve. For this purpose, the valve body has a circumferential collar on the can side that extends beyond the can-side end of the stem. The bag is mounted on a retaining element with a central passage and is connected to the collar via a retaining plate extending laterally (outward of the can). The connection is gas- and liquid-tight.

[0012] The retaining plate of the retaining element can be glued or welded to the valve collar. The connection can be achieved, for example, by ultrasonic welding (HF welding). However, a locking or snap-in connection is preferred, which allows the retaining plate to easily lock onto the pre-assembled bag and the valve collar. It goes without saying that a sealing element must be arranged between the retaining plate and the collar.

[0013] A snap-in connection is achieved via a projection arranged on the outside of the circumferential collar of the valve body and snap-in hooks arranged on the edge of the retaining plate.

[0014] The principle of such snap-in connections is well known. The snap-in connection is designed to be permanent; there is no provision for the valve and retaining plate to be separated.

[0015] The required seal is provided by an O-ring located at the edge of a recess in the retaining plate and sealing against the can-side end of the collar. For this purpose, the can-side end of the collar is beveled toward the inside of the can, so that the bevel faces the can axis, and the O-ring seals against this bevel.

[0016] Such a bevel creates particularly good and lasting contact between the seal and the collar of the valve body, which protects against propellant loss during storage of a filled pressure canister. One advantage of the pressure canister according to the invention is the low propellant loss during storage and service life.

[0017] Alternatively, but not part of the claimed invention, the required seal can also be provided by a sealing element molded or injection-molded onto the outer edge of the retaining plate, for example, made of a thermoplastic elastomer (TPE). Such plastic products consisting of two different materials can be manufactured, for example, using a two-component injection molding process.

[0018] Even with an overmolded sealing element, the sealing effect is achieved through the tight, sealing contact between the retaining plate and the collar. The can-side edge of the collar can be beveled toward the inside of the can, as described above for the O-ring.

[0019] The product bag is secured to a central pin of the holding element. It goes without saying that the central hole of the holding element extends through this pin. The pin itself can be round, but can also take on any other shape compatible with the intended use, for example, polygonal, particularly square, diamond-shaped, or teardrop-shaped. It is secured in place, in particular, by gluing or welding, for example, using ultrasound. A more horizontally circumferential filling of the pin is advantageous, especially during assembly.

[0020] The bag itself is preferably made of plastic and has a multi-layer construction. This multi-layer construction increases tear resistance and prevents the bag from tearing away from the holding element after filling. It is understood that composite materials made of several plastics or using aluminum can be used to improve tightness. Metallizing a plastic film for the bag is also possible.

[0021] The valve part of the bag valve according to the invention is essentially designed according to EP 2 028 131 A1. The valve body has a groove surrounding the stem in which the elastic element is mounted. The elastic element surrounds the stem and, in addition to the spring action (return action after actuation of the valve), provides an additional sealing effect against the stem. For this purpose, the elastic element is preferably made of a thermoplastic elastomer (TPE).

[0022] Alternatively, a coil spring can be used. A combination of a coil spring and a thermoplastic elastomer is also particularly suitable. A retaining ring made of a durable plastic, such as polyoxymethylene, serves as a support for the elastic element at the valve-side end of the stem.

[0023] The invention further relates to pressure vessels equipped with such a bag valve, in particular pressure cans. The propellant in such pressure cans can be, for example, nitrogen or another inert gas, air, or even a conventional propellant gas, for example, a liquefied gas or a liquefied gas mixture (propane, butane, dimethyl ether).

[0024] The bag valve according to the invention enables particularly efficient filling of pressurized cans. For this purpose, the retaining element is connected to the bag, ultrasonically welded, and the bag is suspended in the still-open pressurized can. The retaining element remains outside the pressurized can. The bag can now be filled. Following filling, the retaining plate of the combination of retaining element and filled bag is connected to the collar of the valve, for example by snapping it into place or by ultrasonically welding. The pressurized can is then filled with propellant under a pressure bell, with the pressure in the range of 2 to 14 bar, and – still under the pressure bell – the valve plate is crimped to the can dome. After labeling and packaging, the can is ready for shipping.

[0025] The invention is explained in more detail by the accompanying figures and preferred embodiments. It is understood that the features shown in the figures belong to the invention in any technical context. They show: Figure 1 shows an overall view of a bag valve according to the invention without a bag; Figure 2 shows a detailed view of the holding element; Figure 3 shows a detailed view of the connection between the holding element and the valve collar; Figure 4 shows the individual elements of the bag valve according to Figures 1 to 3 ; Figure 5 a second variant, not part of the claimed invention, of the holding element with molded-on TPE seal; Figure 6 a detailed view of the connection of the holding element according to Figure 5 with the valve collar; Figure 7 a third variant, not part of the claimed invention, of the holding element Figure 8 a detailed view of the connection of the holding element according to Figure 7with the valve collar; and Figure 9 schematically shows the steps in assembling the pressure canister and bag valve, including filling.

[0026] Figure 1shows a bag valve according to the invention without a bag installed. The actual valve is designated by the reference numeral 1, the holding element for the bag by 2. The valve 1 consists of the valve plate 3 with the crimped edge 4, the stem 5, the valve body 6 with a downwardly drawn collar 7, which is aligned with the can side, and the elastic element 8, in this case a sleeve made of a thermoplastic elastomer arranged around the stem 5. The stem 5 has several inlet openings 9 at its can-side end 2 and an outlet opening 10 at the valve-side end. In the area of ​​the outlet opening 10 there is a plastic sleeve 11, which serves as an upper abutment for the elastic element 8. The lower or can-side end of the elastic element 8 is supported in an annular groove in the valve body 6.

[0027] The valve body 6 has a foot 13 that extends laterally in a ring shape and seals the stem against the valve body 6. Sealing lips 12 are located in the contact area between the valve foot 13 and the valve body 6. Alternatively, an O-ring arranged in a groove of the valve body 6 or stem 5 can also be used. Furthermore, the valve body can also have an injection-molded sealing element made of a thermoplastic elastomer (TPE, 2-component injection molding).

[0028] The valve body 6 is fitted into the valve plate 3 and fixed to it in a known manner.

[0029] The retaining element 2 consists of a retaining pin 21 and a retaining plate 22, which are arranged concentrically around a passage 23. The retaining plate 22 extends laterally toward the edge of a surrounding pressure chamber and is connected to the collar 7 of the valve body 6 via a sealing ring 24 and locking elements 25, see detail X.

[0030] The retaining pin 21 itself can have any shape, but is preferably designed in a diamond-shaped, elongated manner, roughly resembling a ship's shape. It has circumferential ribs 26 that serve to better hold a mounted bag.

[0031] The bag valve according to the invention is actuated to remove the bag contents by pressing the stem 5 using a standard adapter. After removal is complete, the elastic element 8 ensures that the valve returns to the closed position. The valve can be actuated again until the bag contents have been completely removed.

[0032] Figure 2shows a variant of the holding element 2 according to the invention with the holding pin 21 and the holding plate 22. A passage 23 runs through the center of the holding element 2, through which the bag contents are poured into the bag and dispensed upon removal. Ribs 26 surround the pin 21 horizontally. To facilitate insertion into a pressurized can and to secure a bag, the pin 21 is tapered at its can-side end, i.e., the side surfaces are beveled.

[0033] Above the pin 21 is a constriction 28, which can serve as a holder when filling a connected bag. The plate 22 has a receptacle 27 for an O-ring, notches 25 arranged around the circumference for securing the retaining element to the collar 7 of the valve body 6, and an inner upstanding edge 29 that extends on the valve side and improves the fit of the retaining element on the collar 7 of the valve plate 6.

[0034] Figure 3shows the detail X from Figure 1 with the collar 7 projecting down from the valve 1 on the can side, the holding plate 22 with its upstanding edge 29 and the receptacle 27 for an O-ring 24. The O-ring 24 in turn lies in the receptacle 27 of the valve plate 22 and is supported on the valve 1 in the area of ​​the collar 7 on an inclined surface 15, the incline of which points inwards towards the can. The collar 7 also has on its outer side (facing outwards from the can) a circumferential projection 16, behind which the locking elements 25 of the holding element 2 engage. The immovable fit of the locking elements 25 on the projection 16 is ensured by the upstanding edge 29 of the holding plate 22, which lies directly against the inner wall of the collar 7.

[0035] Figure 4 shows the individual elements of the Figures 1 to 3together with a bag 30 in the overview. The valve 1 with the collar 7 is locked to the retaining element 2 with the O-ring 24 inserted between them. The bag 30 is connected to the pin 21 of the retaining element 2.

[0036] In the Figures 1 to 4 In the variant of the bag valve according to the invention shown, the valve body is made of HDPE, the holding element is made of PP and the bag is made of several layers of PE.

[0037] Figures 5 and 6 show a further variant of the seal between the valve 1 and the holding element 2. The seal 24 consists of a sealing ring made of a thermoplastic elastomer which is injection-molded onto the holding plate 22 using a 2K process and which, as shown in Figure 6 shown, seals against the bevel 15 of the collar 7 of the valve 1. The sealing principle corresponds to the principle described in the Figures 2 and 3 is shown.

[0038] Figures 7 and 8show a third variant of a seal between the valve 1 and the retaining element 2. In this case, the sealing element is replaced by a welded joint that connects an outer circumferential groove 31 of the retaining plate 22 with a circumferential projection 17 of the collar 7 of the valve 1. In this case, the material of the valve 1 is expediently identical to the material of the retaining element 2, for example, HDPE. The connection is preferably made by ultrasonic welding.

[0039] Figure 9shows a schematic of the assembly principle for a pressurized can equipped according to the invention. In the first step A, the bag 30, which is already connected to the holding element 2, is suspended in a pressurized can 40 with a dome 41. The holding plate 2 remains outside the dome. The bag 30 is filled through the passage of the holding element 2. In the second step B, the valve 1 is clicked onto the holding element 2. The bag valve is lowered further into the can, but is not yet connected to the can dome 41 (C). Propellant (arrow) is introduced into the can via a pressure bell (D) and, still below the bell, the bag valve is crimped to the can dome (E).

[0040] This special process utilizes conventional pressurized cans, such as those used for numerous purposes in industry, trade, and the home. The bag 30 does not need to be filled through the valve; instead, its contents are drawn through the passage of the retaining element. Only then is the bag 30 tightly sealed by clicking open the valve 1. When filled with propellant, no propellant penetrates the bag 30.

[0041] Filling the bag through the valve stem is also possible, but requires subsequent cleaning of the stem. Filling through the valve is usually necessary if the valve and retaining element are welded together.

[0042] The use of a solids valve, as is known from the prior art for polyurethane foam cans, has the advantage that the relatively large cross-section of the stem allows filling and emptying of the bag in a very short time. This is particularly advantageous when it is necessary to fill the bag through the stem.

[0043] The bag valve according to the invention and the pressurized containers equipped with it can be used for a wide variety of viscous and pasty products. In the food sector, examples include honey, cake decorations, cheese, dough, fat, pudding, and creams. In the hygiene sector, toothpaste and soap are suitable products. Creams and ointments are suitable in the cosmetics and medical sectors. In the technical sector, sealants, lubricating grease, and pastes are examples.

Claims

1. Bag-on-valve for a pressure container, in particular pressure cans (40), for dispensing viscous to pasty products, having a valve disk (3), a valve body (6) arranged at the valve disk (3), a stem (5) guided in a central recess in the valve body (6) and having at least one inlet opening (9) for the product contained in the bag (30) which can be released by actuation of the stem, at least one outlet opening (10), an elastic element (8) acting on the stem (5), sealing elements (12) acting between valve disk (3) and valve body (6) and between valve body (6) and stem (5), and a bag (30) arranged on the valve (1) for the product to be discharged through the valve (1), wherein the bag (30) is fixed to a holding element (2), which has a central passage (23), and the holding element (2) has a laterally extending retaining plate (22) which is connected in a sealing manner to a collar (7) of the valve body extending vertically on the can side, characterized in that retaining plate (22) and collar (7) are fixed to one another via a latching connection, wherein the collar (7) has an externally circumferential projection (16) which is engaged behind by latches (25) arranged on the retaining plate (22), and wherein a sealing element (24) is arranged between the retaining plate (22) and the collar (7), wherein the sealing element (24) is a 0-ring (24) which is arranged in a peripheral receptacle (27) of the retaining plate and which seals against the wall (15) at the can-side end of the collar (7), wherein the can-side end of the collar (7) is beveled and the bevel points inwardly of the can onto the sealing element (24) of the retaining plate (22).

2. Bag-on-valve according to claim 1, characterized in that the holding element (2) has a central spigot (21) directed inwards towards the can for securing the bag (30).

3. Bag-on-valve according to claim 2, characterized in that the bag (30) is glued or welded to the spigot (21).

4. Bag-on-valve according to any one of the preceding claims, characterized in that the bag (30) is formed in several layers.

5. Bag-on-valve according to any one of the preceding claims, characterized in that the valve body (6) has a groove (14) which runs around the stem (5) and in which the elastic element (8) which surrounds the stem (5) is mounted.

6. Bag-on-valve according to claim 5, characterized in that the elastic element (8) is formed from a thermoplastic elastomer, a helical spring or a combination thereof.

7. Bag-on-valve according to claim 5 or 6, characterized in that the stem (5) has a retaining ring (11) at the valve-side end as an abutment for the elastic element (8).

8. Pressure can with a bag-on-valve according to any one of claims 1 to 7.

9. Use of a bag-on-valve according to any one of claims 1 to 7 for discharging viscous or pasty products from a pressure container, in particular a pressure can (40).

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