Synthetic resin thin-walled bottle
AssigneeYoshino Kogyosho Co., Ltd.
InventorYataro Yoshino
Life of this patent
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Abstract
This invention provides a synthetic resin thin-walled bottle, a tubular intermediate therefor and a method of producing a thin-walled bottle. The thin-walled bottle has ribs at least at its bottom portion, and the bottle bottom is raised up frusto-conically or has an undulatory shape. The tubular intermediate is first formed with ribs which become thin-walled protuberant ribs after blow molding. The thin-walled bottle is produced by blow-molding the ribbed tubular intermediate.
Claims24
A biaxially oriented synthetic resin thin-walled bottle, made by blow molding an injection molded intermediate, comprising a neck portion defining an opening, a hollow cylindrical barrel body portion interconnecting said neck portion and a bottom portion, said bottom portion having a central part bulged inwardly to form a frusto-conical raised portion and an annular ground contacting wall surrounding said raised portion and connecting with said barrel body portion, wherein:
- the inner surface of said annular ground contacting wall is provided with a plurality of inwardly projecting rigid ribs so that said bottom portion at the positions of said rigid ribs is thicker than the remainder of the bottom portion, said outer surface of said bottom portion being uniformly smooth and continuous at the locations of said internal rigid ribs;
- said rigid ribs being formed integrally with said bottom portion during the blow molding of said injection molded intermediate having a plurality of ridges provided on its internal surface which correspond to said rigid internal ribs of said biaxially oriented bottle, said rigid internal ribs being the result of the expansion of said ridges of said intermediate during biaxial orientation only.
A biaxially oriented synthetic resin thin-walled bottle produced by a method comprising the steps of:
- forming a hollow one-piece intermediate having a first end and a second end with a thin-walled cylindrical portion therebetween, said first end being open and said second end being closed by a bottom provided with a semi-circular cross section, the extremes of said semi-circular cross section being integral with the walls of said cylindrical portion, said bottom of said intermediate being provided with a plurality of raised ridges on its internal surface,
- heating and biaxially orienting said intermediate into the finished shape of said bottle having a bottom portion with a central area bulged inwardly to form a frusto-conical raised portion and connecting with said cylindrical portion of said bottle via an annular ground contacting wall, the inner surface of said annular ground contacting wall having rigid raised reinforcement ribs formed thereon which conform to the shape of said annular wall and correspond to the ridges of said intermediate and are the result of expansion of the ridges of said intermediate during biaxial orientation.
A biaxially oriented synthetic resin thin-walled bottle comprising a neck portion defining an opening, a bottom portion, a barrel portion having a circular cross-sectional shape interconnecting said neck and bottom portions, said bottom portion having a central part bulged inwardly of the bottle to form a frusto-conical raised portion with the slant of said raised portion being undulated in the axial direction of the bottle to form alternate recesses and ridges about a circumferential periphery of said raised portion on the interior of said bottom portion, the width of said recesses being equal to that of said ridges.
Dependencies are inferred from the claim text.