SIMPLE MOLD FOR MOLDING AND MANUFACTURE THEREOF

• Main Authors: HASHIZUME SHINJI, NAKAMOTO NORIHIKO, TANAKA TATSUYA
• Format: Patent
• Language: English
• Published: 08.12.1989
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PURPOSE:To manufacture a simple mold, by which is large number of accurate molded items can be stably molded, by a method wherein gaps in a powder structural body, which is mainly made of gypsum cast in the hollow part of a rubber mold, are impregnated with resin. CONSTITUTION:Slurry, which is prepared with gypsum, reinforcing agent and water, is cast in the recess of a rubber mold 10. Air bubbles in the surroundings of the rubber mold 10 is removed by placing the mold in an evacuating pan 7. By curing the obtained powder structural body 17 having a flat acrylic plate 16 placed thereon at normal temperature, a powder structural body 17 with favorable flat smoothness is obtained. A mold composed of said powder structural body 17 and rubber mold 10 is immersed in a vessel 18 containing resin, the temperature of which is controlled to a certain temperature with a constant temperature water tank 19 containing hot water 20. By evacuating the powder structural body 17 with a vacuum pump 22 through a suction pad 21, which is attached onto the powder structural body 17, the gaps in the powder structural body are permeated and impregnated with the resin. Finally, the body is taken out of the vessel 18 in order to obtain a simple mold. The obtained simple mold has high elasticity and is excellent in dimensional stability and can produce a large number of accurate molded items.