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 present invention relates to a method for changing material in an extrusion device comprising at least two supply devices for supplying feedstock for an extruder, comprising the following steps: identifying a change request for changing material in an extrusion device, predetermining a production stability for a time after the material of at least one supply device has been changed, comparing the predetermined production stability to a threshold value of stability, changing the material in at least one supply device depending on the result of comparison.

A color 3D printer and its method of use are disclosed. The color 3D printer uses a number of chambers to dye a filament to a given color. This colored filament is then extruded, pursuant to an associated 3D model of an object, to produce varying colored physical objects, on demand, with the use of a single filament and a single print head. Further, the color 3D printer features a waste management apparatus which provides a number of ways to dispose of waste fluid.

For the production of polymers in which there are fillers with particle sizes below 10 μm incorporated and homogeneously distributed, a polymer starting material is input into a twin-screw extruder and is melted there to give a melt. In a conveying and mixing section, a suspension, which is formed of the fillers and of a carrier liquid, is injected into the melt. The melt viscosity is reduced by injection of the carrier liquid in the conveying and mixing section in that a cleavable polycondensate is used as polymer and low-molecular-weight cleavage product arising during the polycondensation is used as carrier liquid, and therefore the molten polymer is at least to some extent depolymerized within the conveying and mixing section. That the mixture, which is formed of the melt whose viscosity is reduced by cleavage, of the remainder of the carrier liquid and of the fillers, is homogenized.

The present disclosure relates to the technical field of polymer material, and discloses a device and method for online preparation of a modified polylactic acid material with a polylactic acid melt. The device comprises a twin-screw extruder, a first solid modifier hopper, a polylactic acid melt pipeline and a polylactic acid melt feedstock metering pump, wherein the first solid modifier hopper is connected with Zone I of the twin-screw extruder, the polylactic acid melt pipeline is connected with Zone IV of the twin-screw extruder. The method for online preparation of modified polylactic acid material with the device can avoid degradation of the polylactic acid caused by the secondary processing, improve mechanical property of the prepared polylactic acid and reduce production cost.

The present invention provides a kneading method for a fiber-reinforced thermoplastic resin with which dispersibility of reinforcement fibers is enhanced and sufficient reinforcement fibers having a proper fiber length remain, and a fiber-reinforced thermoplastic resin plasticizing device and an extruding machine for carrying out the method. The kneading method comprises supplying a thermoplastic resin and reinforcement fibers into a cylinder of a plasticizing device, and rotating a screw to obtain a fiber-reinforced thermoplastic resin, wherein the size of a clearance between the bore of the cylinder and the screw is made different between an upstream side in the vicinity of a reinforcement fiber loading port and a downstream side, so that the clearance becomes larger from the vicinity of the reinforcement fiber loading port toward the downstream side compared with the upstream side.

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 n.sub.d of the rotary drive of the metering element of the metering device is adapted.

In a method and a device for producing a powder coating melt, firstly a first powder coating melt is produced from a powder coating premix by means of a screw machine. Powder coating particles are supplied to the first powder coating melt. Then a second powder coating melt is produced by mixing the first powder coating melt and the powder coating particles by means of the screw machine. This allows a simple, gentle and efficient recycling of powder coating particles, in particular of so-called off-spec powder coating particles.

Provided is a thermoplastic resin composition, including (a) 100 parts by weight of a thermoplastic resin including 80-100% by weight of a base resin and 0-20% by weight of a reinforcing resin; (b) 2-60 parts by weight of linear carbon fibers having an average diameter of 1-15 μm; (c) 1-5 parts by weight of carbon nanofibrils having a BET specific surface area of 200-400 m.sup.2/g; (d) 1-15 parts by weight of carbon nanoplates; and (e) 1-25 parts by weight of metal powder, a method of preparing the thermoplastic resin composition, and an injection-molded article manufactured using the thermoplastic resin composition. The thermoplastic resin composition has excellent mechanical properties, e.g., impact strength, and also excellent conductivity, heat resistance, and electromagnetic wave shielding capacity, particularly high shielding efficiency against high-frequency electromagnetic waves, and thus can be used as automobile, electric, and electronic parts, and as a substitute for aluminum alloys and magnesium alloys.

A supplying apparatus and a supplying method of granular material in which granular material is supplied to a measuring container provided on a lower side so as to reach a target measurement value which is determined in advance. The supplying apparatus includes a storage container storing granular material, a valve body provided in the storage container so as to be opened when granular material is supplied, and a control section controlling open and close operations of the valve body. The control section keeps the valve body at an open position until a detection value of a detecting section of the measuring container becomes a predetermined value smaller than the target measurement value when the target measurement value exceeds a threshold value which is determined in advance. The control section opens the valve body in a pulsed way until the detection value of the detecting section becomes the target measurement value when the target measurement value is under the threshold value.