Abstract: The invention relates to a continuous process for preparing aminoplastics and/or phenolics, in which a precondensate solution is prepared in a first extruder (14), the precondensate solution is continuously fed, with addition of additives, to a second extruder (20) with partial filling in the feed section (E) and devolatilization section (G), devolatilized in the second extruder (20) and then formed to give a molding composition or an end product. The process is particularly suitable for preparing melamine resins, in particular melamine-formaldehyde resins, as well as for preparing urea-formaldehyde resins.

Abstract: A process for the preparation of high-quality magnetic dispersions having an Hc>120 kA/m, a residual induction Mr/Mm≧0.9 and an orientation ratio of about 2.7 achieves, with a self-purging single-shaft blade-type kneading apparatus, very advantageous magnetic values of the magnetic coatings and excellent tape characteristics if at least the following features are fulfilled: a) the radial shear gradient in the gap between blade circumference and housing wall is from about 150 to about 1600, in particular from about 500 to about 1400, l/sec b) the circumferential velocity of the kneading blade is from about 20 to about 80, in particular from about 35 to about 60, cm/sec. The magnetic dispersion prepared can be used in particular for data and video recording media having high recording and storage rates.

Abstract: A process for the continuous production of solid, particulate preparations of bioactive substances, in which the bioactive substances are homogeneously dispersed in a matrix of thermoplastic auxiliaries, in a screw extruder divided into a plurality of zones, wherein there is firstly melting of the matrix auxiliaries and mixing of the bioactive components with the matrix auxiliaries in a heatable zone, after which the mixture is cooled, precomminuted and finely ground in a cooling zone, the screw geometry in the cooling zone being selected so that the cooling zone consists of a conveying zone, a mixing zone and a kneading zone.

Abstract: A process for the preparation of high-quality magnetic dispersions having an Hc>120 kA/m, a residual induction Mr/Mm≧0.9 and an orientation ratio of about 2.

Abstract: A process for the preparation of high-quality magnetic dispersions having an Hc>120 kA/m, a residual induction Mr/Mm ≧0.9 and an orientation ratio of about 2.7 achieves, with a self-purging single-shaft blade-type kneading apparatus, very advantageous magnetic values of the magnetic coatings and excellent tape characteristics if at least a) the radial shear gradient in the gap between blade circumference and housing wall is from about 150 to about 1600, in particular from about 500 to about 1400, 1/sec, and b) the circumferential velocity of the kneading blade is from about 20 to about 80, in particular from about 35 to about 60, cm/sec.

Abstract: The present invention relates to a process for producing multilayer, solid drug forms for oral or rectal administration, which comprises coextrusion of at least two compositions which in each case comprise a thermoplastic, pharmacologically acceptable polymeric binder which is soluble or swellable in a physiological environment, and at least one of which contains a pharmaceutical active ingredient, and shaping the coextruded multilayer material to the required drug form.

Abstract: Solid drug forms are produced by mixing and melting at least one pharmacologically acceptable polymeric binder and at least one pharmaceutical active ingredient, with or without conventional pharmaceutical additives, in the absence of a solvent to give a plastic mixture and shaping the mixture to the required drug form by extrusion, where the shaping takes place in two steps, with the extrudate being broken into shaped articles in a first step, and these shaped articles being rounded off in a second step in the plastic state.

Abstract: A process for producing continuous filament fibers from a hydroxy- or amino-alkyl-melamine modified melamine-formaldehyde condensation product comprises filtering the highly concentrated aqueous solution of the melamine-formaldehyde condensation product, forcing the filtrate through a spinneret, drying the extruded filaments in a drying shaft by means of hot air, and treating the dried filaments in a tempering oven at temperatures which rise gradually to a maximum temperature of from 160 to 250.degree. C. to cure the precondensate.

Abstract: A continuous process for preparing bead-form expandable styrene polymers in which the styrene is prepolymerized in bulk to a conversion of 10 to 80%, the prepolymer is dispersed in liquid form in an aqueous phase in the presence of suspension stabilizers, and the polymerization of the prepolymer is completed in an aqueous suspension to a residual styrene content of less than 2000 ppm.

Abstract: A mixing apparatus for multi-component plastics, in particular polyurethane, possesses a mixing chamber (2) with inlet apertures (3) and (4) for the individual plastic components and an outlet aperture (8) for the mixture. In the mixing chamber, a control element (5), which has the same cross-section as the chamber and possesses overflow channels (6) and (7), can be moved to and fro for controlling the component streams. In order to avoid pressure peaks or pressure surges in the transport of the components when the control element passes from the closed position to the mixing position and vice versa, and to provide improved accuracy of metering, the inlet apertures in the inner wall of the mixing chamber, and the corresponding areas of the shell of the control element between its end face (13) and the overflow channels, are matched with one another with regard to their size.