The present invention relates to water and solvent-free polymers, in particular water and solvent-free synthetic rubber products like non-halogenated and halogenated butyl rubber products as well as a process for the production thereof. The invention further relates to a device suitable to accomplish said process.

A method for forming a composition that includes mixing an antimicrobially active botanical oil (e.g., thymol, carvacrol, etc.) and a modified starch polymer within a melt blending device (e.g., extruder) is provided. Unlike the problems associated with proteins, the use of starch polymers allows for a greater degree of flexibility in the processing conditions and is still able to achieve good properties in the resulting composition. The present inventors have also discovered that a plasticizer may be employed to facilitate melt processing of the starch, as well as to enhance the ability of the botanical oil to flow into the internal structure of the starch where it can be retained in a stable manner. The composition is also typically generally free of solvents. In this manner, the starch will not generally disperse before use and prematurely release the botanical oil. Due to the water sensitivity of the modified starch, however, it may be subsequently dispersed by moisture when it is desired to release the botanical oil.

Provided are a polyester white film and a back sheet for a solar cell module using the same, and in particular, provided is a polyester white film having improved light reflectance.

A double-screw extruder for thermoplastic materials, with a first and a second extruder screw, whereby the extruder screws have an inlet and an outlet and a core, helically extending screw flights being arranged through the core from the inlet to the outlet, so that the screw peaks and valleys are circumferential, and the peaks of the first screw penetrate into the valleys of the second screw, and vice versa. The screw flights may have a geometry which is step-shaped in cross section, whereby the steps may be provided such that the stepped course of the peaks is congruent with the stepped course of the valleys.

An extruder screw includes an extruder shaft and at least one extruder segment. The extruder shaft has a prismatic mandrel having external teeth and a longitudinal mandrel axis. The extruder segment has internal teeth and a longitudinal internal-teeth axis and can be slid onto the mandrel, such that the extruder segment can be connected to the mandrel for rotation therewith. The internal teeth have a profile having a meshing profile and, in an inner area between the first and second end faces of the extruder segment, include a prismatic main profile that has a main cross-section. Furthermore, the internal teeth of the extruder segment have an edge profile adjacent to at least one end face of the extruder segment, which edge profile has a smaller edge cross-section than the main profile at least in the area of the meshing profile.

An improved screw has a shaft having a surface and a central axis and at least one flight extending helically along the surface of the shaft in successive turns. A continuous groove is formed in the surface of the shaft and extends between successive, pushing and trailing, turns of the flight at a selected angle greater than zero. The groove defines at least one generally triangular land having a base aligned with a pushing turn of the flight and an apex between successive turns of the flight. The groove also defines another generally triangular land having a base aligned with a trailing turn of the flight. Barriers or dams may be provided on the lands and in the grooves. A second continuous groove may also be formed in the surface of the shaft.

A single screw micro-extruder for a 3D printer includes a feed chamber with an opening for receiving solid plastic pellets. An extrusion barrel extends from the feed chamber and has an inner conically shaped bore between input and output ends. The bore has a mouth at the input end and an exit opening at the output end with a melt section therebetween. A rotatable screw is attached to a torque drive of the printer, and extends through the feed chamber and conical bore of the barrel. A constant or tapered diameter of the screw root core, from the input end toward the output end of the barrel, forms a decreasing channel root depth in a helical path for compression between a root core surface and an inner surface of the bore for pressurizing melt in the melt section of the barrel to exit an extrusion nozzle.

A screw element (100) for an extrusion machine is provided. The screw element (100) includes a first section (200) and a second section. The first section (200 has a first core (212) with a plurality of facets (214) connected to each other along splines (216). The facets (214) and splines (216) extend longitudinally along the screw element (100). The facets (214) and splines (216) can be helically-shaped. The first core (212) increases in diameter in a continuous manner along the direction of flow of material. The first and second sections (200, 300) include one or more helically-shaped flights (218,219) wrapped around the longitudinal axis of the screw element (100).

The invention relates to a process for extruding plastic compositions. The process in particular relates to the conveying, kneading and/or mixing of plastic compositions, in particular of polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends.

A screw includes a screw main body, a conveyance portion conveying a raw material, and a passage provided in the screw main body. The passage includes a first passage element, a second passage element, and a third passage element. The screw main body has a plurality of cylindrical bodies arranged in an axial direction of the rotating shaft. At least a portion of the conveyance portion is formed on outer peripheral surfaces of the cylindrical bodies adjacent to each other, and the passage is formed in the cylindrical body so as to cross over between the adjacent cylindrical bodies.