Preform for producing plastic containers in a stretch blow moulding process

Abstract

A preform for producing plastic containers, more particularly plastic bottles, in a stretch blow moulding process is described, said preform having an essentially elongated preform body (2), one longitudinal end of which has a closed design. At the opposite longitudinal end thereof, the preform body adjoins a neck portion (3) provided with a pouring lip (4), on the outer wall (5) of which neck portion (3) attachment means (6) for form-fit fixing of a closure part fitted with corresponding engagement means are formed. At the transition (15) from the preform body (2) to the neck portion (3), the preform (1), which has no support ring, has a flange (8) that is annularly circumferential, at least in sections, said flange protruding radially beyond an outer wall (7) of the preform body (2). In a region between the flange (8) and the attachment means (6), a circumferential annular groove (9) is formed on the neck portion (3). The annular groove (9) is delimited by the flange (8) and in the direction of the attachment means by an outer shoulder, which extends transversely from a base of the annular groove (9) to the outer wall (7) of the neck portion (3). On an inner wall (11) of the neck portion (3), the transverse outer shoulder (10) forms an inner shoulder (12) that is annularly circumferential, at least in sections, and extends, as seen in the direction of the preform body (2), axially above the annular groove (9) and transitions into an inner wall (13) of the preform body (2) in a manner essentially free of under-cuts.

Description

technical field [0001] The invention relates to a preform without a support ring for the stretch blow molding of plastic containers according to the preamble of claim 1 . Background technique [0002] A large number of plastic containers such as plastic bottles in use today are manufactured by the stretch blow molding process. In the method, a generally elongated, small tubular structure having a base on one of its longitudinal ends and a neck section with a shaped thread section or the like on its other longitudinal end The so-called preforms are inserted into the cavity of the blow mold and blown in by means of a medium blown in with excess pressure. In this case, the preform is additionally extended in the axial direction by means of extension pins inserted through the neck opening. After the stretch / blow molding process, the finished plastic container is released from the blow mold. [0003] The preforms are usually manufactured in a separate injection molding process...

AI Technical Summary

Problems solved by technology

However, most sorting systems fail if the number of misoriented preforms is too large

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