Der Einfluß von Wachsen auf die Eigenschaften,insbesondere die Scheuerfestigkeit von Druckfarben

The influence of Waxes on the Properties of Printing Inks The influence of waxes on the properties of printing inks and printed materials is shown with the examples of straight chain and differently branched hydrocarbons. The waxes in finely dispersed state are imbedded in the printing inks like pigments and retain this state in the dried printing ink film. Polyethylene waxes change the rheological behaviour of the printing inks and above all improve the scratch and scrubb resistance of the finished prints. On the basis of measurements carried out with printing inks and printed matter it has been tried to explain the mechanism of the action of polyethylene waxes on the printing inks.     

Einfluß von Additiven und Verunreinigungen auf Kristallisationsprozesse

Influence of additives and contaminants on crystallisation processes. The presence of additives and contaminants in a crystallising solution can have a considerable influence on the crystallisation properties of the products, such as nucleation and growth kinetics, agglomeration or dispersion of the crystals, and the incorporation of foreign ions into the crystal lattice. These influences are caused by various mechanisms, depending upon the type of additive or contaminant. Tailor-made and multifunctional additives are distinguished. Trace amounts of metal ions can also modify the kinetics of crystallisation. The metal ions can be incorporated to a greater or lesser extent in the crystal, depending upon thermodynamic and kinetic factors.     

Einfluß von thermophysikalischen Stoffdaten auf die Auslegung und den Betrieb von Destillationskolonnen

Influence of thermophysical data on the design and operation of distillation columns. It has become common practice in the petrochemical industry to utilize highly developed process simulators for the design of individual pieces of equipment or entire processes. Apart from actual model development, attention focusses on the calculation and use of efficient solution and converging algorithms in the development of such process simulators. Although frequent reference is made to the importance of the underlying material data in the literature and in practical applications there exist only scattered studies giving a suitable choice of the available substance data models and the sensitivity of the process variables to inaccuracy and uncertainty of the material data and the material data models. The present article illustrates the influence of material data (choice of model, sensitivity) for the example of the design and operation of distillation columns and several methods and recommendations are given for fast estimations. With the aid of appropriate examples, the influence of uncertainties in the underlying measured data and the phase equilibrium models on various process variables (plate number, reflux ratio, distillate and sump concentrations) is demonstrated.     

Einfluß der struktur auf einige eigenschaften von polyurethan- und polyestermelamin-lacken

A method for calculating the crosslink density of systems originating from low molecular weight compounds is described. It is possible to determine quantitatively the influence of the crosslink density and the chemical composition on the glass transition temperature of network structures. This will be illustrated by crosslinked polyurethanes. On polyester melamine resins it will be shown that both the molecular weight of the polyester and the crosslink density of the network play an important role in the development of high solids coating systems as far as the solids content and the sagging are concerned.     

Der Einfluß von Netz- und Hydrophobierungsmitteln auf die Eigenschaften von Zementmörtel

Influence of Wetting and Hydrophobing Agents on the Properties of cement Mortar The relationships between the water requirement of cement mortar, its pore volume and resistence to pressure and water, and the chemical composition of wetting and hydrophobing agents added have been studied. It was found that the rigidity and absorbing capacity are dependent not only upon the density and pore volume of mortar but also upon the chemical structure of the additives. Inspite of reduced density and increased pore volume, it is possible to attain a rigidity of structure and low water absorbence by employing a definite ratio between the hydrophilic and lyophilic ligands in the molecule of the additive.