Abstract: The present invention relates to methods and apparatuses for the purification and reuse of waste air mixed with additives (for example, solvents) or impurities, in particular for the purification and reuse of waste air mixed with solvents from dryer appliances of web-fed offset printing machines, in a first method step the waste air being led through at least one condenser in order to condense out additives or impurities contained in the waste air, in a second method step the waste air, treated according to the first method stop, being led through at least one separator element for the further purification of the waste air to remove condensed additives or impurities contained in it, and, finally, the waste air, treated according to the second method step, being recirculated for the renewed absorption or suction-removal of additives and impurities.

Abstract: A process for removing vaporizable constituents from high-viscosity solutions or melts of thermoplastics by continuous evaporation along a heated devolatilization zone and separation of the vapor phase from the liquid phase in a downstream separating vessel. The plastic solution or melt is first heated stepwise in increments, in the devolatilization zone, while the product is in the form of thin layers from about 0.5 to 4 mm, so as to maintain a temperature difference of less than 50.degree. C.

Abstract: A process and an apparatus for heating or cooling very viscous solutions or melts of thermoplastics in the form of thin layers. The plastic solution or melt is spread under the temperature conditions of the feed solution or melt, and the thin layers are heated stepwise so that the temperature difference between the heat transfer medium and the solution or melt is at all times less than 50.degree. C. and preferably less than 20.degree. C. Viscous solutions or melts of thermoplastics can be heated or cooled rapidly and uniformly under gentle and controlled conditions, to prepare the solutions or melts for further treatment in conventional equipment.

Abstract: A process for admixing additives to plastics and simultaneously removing volatile constituents in a horizontal devolatilizing extruder. Taken in sequence in the direction of flow, the additives are first introduced into the devolatilizing extruder from above, and the plastic melt, solution or dispersion is then introduced from below, while the bulk of the volatile constituents are withdrawn from the devolatilizing extruder at an orifice located vertically above the point at which the plastic is fed in. The process permits the removal of volatile constituents with simultaneous admixture of additives during aftertreatment of plastics, in a single step and at very high throughputs.

Abstract: A process and associated apparatus for filling packages with free-flowing solids through spouts, in which some of the material is initially fed to the package with the latter in its gravity position, the position of the package is changed once or a number of times with shaking of the entire package, and finally the remainder of the material is filled into the package with the latter in its gravity position.