Mould with a movable bottom and horizontal joint plane

Abstract

A mould (12) for producing, from a blank (3), a container (2) having a bottom (6) provided with a seat (8), said mould (12) comprising: - a wall (14) delimiting a cavity (17) and, beyond the cavity (17), a hollow recess (21) opening into the cavity (17) via an opening (20); - a mould bottom (16) that is movable relative to the wall (14), the bottom having an upper surface (27) defining a seat surface (28) having the footprint of the seat (8) of the container (2). In this mould: - the wall (14) has a counterbore (24) that defines, at the top, the hollow recess (21) and that extends perpendicular to and around the opening (20), substantially parallel to the central axis (X); - the upper surface (27) defines a peripheral face (30) that extends flush with the counterbore (24).

Description

technical field [0001] The invention relates to the manufacture of containers, such as bottles or jars, obtained by forming, more precisely by blowing or stretch blowing, from blanks made of thermoplastic material. Background technique [0002] In order to manufacture containers according to the blown technique, manufacture begins by heating a blank (here a preform or an intermediate container that has undergone a primary blowing operation from a preform) to a temperature above the glass transition temperature of the material constituting the blank . The blank is then introduced into a mould, whereupon blowing of the blank takes place by injecting high pressure (generally above 25 bar) gas (eg air) into the blank. [0003] The stretch blow molding technique consists in, in addition to blowing, stretching the blank by sliding rods in order to minimize the eccentricity of the container and to make the distribution of the material as uniform as possible. [0004] The containe...

AI Technical Summary

Problems solved by technology

However, under these conditions, the material used for the bottom of the container does not stretch enough, so the base is not well formed, which reduces the benefits of boxing

[0017] In addition, the essence of reducing the running gap between the bottom of the mold and the wall of the mold is to block the escape of the air present in the mold, which risks poor container formation (at equal cycle times) or reduces cycle time (at equal container mass )

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