DE1209131B - Pressure vessel for dispensing flowable substances - Google Patents

Description

GERMAN

PATENT OFFICE

EDITORIAL

German classes : 17g -3

Number: 1209 131

File number: C 242301 a / 17 g

Filing date: May 29, 1961

Opened on: January 20, 1966

Pressure vessels for flowable materials are common by means of a piston slidably arranged in the container into a space for the dispensed Well separated and a space for the propellant. In known pressure cans of this type a rigid wall acting as a piston is used, which is slidable in the container and seals for Has Behältcrwandimg out. It is also known., to accommodate the initially liquid propellant in such pressurized cans in such a way that as a memory for the pressure medium a wick-like material, such as. B. cotton, is provided, the liquid Pressure medium is held between the fibers. This memory is in the known pressurized can Fixed in a special room, the room itself in a separable, special container can be formed.

It has now been shown that pressure cans, in which the piston consists of a thin, rigid plate are sensitive. Slight deformations of the thin sheet metal walls of the containers already lead to the fact that the pressurized can is unusable, either because the piston is no longer in the interior the can move or the seal between the piston edge and the container wall is lifted will. The piston, which is designed as a thin partition, can also tilt easily or within tip over of the container. In these known containers, the seal is therefore sensitive to sloping or horizontal storage of the can as well as against mechanical effects from impact, drop or, if it is a can made of flexible material, even against finger pressure.

To remedy these disadvantages, a pressure vessel for dispensing flowable substances is now also included a space for the substance to be dispensed and a space for the propellant, which spaces from each other are separated by a piston slidably arranged in the container, its the space for the substance to be dispensed face is impermeable, proposed which thereby is characterized in that the piston has a circumferential around its end face, to the propellant space having extending, sealing side surface, wherein a sponge-like in the cover formed in this way Body is arranged and piston face and side surface made of a thin, pliable material exist.

The pressure vessel is preferably designed so that the sponge-like body is preferably is at least as large as the space enclosed by the side face of the piston. Furthermore, the sponge pressure vessel for dispensing flowable substances

Applicant:

Colgate-Palmolive Company, New York, N.Y.

(V. St. A.)

Representative:

Dr. rer. nat. J.-D. Mr. v. Uexkiill,
Patent attorney,
Hamburg-Hochkamp, Königgrätzstr. 8th

Named as inventor:

John Jacob Küster, Franklin Park, N. J.

(V. St. A.)

Claimed priority:

V. St. v. America June 6, 1960 (34171) -

like body in a relaxed state larger than the container diameter.

It has also proven to be useful if the piston end face and the side face consist of one Part and preferably consist of a lower polyalkylene plastic, in particular polyethylene, while the sponge-like body made of foam, preferably made of polyurethane foam especially of low density, consists and has an open cell structure.

Due to the open cell structure of the piston body, the propellant can remove the ones in it Fill cavities and apply upward and sideways pressure on the closed piston surface and exercise the side portion of the piston. When the dispensing valve opens, it presses Press the piston and the product to be dispensed upwards and out through the dispensing valve. At the same time, the pressure difference between the propellant and the product space and / or through the sponge-like piston body, the sealing surface of the piston firmly against the container wall pressed and a penetration of filling material or propellant prevented. When stored and when closed Dispensing valve, the piston hugs the container wall sufficiently and prevents it a mixture between filling material and propellant. When the pressure is equalized, mixing is even then

509 779/75

prevents if a slightly more permeable material is used for the piston surface or for the cover will; this occurs in particular when the propellant is insoluble in the filling material to be dispensed is. The elasticity of the piston surface and the side wall of the piston as well as that on these surfaces when dispensed Pressure exerted and bearing cause the flexible surfaces to become smaller despite the presence of them Irregularities, such as protrusions or unevenness, adapt well to the container wall and there are leaks impede. Even a passage at the irregularly shaped longitudinal fold can often be avoided will. The flexible sponge body with an open cell structure also contributes to the evenness the flexible surface and prevents tilting or shifting of the piston surface, z. B. falling or sudden bumps. Because the piston has almost the entire cross section of the container fills, it holds the sealing surface securely in place and prevents passage of the propellant into the product chamber of the dispensing container. Preferably the ratio is Piston height to piston diameter at least 0.5, with the cavities still in the sponge-like shape Piston body the amount of propellant necessary for complete emptying of the filling material take up.

In the following, the container according to the invention will be based on an exemplary embodiment and in context will be described in more detail with the drawings. It shows

F i g. 1 is a partially sectioned side view of the dispensing container according to the invention,

F i g. FIG. 2 is a plan view of the FIG. 1 container shown,

3 shows a vertical section along the plane 3-3 through the FIG. 1 and 2 containers shown,

F i g. 4 is a plan view of the piston located in the container;

Fig. 5 is an exploded view of the main parts of the dispensing container;

F i g. 6 is a view of the elastic sponge-like piston in the relaxed state,

F i g. 7 shows a side view of a further embodiment of a filled and closed dispensing container Made of transparent material, whereby the operation of the product, piston and valve can be seen is and

F i g. 8 is a view of the FIG. 7 shown container after it has been completely emptied.

The pressure vessel shown in the figures is a cylindrical aerosol pressure can 11 made of metal, glass, Plastic or a combination of such materials. The can body has either one concave (Fig. 1 and 3) or a flat (Fig. 7 and 8) bottom 13 or 14, which is either crimped with the fuselage or cast in one piece or is shaped. At the top of the can 11 is a drawn, stamped or formed step-shaped or spherically shaped head part 15 is provided with an opening 17 which is smaller than the cross section the can is. In the case of pressurized cans made of metal, a cup-shaped valve socket 19 is inserted with the Valve 21 in the opening 17 with the can body crimped pressure-tight, while with other containers an appropriate valve socket and other seals can be used. About the viscous content to remove from the container, a downward dispensing nozzle 22 with a Button 37 is used, which, however, depending on the product, through a pressure valve with a spray opening or through another dispenser can be replaced.

The container can be cylindrical or a

have an elliptical, polygonal or any shape cross-section. His cross section and / or his Cross-sectional shape can even change, provided that the piston used is sufficient is elastic in order to nestle tightly against the container wall. For example, with a corresponding resilient flask glass containers in the form of so-called hour glasses are used, in which the circular or elliptical cross-section at the top and bottom of the container is larger than in the middle.

The valve opening 24 can preferably be on the sides of the valve, but just as well on the bottom the same be appropriate. If the valve reaches into the container and has openings on the side, the valve presses on the center of the piston when the product is almost completely removed, causing it a small depression is created, into which the content flows and from which it flows through the valve opening can be delivered. Such an arrangement supports the complete and lossless delivery of filling material and also prevents the piston from closing the valve inlet opening.

The piston 23 consists of a sponge-like body 25 with an open cell structure and a contiguous one Partial cover 27, which has a closed end face 29 and an apron-like Has side surface 31. The fluid filling material 33 is located above the end face 29, while the fluid propellant 35 is located below the piston and in its open cells. With the one shown Pistons, the cover and the sponge-like body are separate elements. The body is in that Cover fitted and is held by this in its shape. The one exercised by the sponge The force and the pressure difference create the tight fit of the lateral sealing surface during the delivery.

The body 25 can be made of any elastic, sponge-like material with an open cell structure exist. Polyurethane foam is preferred because this material has different strengths, Porosities and densities are produced and best adapted to the intended use can; it is also non-toxic and does not contain plasticizers, which is what happens when filling foodstuffs or pharmaceutical-cosmetic products is advantageous. The polyurethane foams used here have a specific gravity of 16 to 130gA.

In general, the piston cross-section corresponds to that of the container; he's in the drawings reproduced cylindrically. Although the diameter of the body 25 in the relaxed state is smaller than the interior of the container can be, it should preferably be at least as large as that of the interior of the composite piston enclosed by the side surface of the piston. In general is the piston body as large as the inside diameter of the container or slightly larger, so that the sealing side surface due to the elasticity of the piston body against the container wall

is pressed. This prevents propellant from escaping into the product space and vice versa at the same time a passage of the filling material into the space below the piston surface from which the filling material is avoided could no longer be removed. Even if the spongy body is smaller than that of the Sealing edge would be enclosed space and could not be sealingly placed against the side wall, so can such a composite piston still work effectively and separate the propellant from the product. If, for example, a relatively viscous mass, such as toothpaste, is used as the filling material, in this way, the pressures on both sides of the piston and the viscosity of the creamy filling material are balanced and the low flowability prevent passage through the relatively small gaps, which are present between the piston and the container wall. If the pressure equilibrium is disturbed, For example, when dispensing filling material, the propellant could pass the piston into the filling material chamber flow. However, due to the pressure difference between the filling material space and the propellant space, there is also a Pressure exerted on the edge areas of the piston cover in the direction of the container walls, whereby a passage between the piston and the piston wall is prevented. Then the piston moves above, drives out the product and comes to rest in a position in which there is pressure equalization. In this position of the piston, the viscosity of the contents is sufficient to allow the piston to move again to prevent. In the case of low-viscosity contents, the body 25 should be larger so that it covers the side surface of the Cover presses against the container and achieved such a strong seal that a passage of the Filling material behind the piston is prevented, especially when the dispensing valve is open.

The sponge-like body 25 adheres to the closed piston surface and to the side surfaces the cover and moves upwards with this cover when the product is dispensed. For better adhesion of the body to this cover, an adhesive can be used, or the individual elements can be made in one piece or in such a way that body and cover correspond in shape to one another. Together with the sealing cover the sponge-like body fulfills another important function by tilting, tilting or prevents or counteracts angular movement of the piston. If only a thin one flexible piston surface and sealing side wall are present, so it can easily be in the event of a sudden Shock, for example when the container is dropped, or even only due to the weight of the product, that the piston moves obliquely and thereby a passage opening between the product and Forms propellant. With a resilient body 25, the size of which is approximately the inner diameter of the Corresponds to the container, however, the slope is too small to allow passage. To the piston, however To protect against oblique movement, the ratio of height to diameter should be sufficient be large so that the coaxial position of the resilient piston is not overcome by the tilting forces will. In general, a height to diameter ratio of at least 0.5 is desirable, and it is seldom greater than 1.0. Another advantage of the sponge material with its open cell structure is

stands in the fact that the propellant gas or the liquefied propellant even with relatively thick The sponge penetrates the cell spaces and, when the container is full, only a little extra space below the Sponge claimed. The sponge can therefore rest on the bottom of the container, and so can the contents cannot tilt or move the piston, and the propellant can escape into the product space will be prevented.

ίο The piston cover, which consists of a flexible Surface and a circumferential sealing edge connected to this surface is made of flexible Made of flexible material, which adapts to the container wall despite small irregularities. Numerous plastics, such as polyethylene and other lower polyalkylenes, are suitable for this purpose. Polyvinyl chlorides, polyvinyl alcohols (for non-aqueous systems), and other similar plastics suitable; it can also be metal foils such as aluminum and tin foils, paraffinic or microcrystalline Waxes as well as other sealing substances can be used. In general the cover is a thin film less than 1.6 mm and preferably about 0.12 to 0.63 mm thick. The two Elements of the cover, namely the surface and the side face, can be the same or different Material. The surface and the side face can be connected to each other, or it can each individual element can be attached to the body 25. With some pistons, the cover can come off a coating, e.g. B. a synthetic plastic such as polyvinyl chloride, which on the Sponge applied, melted or dissolved on the sponge surface, so that a Protective skin around the body 25 forms.

The piston surface can have any shape, e.g. B. it can match the shape of the upper part of the dispensing container match, which is generally not necessary or not always It is advantageous because the flexible piston is in any case the upper surface of the container when the product is drained adapts and the entire container contents, as in F i g. 8 shown. Most preferred becomes a disc-shaped piston surface, while the piston body has a vertical cylinder a flat face. The cylinder surface of the piston is enclosed by a sealing surface, which generally extends downwardly at least 6.5 mm from the piston face; in some In cases, however, the circular sealing area can only have the dimensions of the surface, provided that a sufficient seal is possible. The edge surface of the cover of the piston is the piston part pressed against the container wall, which ensures the required sealing engagement. In practice it was found that a bag-shaped piston cover made a thin plastic film (polyethylene film from 0.025 mm) is sufficient, even if the end of the bag does not fit tightly and without creases to the end of the piston. The cover is sufficient as long as it is impermeable in its end face and for as long the sides are in sealing engagement with the container wall.

Pressure vessels with the training according to the invention are no more expensive than the previous pressure cans; they can be sealed and quickly and effectively

result in a product that is better in many respects than the previously known dispensing containers. They can Hitherto customary valves and containers are used, with only the correspondingly shaped Sponge piston is needed. Such foam pistons can be pressed and cheap easily insert mechanically into the container.

Various pressure cans with the various types of piston shapes, covers and arrangements for holding them on the piston body as well as various filling goods which were filled, stored, used and examined were examined. It has been found that toothpaste, hair care products (as an emulsion), powder and even water can be removed almost completely from the container without propellant getting into the product space. Experiments have shown that in general 95 to 99 ⁰ Zo of the filling material is released again, even when more viscous products are used as filling material. This degree of release is much better than in the case of the previously known containers, including the containers with a riser pipe, which in general only release 85 to 90% of their contents.

In some experiments, the operation of the dispensing container has been carefully examined by using it as a container a glass cylinder was used. When the dispensing valve was opened, the product was squeezed out immediately, the piston moving accordingly at the same time. The propellant did not get to the filling material, and the container walls were cleaned by the movement of the sealing piston surface wiped off.

About the resistance of the container, especially against irregularities in the container walls To check, they were deliberately dented in various places and then examined. It turned out that the sponge-like piston element is the sealing surface of the piston presses firmly against the dented wall section and does not let any propellant through. With other attempts the containers have been dropped several times and subjected to hard knocks, such as those used for example can occur during shipping. The piston was not displaced by falling or did not tilt and there was no exchange of contents within the container.

These stresses on the dispensing container according to the invention showed that they could be used without further ado and also theoretically in many respects the aerosol cans currently on the market superior hind. Another advantage is that the manufacturer now offers more products Can pack pressure that were previously unsuitable for aerosol delivery, and that this is economical Manner, whereby a packaging is obtained which provides the consumer with the best possible benefits granted.

Claims (5)

Patent claims: ίο 1. Pressure vessel for dispensing more flowable Substances with a space for the substance to be dispensed and a space for the propellant, which Spaces are separated from each other by a piston that is slidably arranged in the container, whose end face facing the space for the substance to be dispensed is impermeable, thereby characterized in that the piston (23) has a sealing which extends around its end face (29) and extends to the propellant space Has side surface (31), wherein in the cover (27, 39, 31) formed in this way, a sponge-like Body (25) is arranged and piston end face (29) and side face (31) from one thin, pliable material. 2. Pressure vessel according to claim 1, characterized in that the body (25) is preferably is at least as large as the space enclosed by the side surface (31). 3. Pressure vessel according to claim 1 and 2, characterized in that the body (25) in relaxed state is larger than the container diameter. 4. Pressure vessel according to claim 1 to 3, characterized in that the piston end face (29) and the side surface (31) from one part and preferably from a lower polyalkylene plastic, in particular polyethylene, while the body (25) made of foam, preferably made of polyurethane foam, in particular of low density, and has an open cell structure. 5. Pressure vessel according to claim 1 to 4, characterized in that the ratio of Piston height to piston diameter is at least 0.5 and the cavities in the body (25) take up the amount of propellant necessary to completely empty the contents. Considered publications:
French patent specification No. 1046 624. 1 sheet of drawings