Method and apparatus for making an object of a plastic material
AssigneeGrosfillex Sarl
InventorGaston Jacquet
Life of this patent
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Abstract
The apparatus has means (10, 11) for placing a parison (12) between two portions of a blow mold (14, 16). The parison (12) is put on the head of a blowpipe (32) placed between the two mold portions. On closing the mold, the top end of the parison is pinched in a top region of the mold and the bottom end of the parison is clamped against the blowpipe (32). A pre-blow step is performed on the parison to obtain an envelope which is then turned over by moving the blowpipe (32) upwards together with a turnover piston (34, 36), prior to performing a final blow step.
Claims16
A method of manufacturing a container-forming object out of plastics material, wherein the method comprises:
- (a) inserting a parison into a blow mold, having at least two mold portions suitable for being moved relative to each other to open and close the mold, in an open situation thereof by placing a bottom end of said parison on a head of a blowpipe situated between the two mold portions which are spaced apart in said open situation,
- (b) moving the two mold portions towards each other to close the mold at least substantially, the parison being pinched in a top region of the mold, and the bottom end of said parison being clamped against the blowpipe in a bottom region of the mold,
- (c) performing a pre-blow step to obtain a pre-blown envelope having at least a portion of a periphery of the pre-blown envelope in the vicinity of walls of the mold without being pressed thereagainst, said pre-blown envelope having a bottom end portion in the vicinity of a top end of a turnover piston while being remote from the walls of the mold,
- (d) performing a turnover step by displacing the blowpipe together with the turnover piston upwards to turn the bottom end of the pre-blown envelope over onto itself forming a free edge that presents a turned over portion, and
- (e) performing a final blow step to obtain a blown envelope having the shape of the container-forming object.
An apparatus for manufacturing a container-forming object out of plastics material, the apparatus comprising means for making a parison of plastics material, a blow mold having at least two portions suitable for being moved relative to each other to open and close the mold, means for inserting the parison into the mold, a blowpipe, and a turnover piston suitable for being moved inside the mold to form a turnover in the region of a free edge of the container-forming object, wherein the blowpipe is disposed beneath the means for inserting the parison into the mold and is to be found between the two mold portions, the blowpipe having a blowpipe head suitable for receiving a bottom end of the parison when the mold is open, wherein the apparatus includes means for pinching the parison in a top region of the mold, and means for clamping the bottom end of said parison against the blowpipe in a bottom region of the mold, wherein the blowpipe is suitable for being used to perform a pre-blow step so as to obtain a pre-blown envelope having at least a portion of its periphery in the vicinity of walls of the mold which is at least substantially closed, but without being pressed against said walls, said envelope having a bottom end portion in the vicinity of a top end of the turnover piston while being at a distance from the walls of the mold, wherein the blowpipe is suitable for being moved upwards together with the piston to turn the bottom end portion of the pre-blown envelope over onto itself, and wherein the blowpipe is suitable for being used to perform a final blow step in such a manner as to obtain a blown envelope having the shape of the container-forming object.
Dependencies are inferred from the claim text.