Abstract:
A container for containing a liquid or pasty material which is combined with a system for collecting and dispensing without taking in air. The container is rigid and includes a flexible bag which contains the material to be dispensed and which is combined with the collecting system. The bag is produced separately from the rigid container and has an overall cylindrical reservoir which is open at the top portion thereof and which is divided into four areas defined by a rigid upper sidewall, a flexible deformable lower sidewall, and a fillet connecting the flexible side wall to a base.

Description:
This application claims priority to International Application No. PCT/FR2013/050249 filed Feb. 6, 2013 and French Patent Appln. No. 1252358 filed Mar. 15, 2012; the entire contents of each are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a container intended to contain a liquid or pasty material, associated with a system for collecting and dispensing without taking in air, called “Airless”, said container being rigid and having a flexible bag holding the material to be dispensed, and being associated with the collecting system. 
     PRIOR ART 
     A first known technique for making such containers consists of obtaining, by molding, a rigid flask and a flexible bag, in a single operation or in several operations. 
     But these flasks, commonly called “bag flasks”, have a height greater than their diameter, and collapsing of the bag occurs laterally, because it is the sides of the jar that have the greatest surface area and that collapse. 
     This technique is therefore not suited to jars, for cosmetics for example, which are wider than they are high and have a large-diameter opening, close or identical to that of the jar itself. 
     Thus it is demonstrated that the technology of “bag flasks” is not applicable to a jar intended to be “Airless” because the flasks are in principle blow-molded, with a neck that is smaller in diameter than the body of the flask, which is not the case with jars where the opening diameter is large, and it is not known how to make bag type “Airless” containers for 15 ml and 30 ml jars and for 200 ml jars, with non-standard blowing ratios. 
     The solutions proposed and described in documents EP0546898 and GB2184491 related to bags containing the material, the outlet neck whereof has a diameter smaller than the diameter of the bag body, which is necessarily obtained by blow-molding. These solutions therefore do not apply to large-diameter bags with large openings. 
     A second well-known technique is to make piston-type “Airless” flasks. But these are not compact, due to the thickness needed for the piston to operate, and require the development of a new line of jars. It is not possible to make piston-type “Airless” jars for large diameter 200 ml jars, molding tolerances making fits and seals difficult over large diameters. 
     Thus the problem of making containers, particularly large-diameter jars with wide openings, which must be associated with an “Airless” piston type jar, remains as before. 
     DESCRIPTION OF THE INVENTION 
     According to a first phase of the inventive approach, this consists of seeking a compromise between the “Airfree” technique and the “Piston” technique, that is a container having both a flexible bag and an associated piston, so as to obtain an “Airless” system suited to a large-diameter container according to the object being sought. 
     To this end, the invention relates to a container intended to contain a liquid or pasty material, associated with a system for collecting and dispensing without taking in air, said container being rigid and including a flexible bag containing the material to be dispensed, and associated with the collecting system, characterized in that the bag is obtained by plastic injection independently of the rigid container and constitutes a generally cylindrical reservoir, having at its upper part a large opening with a diameter equal to its inner diameter, said bag consisting of four areas consisting of:
         a rigid upper sidewall the upper end edge whereof is intended to cooperate in an airtight manner between the neck of the container or the edge of an optional rigid bowl, a corresponding flange of a lid of the associated dispensing system and a lower peripheral end edge whereof of said area constitutes a rigid band providing the connection with   a flexible and deformable lower sidewall, with an inner diameter identical to that of the upper rigid sidewall and the concentricity whereof is provided by the rigid band, to extend axially from it toward   a fillet or chamfer constituting a connecting and articulating area between the lower flexible sidewall and   a rigid bottom with a diameter smaller than the diameter of the reservoir thus formed, said edge, when subjected to vacuum signal by the collecting system, being drawn upward in the manner of a piston, driving the connecting and articulating area as well as the flexible wall in folding back over itself.       

     The advantages of such a container are the following:
         a compact “Airless” reservoir which can be incorporated into existing reservoirs,   possibility of operating with a low vacuum (10 mbar to 50 mbar) collecting device requiring little energy to be contributed by the user,   a good material retrieval rate (&gt;95%) and good compatibility with very viscous cremes in the jars. The bottom moves to push the material toward the collecting device, which allows operation with very viscous materials.   a large opening diameter identical to that of the jar, which facilitates filling.       

     The present invention also relates to features that will be revealed in the course of the description that follows, and which will need to be considered in isolation or in all their possible technical combinations. 
     This description, given by way of a non-limiting example, will make it easier to understand how the invention can be implemented, with reference to the appended drawings wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective and section view of an “Airless” container and of a collection and dispensing system according to the invention, with a full bag. 
         FIG. 2  shows a perspective and section view of an “Airless” container according to the invention, with an empty bag. 
         FIG. 3  shows an exploded perspective view of the container according to  FIG. 1 . 
         FIG. 4  shows an axial section view of a bag according to the invention. 
         FIGS. 5 and 6  show, at reduced scale, schematically and by comparison with  FIGS. 1 and 2 , a bag according to  FIG. 4 , respectively full and emptied of its material. 
     
    
    
     DETAILED DESCRIPTION 
     The container with the overall designation of  1  in the figures is intended to contain a liquid or pasty material  2 . It is associated with a system  3  for collecting and dispensing without taking in air, said container  1  being rigid and including a flexible bag  4  holding the material to be dispensed  2 , and which is associated with the collecting system  3 . 
     The collecting and dispensing system  3  consist of a dosing chamber  5 , communicating on the one hand with a reservoir  6  constituted by the bag  4 , through a non-return valve  7 , and on the other hand with an outside channel  8 , made of elastically deformable material, or any other means for dispensing the material  2 . 
     According to the invention, the bag  4  is obtained by plastic injection independently of the rigid container  1  and constitutes a generally cylindrical reservoir  6 , having at its upper part a wide opening with a diameter equal to its internal diameter, said bag consisting of four areas constituted by:
         a rigid upper sidewall  9 , the upper end peripheral free edge  10  whereof is intended to cooperate in an airtight manner with a corresponding flange  14  of a cover  15  of the associated dispensing system  3 , and of which one lower end peripheral edge of said area  9  constitutes a rigid band  16  providing a connection with   a flexible and deformable lower sidewall  17 , with an inner diameter identical to that of the rigid upper sidewall and the concentricity whereof is ensured by the rigid band  16 , to extend axially from it toward   a fillet or a chamfer  19  constituting a connection and articulation area between the flexible and deformable lower sidewall  17  and   a rigid bottom  18  with a diameter “d” less than the diameter “D” of the reservoir  6  thus constituted, said bottom, when subjected to a vacuum signal “F” by the collecting system  3 , being pulled upward in the manner of a piston, driving the connection and articulation area  19  as well as the flexible wall  17  in folding back over itself.       

     The container  1  is provided at its upper end with threads  11  that cooperate with threads provided on an outer cover  21 . The container defines an inner volume that can receive an optional rigid bowl  13  that has an upper sidewall  12  with a top surface edge that cooperates with the peripheral free edge  10  of the sidewall  9  of the flexible bag  4 . 
     Tests have demonstrated that good results were obtained when, on the one hand, the rigid upper sidewall  9  of the cylindrical reservoir  6  covers substantially half “h1” of the height “H” of this and its thickness and that of the bottom  18 , are from about 0.8 to 2 mm, and when on the other hand the flexible lower sidewall  17  of the cylindrical reservoir  6  covers substantially half “h2” of the height “H” of this and extends into the fillet or chamber  19  and into a horizontal plane  20  concentric with the rigid bottom  18 , and that its thickness is from about 0.05 to 0.35 mm. 
     A bag  4  thus constituted can, if it is suitably dimensioned of course, be adapted to any container, jar or tube, with a capacity of 10 ml to 2,000 ml, to make them “Airless” in association with an “Airless” collecting and dispensing system  3  which closes the top of the jar- or tube-type container. 
     The operation of such an assembly is as follows: under the influence of the “Airless” (without intake of air) collecting and dispensing system  3 , a dose of material  2  is discharged outside the container  1 , causing a vacuum inside the reservoir  6  because the dose to be discharged outside of the system  3  is not replaced with air. The reservoir  6  experiences a vacuum and compensates for the vacuum by a flexible deformation of its geometry. 
     During this vacuum action, which can be weak (from 10 mbar to 50 mbar), the rigid bottom  18  is sucked upward, in the manner of a piston, consequently driving the flexible sidewall  17  to deform upward, by folding and rolling back over itself, inside the reservoir  6 . The vertical displacement of the rigid bottom  18 , associated with the deformation of the flexible sidewall  17 , causes a reduction in the volume of the reservoir  6 , thus allowing discharge of the material  2  without intake of air. 
     Moreover, the flexible peripheral articulation area  19  forming a corner fillet, connected to the rigid bottom  18  on the one hand and to the flexible lower sidewall  17  on the other hand, makes it possible for the flexible lower sidewall  17  to fold over itself during the upward movement of the piston as aforesaid. This articulation area  19  makes it possible to initiate and to facilitate the turnover of the flexible sidewall  17  onto itself, then to drive this turnover through the upward displacement of the rigid bottom  18  forming a piston, up to the moment that the fold formed by this turnover reaches the rigid upper sidewall  9 , thus blocking displacement of this turnover and of the rigid bottom  18 . 
     At the end of the discharge, the flexible lower sidewall  17  is completely turned over itself and it is raised so as to cover the same height h1 as the rigid sidewall  9 . The rigid bottom or piston  18  is then situated at the very top of the reservoir. 
     The fillet can be straight or rounded. 
     The half-rigid, half-flexible bag  4  is obtained in a single piece in the course of one and the same molding operation, by plastic injection. 
     In practice, to be able to form fine thicknesses of 0.2 mm by injection, highly fluid materials and injection machines with high injection pressures, high injection speeds and mold closing force which can vary in the course of the injection cycle are used. 
     By way of an example, the materials used for making the bag can be LDPE “low density polyethylene” or EVA (ethylene vinyl acetate) or TPE (thermoplastic elastomer) or PU (polyurethane), having very low elastic moduli (&lt;300 MPa) associated with very high fluidity (MFI fluidity&gt;50 g/10 mn of material passing through a calibrated die under 2.16 kg of load and at a temperature of 190° C.). 
     Injection will be carried out at high speed and high pressure, with a closed mold with a very high or variable mold closing force.