Injection molding system and injection molding method for producing fiber-reinforced plastics material parts

A method for producing fiber-reinforced plastics material parts by injection molding, the method comprising the steps of:

• providing an injection molding system, comprising:
• an injection molding device having:
• a first housing;
• a first housing bore formed in the first housing;
• a first feed opening for feeding plastics material into the first housing bore;
• a screw shaft for melting and introducing the plastics material into a mold, wherein the screw shaft is positioned in the first housing bore and is rotatably drivable about a first rotational axis;
• a second feed opening for feeding fibers into the first housing bore;
• and,
• a discharge opening for discharging the plastics material and the fibers from the first housing bore into the mold;
• and,
• a feed device for feeding the fibers into the plastics material located in the injection molding device, wherein the feed device is configured so that cut fibers can be fed through the second feed opening into the first housing bore;
• wherein the feed device comprises:
• a multi-shaft screw machine having:
• a second housing;
• a plurality of second housing bores penetrating one another;
• a plurality of feed screw shafts, which are concentrically arranged in the second housing bores and are rotatably drivable about associated second rotational axes;
• a fiber feed opening for feeding the fibers into the second housing bores;
• and,
• a fiber discharge opening for discharging the fibers from the second housing bores;
• a suction mechanism for sucking the fibers through the fiber feed opening into the second housing bores by means of an air stream;
• and,
• a filter mechanism arranged between the suction mechanism and the second housing bores for filtering the fibers out of the air stream, wherein the filter mechanism forms a plurality of flow channels, wherein in a flow direction of the air stream, each of the flow channels has a flow cross-section that widens;
• feeding plastics material through the first feed opening into the injection molding device;
• melting the plastics material in the injection molding device;
• feeding fibers by means of the feed device through the second feed opening into the molten plastics material;
• mixing the fed fibers into the plastics material by means of the screw shafts;
• and,
• introducing the mixture of plastics material and fibers into the mold to produce a fiber-reinforced plastics material part.

An injection molding system for producing fiber-reinforced plastics material parts, comprising:

• an injection molding device having:
• a first housing;
• a first housing bore formed in the first housing;
• a first feed opening for feeding plastics material into the first housing bore;
• a screw shaft for melting and introducing the plastics material into a mold, said screw shaft being arranged in the first housing bore and rotatably drivable about an associated first rotational axis;
• a second feed opening for feeding fibers into the first housing bore;
• and,
• a discharge opening for discharging the plastics material and the fibers from the first housing bore into the mold;
• and,
• a feed device for feeding the fibers into the plastics material located in the injection molding device, wherein the feed device is configured to feed cut fibers through the second feed opening into the first housing bore,
• wherein the feed device comprises:
• a multi-shaft screw machine having:
• a second housing;
• a plurality of second housing bores penetrating one another;
• a plurality of feed screw shafts, which are concentrically arranged in the second housing bores and are rotatably drivable about associated second rotational axes;
• a fiber feed opening for feeding the fibers into the second housing bores;
• and,
• a fiber discharge opening for discharging the fibers from the second housing bores;
• a suction mechanism for sucking the fibers through the fiber feed opening into the second housing bores by means of an air stream;
• and,
• a filter mechanism arranged between the suction mechanism and the second housing bores for filtering the fibers out of the air stream, wherein the filter mechanism has a plurality of filter elements adjacent to one another and adjacent filter elements form a gap-like flow channel therebetween.