Injection moulding method for the production of moulded parts, moulded part produced by means of injection moulding and also injection mould
AssigneeEms-Patent AG
InventorMing-Jiann Cheung
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for the production of injection-moulded, reinforced moulded parts, the fibre orientation of which is specifically adjusted on a local basis. Via suitable, dynamically controlled supplementary heating in the wall of the injection mould which is used (variotherm heatable channel), a local cavity region is hereby heated at the time of injection to a temperature in the region of or above the solidification temperature (in any case above the crystallisation temperature in the case of partially crystalline plastic materials or above the glass transition temperature in the case of amorphous plastic materials) of the polymer (plastic material moulding compound).
Claims16
A method for the production of moulded parts from thermoplastic moulding compounds comprising reinforcing fibres by injection moulding, in which
- a cavity of an injection mould is overfilled with a thermoplastic moulding compound which is heated to a prescribed temperature ϑFM, is present in the plasticised state and comprises reinforcing fibers, the cavity of the injection mould having in at least one wall at least one variotherm heatable channel extending along a trajectory,
- the injection mould having at least one overflow cavity, the respective overflow cavity being in fluidic communication with the cavity of the injection mould, the at least one variotherm heatable channel beginning at a gate location of the injection mould and being guided up to the at least one overflow cavity so that the thermoplastic moulding compound can emerge out of the cavity of the injection mould and enter into the respective overflow cavity via the at least one overflow cavity;
- before, during and/or after filling of the injection mould, the region of the injection mould which has the at least one variotherm channel of the wall is set to a temperature ϑVT and the remaining region of the wall of the injection mould is set, permanently or at least at times, to a temperature ϑW, wherein ϑW<ϑVT,
- after overfilling, the thermoplastic moulding compound comprising the reinforcing fibres is cooled until solidification, and the solidified moulded part is released from the injection mould;
- wherein, at least one of the following conditions is satisfied when filling the injection mould with the thermoplastic compound or when the thermoplastic moulding compound is cooled after the filling:
- ϑVT=ϑFM±40 K.
Dependencies are inferred from the claim text.