초록 ▼

A truncated cone is disclosed for molding bottoms of plastic containers, such as PET bottles, into geometries which extend convexly inwardly, are thermostable during hot-washing, and allow substantially full visual inspection with minimum shadow effects. The truncated cone is in the form of a frusto

A truncated cone is disclosed for molding bottoms of plastic containers, such as PET bottles, into geometries which extend convexly inwardly, are thermostable during hot-washing, and allow substantially full visual inspection with minimum shadow effects. The truncated cone is in the form of a frustoconical bottom insert, which, in a first blow-molding step, creates an intermediate container with a bottom geometry having a substantially wavy cross section. The wavy cross section of the bottom geometry can be accentuated by means of a second mold with a plateau, which creates a slight, upper domed surface in the bottom geometry of the container molded thereby.

대표청구항 ▼

[ I claim:] [1.] A plastic container comprising:a bottom of the container with a generally inwardly curved shape to define a generally hemispherical dome shape wherein a preliminary bottom is formed by engagement of a bottom portion of a preform with a truncated cone in a first blow-molding operatio

[ I claim:] [1.] A plastic container comprising:a bottom of the container with a generally inwardly curved shape to define a generally hemispherical dome shape wherein a preliminary bottom is formed by engagement of a bottom portion of a preform with a truncated cone in a first blow-molding operation, said preliminary bottom being separated from the truncated cone for developing into the generally hemispherical dome shape of the container bottom;the truncated cone having a substantially planar lateral surface and a disk shaped top; the generally hemispherical dome shape consisting essentially of a disk shaped dome center portion, proceeding radially outwardly through annulus shapes successively defining in cross section:a first outward curved segment, inclined with respect to an axis of the container,an inward curved segment, anda second outward curved segment leading to a side wall of the container; and,wherein the dome center and each of the segments join smoothly to at least one adjacent segment whereby the container is viewable through the bottom substantially without obstruction by shadow formation.