Container with a rim portion defining an opening, method and apparatus making said container

Abstract

A method is provided for making a container having a body and a rim defining an opening for the container, the opening being capable of being closed by a push-on lid, the container being made of a material which is susceptible to deformation when heated.

1 - 35 . (canceled) 
     
     
         36 . An apparatus for making a container having a body and a rim portion defining an opening for the container, the opening being capable of being closed by a push-on lid,
 wherein the container can be made from a preform made of a material which is susceptible to deformation when heated, the preform being in the shape of a closed-end tube with a rim at its mouth, the rim comprising:   an outward generally-radial flange having an upper surface and a lower surface, the flange extending from a radially inner end to a radially outer end, the tube depending from the radially inner end of the flange;   a first detent formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located near the radially inner end of the flange; and   a second detent formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located near the radially outer end of the flange;   the apparatus comprising:   pressure moulding apparatus having mould parts defining a mould cavity and further comprising: (i) a securing component for permitting the location of the preform in the mould cavity with the second detent in a fixed location therein, (ii) a generator for yielding a pressure differential between the interior of the tube and the exterior for expanding the tube into contact with the mould parts defining the mould cavity; (iii) a shield for shielding the first detent from the pressure that is applied to expand the tube; and (iv) a source of controlled downward pressure for urging the flange and the first detent downwardly and outwardly relative to the second detent such that the upper surface of the flange faces inwardly and the first detent projects inwardly into the opening for the container, with its elongate axis at an angle of from 60° to 120° to the elongate axis of the second detent, such that the first detent forms an internal rim.   
     
     
         37 . The apparatus of  claim 36 , wherein the shield is provided by the pressure moulding apparatus including a section within which the first detent may be located, which section can act to shield the first detent from the pressure that is applied to expand the tube. 
     
     
         38 . The apparatus of  claim 37 , wherein the pressure moulding apparatus includes a corridor, within which the first detent can be located, whereby when the preform is in the apparatus a wall of the corridor contacts the preform at a point between where the tube extends from the radially inner end of the flange and the first detent, such that the wall forms a barrier between the first detent and the parts of the preform that are exposed to the pressure that is applied to expand the tube. 
     
     
         39 . The apparatus of  claim 36 , wherein the source of controlled downward pressure can apply a pressure of 600 kPa or higher. 
     
     
         40 . The apparatus of  claim 39  wherein the source of controlled downward pressure can apply a pressure of 1000 kPa or higher. 
     
     
         41 . The apparatus of  claim 36  wherein the source of controlled downward pressure can apply a pressure for a duration of from 0.1 to 1 second. 
     
     
         42 . The apparatus of  claim 36  wherein the source of controlled downward pressure further comprises a mechanical device for placing controlled downward pressure on the first detent. 
     
     
         43 . The apparatus of  claim 42  wherein the source of controlled downward pressure further comprises a piston connected to the mechanical device for placing controlled downward pressure on the first detent. 
     
     
         44 . The apparatus of  claim 36  wherein the source of controlled downward pressure further comprises a source of pressurised gas for placing controlled downward pressure on the first detent. 
     
     
         45 . The apparatus of  claim 44  wherein the pressurised gas is selected from the group comprising nitrogen and air. 
     
     
         46 . The apparatus of  claim 44  and further comprising a nozzle connected above the first detent for blowing gas onto the first detent to cause the downward movement. 
     
     
         47 . The apparatus of  claim 45  and further comprising a nozzle connected above the first detent for blowing gas onto the first detent to cause the downward movement. 
     
     
         48 . The apparatus of  claim 46 , and further comprising a controller connected to the source of downward pressure for controlling the pressure of the gas and the time for which the gas is applied so as to ensure that the first detent projects inwardly into the container, with its elongate axis at an angle of from 60° to 120° to the elongate axis of the second detent, such that the first detent forms an internal rim. 
     
     
         49 . The apparatus of  claim 36 , wherein the source of controlled downward pressure can apply a pressure of 600 kPa or higher for from 0.1 to 1 second. 
     
     
         50 . The apparatus of  claim 36 , wherein the securing component that permits the location of the preform in the mould cavity with the second detent in a fixed location therein comprises a shaped cavity or seat for receipt of the second detent. 
     
     
         51 . The apparatus of  claim 36  wherein the apparatus further comprises:
 injection moulding apparatus shaped and arranged to produce a preform in the shape of a closed-end tube with a rim at its mouth, the rim comprising: (a) an outward generally-radial flange having an upper surface and a lower surface, the flange extending from a radially inner end to a radially outer end, the tube depending from the radially inner end of the flange; (b) a first detent simultaneously formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located at or near the radially inner end of the flange; and (c) a second detent simultaneously formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located at or near the radially outer end of the flange. 
 
     
     
         52 . A container having a body and a rim defining an opening for the container, the opening being capable of being closed by a push-on lid, the container being made of a material which is susceptible to deformation when heated, and the container having a first detent projecting inwardly into the container to form an internal rim,
 the container being obtainable by a method comprising the steps of:   a) providing a preform made of a material which is susceptible to deformation when heated, the preform being in the shape of a closed-end tube with a rim at its mouth, the rim comprising: an outward generally-radial flange having an upper surface and a lower surface, the flange extending from a radially inner end to a radially outer end, the tube depending from the radially inner end of the flange; a first detent simultaneously formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located at or near the radially inner end of the flange; and a second detent simultaneously formed with the flange as an upstanding elongate projection from the upper surface of the flange, which detent is located at or near the radially outer end of the flange;   b) placing the preform in a pressure moulding apparatus at an elevated temperature with the preform being located in the apparatus at least in part by the second detent;   c) expanding the tube under pressure to form the body of the container; and then   d) moving the first detent downwardly and outwardly relative to the second detent so that the first detent projects inwardly into the opening for the container;   wherein the movement of the first detent downwardly and outwardly relative to the second detent is controlled to only occur after step c), and such that after step d) the first detent projects inwardly into the container, with its elongate axis at an angle of from 60° to 120° to the elongate axis of the second detent, such that the first detent forms an internal rim.   
     
     
         53 . The container of  claim 52 , further comprising a lid, wherein the lid seals the container, the lid having a peripheral trough suitable for receipt of and engagement with the first upwardly facing detent; and an engaging portion located radially inwardly from the peripheral trough for receipt under and engagement with the inwardly facing detent, to secure the lid on the container.