MANUFACTURING METHOD OF HOLLOW MOLDED ARTICLE

• Main Authors: MIOKI TAKASHI, ISHIDA ATSUKO, MOCHIZUKI AKIHIRO
• Format: Patent
• Language: English; Japanese
• Published: 08.03.2018
• 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

PROBLEM TO BE SOLVED: To mass-produce a hollow molded article securing volume of a hollow part even though it is thin and small size at low cost with good efficiency.SOLUTION: The manufacturing method includes (A) a primary molding process for molding a pair of semi-hollow molded articles 31 and 32, (B) an abutment process for abutting junctions 31A and 31B of the semi-hollow molded articles 31 and 32 each other, (C) a filling process for filling a hollow part 33 of the pair of semi-hollow molded articles 31 and 32 with a fluid 41 before or after the abutment process, (D) a secondary molding process for injecting a molten resin 35' to an outer periphery of junctions 31A and 31B, integrating the pair of semi-hollow molded articles 31 and 32 at a state that pressure from inside to outside of the pair of semi-hollow molded articles 31 and 32 is pressure from outside to inside or more to obtain a hollow molded article and (E) a fluid discharge process for discharging the fluid 41 from the hollow part 33 of the hollow molded article. In the case, the boiling point of the fluid 41 filled in the (C) filling process is higher than a temperature of a material injected in the (D) secondary molding process.SELECTED DRAWING: Figure 1 【課題】薄肉、小型であっても中空部の容積が確保された中空成形品を低コストで効率よく量産する。【解決手段】本発明の製造方法は、（Ａ）一対の半中空成形品３１、３２を成形する１次成形工程と、（Ｂ）半中空成形品３１、３２の接合部３１Ａ、３１Ｂどうしを突き合わせる突き合わせ工程と、（Ｃ）突き合わせ工程の前又は後に、一対の半中空成形品３１、３２の中空部３３に流動体４１を充填する充填工程と、（Ｄ）接合部３１Ａ，３１Ｂの外周に、溶融樹脂３５'を射出し、一対の半中空成形品３１、３２の内部から外部にかかる圧力が、外部から内部にかかる圧力以上である状態で、一対の半中空成形品３１、３２を一体化し、中空成形品を得る２次成形工程と、（Ｅ）中空成形品の中空部３３から流動体４１を排出する流動体排出工程とを含む。その際、（Ｃ）充填工程で充填する流動体４１の沸点は、（Ｄ）２次成形工程で射出する材料の温度よりも高い。【選択図】図１