Method for forming lined container closures

Claim 1

THE PROCESS OF FLUXING LININGS ON CONTAINER CLOSURES WHILE RETAINING THE PROTECTIVE OR LITHOGRAPHIC COATING ON THE CLOSURE IN AN UNDAMAGED CONDITION BY HEATING THE CLOSURE IN A BLAST OF HEATED AIR SAID LININGS BEING FORMED OF A PLASTISOL COMPRISING SMALL PARTICLES OF A PASTE-FORMING SYNTHETIC RESIN SUSPENDED IN A NON-VOLATILE PLASTICISER FOR THE RESIN, SAID RESIN BEING SUBSTANTIALLY INSOLUBLE IN THE PLASTICIZER AT ATMOSPHERIC TEMPERATURE BUT BEING COMPLETELY SOLUBLE IN THE PLASTICIZER AT AN ELEVATED FLUXING TEMPERATURE AND FORMING AT THIS ELEVATED TEMPERATURE A PERMANENT GEL WHICH BECOMES ELASTIC AND RUBBERY UPON SUBSEQUENT COOLING WHICH COMPRISES ARRANGING THE LINED CLOSURES ON AN OPEN MESH SUPPORT, SAID SUPPORT BEING OF SUCH OPEN MESH THAT WHEN IT IS LOADED WITH CLOSURES TO BE TREATED 30 TO 70% OF ITS AREA IS STILL FREE FOR THE PASSAGE OF AIR THERETHROUGH, DIRECTING A CONTINUOUS STREAM OF HEATED AIR UPON SAID CLOSURES AND AROUND AND PAST THE SAME, SAID STREAM CONTINUOUSLY DISCHARGING THROUGH SAID MESH SUPPORT, SAID AIR BEING HEATED TO A TEMPERATURE NOT SUBSTANTIALLY LESS THAN 300* F. SUFFICIENT TO FLUX THE LINING AND NOT GREATER THAN THE TEMPERATURE AT WHICH THE COATING ON THE CLOSURES WOULD DISCOLOR WITHIN A HEATING TIME OF TWO MINUTES, SAID FLOW OF AIR HAVING A VELOCITY THROUGH THE FREE AREAS OF THE SUPPORT IN EXCESS OF 1500 FEET PER MINUTE AND SUFFICIENT TO CAUSE THE CLOSURES TO ATTAIN A TEMPERATURE WITHIN 5* F. OF THE TEMPERATURE OF THE HEATED AIR WITHIN A PERIOD NOT EXCEEDING 60 SECONDS, REMOVING THE FLUXED CLOSURES FROM THE STREAM OF HEATED AIR WITHIN A PERIOD SUCH THAT THE OVERALL TIME OF EXPOSURE TO THE HEATED AIR IS LESS THAN TWO MINUTES AND COOLING THE CLOSURES.