Patent EP-2236261-A2 (EP)
Inventor: GRAF MATTHIAS
IPC: B29C48/365
Filed: 2010-03-29
Abstract: The method for time-wise production and continuous supply of resin-filler mixture (9) in the production of plastic mold part (18) with or without fibers (10) for reinforcing, comprises mixing a portion of the resin as a pre-mixture and homogenizing the mixture together with a filler (11) and/or fiber in an extruder (13) to resin-filler mixture. The individual portion of a determined pre-mixture is gravimetrically regulated under intake pressure over dosing valve from different supply containers and is dosed in a mixing head for the production of the pre-mixture. The method for time-wise production and continuous supply of resin-filler mixture (9) in the production of plastic mold part (18) with or without fibers (10) for reinforcing, comprises mixing a portion of the resin as a pre-mixture and homogenizing the mixture together with a filler (11) and/or fiber in an extruder (13) to resin-filler mixture. The individual portion of a determined pre-mixture is gravimetrically regulated under intake pressure over dosing valve from different supply containers and is dosed in a mixing head for the production of the pre-mixture. The individually applied portion is subsequently or simultaneously mixed in mixing head to the pre-mixture by a stirring device. The pre-mixture is delivered to a dosing container, which guides during the process over a second weighing apparatus arranged to the dosing container, and an associated second control- or regulation device, and a conveyor pump to the extruder for the production of resin-filler mixture. A further pre-mixture is produced during the continuous delivery of the pre-mixture to the extruder in the mixing head. The intake pressure is applied to the portion at the dosing valve over conveyor pump and/or over supply container hydrostatically arranged against the dosing valve. The portion of the pre-mixture is subsequently supplied in the mixing head. The continuous conveying of the pre-mixture from the dosing container into the extruder is carried out in gravimetrically or volumetrically controlled manner. The reception of the pre-mixture from the dosing container is carried out by the dosing pump for the period on a volumetric dosage during the transition of the pre-mixture from the mixing head into the dosing container and is regulated for the period of the dosing pump with respect to the output on an average value of a preceding period. The pre-mixture is continuously transported into the extruder and the filler and/or a thickener is supplied corresponding to quantity- or weight moderate ratio. The fibers are continuously brought as short- and/or long fiber in first and/or second extruder. The transition of the further pre-mixture from the mixing head into the dosing container is carried out in a change of the mixture ratio of the portions to each other and/or the supply of new and/or other portion. The moment of the delivery of new pre-mixture from the mixing head into the dosing container is dependent upon the value of a level measurement and/or a measured actual quantity of the old pre-mixture in the dosing container. The level measurement is carried out over the weighing device and/or with an ultrasonic measurement and/or with a hydrostatic sensor, and/or the control- and/or regulating device recognizes or calculates the actually promoted quantities of the old pre-mixture. The first quantitatively large portion of the pre-mixture is dosed in the mixing container before the quantitatively small or very slight portion is dosed into the mixing container. The portion of the pre-mixture is held by the conveyor pump from the supply container and is supplied to the dosing valve. A multi-stage or dripless valve is used as dosing valve. An independent claim is included for a plant for time-wise production and continuous supply of resin-filler mixture in the production of plastic mold part with or without fibers for reinforcing.