Aga Aktiebolag

Mikael Ors&eacute;n

The present invention relates to the fabrication of a moulded detail in a gas assisted moulding process, wherein molten polymer ( ) is injected into the mould cavity ( ) of a moulding tool, pressurized fluid ( ) is supplied to the mould cavity through at least a first opening ( ) to form a cavity ( ) in the polymer and force the polymer towards the inner walls of the mould cavity, pressurized fluid ( ) is thereafter supplied to the mould cavity through at least a second opening ( ) localized remotely front said first opening to form a passage ( ) through the polymer to said cavity, the polymer is cooled, pressurized fluid is removed and the mould cavity is opened to remove the moulded detail. The invention comprises that substantially equal amounts of pressurized fluid are supplied to the mould cavity through at least one of said openings ( ) and are simultaneously removed from the mould cavity through at least an other of said openings ( ), while the polymer being cooled, the pressure being held substantially constant in said mould cavity and the supplied amount having a lower temperature than the removed amount, such that heat (Q) is conveyed from the mould cavity via the arisen fluid flow and the cooling is speeded up.

Gas assisted moulding

The present invention relates to a method and a device for point cooling. The cooling device comprises a cooling channel provided with a defined small end surface ( ) and an outlet valve ( ) separated therefrom, a container ( ) with liquid carbon dioxide and an access conduit ( ) connected to said container ( ) provided with a nozzle ( ) localized to said cooling channel, whereby liquid carbon dioxide is brought to flow from the container out through said nozzle. The invention further comprises to choose the overpressure of the container, adjust the outlet valve ( ) and design the nozzle in such a way that the pressure in the cooling channel ( ) is kept above the so-called triple point of carbon dioxide and that the distance between the nozzle ( ) and the defined small end surface ( ) is adapted so as to substantially gasify the carbon dioxide at said end surface. The device is particularly intended for point cooling of a injection moulded or cast detail ( ) with a sharp edge ( ) or a varying material thickness, whereby the cooling channel ( ) is provided in a moulding tool ( ) intended for the detail.

Growing community of inventors

Åkersberga, Sweden

Mikael Orsén

Growing community of inventors

Åkersberga, Sweden

Mikael Ors&eacute;n

Mikael Orsén