GB875942A - Apparatus and process for producing capsules - Google Patents

Abstract

875,942. Moulding capsules by extrusion. PFIZER & CO. Inc., CHAS. June 19, 1959 [June 27, 1958 ; April 16, 1959], No. 21090/59. Class 87(2). [Also in Group XVII] In apparatus for producing filled capsules (see Group XVII) a mixture including gelatin is extruded under a pressure of at least 350 p.s.i. and at a temperature between 140‹ and 240‹F. to form a continuous tube in a plastic state, the tube being filled with the material to be encapsulated as it is being formed and successive lengths thereof being laterally compressed from opposite sides to provide a series of filled capsules. Gelatin is introduced to a hopper 2 provided with an agitator 6 and which is cooled by a water jacket 8, and is fed along a barrel 12 by a water cooled, screw conveyer 10 at a pressure of at least 350 p.s.i., through a screen 70, Fig. 2. to a crosshead die 30. The barrel 12 is provided with heaters 24, 26 so that the gelatin is in a fused state at the die 30 where it is extruded about a mandrel 76 to form a continuous tube 32. The filling is provided in a hopper 34. The tube may be filled with a powder fed downwardly by an auger 36 (as shown), a paste fed by an auger or force fed by a pump or a liquid fed by a pump or gravity. A series of capsules are punched from the tube by punches 42a. In a modified die, Fig. 18 (not shown), for producing a capsule having two compartments, the mandrel 76 is provided with two passages communicating with two different sources of filling and the base of the mandrel is provided with a slot in which gelatin is extruded to form the central wall of each capsule. In a modification, Fig. 20, the extruded tubing 236 is formed with a slit 238 to permit air to be expelled therethrough and a filament 240 (not shown) is formed diametrically opposite the slit. After a short distance the slit reseals itself and the filament attaches itself to the tube. Specification 591,402 is referred to.