TOPIC
Bio-Minimum-Lubrication
Abbildung 1: Profactor Produktionsforschungs GmbH
The goal of this project consisted in the development of an appropriate system for “Bio-Minimum-Lubrication” using an oil-in-water emulsion from renewable raw materials. The project was realized by Profactor in cooperation with Agatex Feinchemie GmbH and TPS Technische Produkte.
The profile of specifications required for the minimum cooling lubrication system had been developed by the project team in cooperation with representatives of various participating enterprises (Protan Produktionstechnik, Josef Haidlmair Werkzeugbau, and VA Tech Mechatronics). The profile comprises the production technology, chemical and physical properties of the cooling lubricant, dosing and delivery, occupational and environmental safety as well as availability of raw materials. Desired metal working processes include milling with a focus on HSC, turning, tapping and threading, reaming, drilling, sawing and, subsequently, also punching / blanking and drawing. Possible materials include nonferrous metals (copper, bronze), (stainless) steel, composite materials (e.g. copper and steel), sintered metals, plastics, and aluminum.
A study on the availability of domestic raw materials yielded positive results. The researchers examined the potential growing area and yields for oil crops using rape, sunflower, soybean, winter pumpkin, St. Mary thistle, false flax (Camelina sativa), and safflower (saffron thistle) as potential crops. The additional potential growing area amounts to some 100,000 hectares of rotational fallow land. Taking into account crop succession, some 25% of this area could be used for the cultivation of oil crops. This corresponds to a potential yield of 62,000 tons of oil. In addition, the researchers ascertained the production capacity, rate of utilization, and technical equipment of Austrian oil mills.
LABORATORY TESTS
First the laboratory at Agatex developed 20 different emulsifier/lubricant combinations and tested their properties. Two pilot products were used in the subsequent practical tests of the pump-nozzle system. Of the three delivery systems tested by Profactor a commercially available system was selected and adapted with a view to flexibility and optimum adjustability.
Abbildung 2: Profactor Produktionsforschungs GmbH
The tests in the machining laboratory aimed to model the production processes used by the project partners as precisely as possible and to identify optimized cutting and cooling lubricant parameters. Target values referred to technological and economic aspects as well as to lubricant consumption and emission levels. 35 spraying tests used varying pressure conditions for the application of cooling lubricant and air supply. The researchers used two types of emulsion, oil, and different mixture ratios of the emulsions. Pressure conditions and the composition of the lubricant proved to be the main determining factors for aerosol concentration. The variants using emulsions yielded positive results, both, concerning consumption and with a view to emissions.
The subsequent milling tests examined three practice-oriented applications for minimum cooling lubrication with different work piece materials (brass - milling, sintered steel - thread molding, and C45 - milling). While the brass cutting tests focused on measuring emission levels, the objective of the second test series examined the feasibility of the minimum cooling lubricant system with emulsions in drilling and thread molding, respectively. In the third test series, various geometric shapes were cut out of a steel block. The test aimed to examine mist formation and wear of the cutter head.
In general, the laboratory tests have shown that the new emulsion-based minimum cooling lubricant system causes lower emission levels compared to conventional flood lubrication, but also compared to oil-based minimum cooling lubrication. Tool wear, surface finish of the components, dimensional accuracy, and cutting parameters are comparable with those of other systems. It was, however, not possible to examine tool life in these laboratory tests.
Abbildung 3: Profactor Produktionsforschungs GmbH
