Kraussmaffei Technologies Gmbh

Maximilian Schadhauser

Stefan Moser

Martin Würtele

Stefan Schierl

Nicolina Topic

A method is described for producing fibre-reinforced plastic moulded parts, wherein endless fibre strands are fed by a fibre braking device and/or cut fibres via a gravimetric metering device, and a plastic material to be melted, by a volumetric metering device are fed to a single-screw plasticizing unit. Plastic material which is molten and is mixed with fibre material is injected into a moulding tool by an injection stroke of the plasticizing screw. According to the application, the ACTUAL mass flow of the plastic material is calculated from the ACTUAL volume flow of the plastic material and from the ACTUAL mass flow of the fibre material. The ACTUAL mass flow of the plastic material is compared to a TARGET mass flow of the plastic material, and the rotation speed nof the rotary drive of the metering element of the metering device is adapted.

Method for the production of plastic moulded parts

A shearing part for a plasticising screw has at least one inlet channel and at least one outlet channel, which run helically around or parallel to the longitudinal axis (X) of the shearing part. The inlet channel is open upstream and closed downstream. The outlet channel is open downstream and closed upstream. The inlet outlet channels are arranged lying directly adjacent to one another and contiguous to one another, and are connected directly with one another fluidically, so that inflowing melt can flow over directly from the inlet channel into the outlet channel, wherein a flow direction transversely to longitudinal axis (X) of the shearing part is produced. The inlet channel has a depth (T) at which shearing action on the melt is substantially avoided. The outlet channel is configured as shearing surface, so that shearing action is present onto melt flowing through the outlet channel.

Shearing part

An endless-fibre-reinforced plasticate is described for the additive manufacture of endless-fibre-reinforced plastic components. A plastic material is introduced via a first filling opening into a single-screw extruder and is melted. A mass flow dmF/dt of dry, endless fibre strands is introduced via a second filling opening into the single-screw extruder, impregnated with plastic melt and discharged as fibre-reinforced plasticate. Remote from the second filling opening with regard to conveying, the screw of the single-screw extruder is configured that the fibre strands are discharged substantially undamaged. The mass flow dmF/dt is kept in a first mass flow target ratio to a mass flow dmS/dt of plastic melt discharged from the single-screw extruder, or the mass flow dmF/dt is kept in a second mass flow target ratio to a mass flow dmP/dt of fibre-reinforced plasticate discharged from the single-screw extruder, the exiting endless fibre strands are substantially completely impregnated with plastic melt.

Method and device for the production of a fibre-reinforced plasticate

A method and a device for producing fibre-reinforced plastic mouldings, using coated fibre strands. For the coating of the fibre strands, an air flow of ionised air is produced and guided through a Venturi nozzle. Powder from a storage container is taken by means of a screw conveyor and supplied to the Venturi nozzle, a flow of a powder-air mixture being present or forming behind the Venturi nozzle in the direction of flow. This stream is introduced into a chamber and fibre strands that are earthed or ionised unlike the powder are passed through the chamber and through the powder-air mixture flowing through the chamber, powder particles being deposited on the fibre strands. The fibre strands guided out of the chamber therefore have a coating, and the fibre strands coated in this way are supplied to a plasticising device of an injection moulding machine or an extrusion machine.

Method and apparatus for producing fibre-reinforced plastic mouldings

An injection moulding machine for producing fibre-reinforced plastic mouldings, having a closing unit and an injection unit, wherein the injection unit has a cylinder and a screw that can be rotated and displaced in the longitudinal direction in the cylinder, the screw having a backflow stop. In the cylinder, filling openings are provided for feeding in a plastic material to be melted and fibre material. To reduce fibre breakage and ensure good mixing, according to the invention a mixing part is provided downstream and/or upstream of the backflow stop, the mixing part being connected to the screw in a rotationally fixed manner for conjoint rotation therewith and having a cylindrical main body with drop-shaped mixing elements arranged thereon.

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Unterhaching, Germany

Maximilian Schadhauser