Method of controlling the position of an extruded preform in a blow mold

摘要: A method of making tubular bodies from thermoplastic material by extruding a parison through an extruder head die slit which is then expanded in blow mold. The position the and particularly thickened portion thereof regulated and/or controlled relative to critical cross-sectional regions hollow body blown therefrom. separated lower waste portions net weight measured order control regulate change as need be upon deviation reference value. latter beneficial accumulation operation, while continuous either waste-portion compared with characteristic or markings reflective article are sensed.