The present invention relates to a technical field of 3D printing, and more particularly to a 3D printer spray nozzle structure and a method thereof for controlling speed and precision. According to the present invention, a feeding pipeline is embedded in an external shell, the feeding pipeline and an extruder are coaxially connected; the extruder is driven by a driving device, so as to rotate relative to the feeding pipeline. A rotation angle of the extruder relative to the feeding pipeline is controlled by rotation of a motor, for controlling a filament area actually sprayed by the extrude, in such a manner that printing speed and precision is controlled for suiting different requirements of different printing area. The present invention controls the printing speed and precision, for improving overall printing speed with precision requirements satisfied, and is applicable to 3D printer spray nozzle structure and controlling.

Described herein are methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes extrusion of all material components, including a liquid crosslinking agent, to manufacture extruded structures for production of irradiation crosslinked polypropylene foam.

Described herein are methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes extrusion of all material components, including a liquid crosslinking agent, to manufacture extruded structures for production of irradiation crosslinked polypropylene foam.

The invention relates to novel screw elements for multi-screw extruders with screw profiles co-rotating in pairs and being fully self-wiping in pairs, to the use of the screw elements in multi-screw extruders and to a process for extruding plastic compositions.

A dimension in a Y-direction of a slit section (26) decreases gradually as a distance from an inflow port (23) in an X-direction increases. A cross-section of a manifold section (25) that is orthogonal to the X-direction decreases gradually as a distance from the inflow port (23) in the X-direction increases.

Aspects of the disclosure relate to methods for making large areas of high aspect ratio micro or nanostructured foil using existing extrusion coating equipment. A method is disclosed for producing a high aspect ratio micro- or nanostructured thermoplastic polymer foil, or a nanostructured thermoplastic polymer coating on a carrier foil, comprising at least one high aspect ratio nanostructured surface area. The method comprises applying a high aspect ratio nanostructured surface on an extrusion coating roller and maintaining the temperature of the roller below the solidification temperature of the thermoplastic material. A thermoplastic foil and a thermoplastic coating made by the method is also disclosed.

A kneading apparatus having a kneading unit made up of a plurality of segment parts detachably mounted on a shaft disposed in the barrel includes a first segment part having a first length L1 related to an outer diameter D, a second segment part having a second length L2 shorter than the first length L1, and a third segment part having a third length L3 longer than the first length L1; the first length L1 is [the outer diameter Da coefficient a]; the second length L2 is [the first length L1/a coefficient b]; the third length L3 is [the first length L1the coefficient b]; the third length L3 is [L1+L2]; and the kneading unit has a segment pattern made up of a plurality of segment parts and mounted on the shaft interchangeably with another segment pattern.

The invention relates to an apparatus and a process for producing pigment-containing, in particular carbon-black-containing, polymer mixtures comprising polycarbonates and optionally elastomers, and/or other components, where the mouldings produced therefrom have, after the shaping process via injection moulding or via extrusion, improved surface properties and improved mechanical properties.

An air ring has a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior that is unobstructed vertically above the main body. A generally circular forming-cone assembly is received in the generally circular interior of the main body, and includes at least one annular lip defining a passage through which pressurized air from the plenum exits the air ring for impingement upon the polymer tube. A plurality of fasteners secure the forming-cone assembly in the interior of the main body, the fasteners and forming-cone assembly being unobstructed vertically above the air ring, wherein the fasteners are accessible from vertically above the air ring and the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.

Embodiments of an extruder comprise an extruder housing having an internal wall and a single screw coaxially disposed within the extruder housing, the single screw comprising a shank, wherein the shank and/or a region of the internal wall proximate the shank comprises helical channels. The extruder further comprises a feed channel downstream of the shank, and a visco-seal comprising the helical channels and the annular gap between the shank and the internal wall, wherein the annular gap is variable across its length.