Provided is a method for producing a resin molded article, capable of reducing deterioration of resin during melt extrusion. The method includes passing a resin fed from a hopper for resin through a molding machine provided with the hopper, an extruder, and a pressure control device in this order, to produce a resin molded article, the resin pressure between a tip of the extruder and an inlet port for resin of the pressure control device being 15.0 MPa or lower.

A controlled, variable speed vacuum pump with a flow limiter connected to the suction head of the vacuum pump conveys granular plastic resin material from a supply to receivers retaining and dispensing resin when needed by a process machine.

A nozzle, a tundish arrangement used for the production of granulated material, and a method and apparatus for the production of a granulated material with an improved size distribution are provided. The grain size and grain size distribution is controlled by a nozzle having a specific design. The nozzle comprises an upper inlet opening, sidewalls forming a channel, a bottom and at least one outlet opening or at least one row of outlet openings at the lower end of the channel. The outlet opening(s) in the channel have a size of at least 5 mm in the smallest dimension. A cross sectional area of the channel at the inlet A.sub.C is at least 3 times bigger than the total area of the outlet openings A.sub.T.

A process for continuously preparing a polyolefin composition made from or containing a polyolefin and carbon black in an extruder device. The process includes the steps of supplying polyolefin in form of a polyolefin powder and carbon black to a mixing device; alternatively, (a) measuring the flow rate of the polyolefin powder supplied to the mixing device or (b) measuring the flow rate of the polyolefin pellets prepared in the extruder device; adjusting the flow rate of the carbon black to the mixing device in response to the measured flow rate of the polyolefin powder or adjusting the flow rate of the polyolefin powder to the mixing device in response to the measured flow rate of the polyolefin pellets; melting and homogenizing the mixture within the extruder device; and pelletizing the polyolefin composition into the polyolefin pellets.

The invention relates to mixing elements having an increased number of base geometry periods per longitudinal section and an improved dispersing effect for multi-shaft screw extruders comprising screw shafts that co-rotate in pairs. The mixing elements have clearances that are configured according to the method of spatial equidistants or according to the method of longitudinal equidistants. The invention further relates to the use of the mixing elements in multi-shaft screw extruders, a corresponding screw extruder comprising the mixing elements, and a method for extruding plastic masses.

A liquefier assembly for use in an additive manufacturing system to print three-dimensional parts, which includes an upstream pressure-generating stage and downstream flow-regulating stage. The upstream pressure-generating stage includes a drive mechanism, a liquefier configured to melt a consumable material receive from the drive mechanism to produce a molten material in a pressurized state. The downstream flow-regulating stage includes a gear assembly having a casing assembly and a pair of gears disposed within the interior cavity and engaged with each other to regulate a flow of the pressurized molten material through the gear assembly for controlled extrusion.

An assembly for use in an additive manufacturing system to print a three-dimensional part that includes an extruder comprising a gear and a motor that turns the gear, wherein rotation of the gear regulates a flow of material out of the extruder. A controller, provides a control signal to the motor to control the rate at which the motor turns the at least one gear and incorporates a time-varying signal into the control signal to reduce ripples in the material output by the extruder.

A thermoplastic composite structure is produced by extruding a bead of composite material to a desired cross sectional shape. An extruder extrudes the polymer bead containing reinforcing fibers, using a low compression first extruder stage where the polymer is mixed and de-gassed, and a high compression second stage where the polymer is consolidated and extruded. The cross sectional profile of the polymer bead may be altered using a variable extruder gate.

A thermoplastic composite structure is produced by extruding a bead of composite material to a desired cross sectional shape. An extruder extrudes the polymer bead containing reinforcing fibers, using a low compression first extruder stage where the polymer is mixed and de-gassed, and a high compression second stage where the polymer is consolidated and extruded. The cross sectional profile of the polymer bead may be altered using a variable extruder gate.

The invention relates to mixing elements that have a larger number of basic geometric periods per section and an improved dispersing effect for multi-shaft screw extruders comprising screw shafts that co-rotate in pairs. The invention further relates to the use of the mixing elements in multi-shaft screw extruders, a corresponding screw extruder comprising the mixing elements, and a method for extruding kneadable materials.