Patent GB-1501802-A (GB)
Title: Method of producing a pack containing a sterile liquid
IPC: C04B7/14
Filed: 1976-01-23
Abstract: 1501802 Producing a pack containing a sterile liquid PAPETERIES DE BELGIQUE SA 23 Jan 1976 [24 Jan 1975] 02763/76 Heading B8C In a method for the production in an enclosure of a pack containing a sterile liquid, prior to a pack forming and filling step, a sterilization step comprises sterilizing the enclosure over a period of 10 to 40 minutes by means of water heated to a temperature of between 120‹ and 150‹ C. and at a pressure of between 3 and 5 kg./cm.<SP>2</SP> gauge, replacing the hot water by sterile cold water to cool the enclosure to ambient temperature, discharging the sterile water from the enclosure, and drying the enclosure by continuously blowing compressed sterile air into the enclosure at a temperature of between 60‹ and 70‹ C. The pack forming and filling step comprises feeding along a path through the enclosure a flexible web of packforming material made of at least one layer of synthetic plastics material that is weldable by pressure, continuously injecting a sterile gas into the enclosure whilst the web is being fed through the enclosure, sterilizing the two faces of the web, folding the web over in the enclosure to form it into a longitudinally open tube, feeding the tube downwardly past a filling pipe which projects into the tube through the longitudinal gap in the tube, and successively welding the tube first longitudinally and then transversely below the pipe, introducing a sterile liquid into the portion of the longitudinally welded tube above the transverse weld, and separating the tube at the transverse weld to form individual liquid-containing packs. An enclosure is closed hermetically to resist an internal pressure of at least 6 kg./cm.<SP>2</SP> by sealing with gaskets (45, 46), 47 respectively a web inlet adjacent a roller 16, a packet outlet passage 13 and openings over hermetically sealed gloves, and then water, at the necessary temperature and pressure, is introduced through a filling pipe (6), regulated by a valve (8), into the enclosure to circulate therethrough for a period of 10-40 minutes. The enclosure (2) is then cooled to ambient temperature by the introduction of cold sterile water and the latter is discharged by gravity. In order to maintain the enclosure sterile, slightly pressurized sterile air, at a temperature between 60‹ and 70‹ C. is blown continuously into it. A receptacle is filled with oxygenated water 15 at an aqueous concentration of between 5 and 30% and at a temperature of between 60‹ and 70‹ C. maintained by an electrical heating element, not shown. A rotatable heater drum 18, is heated to a temperature of between 90‹ and 95‹ C. by circulating hot oil in the annular space between inner and outer walls of the drum and the composite web, having previously been scored longitudinally and transversely, is then introduced into the closure 2 through the slot 12. The web, preferably formed of five hot laminated layers comprising respectively from outer to inner layer, polyethylene, aluminium foil, polyethylene, cardboard, and polyethylene, is introduced into the aseptic enclosure (2) over the roller 16, and passes into the bath 15 and travels around the drum 18. The web is then picked up by the rollers 28, 30, turned through 90 degrees by rollers 31, 32, 33 and guided upwards into a sheath like portion of the enclosure where it is dried and folded along longitudinal fold lines by folding rollers. The folded web then passes between pairs of rollers (38), 39 and 41, (43) and enters a descending portion of the enclosure. In the latter the folded web is opened, by a plate 50 into, a longitudinally open tube which is welded longitudinally between pressure rollers (53, 59) and is filled with sterile liquid by the filler pipe (6) which moves downwardly into the welded tube which is continuously discharged from the enclosure through the opening 13. The tube is then welded transversely and cut into separate pouch lengths. The rollers (38, 40) are eccentrically mounted so as to be manually movable towards the co-operating rollers 39, 41 to cause the web to be advanced, manual feeding of the web also being facilitated by a number of hermetically saled gauntlets accessible from the exterior of the enclosure and fitted in orifices (44) fitted with removable gaskets (45). Hot water is preferably charged through the tube (6) and the valve (8) before the charging of the tube with sterile liquid, e.g. milk.