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Environmentally Conscious Design & Manufacturing. Class 14: Cost Factors in Machining Operations . Prof. S. M. Pandit. Manufacturing Economics & the Environment. Life cycle view Raw material Manufacturing Design Production (Scheduling, Planning, Machining) Use Post-use
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Environmentally Conscious Design & Manufacturing Class14: Cost Factors in Machining Operations Prof. S. M. Pandit
Manufacturing Economics & the Environment Life cycle view • Raw material • Manufacturing • Design • Production (Scheduling, Planning, Machining) • Use • Post-use • Materials handling • Energy production
Manufacturing Economics & the Environment • Product Life Cycle • Use Power Generation • “Waste” • Energy • Materials • Fluids Post Use Manufacturing Material Handling and Logistics Raw Material Extraction
Raw Material • Design requirements • With/ without environmental considerations • Quality factor • Quality deterioration/ improvement • Inspection • Cost of raw material • Natural (extraction cost) • Man-made (development costs - temporal)
Post Use • Reuse / Remanufacture / Recycle / Disposal Environmental Impact “Cost” Material cost Design costs Option chosen
Material Handling Cost Item Choice (Design) Equipment A B C Tractor truck 34 583 239 Forklift truck 21 1779 338 Hand truck 19 * 203 Data from Material & Design choice Add to total cost Manufacturing Facilities Location, Planning and Design D.R. Sule (PWS Kent Publ. Co., 1988)
Manufacturing Cost Factors • Machine Tool • Machining • Process parameters wear rate • Tool / Workpiece interaction • Work (job) chips • Tool wear / failure debris • Fluid use mist, disposal • Process scheduling energy use • Production planning productivity factors
Machining Costs • Machine Tool • Power requirements • Initial costs • Depreciation • Flexibility • Maintenance • Expected use
Machining Costs Tool type Work - piece Fluid application Quality requirements Productivity needed • Process parameters • Speed • Feed • Depth of cut Tool wear Power consumed Power=Feed Rate(Feed Force+Friction Force)/ (hMech* hMech) Engineering Formulas (7th Ed.,1998) K.Gieck & Reiner Gieck., Mc Graw Hill
Machining Costs • Process Parameters • Tool type • Insert • Rake, • Non - Insert Cost Material, Dry/wet Material • Cutter Type (turning, milling, ..) • Single point / Multi point / Form tool
Machining Costs Work - piece • Volume of material removed (m3) • Tool type needed (insert …) • Cutting fluid needed (Y/N, flow rate) Cost
Machining Costs L Volume removed:
Machining Costs • Chips • Continuous (bad) • Interferes in machining - Flush with cutting • fluid ? • Discontinuous (good) • Need to adjust • Work material • Machining parameters • Tool geometry • Dust
Machining Costs • Factors influencing fluid application costs • Type of fluid • Synthetic / natural oils / semi-synthetic • Straight oils • Air / inert gas • Flow rate • Heat transfer requirements • Lubrication & chip transport • Chip adhesion
Machining Costs • Tool • Excessive wear rate v/s cost • Catastrophic failure • inclusions in work • incorrect parameters • shock loading (temperature / load induced)
Machining Costs • Fluid Use • Mist collectors • Pumps and tanks (circulation) • Filtration • Maintenance system • Additives / Initial cost • Disposal (bioremediation / chemical treatment)
Scheduling Scheduling L.P. formulation Cost Quality Environment Cost Difference
Case Study Alternative 1 Alternative 2 • Machining • Tool • Work • Cutting Fluid • Power, labor, m/c tool • Environment ? Cost items