Method for assembling a dispensing system for dispensing a fluid medium

Abstract

The invention provides a method for assembling a dispensing system (1) for dispensing a fluid medium under pressure, the method including: providing a valve cup (10) including a valve (50) and a bag (100), the valve (50) configured to attach to an opening of the bag (100), wherein the valve cup (10) is either formed from a first plastic or includes a lining (70) formed from the first plastic; inserting the valve (50) into the opening of the bag (100) and fluidly sealing the bag (100) to the valve (50); providing a container (30), the container (30) including an opening (32) and suitable for storing a fluid medium under pressure and formed, at least in part, from a second plastic; inserting the bag (100) into the container (30) and positioning the valve cup (10) at the opening (32) of the container (30); pressurising the internal volume of the container (30); and welding the valve cup (10) to the container (30) to thereby provide a seal between the valve cup (10) and the opening (32) of the container (30).

1 . A method for assembling a dispensing system for dispensing a fluid medium stored under pressure, the method including:
 providing a valve cup including a valve and a bag, the valve configured to attach to an opening of the bag, wherein the valve cup is either formed from a first plastic or includes a lining formed from the first plastic;   inserting the valve into the opening of the bag and fluidly sealing the bag to the valve;   providing a container, the container including an opening and suitable for storing a fluid medium under pressure and formed, at least in part, from a second plastic;   inserting the bag into the container and positioning the valve cup at the opening of the container;   pressurising the internal volume of the container; and   welding the valve cup to the container to thereby provide a seal between the valve cup and the opening of the container.   
     
     
         2 . The method of  claim 1 , wherein the valve cup is formed from the first plastic material, and the first plastic material is a semi-crystalline polyester. 
     
     
         3 . The method of  claim 1 , wherein the first plastic material has a degree of crystallinity greater than 35%, preferably greater than 38%, when measured using differential scanning calorimetry. 
     
     
         4 . The method of  claim 1 , wherein the first plastic material is selected from the group consisting of: crystallised PET, PBT, PEN, PEN/PET copolymers, or a blend of any of the foregoing; and the second plastic material is a polyester, preferably PET. 
     
     
         5 . The method of  claim 1  wherein the container is entirely formed from the second plastic material. 
     
     
         6 . The method of  claim 1 , wherein the second plastic material is a semi-crystalline polyester. 
     
     
         7 . The method of  claim 6 , wherein the second plastic material has a degree of crystallinity greater than 35%, preferably greater than 38%, when measured using differential scanning calorimetry. 
     
     
         8 . The method of  claim 7 , wherein the second plastic material is selected from the group consisting of: crystallised PET, PBT, PEN, PEN/PET copolymers, or a blend of any of the foregoing, and the first plastic material is a polyester, preferably PET. 
     
     
         9 . The method of  claim 1 , wherein the valve cup is formed from a metal or rigid material, and the valve cup includes the polyester lining provided at at least a portion of the valve cup that faces the container when assembled, wherein the polyester lining is either held by the valve cup or is coated onto the valve cup. 
     
     
         10 . The method of  claim 1 , wherein welding the valve cup to the container includes welding the valve cup to the container by any one of: friction welding, ultrasonic welding, and laser welding. 
     
     
         11 . The method of  claim 1 , wherein pressurising the container includes pressurising the volume of the container between the inside of the container and the outside of the bag to between 1 to 3 bar, preferably between 1.5 to 2.5 bar, by undercup gassing. 
     
     
         12 . The method of  claim 1 , the valve cup including an inverted U-shaped receiving portion and the container including a lip portion, wherein prior to welding the valve cup to the container, the method further includes snap fitting the inverted U-shaped receiving portion to the lip portion. 
     
     
         13 . The method of  claim 1 , further comprising, before inserting the bag into the container, folding the bag so as to decrease the footprint of the bag to less than the diameter of the opening of the container. 
     
     
         14 . The method of  claim 13 , wherein folding includes twisting the bag around a central axis of the valve or folding the bag into a concertina pattern.