Method and molding unit for producing containers with long boxing travel
AssigneeSidel Participations
InventorsMikael Derrien, Pierrick Protais
Life of this patent
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Abstract
A method of producing a container (2) from a blank (3) made of plastics material within a mould (4) which is provided with a wall (5) defining a cavity (6) bearing the impression of the container (2), and with a mould base (8) which can move relative to the wall (5) between a retracted position in which it extends in set-back manner relative to the cavity (6) and a deployed position in which it closes the cavity (6). The method includes a boxing stage in which the mould base (8) moves from its retracted position to its deployed position, the travel (C) of the mould base (8) between its retracted position and its deployed position being greater than 20 mm.
Claims18
A method for manufacturing a container (2) from a parison (3) made of plastic material, within a mold (4) that is equipped with a wall (5) that defines a cavity (6) bearing the impression of the container (2), and a mold base (8) that can move in relation to the wall (5) between a retracted position in which it extends retracted in relation to the cavity (6), and a deployed position in which it closes the cavity (6), and the wall (5) having at a lower part an opening (7) that defines a passage for the mold base (8), the method comprising:
- a phase for inserting the parison (3) into the mold (4);
- a pre-blow-molding phase comprising the injection into the parison (3) of a pressurized fluid at a so-called pre-blow-molding pressure (P1), thus causing the plastic material to extend beyond the cavity (6) in an axial direction;
- a blow-molding phase, following the pre-blow-molding phase, and comprising the injection into the parison (3) of a pressurized fluid at a so-called blow-molding pressure (P2) that is higher than the pre-blow-molding pressure (P1);
- and
- a boxing phase comprising the movement of the mold base (8) from the retracted position toward the deployed position, wherein the boxing phase is initiated before the blow-molding phase;
- wherein the travel (C) of the mold base (8) between the retracted position and the deployed position is greater than 20 mm and less than or equal to 60 mm;
- and
- wherein the opening (7) includes an axial extension (D) corresponding to the travel (C), the axial extension (D) being greater than or equal to 20 mm to allow the opening (7) to fully receive an upper surface (9) of the mold base (8) in the deployed position.
A molding unit (1) for manufacturing a container (2) from a parison (3) made of plastic material, the molding unit (1) comprising:
- a mold (4) that is equipped with a wall (5) that defines a cavity (6) bearing the impression of the container (2), the mold configured to allow the plastic material to extend beyond the cavity (6) in an axial direction during a pre-blowing operation, and a mold base (8) that can move in relation to the wall (5) between a retracted position in which it extends retracted in relation to the cavity (6), the wall (5) having at a lower part an opening (7) that defines a passage for the mold base (8), and a deployed position in which it closes the cavity (6);
- and
- a lower end-of-travel stop (23) that defines the retracted position of the mold base (8), and an upper end-of travel stop (24) that defines the deployed position of the mold base (8);
- wherein the travel (C) of the mold base (8) defined by the stops (23, 24) is greater than 20 mm and less than or equal to 60 mm;
- and
- wherein the opening (7) includes an axial extension (D) corresponding to the travel (C), the axial extension (D) being greater than or equal to 20 mm to allow the opening (7) to fully receive an upper surface (9) of the mold base (8) in the deployed position.
Dependencies are inferred from the claim text.