Verarbeitung von PVC auf kalandern. Formgebung im walzenspalt

Shaping in the nip of the calender is characterized by the presence of a spindle-shaped bead of superfluous melt, i.e. bank, front of the nip. The melt transported to the nip by the drag set up by the rolls is then subjected to partial change in flow. The rerouted melt flows into the bank and is replaced by melt transported from the bank into the nip. The currents at the interior of the bank are also governed by its outer movement, a rotating movement, which is superimposed by a spiral undulation, and this decisively affects the quality of the film. The bank is formed by the melt which is severely sheared in the nip and high temperatures are correspondingly displayed. The length of time the melt remains in the bank is thus decisive for thermal loading during calendering. With the Luvitherm process, in which no true melt is present in the calender sheared material is collected in the nip in flake form before the nip and is again drawn through the nip in irregular sequence. Here also, calendering is governed by the flow conditions at the entrance to the nip.     

Industrielle Anwendung von zeolithischen Katalysatoren beim Hydrocracken

Industrial application of zeolitic catalysts in hydrocracking . For maximum production of gasoline by hydrocracking using zeolite type catalysts two cracking schemes are presented and the operation conditions, feedstocks, yields, and material balances are discussed. The advantages of zeolitic hydrocracking catalysts are outlined. The main catalyst parameters controlling activity and selectivity are described and a scheme for the preparation of zeolitic catalysts is given, which illustrates the superiority of zeolitic hydrocracking catalysts over amorphous ones. Finally, the hydrocracking of residues is reviewed and a typical process together with the product characteristics and yields obtained is described.     

Neuere technische Entwicklungen der industriellen Herstellung von Speisefetten I

Recent Technical Developments in the Industrial Manufacture of Edible Fats The development in the oilseed processing during the past decade was aimed toward increasing the capacity of the production units, especially of extraction plants, and, in connection herewith, towards reduction of costs. In the field of fat-refining considerable progress from chemical and technological view-point was achieved during the same decade. The advances in processing technique comprise primarily of efforts to change over to continuous or semi-continuous processes apart from the technical requirements that are to be fulfilled due to chemical developments and modifications. In the present contribution, processes are reported which were either found to be totally successful in the actual practice or whose projecting and trial have already been successfully completed. In the general technology, the decisive step towards automation could be scaled by a systematic approach, which led to a well-defined characterization of the fat-refining process. The important features of the above are: multi-channelled and multi-step processes or sequence of processes of various types with frequent change of material over a main path, numerous multi-channelled process-loops and a few subsequent single or multi-channelled processes for the treatment of by-products and waste products.     

Expander zur Verarbeitung von Ölsaaten

Expanders used for pretreatment of oilseeds. For quite a couple of years expanders are used for pretreatment of oilseeds, especially for soybeans and cottonseed. By increase of the bulk weight and the percolation rate the capacity of the extraction plant can be optimized. Energy consumption or phosphatides in the degummed oil hardly play any role when thinking about integration of expanders into an extraction plant. Recent developments allow to take the expander as a continuous unit, where the important parameters like temperature, moisture, time, and in some cases pressure and shear forces can be controlled. This allows to influence not only the character of the extraction meal but also the quality of the extracted oil.     

Reinhaltung von Luft und Wasser bei der Verarbeitung von Lacken I

Maintenance of Clean Air and Water in the Manufacture of Paints I Pollution laws, exhaust limitation of drying ovens, suitable measuring procedures etc. should enable to achieve purer exhaust air. Water pollution law aims at preventing contamination caused by detergents, by storage of heating oil and solvents, trickling chambers, cleaning of barrels, electrophoresis etc.     

Fortschritte in der Gewinnung und Verarbeitung von Pflanzenlecithinen

Progress in Production and Processing of Vegetable Lecithines Production and processing of vegetable lecithines, won as secondary products of edible oil production, have only very seldom been the subject of publications in German literature during the last decades. Since 1950 remarkable improvements have been achieved in this field. In detail they concern the hydratation methods, the fractionation procedures which are worked out to separate neutral lipids, unwelcome phosphatides and oligosaccharides as well chemical and enzymatical reactions by which the emulsifiability and the dispersing power of the lecithine preparations can be improved. The present report bases on scientific publications and patent literature. It considers beyond that the results obtained in the author's laboratory.     

Untersuchung und Beurteilung von PAK in Speisefetten und -ölen

Investigation and Legal Evaluation of Polycyclic Aromatic Hydrocarbons in Vegetable Fats and Oils The analysis of 40 native and refined commercially available vegetable fats and oils reveals the influence of the environment and the treatment on the contamination with PAHs. Totally refined oils and fats have no or only a low contamination of PAHs whereas grapeseed oil contains PAHs to a high extent. This fact has to be deduced to the old-fashioned drying process of the pressed grapes. The analytical procedure with HPLC and fluorimetric detection was done after alcaline hydrolysis. The PAHs were extracted using the distribution between DMF, cyclohexane and water. The legal evaluation of high contaminated is discussed in regard of national and international regulations.     

Qualitätsbestimmende Eigenschaften bei der Verarbeitung von Rapssaat

Characteristics of Quality for the Processing of Rapeseed Among quality characteristics of oilseeds high extraction rates by the lowest possible technical expenses rank first for oilmilling. Apart from weight of cargo, oil content, humidity and contamination are therefore the most decisive determinants of price quotations. But for efficient oil extraction further criterions are essential such as structure and hardness of the seed, content of free fatty acids, phospholipids (gums), unsaponifiables, colour bodies or pollutants. In addition, the nutritional qualities of the meal, especially its content of glucosinolates and protein, deserve increasing interest. Each of these characteristics typically differs in its modificability by means of breeding and processing. From two experiments with industry scale processing of rapeseed from new varieties low in erucic acid and glucosinolate, results were obtained in 1975 and 1976 confirming the technological equivalency of the traditional and the new rapeseed varieties. Simultaneous genetic improvement of oil and protein content is limited by a negative physiological correlation between these two important quality characteristics. But probably the maximum capacity with regard to these traits is not yet realized in the present varieties. According to the results of an experiment with more than 4000 plants and their progenies progress in protein selection varies within different subgroups of a total of breeding stocks preselected for oil content and thousand-seed-weight, respectively.