Abstract:
A method for sealing a pouring opening of a container and a container with corresponding structure are described. A sealing element formed of a flat laminated material that covers the pouring opening is connected peripherally of said pouring opening, preferably by welding, to a rim portion of the container. Furthermore, the sealing element is connected e.g. by adhesion, to a lid covering the pouring opening of a closure capmounted on the container. The adherence force of the connection between the closure cap and the sealing element is greater than that between the sealing element and the rim portion of the container. In order to break the sealing element away from the rim portion of the container, the lid must be pivoted away. The arrangement consisting of a container and a closure cap is particularly suitable for storing powdery chemical substances, such as are used e.g. in photographic developing equipment. Opening the lid for the purposes of gaining access to the contents of the container may be effected mechanically.

Description:
[0001]    This application is a Continuation of PCT application Ser. No. PCT/EP00/0886 filed Sep. 12, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to a method for sealing a pouring opening of a container by means of a sealing element covering the pouring opening and formed of a flat laminated material, according to the preamble of claim 1. Furthermore, it relates to a container having a correspondingly sealed pouring opening.  
           [0004]    2. Descritption of the Related Art  
           [0005]    The invention relates especially, but not exclusively, to containers for storing photochemical substances for use in photographic developing equipment. Three or more containers filled with different photochemical substances are frequently employed in such equipment. Hithert use has mainly been made of liquid substances that are stored in containers which have to be manually inserted into the photographic developing equipment and emptied into storage means located therein. Despite the fact that powdery substances offer many advantages in comparison with liquid substances, the use thereof has generally been avoided until now since powdery substances are sensitive to moisture and can easily become unusable in the environments in which they are employed due to absorption of moisture. Moreover, until now, powdery substances could not be handled in a dust-free manner in photographic developing equipment.  
           [0006]    Consequently, there is a need for a hermetically sealed container for storing preferably powdery substances, without running the risk that these substances will become unusable due to the effects of moisture or other influences, whereby the container should be capable of being mechanically opened and emptied in a dust-free manner in an equipment or device in which the substances are processed.  
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the invention to provide a hermetically sealed container for storing chemical, preferably powdery substances, without running the risk that these substances will become unusable due to the effects of moisture or other influences. Another object of the invention is to provide a hermetically sealed container for storing chemical, preferably powdery substances, which may be mechanically opened and emptied in a dust-free manner in an equipment or device in which the substances are processed.  
           [0008]    The method according to the invention for sealing a pouring opening of a container, includes the steps of providing a closure cap mountable on the container for covering the pouring opening, connecting a sealing element formed of a flat laminated material to a wall portion of the closure cap covering the pouring opening, mounting the closure cap comprising the sealing element on the container so that the sealing element engages with a rim portion of the container, and subsequently producing a connection between the sealing element and the rim portion whilst maintaining said engagement, whereby the adherence force of the connection between the closure cap and the sealing element is selected to be greater than that between the sealing element and the rim portion.  
           [0009]    A feature of the invention is that the pouring opening of the container can be closed in hermetically sealed manner by means of the sealing element formed of a flat laminated material that can be readily formed gas-tight and/or moisture-proof, so that e.g. moisture-sensitive powdery substances can be stored therein for long periods and in damp conditions without problems thereby arising. The sealing element may be connected to a portion of the container located peripherally of the pouring opening such that it can be peeled off, or, it may incorporate a weakened line along which it can be torn open. The hermetic sealing of the container opening is formed in such a manner that emptying the contents of the container in a device or equipment, e.g. a photographic developing equipment, does not in principle require operating personnel. Rather, this process can be performed mechanically in the equipment or the device due to a special design of a closure cap that is mountable on the container and also has the sealing element firmly attached thereto. If so desired however, the container could also be opened manually. After use, it is preferred that the closure cap be re-closed either mechanically or manually. Residual substances in the container, which may, for whatever reason, still be present in the container after it has been emptied, are thereby effectively prevented from accidentally entering the environment e.g. when removing the container from the apparatus or during a onward transportation thereof.  
           [0010]    In a container according to the invention having a pouring opening, in which a sealing element covering the pouring opening and formed of a flat laminated material is connected to a rim portion of the container peripherally of the pouring opening, the sealing element is further connected to a wall portion of a closure cap mounted on the container, said wall portion covering the pouring opening, whereby the adherence force of the connection between the closure cap and the sealing element is greater than that between the sealing element and the rim portion of the container.  
           [0011]    Due to its construction, the container according to the invention is not only simple to fabricate, but it can be stored, transported and handled in dust-free manner when in use, and can be disposed of after such use without problem.  
           [0012]    Although the invention has special advantages when used for powdery substances, it should be understood that the invention is not limited thereto, but can also be used, to advantage, for liquid substances should this be desired. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The invention will be described in more detail hereinafter with the aid of the embodiments and reference to the drawings. In the drawings:  
         [0014]    [0014]FIG. 1 is a partially fragmented, longitudinal sectional view of an arrangement of a container and a closure cap according to an embodiment of the invention,  
         [0015]    [0015]FIG. 1A is a detail of the arrangement of FIG. 1 for the purposes of illustrating the mounting of the closure cap on the container,  
         [0016]    [0016]FIG. 2 is a view similar to FIG. 1 with the closure cap of the arrangement in an open position,  
         [0017]    [0017]FIG. 3 is a top view of a sealing element made of a flat material according to a modified embodiment of the invention when viewed along the sectional line III-III in FIG. 1, and  
         [0018]    [0018]FIG. 4 is a perspective overall view on a reduced-scale of the arrangement of a container and closure cap according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    In the embodiment shown in FIG. 1, the general reference number  1  denotes a container. The container  1  is only shown in fragmentary manner at a portion thereof close to a neck portion  3  defining a pouring passage  2 . The rest of the container  1  may be formed in any suitable manner in dependence on the fluid stored therein and the intended use thereof. The container  1  is preferably a blow-moulded part of a suitable synthetic material. Basically however, metallic materials could also be used for the container.  
         [0020]    A closure cap covering the pouring passage  2  and bearing the general reference  4  is mounted on the neck portion  3 . The closure cap  4  may, if so desired, be mounted on the neck portion  3  by means of a screw-type connection (not shown). However, the closure cap  4  is preferably attached to the neck portion  3  by a force-fit, using a so-called bounce-on operation, whereby, as is shown in FIG. 1A, a projection  6  projecting radially inwardly from the inner periphery of a rim  5  of the closure cap is made to engage below a projection  7  extending radially outwardly from the outer periphery of the neck portion  3 . The projections  6 ,  7  may extend in continuous manner peripherally of the cap rim  5  and neck portion  3 , respectively. However, they could also be in the form of a plurality of peripherally distributed projecting sections.  
         [0021]    A pair of longitudinal ribs  8  may be formed on the outer periphery of the neck portion  3  at diametrically opposite positions thereof, each rib engaging in a longitudinal recess  9  in the inner periphery of the cap rim  5  so as to guide the closure cap  4  longitudinally when it is being bounced onto the neck portion  3  and to ensure that the bounce-on operation can only be effected when the closure cap  4  is aligned in a predetermined manner relative to the neck portion  3 .  
         [0022]    In the present embodiment of the invention, the closure cap  4  is provided with a lid  11  which is hinged at  10  to the cap rim  5 , thereby the lid forms at least part of the bottom of the closure cap. The lid  11  can be pivoted about the point of articulation  10 , which is preferably a film hinge formed by a reduction in the cross-section of the wall, from a closed position, in which the lid  11  covers the pouring passage  2 , into an open position (c.f. FIG. 2). Furthermore, apart from at the point of articulation  10  itself, the lid  11  may be peripherally connected through a number of break-away webs  12  (only one web is shown in FIG. 1) to the cap rim  5 . Thereby a tamper proof function is obtained, in that a pivotal movement of the lid  11  from the closed position into the open position requires an external force to be applied to the lid  11 , which is sufficiently large as to break the webs  12 . The intact state of the webs  12  therefore indicates to a user that the contents of the container have not been manipulated in any way prior to the usage thereof for their legitimate purpose.  
         [0023]    An inter-engaging hook  13  is provided on the upper face of the closure cap  4  so as to retain the lid  11  in its closed position when the lid  11  is pivoted back from the open position into the closed position. During this operation, a rim portion of the lid  11  engages against the inter-engaging hook  13  thereby bending it somewhat radially outwardly. After the lid  11  has passed-by the inter-engaging hook  13  springs back into its starting position wherein the inter-engaging hook  13  projects beyond a rim portion of the lid  11 . When the lid  11  is next opened, the inter-engaging hook  13  can spring back in an analogous manner. However, the inter-engaging hook  13  may be constructed in such a manner that a renewed opening of the lid  11  cannot occur or can only be effected under more difficult conditions.  
         [0024]    A lug member  16  having e.g. a T-shaped configuration may be formed on the upper face of the lid  11  in order to enable an opening force to be applied to the lid  11  either manually or mechanically.  
         [0025]    As is shown in FIG. 1, a sealing element  18  formed of a multi-layered, flat laminated material is placed on an annular rim portion  16  of the neck portion  3  so as to close the pouring passage  2 . Although the sealing element  18  could be made of other laminate materials, it is preferred that the sealing element  18  includes a barrier layer of a gas impervious film material, preferably of a suitable metal, such as aluminium. The barrier layer not only prevents the gases from penetrating or diffusing through the sealing element  18  but it also reliably seals the interior of the container  1  from the entry of moisture. Furthermore, thin layers of synthetic materials are applied to the opposite surfaces of the barrier layer. A preferred synthetic material is a material from the group of polyolefines, whereby polypropylene (PP) is preferred on the surface of the sealing element  18  facing the lid  11  whilst polyethylene (PE) is preferred on the surface facing the neck portion  3 . Furthermore, a thicker layer of a suitable foamed material is preferably provided between the barrier layer and the layer of synthetic material facing the lid  11 , thereby providing the sealing element with padding-like properties. Furthermore, if desired, a thin isolating layer of another synthetic material, e.g. polyethylene terephthalate (PET) may be provided between the barrier layer and the layer of synthetic material facing the neck portion  3 .  
         [0026]    A sealing element  18  formed as previously described may include e.g. an aluminium-barrier layer having a thickness of ca. 30 μm and a foamed layer consisting of a material, such as is obtainable e.g. under the trade name Alkozell from Alfelder Kunststoffwerke Herm. Meyer GmbH, Hildesheimer Str. 78, D-31061 Alfeld, and having a thickness of ca. 1.5 mm and a density of e.g. 300 g/m 3 . The remaining layers of synthetic material may be between 10 and 20 μm thick, whereby the isolating layer of PET may be thinner than the other layers of synthetic material. However, it should be understood that the invention is neither limited to the aforesaid construction of the sealing element  18  nor to the particular thickness dimensions indicated.  
         [0027]    According to the invention, the sealing element  18  is connected to the upper rim portion  17  of the neck portion  3  and also to the lower surface of the lid  11  in a suitable manner. In particular, the connection thereof to the lower surface of the lid  11  is such that the latter cannot be pivoted into the open position without previously separating the sealing element  18  from the neck portion  3 .  
         [0028]    In a first step a connection of the sealing element  18  to the lower surface of the lid  11  is effected whilst the closure cap  4  is still not mounted on the neck portion  3 . The connection is preferably produced by using an adhesive, and most preferably by means of a hot- or multi-component adhesive. Suitable types of adhesive are known to a skilled person. A suitable hot adhesive called Lunamelt® PS 3406C can be obtained for example from H. B. Fuller GmbH, An der Roten Bleiche 2-3, D-21335 Lüneburg. The adherence force between the sealing element  18  and the lower surface of the lid  11  should be greater than the adherence force between the sealing element  18  and the upper rim portion  17  of the neck portion  3 . This can be achieved by selecting an adhesive having a suitably high specific adherence force and/or by means of an area for the application of the adhesive suitably dimensioned.  
         [0029]    In a further step a connection between the sealing element  18  and the rim portion  17  of the neck portion  3  is effected, after the closure cap  4  and the sealing element  18  adhering thereto has been mounted on the neck portion  3 . The connection is preferably produced by a welding process, and especially by means of an induction welding process. The induction welding of synthetic materials is known to a skilled person, so that more specific details in regard to this technique are superfluous. The barrier layer of metallic material for the sealing element  18  is effective, in the case of an induction welding process, such as to cause the development of heat to be concentrated in a portion of the sealing element  18  between the barrier layer and the rim portion  17 , whilst the remaining portions of the sealing element  18  are essentially unaffected thereby. The welding pressure required for the welding process is applied by selecting the opposed positions of the respective inter-engaging projections  6 ,  7  on the cap rim  5  and the neck portion  3  in such a manner that, in the mounted position, the closure cap  4  and the sealing element  18  will be pressed with a particular force against the rim portion  17  of the neck portion  3  and retained by this force during the welding process. The foamed layer of the sealing element  18  is deformed to a certain extent by the aforesaid retention force. The pressure applied will thereby be distributed uniformly around the periphery of the rim portion  17  and a homogenous welded connection thereby obtained. It should be understood that connection techniques other than welding could be used, if a container  1  of a metallic material is provided. In this case, an adhesive connection between the sealing element  18  and the rim portion  17  of the neck portion  3  would be suitable. An adhesive connection of this type could also be provided instead of a welded connection if the parts that are to be connected both consist of a synthetic material.  
         [0030]    The adherence force between the sealing element  18  and the lid  11  on the one hand, and between the sealing element  18  and the rim portion  17  of the neck portion  3  on the other are made to differ. The effect is thereby achieved that when pivoting the lid  11  by means of an external force exerted thereon, the connection of the sealing element  18  to the rim portion  17  can be overcome and access to the pouring passage  2  thereby obtained without simultaneously detaching the sealing element  18  from the lid  11 . It has been established that in the case of a closure cap  4  having a nominal diameter of 14 mm and a thickness of the rim portion  17  of just a few millimetres, the adherence force between the sealing element  18  and the rim portion  17  should amount to e.g. circa 20 N, so as to obtain reliable sealing of the pouring passage  2  on the one hand, and to prevent premature detachment of the sealing element  18  from the rim portion  17  on the other.  
         [0031]    In the embodiment of the invention described hereinabove, it was assumed that when pivoting the lid  11  into the open position, the sealing element  18  would be completely detached from the rim portion  17  of the neck portion  3  by virtue of a so-called “peeling” process. In contrast thereto, a modified embodiment shown in FIG. 3 envisages that a weakened location in the form of a rupture line  19  be provided along an inner portion  20  of the sealing element  18  which spans the pouring passage  2  so that the sealing element  18  will be ruptured along this line when pivoting the lid  11  upwardly. Under these circumstances, the magnitude of the adherence force between the sealing element  18  and the rim portion  17  of the neck portion  3  can be selected in an arbitrary manner. It merely has to be ensured that the adherence force be greater than the force which has to be applied in order to rupture the sealing element  18  along the rupture line  19 . Furthermore, it should be understood that in the case of this modified embodiment of the invention, the connection between the sealing element  18  and the lid  11  is confined to a portion of the sealing element  18  which is bounded by the rupture line  19 .  
         [0032]    Furthermore, as can be appreciated especially from FIG. 4, the closure cap  4  may be provided with guide rails  14 ,  15  which project radially outwardly from diametrically opposite positions of the cap rim  5 . With the aid of these guide rails  14 ,  15 , the closure cap  4  can be inserted together with the container  1  into a suitably shaped receptacle of a device which may be provided with mechanical means for pivoting the lid  11  into the open position and emptying the contents of the container.  
         [0033]    Although the invention was described hereinabove on the basis of embodiments in which the closure cap comprises a lid which simultaneously forms the bottom or end wall of the closure cap, opening of the container could also be effected by means of a closure cap which does not have a lid but which can be lifted or moved by an external force in an axial direction relative to the container neck in order to exert a force on the sealing element which will enable it to become released from the container neck. Numerous other modifications and variations of the present invention are possible in the light of the above teaching. It is therefore to be understood that the invention may be practiced otherwise within the scope of the invention indicated by the appended claims