The Experts below are selected from a list of 9576 Experts worldwide ranked by ideXlab platform
Konrad Wegener - One of the best experts on this subject based on the ideXlab platform.
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conditioning and monitoring of grinding wheels
Cirp Annals-manufacturing Technology, 2011Co-Authors: Konrad Wegener, Friedrich Kuster, Hans Werner Hoffmeister, B Karpuschewski, W C Hahmann, Mohammad RabieyAbstract:Abstract The preparation of grinding tools is the most important enabling factor in the grinding Process. It influences the material removal rate, the grinding forces, the surface quality as well as the material properties of the subsurface zone, and is the key issue for subsequent wear of grinding tools. The evolving and conventional conditioning technologies are reviewed based on technical and commercial aspects. Terms in the field of conditioning are defined. Strong emphasis today is put on the description and monitoring of the abrasive layer. For optimization of the Dressing Process, prediction of the grinding wheel topography and the ground surface are emerging scientific topics.
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a study on laser touch Dressing of electroplated diamond wheels using pulsed picosecond laser sources
Cirp Annals-manufacturing Technology, 2011Co-Authors: Claus Dold, Friedrich Kuster, Robert Transchel, Mohammad Rabiey, P Langenstein, Christian Jaeger, Frank Pude, Konrad WegenerAbstract:Abstract An investigation to explore the possibility of touch Dressing of electroplated diamond wheels using a pulsed picosecond laser (ps-laser) beam (Yb:YAG) is presented. The laser beam is irradiated on the wheel to cut the diamond grains within a defined grain protrusion without any thermal damage on the nickel bond. The laser parameters were systematically varied to achieve a reliable touch Dressing Process. The microscopic investigations prove thermal damages neither on the diamond grain nor on the bond. Series of SiC wheel Dressing experiments were carried out to compare mechanical touch Dressing of the electroplated diamond wheel with laser dressed wheels.
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On-machine wire electrical discharge Dressing (WEDD) of metal-bonded grinding wheels
The International Journal of Advanced Manufacturing Technology, 2010Co-Authors: Eduardo Weingärtner, Sascha Jaumann, Friedrich Kuster, Konrad WegenerAbstract:Metal-bonded diamond wheels, due to its strong grain retention and thermal conductivity properties, are generally used for grinding difficult-to-cut materials, such as high-performance ceramics. On the other hand, the poor dressability of this type of bond limits its application. This study aims to evaluate the use of a wire electrical discharge machining (EDM) principle for truing and Dressing metal-bonded grinding wheels. Through the EDM Process, the electrically conductive grinding bond is eroded, so that grain protrusion can be generated. For evaluating this Dressing Process, a wire electrical discharge Dressing unit was designed, manufactured, and integrated into a universal cylindrical grinding machine. The Dressing Process is carried out using the grinding oil also as dielectric fluid. High material removal rates were achieved. Cylindrical plunge grinding tests on silicon nitride workpieces indicated that in comparison to conventionally dressed wheels, smaller cutting forces and wheel wear are achieved by using EDM-dressed grinding wheels.
Friedrich Kuster - One of the best experts on this subject based on the ideXlab platform.
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a study on laser touch Dressing of electroplated diamond wheels using pulsed picosecond laser sources
Cirp Annals-manufacturing Technology, 2011Co-Authors: Claus Dold, Friedrich Kuster, Robert Transchel, Mohammad Rabiey, P Langenstein, Christian Jaeger, Frank Pude, Konrad WegenerAbstract:Abstract An investigation to explore the possibility of touch Dressing of electroplated diamond wheels using a pulsed picosecond laser (ps-laser) beam (Yb:YAG) is presented. The laser beam is irradiated on the wheel to cut the diamond grains within a defined grain protrusion without any thermal damage on the nickel bond. The laser parameters were systematically varied to achieve a reliable touch Dressing Process. The microscopic investigations prove thermal damages neither on the diamond grain nor on the bond. Series of SiC wheel Dressing experiments were carried out to compare mechanical touch Dressing of the electroplated diamond wheel with laser dressed wheels.
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conditioning and monitoring of grinding wheels
Cirp Annals-manufacturing Technology, 2011Co-Authors: Konrad Wegener, Friedrich Kuster, Hans Werner Hoffmeister, B Karpuschewski, W C Hahmann, Mohammad RabieyAbstract:Abstract The preparation of grinding tools is the most important enabling factor in the grinding Process. It influences the material removal rate, the grinding forces, the surface quality as well as the material properties of the subsurface zone, and is the key issue for subsequent wear of grinding tools. The evolving and conventional conditioning technologies are reviewed based on technical and commercial aspects. Terms in the field of conditioning are defined. Strong emphasis today is put on the description and monitoring of the abrasive layer. For optimization of the Dressing Process, prediction of the grinding wheel topography and the ground surface are emerging scientific topics.
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On-machine wire electrical discharge Dressing (WEDD) of metal-bonded grinding wheels
The International Journal of Advanced Manufacturing Technology, 2010Co-Authors: Eduardo Weingärtner, Sascha Jaumann, Friedrich Kuster, Konrad WegenerAbstract:Metal-bonded diamond wheels, due to its strong grain retention and thermal conductivity properties, are generally used for grinding difficult-to-cut materials, such as high-performance ceramics. On the other hand, the poor dressability of this type of bond limits its application. This study aims to evaluate the use of a wire electrical discharge machining (EDM) principle for truing and Dressing metal-bonded grinding wheels. Through the EDM Process, the electrically conductive grinding bond is eroded, so that grain protrusion can be generated. For evaluating this Dressing Process, a wire electrical discharge Dressing unit was designed, manufactured, and integrated into a universal cylindrical grinding machine. The Dressing Process is carried out using the grinding oil also as dielectric fluid. High material removal rates were achieved. Cylindrical plunge grinding tests on silicon nitride workpieces indicated that in comparison to conventionally dressed wheels, smaller cutting forces and wheel wear are achieved by using EDM-dressed grinding wheels.
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Special wire guide for on-machine wire electrical discharge Dressing of metal bonded grinding wheels
CIRP Annals - Manufacturing Technology, 2010Co-Authors: Eduardo Weing??rtner, Sascha Jaumann, Friedrich Kuster, Mario BoccadoroAbstract:To improve accuracy in wire electrical discharge Dressing (WEDD), special attention should be given to wire vibration. In this work, the use of a specially designed wire guide is proposed, which is responsible for both ensuring the stability of the wire and improving the efficiency of dielectric delivery to the Dressing zone. For carrying out experiments with metal bonded diamond grinding wheels, a WEDD-device was designed, manufactured and integrated into a grinding machine. High erosion material removal rates and Dressing accuracy were achieved, thus demonstrating the feasibility and efficient performance of this in situ Dressing Process. ?? 2010 CIRP.
C. O. Gill - One of the best experts on this subject based on the ideXlab platform.
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The effects on product of a hot water pasteurizing treatment applied routinely in a commercial beef carcass Dressing Process
Food Microbiology, 2000Co-Authors: C. O. Gill, J BryantAbstract:Abstract The effects of a pasteurizing treatment on the microbiological condition and the appearance of carcasses, routine in a commercial carcass Dressing Process, were examined. Beef carcass sides were pasteurized with water at 85°C. During 2-h periods, all sides from the Dressing Process were treated for 8, 9, 10, 11 or 12 s. During each period, microbiological samples were obtained by swabbing five randomly selected sides before and five others after the treatment, with a single sample being obtained from 25 treated and 25 untreated sides from each treatment time. All treatments similarly reduced the log mean numbers of total aerobic counts by about 1 log unit, but the reductions in the log total numbers of coliforms or Escherichia coli recovered from 25 samples increased with increasing treatment time, to >2 log units with treatment times of 11 or 12 s. Cooling of the sides did not obviously reduce the numbers of total aerobic bacteria on beef sides, but there were small reductions in the numbers of coliforms and E. coli on both treated and untreated sides. After cooling, sides treated routinely for 10 s yielded total aerobic counts at log mean numbers of about 2 log cfu cm −2 , and coliforms and E. coli at log total numbers of −2 , respectively. After the carcass breaking Process, loin primal cuts and manufacturing beef from such sides yielded total aerobic counts at log mean numbers of about 3 and about 4 log cfu cm −2 , respectively; coliform counts at log total numbers of about 3 and about 4 log cfu 2500 cm −2 , respectively; and E. coli counts at log total numbers >2 log cfu 2500 cm −2 ; which indicated that product was contaminated from improperly cleaned equipment during the carcass breaking Process. When sides treated for 10 s with water that had previously been used to treat 120 or more sides were compared after cooling with untreated sides from the same carcasses, the appearances of treated sides were judged to be less desirable than those of the untreated sides because of the less desirable appearance of the fat tissue on the treated sides. However, the mean differences between untreated and treated sides for overall appearance and the appearance of fat tissue were only 0·45 and 0·46 assessment units, respectively, for assessments on a seven-point scale. The small adverse effect of the pasteurizing treatment on the appearance of beef carcass sides apparently did not affect the value of the meat. Thus, the data indicated that, in commercial practice, pasteurizing treatment times should be set by reference to reductions in numbers of E. coli rather than of total aerobic counts, to assure the maximum possible reduction in the number of enteric pathogens; that protein suspended in the circulating water of pasteurizing equipment will accumulate to levels that affect the appearance of carcass fat, unless the water is changed at appropriate intervals or actions are taken to remove the protein from the water or carcass surfaces; and that pasteurizing of carcasses alone is inadequate for assuring the safety of meat when recontamination of product with enteric organisms occurs during the carcass-breaking Process.
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TRIMMING, VACUUM CLEANING OR HOT WATER‐VACUUM CLEANING EFFECTS OF LAMB HINDSADDLES1
Journal of Muscle Foods, 1998Co-Authors: C. O. Gill, L M BakerAbstract:Swab samples were obtained from the hindsaddles of randomly selected lamb carcasses before and after the routine operations of trimming, vacuum cleaning unaccompanied by heating of the surface, or hot water-vacuum cleaning in a commercial carcass Dressing Process. For each operation, two pairs of sample sets, each pair of 25 samples collected before and 25 samples collected after the operation were obtained The total aerobes, coliforms and Escherichia coli recovered from each sample were enumerated. For each set, values for the mean, standard deviation and log of the arithmetic mean were calculated on the assumption that the log values were normally distributed. For any pair of total count, coliform or E. coli data sets, the log means generally differed by
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Assessment of the hygienic performance of a sheep carcass Dressing Process.
Journal of food protection, 1998Co-Authors: C. O. Gill, L. P. BakerAbstract:Swab samples were obtained from the surfaces of randomly selected carcasses passing through a sheep carcass-Dressing Process. A single sample was obtained from a randomly selected site on the surface of each carcass. Twenty-five such samples were collected at each of four stages in the Process. The aerobio bacteria, coliforms, and Escherichia coli recovered from each sample were enumerated. Values for the mean log and standard deviation of each set of 25 log10 values were calculated on the assumption that the log values were normally distributed. The log of the arithmetic mean was estimated from the mean log and standard deviation values for each set. The results showed that bacteria, including coliforms that were largely E. coli, were deposited in high numbers during skinning operations, mainly on the butts and shoulders of carcasses. The mean numbers of coliforms and E. coli on carcasses were little affected by eviscerating and trimming operations, although they were redistributed from the sites they oc...
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Hygienic Effects of Trimming and Washing Operations in a Beef-Carcass-Dressing Process †.
Journal of food protection, 1996Co-Authors: C. O. Gill, M. Badoni, T. JonesAbstract:Swab samples were obtained from the surfaces of randomly selected beef carcasses passing through a high-speed Dressing Process. A single sample was obtained from a randomly selected site on the surface of each selected carcass. Fifty such samples were collected at each of four stages in the Process. The aerobic bacteria, coliforms, and Escherichia coli recovered from each sample were enumerated. Values for the mean log units and standard deviations of each set of 50 log values were calculated on the assumption that the log values were normally distributed. The log of the arithmetic mean was estimated from the mean log and standard deviation values for each set. The results show that the average numbers of E. coli , coliforms, and aerobic bacteria which are deposited on carcasses during skinning and evisceration are not reduced by trimming, and that washing approximately halves the average numbers of those bacteria on carcasses. It is concluded that commercial trimming and washing operations are not effective means of decontaminating beef carcasses.
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hygienic effects of trimming and washing operations in a beef carcass Dressing Process
Journal of Food Protection, 1996Co-Authors: C. O. Gill, M. Badoni, T. JonesAbstract:Swab samples were obtained from the surfaces of randomly selected beef carcasses passing through a high-speed Dressing Process. A single sample was obtained from a randomly selected site on the surface of each selected carcass. Fifty such samples were collected at each of four stages in the Process. The aerobic bacteria, coliforms, and Escherichia coli recovered from each sample were enumerated. Values for the mean log units and standard deviations of each set of 50 log values were calculated on the assumption that the log values were normally distributed. The log of the arithmetic mean was estimated from the mean log and standard deviation values for each set. The results show that the average numbers of E. coli , coliforms, and aerobic bacteria which are deposited on carcasses during skinning and evisceration are not reduced by trimming, and that washing approximately halves the average numbers of those bacteria on carcasses. It is concluded that commercial trimming and washing operations are not effective means of decontaminating beef carcasses.
Mario Boccadoro - One of the best experts on this subject based on the ideXlab platform.
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Special wire guide for on-machine wire electrical discharge Dressing of metal bonded grinding wheels
CIRP Annals - Manufacturing Technology, 2010Co-Authors: Eduardo Weing??rtner, Sascha Jaumann, Friedrich Kuster, Mario BoccadoroAbstract:To improve accuracy in wire electrical discharge Dressing (WEDD), special attention should be given to wire vibration. In this work, the use of a specially designed wire guide is proposed, which is responsible for both ensuring the stability of the wire and improving the efficiency of dielectric delivery to the Dressing zone. For carrying out experiments with metal bonded diamond grinding wheels, a WEDD-device was designed, manufactured and integrated into a grinding machine. High erosion material removal rates and Dressing accuracy were achieved, thus demonstrating the feasibility and efficient performance of this in situ Dressing Process. ?? 2010 CIRP.
Eduardo Weing??rtner - One of the best experts on this subject based on the ideXlab platform.
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Special wire guide for on-machine wire electrical discharge Dressing of metal bonded grinding wheels
CIRP Annals - Manufacturing Technology, 2010Co-Authors: Eduardo Weing??rtner, Sascha Jaumann, Friedrich Kuster, Mario BoccadoroAbstract:To improve accuracy in wire electrical discharge Dressing (WEDD), special attention should be given to wire vibration. In this work, the use of a specially designed wire guide is proposed, which is responsible for both ensuring the stability of the wire and improving the efficiency of dielectric delivery to the Dressing zone. For carrying out experiments with metal bonded diamond grinding wheels, a WEDD-device was designed, manufactured and integrated into a grinding machine. High erosion material removal rates and Dressing accuracy were achieved, thus demonstrating the feasibility and efficient performance of this in situ Dressing Process. ?? 2010 CIRP.
