Dry grinding of waste wood fiberboard: Theoretical and practical aspects affecting the resulting fiber quality

This paper presents the results of research on the treatment of secondary wood fibre semi-finished materials using a dry-grinding-type rotary cutting mill and the possibility of their use in finished products for various purposes. The physical phenomena, processes, and regularities of the treatment of secondary wood fibre materials in dry processing conditions were determined and evaluated. The influence of grinding plant design parameters on wood fibre quality indices was evaluated. Mechanical effects on wood fibre waste of face-cross cutting (cutting, crumpling, collapsing, and breaking) and the dry grinding environment (breaking, collision, defibering, and fibrillation) was studied. These phenomena contribute to the formation of external and internal fibrillation of secondary wood fibre and an increase in the specific surface area. This is achieved in the absence of high temperatures and pressure, in the absence of chemical additives, and without the application of water and vapour. The effectiveness of secondary wood fibre semi-finished material treatment was demonstrated under dry processing conditions, thus confirming the environmental and economic feasibility of this method.

SURFACE ROUGHNESS IMPROVEMENT OF PARTS MADE OF POLYMERIC MATERIALS OBTAINED BY MEANS OF ADDITIVE TECHNOLOGIES

In the paper there is under consideration an effort to achieve the roughness index of Ra <0.8 with the aid of soft abrasive tool use. As a result the purpose of this work became development of the technology for surface quality improvement of parts manufactured with the aid of additive technologies. The authors carried out a number of experiments with the samples manufactured with the aid of the method of FDM print. With the aid of 3D Ultra 3 printer of EnvisionTec company. The samples were made of ABS-plastic in the amount of 6 pieces. On each sample there were defects after printing which contributed to the deterioration of surface quality in products. By means of TR220 profilometer there was measured roughness before and after the experiment. There was carried out dry processing and with the use of SCL. As a result, dry processing resulted in worsening surface quality, heavy wear of an abrasive tool and grain contamination. Analyzing the data obtained from the profilometer in the experiment and SCL use a considerable improvement of the surface layer quality at minimum allowance is observed. Investigation methods: in the work basis there are experimental methods of investigation. The investigations are carried out with the use of a microscope and profilometer. Processing investigation results was carried out as a result of the comparison of the measuring data obtained. Work Novelty: there are defined conditions of soft abrasive tool operation and SCL impact upon Ra indices. The results obtained indicate a possibility of Ra improvement on a part surface which is achieved due to a combined shaping with the aid of additive technologies and further machining carried out on a single technological basis. The experience without SCL use has shown the overheating possibility the result of which is a meltback and plastic sticking both on the surface, and on abrasive grains of the cutter which is inadmissible and results in considerable worsening of Ra on the surface machined and cutter wear. In view of this the SCL use in finishing is promising, but to achieve better results SCL chemistry must be improved.

PROCESSING CHARACTERISTICS AND ACCEPTABILITY OF JACKFRUIT (Artocarpus heterophyllus Lam.) SEEDS, PHYSICAL AND FUNCTIONAL PROPERTIES OF ITS FLOUR

Jackfruit possess 100-400 seeds which are oval, brown and edible after processing. A study was undertaken to investigate ‘processing characteristics and acceptability of jackfruit seeds and to evaluate physical and functional properties of its flour’. Ripe jackfruits procured from a single tree at University of Agricultural Sciences, Dharwad campus were cut, and seeds were separated. Seeds were processed by boiling, pressure cooking, pan roasting, microwave roasting, baking. Unprocessed seeds served as control. Effect of processing on characteristics of jackfruit seed was evaluated. Seeds were subjected to sensory evaluation by semi- trained panel members using 9 point hedonic scale. Processed seeds were converted to flour and analyzed for physical and functional properties. Results revealed that weight, volume and edible portion of seeds increased in wet processing but decreased in dry processing. Boiling resulted in better acceptability with acceptability index of 83.15 per cent. Pressure cooked and pan roasted seeds were on par with boiled seeds followed by baked seeds, while microwave roasted seeds had lower acceptability. Flour yield was significantly higher in unprocessed jackfruit seeds (42.17 ± 0.06 %). Increase in bulk density was recorded with processing. All processing methods resulted in increased water absorption and oil absorption capacity of jackfruit seed flours. Swelling capacity of jackfruit seed flour increased during moist processing (6.46±0.11 % in boiled and 6.24±0.10 % pressure cooked seeds) and did not decrease significantly in dry processing. The solubility of flours increased during boiling (21.07±0.05%) and decreased significantly on dry processing (15.63 ± 0.20%). Jackfruit seed flour possess good functional property and hence can be used at domestic, commercial and industrial purpose KEY WORDS: Dry processing, Flour, Jackfruit seed, Moist processing

Economic and Socio-Environmental Benefits of Dry Beneficiation of Magnetite Ores

In our previous studies, we demonstrated the performance of novel superfine crusher and pneumatic planar magnetic separator as energy-efficient technologies for dry processing of magnetite ores. The present study investigates the economic and socio-environmental benefits of applying these technologies in conceptual dry magnetite ore processing flowsheet. The outcome of the study is compared with that of a conceptual wet processing flowsheet for the same ore. The cost estimations used are based on the Brook Hunt C1 methodology whilst revenue estimations are based on the Platts Iron Ore Index specification. The demonstrated economic and socio-environmental benefits show that dry processing flowsheet offers significant energy and cost savings and improved revenue generation compared with the wet process flowsheet. These findings are vital to the magnetite industry, particularly in water- and energy-scarce regions as a benchmark for future studies aimed at deepening and expanding the knowledge base of dry beneficiation of magnetite ores.