Technical field

The present invention relates to a venting cap or container for containing viscous or liquid products. The present invention relates more particularly to a cap or container which allows an automatic escape of excess pressure generated inside said container.

Background of the invention

Containers for containing viscous or liquid products have been extensively described in the art as well as their numerous possible applications. Some food products like fruits juices tend to ferment rather rapidly after the containers in which they are packaged have been opened. The fermentation involves gases which cause internal gas pressure to increase, especially if there is relatively little "head space" above the level of the food product in the container. Apart from fermentation, excessively high internal gas pressure in a container can arise in other ways, for example by the release of gaseous oxygen provided by the slow decomposition of hypochlorite or other bleaches or because of an increase of temperature.

Such a phenomenon can create safety issues in that the pressure which builds up inside a hermetically closed container might cause the closure of said container to blow therefrom. Also, if the container is made of plastic material, it can be deformed sufficiently to render it commercially unacceptable from a consumer's viewpoint.

In the art, solutions to these problems have been proposed, for instance by designing containers of specific shapes, whereby the container has optimal resistance to pressure build-up, limiting the degree of deformation. This type of solution has the drawback that it limits the flexibility of shape, material selection and material thickness when designing such containers.

Other solutions relate to various venting caps for such containers, which allow the gas generated inside the container to escape. Such caps have been described for instance in EP-B-0 187 106 issued September 21, 1988 and entitled "A device for the sealing of containers, having a valve to allow the automatic escape of gases under excess pressure", in GB-2 170 790 issued August 3, 1988 and entitled "Hand-held dispenser with automatic venting" and in WO-91 03406, entitled "Pressure venting closure". These venting caps have the drawback that they are rather complicated in structure and thus involve expensive manufacturing.

It is therefore an object of the present invention to provide a venting cap or container. It is a further object of the present invention to provide a venting cap which is more simple than the caps of the prior art. Indeed, the present invention allows to reduce the number of parts or of operations for the manufacturing of said venting cap or container over the venting devices disclosed by the prior art. Furthermore, the present invention has the advantage

that it is applicable not only to the cap but also to the body of a container.

Other venting devices of the prior art comprising annular liner have been described for instance in GB-2 032 892. This cap comprises top recesses and a liner juxtaposed to the top of the cap which allows for pressure relief via said recesses and a thread in the side of the cap. The cap of the previously mentioned prior art is incompatible for use with a container wherein the contained liquid is to be dispensed through a small opening. Thus, it does not work satisfactorily on small orifice or opening of containers. It is therefore another object of the present invention to provide a venting cap or container which allows for the dispensing of the contained liquid through a small opening while ensuring appropriate venting.

An advantage of the present invention is that the venting system is applicable to the cap of a container or to the body of said container or to both. This allows for a greater flexibility in designing various containers with different venting capacities. This flexibility is increased in that the venting capacity can be very easily adjusted as will be understood from the following description.

Summary of the invention

Referring to Figure 1 the present invention is a container (2) and/or a cap (1) for said container comprising a peripheral lateral wall (3) . Said lateral wall comprises perforations (4) and said container and/or cap further comprises an elastic band (5) which covers said perforations on the outside of said lateral wall.

According to the present invention, the extra pressure is released through said perforations in said lateral wall as

said elastic band expands elastically. This system acts like a valve. The rate of flow of the gases from the container can be controlled by the number and size of perforations and the elasticity of the band. The pressure at which venting occurs can be controlled by the elastic properties of the band.

Detailed description of the invention

In order to make the invention more readily understood, reference will now be made to the accompanying drawings, in which ; Figure 1 is a fragmentary, vertical sectional view of the venting cap in accordance with a preferred embodiment of the invention. Figure 1 shows the relative positions of the perforations of the lateral wall and an elastic band at normal internal gas pressure; (hereinafter closed position) Figure 2 is a top plan view of a venting cap of Figure 1, taken along line A-A of Figure 1.

Figure 3 is a fragmentary, vertical sectional view similar to Figure 1 but shows the radial elongation of the elastic band as extra pressure is generated inside the container (hereinafter open position) . As it elongates radially said band uncovers the perforations in the lateral wall of the cap, to allow excess gas pressure to be vented through the perforations.

The cap (11 according to the present invention comprises a body (7) . The body of said cap comprises a lateral wall (3) and a top (9) . The container (2) according to the present invention comprises a lateral wall (3) and a base. At least a portion of the inside of the wall of the body of the cap comes into contact with the exterior of a portion

(neck) (6) of said lateral wall of the container onto which the cap is affixed. The cap according to the present

invention can be permanently or removably affixed to the container by a variety of means. A cap according to the present invention can be removably affixed so as to allow for dispensing of the product without having to be removed from the container, and be removed for instance when it is needed to dispense large amounts of liquid, or to allow for the container to be refilled. Such caps can be screwed or snapped onto the container.

The cap according to the present invention may further comprises a closure. A variety of closures are available to the man ordinary skilled in the art which are suitable for use herein, provided said closures ensure a leak-tight closure to the exterior opening of said cap. Such closures include flip top closures or anti clogging closures (ACC) , or means to allow the dispensing of the contained liquid as a spray.

Although not limited thereto, the container according to the present invention is preferably made of any plastic material available to the man skilled in the art, i.e. high or low density polyethylene (HDPE or LDPE) , polypropylene (PP) , polyethylene terephtalate (PET) . The container can also be a rigid container such as for instance metal like spray bottles. The cap according to the present invention is preferably made of the following compounds, high or low density polyethylene (HDPE or LDPE) , polypropylene (PP) , polystyrene or other polymers commonly used in packaging.

It is essential for the purpose of the present invention that said lateral walls (3) of the cap (1) and/or the container (2) comprise perforations (4) to let gases through to the ambient, thereby ensuring pressure relief. The shape, size and the number of the perforations (4) may be easily selected so as to determine at which level of pressure the extra gases will release through said perforations (4) . Thus, the shape, the size and the number

of the perforations are critical for the present invention. It is therefore an advantage of the present invention that the number, the shape and the size of perforations will be available to control the flow rate of the gases from said venting container or cap.

Furthermore, the location of said perforations is also critical for the present invention. Said perforations may be located on the cap (1) , the container (2) or both. In the embodiment where said perforations (4) are located on said cap (1) , and the totality of the interior of said lateral wall (3) of said cap (1) comes into contact with a portion (neck) (6) of the outside of the lateral wall (3) of said container (2) , then both lateral walls (3) of said cap (1) and said portion (6) of said container must comprise perforations (4) . Said perforations must coincide when said container is closed by said cap.

Another essential element of the venting container or cap according to the present invention is an elastic band (5) . Said elastic band must be shaped, dimensioned and situated on the outside of said lateral wall so as to cover said perforations. It is also critical for the present invention that said elastic band (5) covers the perforations (4) on said lateral wall (3) in a leak-tight manner. Said elastic band must be impermeable to the liquid contained in the container, so as the liquid does not pass through the elastic band. Said band must be tight enough to seal the container making it liquid-tight when it is in closed position. The degree to which said elastic band needs to be pressed against the exterior of said lateral wall depends mainly on physico-chemical properties of the liquid contained in the container and the compressibility of the elastic material.

Furthermore, the elastic band (5) must be flexible so that it may flex as the pressure builds up inside said container.

In an open position the gas escapes through the perforations (4) and passes between the lateral wall (3) and the expanded elastic band (5) . As the pressure drops, the elastic band returns to its original position on the surface of said lateral wall blocking the perforations and providing leak-tightness again. The elastic band according to the present invention has therefore the property to expand when the pressure in the container builds up and also to retract when said pressure drops.

The selection of an appropriate material for such band will depend on the liquid to be contained in the container, and thus will vary in each instance. The critical factors to be met by said material are impermeability, flexibility and chemical compatibility or resistance. Suitable elastic band for use herein can be made of a highly cross linked material, like silicones, ethylene-propylene rubber (EPDM) , polyurethane, inert rubber or highly crosslinked ethyl vinyl acetate.

In a preferred embodiment of the present invention the elastic band is a tubular concentric sleeve. In another embodiment of the invention the elastic band is a patch. Said patch is affixed on the outside of the lateral wall of the cap or the container by three or only two of its sides.

It is possible to combine patches and tubular sleeves in one embodiment, or to combine two tubular concentric sleeves covering perforations of different sizes. Additionally, this elastic sleeve or patch can also be used as a label.

There are many possible variants to provide said venting cap or container. An embodiment of the present invention

is a venting cap. Said venting system can be located either on the inferior or on the superior of the side wall of the body of the cap.

In another embodiment of the present invention is a venting container. Said venting system will be located on the upper exterior part of the lateral wall.

In another embodiment of the present invention, there are several venting systems arranged on the exterior of the lateral wall of said body of the cap or body of the container or of both.

The containers according to the present invention are destined to contain numerous possible liquid or viscous products such as food products like fruits juices, detergent compositions comprising hypochlorite or other bleaches.

Example

Figure 1 illustrates a venting cap generally designated by the number (1) , adapted to be employed with a container (2) having a neck portion (6) . This cap according to the invention comprises a body (7) and a closure (8) . The body of said cap comprises a side wall (3) and a top (9). Said side wall comprises an inferior (10) and a superior part (11) . The inferior side wall (10) of the body (7) comes into contact with the exterior of the neck (6) of the container (2) onto which the cap (1) is affixed. It is essential that said side wall comprises means to let gases through to the ambient, thereby ensuring pressure relief. In the present example, these means are located on the superior part (11) of the body of the cap. Said cap comprises perforations (4) along the length of its perimeter covered by a concentric elastic

tubular sleeve (5) . Contact between the bottle neck and the cap is leak free.

In the embodiment relating to the previous example the material used for the container is a high density polyethylene (HDPE) whereas the material used for the cap is a polypropylene (PP) .

The sleeve is made of a highly crosslinked material, like ethyl vinyl acetate.

The bottle described in the previous example is destined to contain liquid detergent bleach containing compositions comprising either hypochlorite or peroxygen bleaches.