Abstract: A process for extruding plastic compositions is provided. The process comprises providing a multi-screw extruder with screw elements and conveying, kneading, mixing, degassing or compounding the plastic compositions in the multi-screw extruder using the screw elements.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: A process for extruding plastic compositions is provided. The process comprises providing a multi-screw extruder with screw elements and conveying, kneading, mixing, degassing or compounding the plastic compositions in the multi-screw extruder using the screw elements.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to a process for extruding plastic compositions, in particular 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 with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: 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.

Abstract: The invention relates to a device for dispersing gas into a liquid. The devise has a number n of successive zones Z1, Z2, . . . , Zn having static mixing elements, wherein each zone Zi has a length Li and an effective diameter Di. The mechanical energy input Et, which is standardized to the particular ratio Li/Di and acts on the gas/liquid mixture, increases from zone to zone in the flow direction. In this connection n is a whole number greater than or equal to 3 and i is an index which runs through the whole numbers from 1 to the number n of zones. The invention further relates to a method for dispersing gas into a liquid using the device according to the invention.

Abstract: The invention is directed to an extruder (10), particularly for extruding a synthetic rubber product, which comprises a barrel (24), one or several extruder elements (12, 14), particularly one or several extruder screws and/or a kneader elements (14), arranged inside the barrel (24) for conveying the product, optionally an inlet port for feeding a stripping agent into the barrel (24) and an outlet port for removing volatile compounds from the product and, where applicable, the stripping agent. According to the invention a perforated die plate (26) is fixed to the barrel (24) in flow direction before the outlet port. Since the die plate (26) is not fixed to the extruder elements (12, 14) but to the barrel (24) a circumferential clearance between the die plate (26) and the barrel (24) is prevented so that no extruded material is passing the die plate (26) radially outside.

Abstract: The invention is directed to an extruder (10), particularly for extruding a synthetic rubber product, which comprises a barrel (24), one or several extruder elements (12, 14), particularly one or several extruder screws and/or a kneader elements (14), arranged inside the barrel (24) for conveying the product, optionally an inlet port for feeding a stripping agent into the barrel (24) and an outlet port for removing volatile compounds from the product and, where applicable, the stripping agent. According to the invention a perforated die plate (26) is fixed to the barrel (24) in flow direction before the outlet port. Since the die plate (26) is not fixed to the extruder elements (12, 14) but to the barrel (24) a circumferential clearance between the die plate (26) and the barrel (24) is prevented so that no extruded material is passing the die plate (26) radially outside.

Abstract: The invention relates to a device for dispersing gas into a liquid. The devise has a number n of successive zones Z1, Z2, . . . , Zn having static mixing elements, wherein each zone Zi has a length Li and an effective diameter Di. The mechanical energy input Et, which is standardised to the particular ratio Li/Di and acts on the gas/liquid mixture, increases from zone to zone in the flow direction. In this connection n is a whole number greater than or equal to 3 and i is an index which runs through the whole numbers from 1 to the number n of zones. The invention further relates to a method for dispersing gas into a liquid using the device according to the invention.

Abstract: The invention relates to an apparatus and a process for devolatilizing solvent-containing polycarbonate solutions. By employing the inventive apparatus, polycarbonates with low residual values of volatile constituents are produced from solvent-containing polymer melts, which improved optical properties, especially yellowness index, with the aid of an apparatus combination of a flash devolatilizer and a vented extruder.

Abstract: The invention relates to an apparatus and a process for devolatilizing solvent-containing polycarbonate solutions. By employing the inventive apparatus, polycarbonates with low residual values of volatile constituents are produced from solvent-containing polymer melts, which improved optical properties, especially yellowness index, with the aid of an apparatus combination of a heatable tubular devolatilizer and a vented extruder.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to an apparatus and a process for devolatilizing solvent-containing polycarbonate solutions. By employing the inventive apparatus, polycarbonates with low residual values of volatile constituents are produced from solvent-containing polymer melts, which improved optical properties, especially yellowness index, with the aid of an apparatus combination of a flash devolatilizer and a vented extruder.

Abstract: The invention relates to an apparatus and a process for devolatilizing solvent-containing polycarbonate solutions. By employing the inventive apparatus, polycarbonates with low residual values of volatile constituents are produced from solvent-containing polymer melts, which improved optical properties, especially yellowness index, with the aid of an apparatus combination of a heatable tubular devolatilizer and a vented extruder.

Abstract: Evaporator apparatus (1) for the treatment of viscous media comprised of at least a feed chamber (2) having a perforated tray (3), a tube-bundle heat exchanger (4) connected thereto having perpendicularly arranged tubes (8) and a devolatilization chamber (5) connected thereto, a discharge unit (6) for the product and a vapor take-off (7) for removing volatile components, the tubes (8) of the heat exchanger (4) having a rectangular cross section over the greater part of their length.

Abstract: The invention relates to a process for extruding plastic compositions, in particular 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 with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

Abstract: The invention relates to a process for extruding plastic compositions, in particular 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 with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

Abstract: Static mixer module, consisting of a disc which is provided with a multiplicity of orifices (6) and is structured on its front side and on its rear side by means of channels (4, 5), and in which the orifices (6) are made in the flanks (8) of the inlet channels (4) and open into the flanks (9) of the mixing channels (5). Furthermore, a mixer arrangement is described, which consists of at least two static mixer elements arranged one behind the other, at least one mixer element being a disc-shaped static mixer module. The mixer module and the mixer arrangement are used in pipelines and housings through which a flow passes.