Method For Peeling Off Or Separating A Sealing Film Sealed Onto The Rim Of The Neck Of A Bottle Or The Like And Screw Cap For Carrying Out Said Method

Abstract

In a method for the at least partial detachment or separation of a sealing film or foil 14 that is sealingly attached to a rim 11 of a neck 3 of a container, vessel, bottle 1 , or the like, which rim 11 has a circular sealing surface 12 and the neck 3 has a male thread 4 and a center axis 5 , and a screw cap 7 having a female thread 6 complementary to said male thread 4 is screwed down onto the male thread 4 of the sealed neck 3 whilst the screw cap 7 can be unscrewed at any later point in time, as desired, when the screw cap 7 is unscrewed from the neck 3 , said sealing film 14 is at least partially detached from said rim 11 of the neck 3 , radially, starting from the periphery of the rim and progressing inwardly toward the center axis 5 , to be subsequently lifted off from said rim 11.

1 . A method for the at least partial detachment or separation of a sealing film or foil that is sealingly attached to a rim of a neck of a container, vessel, bottle, or the like, which rim has a circular sealing surface and the neck has a male thread and a center axis, and a screw cap having a female thread complementary to said male thread is screwed down onto the male thread of the sealed neck while the screw cap can be unscrewed at any later point in time, as desired, 
     characterized in that 
     when the screw cap is unscrewed from the neck, said sealing film is at least partially detached from said rim of the neck, radially, starting from the periphery of the rim and progressing inwardly toward the center axis, to be subsequently lifted off from said rim. 
   
   
       2 . A method as defined in  claim 1 , 
     characterized in that 
     prior to the initial screwing of the screw cap onto the male thread of the neck, a reinforcement disk coated on one side with an adhesive is inserted into the screw cap and, when the cap is subsequently screwed onto the neck, said disk will be pressed with its adhesive against the sealing film that is sealingly attached to the rim of the neck, while a surface-to-surface bonding of the reinforcement disk with the sealing film is achieved after the cap has been screwed down. 
   
   
       3 . A method as defined in  claim 2 , 
     characterized in that 
     induction welding is used for surface-to-surface bonding of the reinforcement disk to the sealing film, a thermoplastic compound being used as adhesive. 
   
   
       4 . A method as defined in  claim 1 , 
     characterized in that 
     reinforcement of the sealing film has been achieved by using a sealing film which has already been reinforced by a surface-to-surface bonded reinforcement disk, or a sealing film that has been stiffened or is resistant to bending. 
   
   
       5 . A method as defined in  claim 1 , 
     characterized in that 
     a glue, lamination, or sealing wax composed of substantially PE, PET, polyester, or polystyrene, or a combination of these substances, may be used as an adhesive on the surface of the reinforcement disk facing the sealing film. 
   
   
       6 . A screw cap for the implementation of the method as defined in  claim 1 , comprising a top section and also a sleeve section having an female thread and an open end to enable screwing of the cap onto, and unscrewing thereof from, a male thread of a neck having a rim of a bottle or the like, which neck is hermetically sealed by a sealing film which has a radially overlapping circumferential zone and which is sealingly attached to a circular sealing surface of the rim of the neck, and which is capable of being detached and/or destroyed in order to expose the contents of a bottle, 
     characterized in that 
     it has at least one detachment knife disposed on the sleeve section between the female thread and the top section and along the inside periphery of the sleeve section, which knife, in its starting position prior to being screwed down, extends obliquely toward the open end of the screw cap and inwardly toward the center axis of the neck or of the screw cap, wherein the distance of the detachment knife from the center axis prior to screwing down is less than the outside diameter (D) of the rim of the neck, which detachment knife is resiliently displaced as the screw cap is screwed down onto the neck of the bottle, and, due to the pressure imposed by the rim of the neck and the circumferential zone of the sealing film the detachment knife with its knife edge resiliently bends upwardly and comes to rest on the outer periphery of the neck above the male thread and beneath the radially-overlapping circumferential zone of the sealing film, and is resiliently deformed and resiliently pre-stressed toward the center axis once the cap is screwed down, 
     further characterized in that, 
     when the cap is unscrewed, the knife edge of the detachment knife is disposed initially obliquely in relation to the sealing film and toward the center axis, and then, due to its resiliency by springing back, continuously penetrates further radially inwardly toward the center axis between the overlapping circumferential zone of the sealing film and the rim of the neck of the bottle, wherein the sealing film is adapted to be progressively separated from the rim of the bottle toward the center axis and to be stored in the screw cap between the detachment knife and the top section. 
   
   
       7 . A screw cap as defined in  claim 6 , 
     characterized in that 
     a plurality of individual detachment knives is fixed to the sleeve section and distributed around the inside periphery of the sleeve section in the circumferential or rotational direction (A), which knives, being disposed radially about the center axis in a common plane, leave a clearance (W) in the zone of the center axis which has a smaller diameter than that of the circular sealing surface of the rim of the neck of the bottle or the like. 
   
   
       8 . A screw cap as defined in  claim 6 , 
     characterized in that 
     each individual detachment knife has a knife edge that partially extends in the unscrewing direction (A) or a component thereof pointing in said unscrewing direction (A). 
   
   
       9 . A screw cap as defined in  claim 8 , 
     characterized in that 
     each knife edge of the detachment knife is concavely curved and has a radially projecting, pointed cutting projection trailing in the rotational unscrewing direction (A). 
   
   
       10 . A screw cap as defined in  claim 6 , 
     characterized in that 
     at least one circular pressure lip is formed on the inside surface of the top section of the screw cap, disposed about the center axis opposite to the circumferential zone of the sealing film with its reinforcement disk, if present, which lip presses the circumferential zone of the sealing film and the reinforcement disk, if present, onto the rim of the neck and nestles thereon as the screw cap is screwed down. 
   
   
       11 . A screw cap as defined in  claim 6 , 
     characterized in that 
     the detachment knife is configured to extend around the inside periphery of the sleeve section in the form of an annular knife. 
   
   
       12 . A method for the at least partial detachment or separation of a sealing film or foil that is sealingly attached to a rim of a neck of a container, vessel, bottle, or the like, which rim has a circular sealing surface and the neck has an male thread and a center axis, and a screw cap having a female thread complementary to the male thread and capable of being screwed down onto the male thread of the sealed neck unscrewed at any later point in time, as desired, 
     characterized in that 
     an intermediate layer of a thermoplastic compound, glue, and/or a sealing wax is introduced between the top section and the neck before the screw cap is screwed down onto the neck of the container or the like, the intermediate layer being pressed onto the sealing film by the inside surface of the top section as the screw cap is screwed down onto the neck of the container, and the inside surface is glued or welded to the surface of the sealing film in such a way that the sealing film firmly adheres to the inside surface and the sealing film is at least partially entrained by the screw cap when the latter is unscrewed from the neck of the container or bottle. 
   
   
       13 . A method as defined in  claim 12 , 
     characterized in that 
     the sealing film has, at least at certain points, embossments or perforations configured as breaking points in the circumferential direction within the clearance (W) of the neck, and with the aid of the intermediate layer, the inside surface of the top section is only glued or welded to the surface of the sealing film in the region of the surface surrounded by said embossments or perforations. 
   
   
       14 . A method as defined in  claim 13 , 
     characterized in that 
     a disk consisting of at least two layers is used as the sealing film, wherein the layer facing the inside surface of the top section is composed substantially of PE, PET, or aluminum and the layer facing the neck is composed substantially of PE, PET, or sealing wax, or a combination of the aforementioned substances. 
   
   
       15 . A method as defined in  claim 14 , 
     characterized in that 
     only the layer of the sealing film facing the inside surface a of the top section is embossed or perforated, at least at certain points, within the clearance (W) of the neck. 
   
   
       16 . A method cap as defined in  claim 13 , 
     characterized in that 
     an embossment or perforation forming a complete circle is used. 
   
   
       17 . A screw cap for implementing the method as defined in  claim 12 , especially one of plastics material, having a top section and a sleeve section having a female thread and an open end for screwing onto, and unscrewing from, a male thread of a neck with a rim of a bottle or the like, which is hermetically sealed with a sealing film that is sealingly attached to a circular sealing surface of the rim of the neck, 
     characterized in that 
     the top section has an inverted, anvil-like, inner, plate-like projection facing its inside surface, so configured that the inside surface is capable of bringing the intermediate layer to bear against the surface of the sealing film when the screw cap is screwed down. 
   
   
       18 . A method or screw cap as defined in  claim 1 , 
     characterized in that
 the vessel, container, bottle or the like used is composed of plastics material or glass or the like. 
 
   
   
       19 . A method or screw cap as defined in  claim 1 , 
     characterized in that 
     the sealing film, especially when made of aluminum and/or plastics material, has a circumferential zone radially overlapping the rim of the neck. 
   
   
       20 . A screw cap as defined in  claim 1 , 
     characterized in that 
     it is itself composed of plastics material. 
   
   
       21 . A screw cap as defined in  claim 1 , 
     characterized in that 
     the degree of lift between the screw cap and the neck given by the thread pitch and the mating of a male thread with a female thread used is, in the fully screwed-down position of the screw cap on the container, at least equal to the length of the detachment knife or knives, this length in turn being at least equal to the radial distance between the inside periphery of the sleeve section, from which the detachment knife projects outwardly, and an imaginary circle on the sealing surface between the sealing film and the rim. 
   
   
       22 . A screw cap as defined in  claim 21 , 
     characterized in that 
     the circumference of the imaginary circle is formed by the inside periphery of the rim of the neck. 
   
   
       23 . A screw cap as defined in  claim 21 , 
     characterized in that 
     the thread pitch and the thread mating are dimensioned in such a way that each 360° turn of the screw cap raises the screw cap approximately 9 mm from the neck. 
   
   
       24 . A screw cap as defined in  claim 21 , 
     characterized in that 
     the female thread is configured as a triple thread. 
   
   
       25 . A screw cap as defined in  claim 21 , 
     characterized in that 
     the at least one detachment knife is disposed on the inside periphery of the sleeve section above the female thread toward the top section, and the thread path of the female thread has gaps, the width u of which is substantially equal to, or slightly greater than, the width of the detachment knife or detachment knives in the circumferential direction of the inside periphery, so that when the screw cap is removed upwardly from the mold (not shown), the at least one detachment knife can be pressed downwardly into the gaps and remain briefly therein until they emerge from the mold and are exposed. 
   
   
       26 . A screw cap as defined in  claim 21 , 
     characterized in that 
     the detachment knife or each of the detachment knives used always has a free end provided with a knife edge, which end is curved or bent toward the rim when the sealing surface is penetrated between the sealing film and the rim. 
   
   
       27 . A screw cap as defined in  claim 26 , 
     characterized in that 
     the free end of the at least one detachment knife is also curved on both sides in such a way that it has a spoon-like, concave curvature. 
   
   
       28 . A screw cap as defined in  claim 27 , 
     characterized in that 
     a counter-pressure lip (FIG. ( 16 ) in the form of an annulus is provided on the inside of the top section between at least one concentrically disposed pressure lip and the inside surface of the sleeve section.