method of manufacturing hollow article having constant thickness by blow molding manufacturing apparatus and hollow article

According to an embodiment of the present invention, provided is a hollow article manufacturing method. An extrudate containing a hollow portion is extruded by extrusion molding, and the extrudate is supported by guide ribs so as to be located at the center of the inside of a mold and is seated in the mold for blow molding the extrudate. The extrudate is brought into close contact with an inner wall of the mold by the blow molding process in which air is blown, and is formed into the inner wall shape of the mold. 본 발명의 일 실시예에 따르면, 압출성형에 의하여 중공부를 포함하는 압출물이 압출되고, 압출물을 블로우 성형하기 위한 금형의 내부에 압출물이 금형 내부의 중심에 위치하도록 가이드 리브에 의해 지지되며 안착되고, 공기를 불어넣는 블로우 성형 공정에 의해 압출물이 금형의 내벽에 밀착되어 금형의 내벽 형상으로 성형되는, 중공품 제조방법이 제공된다.