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Reduction of wheat middlings using a conventional and eight-roller milling systems
Fi?te? Aleksandar Z.,Vukmirovi? ?uro M.
Acta Periodica Technologica , 2009, DOI: 10.2298/apt0940025f
Abstract: Possibilities for the rationalization of the wheat flour milling process using the eightroller mill on the 1M and 2M passages of the reduction system have been investigated. At the same roll gaps and under the same sieving conditions, the lower flour yield has been obtained using an eight-roller mill compared to the conventional milling system (5-8 %) followed by a higher energy requirements for grinding. By decreasing the roll gap setting and increasing the upper size limit of flour in the process with the eight-roller mill it is possible to increase flour yield and therefore decrease milling energy consumption per unit mass of flour produced without deterioration of flour quality as determined by ash content. With appropriate adjustments of the processing parameters in the eight-roller milling system it is possible to achieve similar milling results to those in the conventional system, while the overall investment, energy and maintenance costs are significantly lower.
RESEARCH REGARDING THE INFLUENCE OF HYDROTHERMAL PROCESSING ON THE WHEAT MILLING PROCESS AND ON THE QUALITY OF FLOUR
RUSU TITI,NECULAIASA VASILE
Journal of Engineering Studies and Research , 2010,
Abstract: The study is explaining the way in which the hydrothermal processing of wheat is influencing the technological characteristics of the wheat berries and the baking quality of the resulting flour. Also there were established the correlations between the manners of conditioning and the degree of flour extraction, the specific power consumption and the quality of the products and of the sub-products resulting after the milling process.
Influence of Wood Flour and Modifier Contents on the Physical and Mechanical Properties of Wood Flour-Recycle Polypropylene Composites  [PDF]
Fauzi Febrianto,Dina Setyawati,Myrtha Karina,Edi Suhaimi Bakar
Journal of Biological Sciences , 2006,
Abstract: The objectives of this research was to evaluate the physical and mechanical properties of composites of Wood Flour (WF) and Recycle Polypropylene (RPP) prepared under various WF contents, WF sizes and modifier contents. WF from mixed-soft wood species and Eucalyptus deglupta Blume species were used as filler. The composites composed of 0-70% WF, 0-70% Polypropylene (PP) or RPP, various sizes of WF (60-80; 80-100 and < 120 mesh), various contents of MAH modifier (0, 1, 2.5, 5, 7.5 and 10%) and 15% Dicumyl Peroxide (DCP) initiator (based on MAH weight). Kneading conditions were set at 170 °C, 10-50 rpm for 15 min. The physical and mechanical properties of composites were greatly affected by WF content, WF size and modifier content. The greater the WF loading resulted in the greater was the reduction of tensile strength and breaking elongation values and at the same time the greater was the increasing of Young`s modulus value. The smaller the WF size resulted in the greater the tensile strength of composites. Addition of MAH modifier improved the physical and mechanical properties of composites. WF-RPP composites with 120 mesh WF size and 2.5% MA modifier had tensile strength, breaking elongation and Young`s modulus about 2.15, 2.27 and 1.18 times, respectively higher compared with composites free-MAH modifier and absorbed considerably less water. Scanning Electron Microscope (SEM) indicated that addition of MAH improved the adhesion between WF and RPP.
Compound machining of silicon carbide ceramics by high speed end electrical discharge milling and mechanical grinding
RenJie Ji,YongHong Liu,YanZhen Zhang,Fei Wang,BaoPing Cai,Hang Li
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4822-3
Abstract: A compound process that integrates end electrical discharge (ED) milling and mechanical grinding to machine silicon carbide (SiC) ceramics is developed in this paper. The process employs a turntable with several uniformly-distributed cylindrical copper electrodes and abrasive sticks as the tool, and uses a water-based emulsion as the machining fluid. End electrical discharge milling and mechanical grinding happen alternately and are mutually beneficial, so the process is able to effectively machine a large surface area on SiC ceramic with a good surface quality. The machining principle and characteristics of the technique are introduced. The effects of polarity, pulse duration, pulse interval, open-circuit voltage, discharge current, diamond grit size, emulsion concentration, emulsion flux, milling depth and tool stick number on performance parameters such as the material removal rate, tool wear ratio, and surface roughness have been investigated. In addition, the microstructure of the machined surface under different machining conditions is examined with a scanning electron microscope and an energy dispersive spectrometer. The SiC ceramic was mainly removed by end ED milling during the initial rough machining mode, whereas it is mainly removed by mechanical grinding during the later finer machining mode; moreover, the tool material can transfer to the workpiece surface during the compound process.
Effect of Two Milling Techniques and Flours Particle Size on Some Physicochemical Properties of Millet Flour
Brou Kouakou,Camara Fatou,N`Dri Yao Denis,Akaffou N`Guessan Lucien Marius,Djeni N`Dede Theodore
Journal of Food Technology , 2013,
Abstract: Two techniques of milling (milling with wooden mortar and milling with hammer grinder) for the production of millet flours were compared in term of physical, biochemical and nutritional aspects and digestibility of the produced flours. A batch of millet grains with candle (Pennisetum glaucum L. R.BR) was purchased from a local market for flour production, while the flour digestibility tests were achieved with an enzymatic crude extract get from gastric juice of and snails (Archachatina marginata). The different rough flours obtained from both milling techniques showed significant differences (p<0.05) in their granulometric profiles and their biochemical composition. The mortar milling gave flours with higher contents in dry matter, ash and sugars (total and reducing sugars) than hammer grinder one, excepted for total carbohydrates and starch. In addition, each flour fraction obtained after sieving rough flours also presented significant differences (p<0.05) in the biochemical composition and the digestibility. The flours with large particles (0.315 and 0.630 mm) had highest dry matter content and ash, but the flour with small particles (0.160 mm) was rich in soluble sugars, total carbohydrates and most digestible.
Design, fabrication and performance analysis of a planetary roll mill for fine grinding
Ajaka E. O.,Akinbinu V. A.
Journal of Engineering and Applied Sciences , 2011,
Abstract: Reducing milling cost in mineral processing is a problem that has defiled all serious attempts while milling still takes up to 60% of comminution cost. The planetary roll mill is a new innovation for faster and finer grinding. It is designed and fabricated with grinding rolls rotating in a number of arms inside a grinding sphere. A test run of the complete machine with crushed granite and sandstone shows that the machine grinds to fine consistency within a short period of time. A comparison of the products of the machine with that of a standard Denver Laboratory Ball Mill shows that the machine is about 30% more efficient than the ball mill in terms of duration of grinding to a particular size consistency. One advantage of the planetary roll mill is that is can be used as a ball mill if the need arises. It is therefore recommended that this mill be developed for both research and industrial uses.
The Influence of Milling on the Dissolution Performance of Simvastatin  [PDF]
Ulrike Zimper,Jaakko Aaltonen,Karen Krauel-Goellner,Keith C. Gordon,Clare J. Strachan,Thomas Rades
Pharmaceutics , 2010, DOI: 10.3390/pharmaceutics2040419
Abstract: Particle size reduction is a simple means to enhance the dissolution rate of poorly water soluble BCS-class II and IV drugs. However, the major drawback of this process is the possible introduction of process induced disorder. Drugs with different molecular arrangements may exhibit altered properties such as solubility and dissolution rate and, therefore, process induced solid state modifications need to be monitored. The aim of this study was two-fold: firstly, to investigate the dissolution rates of milled and unmilled simvastatin; and secondly, to screen for the main milling factors, as well as factor interactions in a dry ball milling process using simvastatin as model drug, and to optimize the milling procedure with regard to the opposing responses particle size and process induced disorder by application of a central composite face centered design. Particle size was assessed by scanning electron microscopy (SEM) and image analysis. Process induced disorder was determined by partial least squares (PLS) regression modeling of respective X-ray powder diffractograms (XRPD) and Raman spectra. Valid and significant quadratic models were built. The investigated milling factors were milling frequency, milling time and ball quantity at a set drug load, out of which milling frequency was found to be the most important factor for particle size as well as process induced disorder. Milling frequency and milling time exhibited an interaction effect on the responses. The optimum milling settings using the maximum number of milling balls (60 balls with 4 mm diameter) was determined to be at a milling frequency of 21 Hz and a milling time of 36 min with a resulting primary particle size of 1.4 μm and a process induced disorder of 6.1% (assessed by Raman spectroscopy) and 8.4% (assessed by XRPD), at a set optimization limit of < 2 μm for particle size and < 10% for process induced disorder. This optimum was tested experimentally and the process induced disorder was determined to be 6.9% (± 2.2) by Raman spectroscopy and 7.8% (± 2.3) by XRPD. Subsequent intrinsic dissolution testing revealed that the process induced disorder was negligible with regard to the dissolution rate. The predicted primary particle size of 1.4 μm could be confirmed experimentally, but due to agglomeration of the primary particles a dissolution rate advantage was not shown, highlighting the importance of dissolution testing at an early stage of drug development.
The Grinding Wheel Performance in the Transverse Cylindrical Grinding of an Eutetic Alloy
Bianchi, Eduardo Carlos;Silva, Eraldo Jannone da;Vargas, Vinicio Lucas;Magagnin, Thiago Cardoso;Monici, Rodrigo Daun;Vicari Filho, Osmar;Aguiar, Paulo Roberto de;
Materials Research , 2002, DOI: 10.1590/S1516-14392002000400007
Abstract: this paper presents a research in which the performance of two different grinding wheels (a conventional and a cbn wheel) was evaluated in a transverse cylindrical grinding of a eutectic alloy. three cutting conditions were tested: rough, semi-finishing and finishing. as evaluating parameters, the cutting force, the roughness and the wheel wear were measured. as a result, the best values of the cutting force and the roughness were obtained when grinding with the conventional wheel, due to the best dressing operation performed, for all the cutting conditions. the cbn presented the best g ratio values. although, the g ratio values observed for the cbn wheel were lower than the expected one due to the non-effective dressing operation applied. in the conditions tested, in terms of cutting force and roughness, the conventional wheel is the best choice. in terms of g ratio, a cost analysis is crucial to determine if the differences observed among the wheels can justify the use of the cbn wheel. in a positive case, the dressing operation must be improved.
The Grinding Wheel Performance in the Transverse Cylindrical Grinding of an Eutetic Alloy
Bianchi Eduardo Carlos,Silva Eraldo Jannone da,Vargas Vinicio Lucas,Magagnin Thiago Cardoso
Materials Research , 2002,
Abstract: This paper presents a research in which the performance of two different grinding wheels (a conventional and a CBN wheel) was evaluated in a transverse cylindrical grinding of a eutectic alloy. Three cutting conditions were tested: rough, semi-finishing and finishing. As evaluating parameters, the cutting force, the roughness and the wheel wear were measured. As a result, the best values of the cutting force and the roughness were obtained when grinding with the conventional wheel, due to the best dressing operation performed, for all the cutting conditions. The CBN presented the best G ratio values. Although, the G ratio values observed for the CBN wheel were lower than the expected one due to the non-effective dressing operation applied. In the conditions tested, in terms of cutting force and roughness, the conventional wheel is the best choice. In terms of G ratio, a cost analysis is crucial to determine if the differences observed among the wheels can justify the use of the CBN wheel. In a positive case, the dressing operation must be improved.
THE BEHAVIOUR OF THE MODERN CONSUMER FOR THE MILLING AND BAKERY PRODUCTS
MARA TURNEANU,I. PETROMAN
Lucr?ri ?tiin?ifice : Management Agricol , 2009,
Abstract: The products resulted from cereal grinding are destined to human consume, being base elements for all consumer categories and also materials for different industrial sectors. The harmlessness of these products is extremely important for the securing and maintaining the health of the human organism. Any producer that wishes the growth of the market quota of the products that he makes must establish a firm policy to secure consume safety so that his products will not affect the consumer’s health and will be appreciated and implicitly will be requested on the market. In this way the managerial team of the milling and bakery unit must elaborate a safety policy for aliments that needs to have the following: -To respect the rules of the good practice guide for the safety of products resulted from cereal grinding (GHP, GMP) and to apply HACCP plans; - To project and implement a management system of aliment safety based on the HACCP method. On the grocery products market – flour, corn flour, and semolina – will remain in competition only the ones who will invest in the production capacities, and so the great players will remain. Influenced by the buying and consume behaviour, the market of grocery products – flour, corn flour and semolina – is on an ascendant trend, demonstrated by the presence on this category of producers that act on a national level and also of those present only at a regional level. Dominated in a proportion of 70% of the principal five – six big players, the Romanian market of grocery products, steps forward by a strong competitive character. At a geographical region level there are numerous small local players, producers or packers that enjoy a good notoriety in their coverage area. The last years show a volume drop of the flour category and a growth of the corn flour request, semolina being a complementary secondary product.
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