BLANK FOR BLOW MOULDING OF VESSEL, RE-USABLE VESSEL AND BLOW-OUT MOULD Russian patent published in 1996 - IPC

FIELD: manufacture of building materials. SUBSTANCE: interior surface of blank bottom is in fact made hemispherical and the thickness of bottom wall is directed step-by-step from thickened part along longitudinal axis of the closed end. From its exterior surface the closed blank end has axial protuberance of lengthened shape directed outside for interacting with the surface of blow-out mould in the process of vessel blow-out. Part of blow-out mould shaping the vessel foundation is made with central axial hollow of lengthened shape for interacting with exterior axial protuberance of blank of lengthened shape. The mould cavity has a slope towards the hollow for securing the increase in wall thickness of central cupola-shaped part of vessel. EFFECT: facilitated manufacture. 18 cl, 9 dwg