摘要:
The invention relates to a method of manufacturing a plastic frame for a two-wheeler having at least one hollow space in the interior by means of plastic injection molding having a series of method steps, wherein a fluid is injected to displace the plastic core from the component cavity after the injection of a preferably thermoplastic plastic melt into a closed injection molding tool.
摘要:
A mould assembly (60) and a method of use in injection moulding of a part having a functional cavity therein. The mould assembly has a recess (72) to receive a hollow tubular insert (48) intended to be placed in the mould assembly before the injection of a mouldable material into the cavity and to remain in the part after moulding. A gas supply arrangement supplies pressurised gas to the hollow tubular insert at a selected stage during the injection process whereby to form the functional cavity in the part.
摘要:
A system and process for gas assisted plastic injection molding. The plastic material is injected into the mold cavity and the molding pressure is held for a period of time. Thereafter, gas is injected into the plastic material and the pressure is again held for a period of time. Thereafter, valve members are opened allowing plastic to be expelled into one or more secondary cavities, or to be expelled back into the machine barrel.
摘要:
A system and process for gas assisted plastic injection molding. The plastic material is injected into the mold cavity and the molding pressure is held for a period of time. Thereafter, gas is injected into the plastic material and the pressure is again held for a period of time. Thereafter, valve members are opened allowing plastic to be expelled into one or more secondary cavities, or to be expelled back into the machine barrel.
摘要:
A method and an apparatus for producing plastic objects with hollow spaces is disclosed. The method comprises the following steps: establishing a fluid connection (9) between the main cavity (2) of a mold (1) and an overflow cavity (8) and injecting a sufficient amount of plastic melt into the cavity (2) of the mold (1) along a melt flow path, which extends from a plasticizing unit (4, 5) through a plastic injection nozzle (3) into the mold (1), such that plastic melt passes from the main cavity (2) into the overflow cavity (8). The fluidic connection (9) between the main cavity (2) and the overflow cavity (8) is then broken-off prior to the introduction of a pressurized fluid, especially a pressurized gas, into the melt in the cavity (2) by means of at least one fluid injection nozzle (7), so that the melt situated in the cavity (2) is distributed in the cavity (2) while forming a hollow space, and is pressed against the cavity walls of the mold (1). The thus formed molded part is then allowed to cool down to a temperature below the melting point of the plastic melt, the cavity pressure is relieved, and the molded part is removed from the mold. The method advantageously achieves the result that the produced molded parts do not have any gas exit openings and the waste in the overflow main cavity (8) remains minimal.
摘要:
The invention relates to a device for the injection moulding of a moulded part (2) comprising a void (1), wherein a projectile (10) can be positioned at a fluid injection nozzle (8) in the region of a fluid aperture (9), which projectile (10) can be caused to flow in the direction of the longitudinal axis (L). To allow the production of moulded parts with enclosed voids in a better way the invention is characterized in that the fluid injection nozzle (8) comprises a section (11) entering into a cavity (5) of a mould, which section (11) is free from any undercut in a direction (E) of insertion of the fluid injection nozzle (8) into the cavity (5), wherein an angle (α) is arranged between a longitudinal axis (L) and the direction (E) of insertion.
摘要:
In an injection molding method to manufacture hollow plastic parts, at least one plastic part's hollow is shaped by evacuating an internal portion of the flowable material of an injection mold's cavity using a pressurized gas, and a gate of the mold and thereupon the molded article's aperture so made will be sealed off. After the flowable material has been moved from a blind duct into the gate and partly forced back into the hollow, the molded article will be ejected from the injection mold.
摘要:
An injection molding method to manufacture hollow plastic parts, whereby at least one plastic part's hollow is shaped by evacuating an internal portion of the flowable material of an injection mold's cavity (12) using a pressurized gas and a gate of said mold (10) and thereupon the molded article's aperture so made shall be sealed off, characterized in that, following said flowable material's being removed from a blind duct (24) into a gate branched to it and after being partly forced back into said hollow, said molded article shall be elected from the injection mold (10).
摘要:
A mould assembly (60) and a method of use in injection moulding of a part having a functional cavity therein. The mould assembly has a recess (72) to receive a hollow tubular insert (48) intended to be placed in the mould assembly before the injection of a mouldable material into the cavity and to remain in the part after moulding. A gas supply arrangement supplies pressurised gas to the hollow tubular insert at a selected stage during the injection process whereby to form the functional cavity in the part.
摘要:
The invention relates to a method and an apparatus for injection molding thermoplastic molded parts, having at least one cavity. The method comprises the following steps: a) injecting thermoplastic melt from an injection unit along a melt flow path into the cavity of an injection molding tool; b) injecting a fluid into the still liquid plastic material, so that the plastic material is pressed against the walls of the cavity; c) allowing the plastic material to cool until it forms the self-supporting molded part; and d) removing the molded part from the cavity of the injection molding tool.