The invention relates to apparatus and method for producing containers by working plastic material, the containers being arranged for containing a fluid product.[0001]
Containers are known obtained by thermo-forming a sheet material, for example a film of plastic material, arranged for containing a fluid or semi-fluid product, which may be poured through a suitable pouring outlet of the container.[0002]
These containers are opened by removing therefrom an end portion of container so as to obtain an opening in said containers.[0003]
These containers have a drawback consisting in that once they have been opened they can not be closed again and therefore an undesired pouring may take place, so causing a certain consumption of said product. Furthermore, outflow of product may cause soiling of parts of the body and/or clothes of a user as well as of the region surrounding the container.[0004]
International patent application WO 95/12531 discloses a container suitable for being closed again, comprising a container body arranged for containing a fluid product and a self-closing valve arranged for allowing said product to be poured, once the container has been opened, only when a pressure is applied by a user on the walls of the container body.[0005]
In particular, the aforesaid patent application discloses a first version of container comprising a valve in which a first film and a second film define a duct through which the product is distributed.[0006]
The first film constitutes a hemispherical dome facing the second film, which, on the contrary, is substantially undeformed so as to form a substantially flat portion.[0007]
During pouring, the fluid product may flow out from the container passing through the duct defined between the hemispherical dome and the underlying flat portion. After pouring, the user has to deform the hemispherical dome, substantially flattening it, by applying on the hemispherical dome a slight pressure in order to bring the first film in contact with the second film, so causing the duct to be closed.[0008]
Therefore, the container described in WO[0009]95/12531 can not be closed again without intervention of the user.
International patent application WO[0010]95/12531 further discloses a second version of container in which the distribution valve is provided with a pipe suitable for allowing the product to flow out, said pipe being defined by a first film and a second film which, as previously described, in a distributing position, are arranged so as to constitute, respectively, a dome and a flat portion. In a closing position, on the contrary, the first film may be deformed so that the dome, having initially a convex profile towards the outside of the container, constitutes a concave portion which may be received into a suitable recess obtained from a simultaneously deformation of the second film.
In this manner, the valve hermetically closes the container, so preventing the product from being distributed even in the case in which a certain pressure is applied on the walls of the container body.[0011]
International patent application WO 99/10252 discloses a container obtained by thermoforming a sheet material and comprising a closing valve arranged for allowing the product contained in the container to be poured in a partial and deferred manner.[0012]
The container comprises a lower, relatively thick, film having a shaped profile so as to define a container body and an upper film thinner than the lower film and arranged in substantially flat position. The lower film and the upper film are welded along the border of the container.[0013]
At one end of the shaped film there is a region comprising a plurality of recesses mutually separated by protuberances arranged therebetween. The upper film and the protuberance cooperate for forming the closing valve preventing the product contained in the container from being distributed when no force acts on the aforesaid container body.[0014]
Working of the valve is substantially based on the deformability of the upper sheet: in fact, once the pressure which caused pouring of the product is finished, the upper sheet is forced to penetrate, at least partially, into each one of the recesses, so being in contact with the protuberances arranged therebetween and thus preventing the product from further flowing out.[0015]
A drawback of the above mentioned containers is that their production is very complicated.[0016]
Obtaining substantially hemispherical recesses and domes is, in fact, quite difficult and may remarkably compromise the productivity of the plants arranged for producing such containers.[0017]
Furthermore, in case of containers made with a pair of films having different thickness, problems can take place connected to differences of thermal expansions which make problematic coupling the films.[0018]
An object of the invention is to improve containers obtained by thermoforming and provided with a controlling valve for distributing a product contained therein.[0019]
A further object of the invention is to obtain a thermoformed container in which a valve may be easily obtained suitable for effectively controlling the flow of product through a distributing pipe.[0020]
A further object of the invention is to obtain an apparatus and a method for producing thermoformed containers provided with a controlling valve For distributing a fluid product contained therein.[0021]
In a first aspect of the invention, a container is provided preferably obtained by thermoforming a first film and a second film of thermoformable material, comprising container body means arranged for containing a fluid product and pipe means arranged for controlling distribution of said product from said container, characterized in that said pipe means defines a non-rectilinear path for said product along progressively decreasing sections of said pipe means.[0022]
In an advantageous version, the first film defines a first concave portion of said pipe means, whereas the second film may define a second concave portion of said pipe means extending internally to said first portion.[0023]
In a second aspect of the present invention, a container is provided, comprising container body means arranged for containing a fluid product and pipe means arranged for controlling distribution of said product from said container, characterized in that, said pipe means comprises a first concave portion and a second concave portion, said second concave portion extending internally to said first concave portion.[0024]
Owing to these aspects of the invention, it is possible to obtain a container provided with pipe means which define valve means suitable for controlling outflow of a fluid product.[0025]
The pipe means preferably define a curvilinear path along which, at the end of the distribution of the product, a small bubble of air is sucked back from the external environment into the container; such bubble of air is trapped between the pipe means so opposing undesired outflows of product.[0026]
Furthermore, as the pipe means has a section having a very Little surface extension and the fluid product flows with friction on the walls of said pipe means, pouring is very difficult, if not absolutely prevented, even in case in which the air bubble has penetrated into the container body means and therefore does not further oppose the passage of the product through the pipe means.[0027]
It has been verified that the pipe means according to the invention prevents dripping or loss of product even in case of highly fluid product.[0028]
Since the liquid outflow inhibiting effect is not due to contact between the two films constituting the valve means, but is achieved by forming pipe means sufficiently narrow and having walls which are constantly separated by a pre-established distance, it is not necessary to use film of different thickness, and in particular thin films, in order to have high deformability.[0029]
That allows to remarkably simplify the producing process since film of any thickness may be used, particularly films having thickness equal to each other, which may be simultaneously thermoformed by means of a single apparatus.[0030]
In a third aspect of the invention, an apparatus for producing containers is provided, comprising thermoforming means arranged for thermoforming first film means and second film means of thermoformable material for obtaining said containers, characterized in that said thermoforming means comprises forming mould means arranged for obtaining into said containers pipe means having a non-rectilinear path suitable for inhibiting undesired outflows of product after opening.[0031]
In a fourth aspect of the present invention, an apparatus for producing containers is provided, comprising thermoforming means arranged for thermoforming thermoformable sheet material for obtaining said containers, characterized in that said thermoforming means comprises forming mould means provided with a protruding element arranged for deforming said thermoformable sheet material.[0032]
In an advantageous version, the thermoforming mould means comprises first half-mould means provided with at least one cavity arranged for deforming the first film in order to obtain a first concave portion of said pipe means, and preferably, second half-mould means provided with at least a protruding element arranged for deforming the second film in order to obtain a second concave portion of said pipe means, said second concave portion extending internally to said at least one cavity.[0033]
Owing to this aspect of the invention, it is possible to obtain an apparatus allowing to effectively produce containers provided with pipe means acting also as distributing valve arranged for controlling outflow of a fluid product from said containers. Such apparatus is suitable for simultaneously working a pair of films of any thickness by thermo-welding and thermoforming said films in order to obtain the desired containers.[0034]
In a fifth aspect of the invention, a method for producing containers is provided, comprising thermoforming thermoformable sheet material for defining in said containers container body means arranged for containing a fluid product and pipe means arranged for controlling distribution of said product from said containers, characterized in that said thermoforming comprises defining in said pipe means a non-rectilinear path suitable for inhibiting undesired outflows of product after opening.[0035]
In an advantageous version, said defining comprises obtaining in the pipe means a first concave portion and a second concave portion of said sheet material extending into said first concave portion.[0036]
Owing to this aspect of the invention, it is possible to obtain a method for producing containers provided with pipe means acting also as distributing valve arranged for controlling outflow of a fluid product from said containers.[0037]