Reconfigurability approach in manufacture of moulds and dies

Manufacturing of moulds and dies based on the rigid and traditional arrangement of dedicated workstations in a production system can no more stand the test of time. The dynamic and competitive nature of the market is compelling managements in the industry to look for a manufacturing system that (1) will ensure high quality product, (2) will pave way for a quick changeover to a new setup to be able to accommodate the new products, (3) will ensures short lead times in product/process changeover, and (4) that will make its product come out at a relatively low cost. An emerging strategy that might enable industries to cope with the rapidly changing product specifications is based on reconfiguring the manufacturing systems. A manufacturing strategy that is based on reconfiguration of the manufacturing systems may help accommodate emergent product changes in short periods at the lowest possible costs by combining certain levels of flexibility and customised automation. In this paper the principles of reconfigurability is being considered for mould and die making industry.AMTS (CSIR), Department of Science and Technology, Republic of South Africa.http://www.ttp.net/1022-6680.htmlhb201

Prediction of tool life by statistic method in end-milling operation

The aim of the this study is to develop the tool life prediction model for P20 tool steel with aid of statistical method, using coated carbide cutting tool under various cutting conditions. This prediction model was then compared with the results obtained experimentally. By using Response Surface Method (RSM) of experiment, first and second order models were developed with 95% confidence level. The tool life was developed in terms of cutting speed, feed rate, axial depth and radial depth, using RSM and design of experiment. In general, the results obtained from the mathematical model are in good agreement with that obtained from the experiment data’s. It was found that the feedrate, cutting speed, axial depth and radial depth played a major role in determining the tool life. On the other hand, the tool life increases with a reduction in cutting speed and feedrate. For end-milling of P20 tool steel, the optimum conditions that is required to maximize the coated carbide tool life are as follow: cutting speed of 140 m/s, federate of 0.1 mm/rev, axial depth of 1.5 mm and radial depth of 2 mm. Using these parameters, a tool life of 39.46 min was obtained

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The design and development of a reconfigurable manufacturing system

As a result of increasing global industrial competition, it has become essential for world economies to implement an effective industrial strategy that reliably and quickly addresses sudden changes in product design. An emerging strategy that might enable industries to cope with rapidly changing product specifications is based on reconfiguring the manufacturing systems. In this paper, the authors present the development of a manufacturing system that will be easily reconfigurable. The developed manufacturing system exhibits the ability and potential for a rapid alteration of manufacturing capacity and the fast integration of new products into the existing manufacturing system.As gevolg van toenemende wêreldwye industriële mededinging het dit noodsaaklik geword vir wêreld-ekonomieë om ’n effektiewe industriële strategie te implementeer om betroubaar en vinnig skielike veranderinge in produkontwerp te hanteer. ’n Nuwe strategie, wat nywerhede moontlik in staat kan stel om vinnig veranderende produkspesifikasies te hanteer, is gebaseer op herkonfigurasie van vervaardigingstelsels. In hierdie artikel word die ontwikkeling van ’n vervaardigingstelsel wat maklik her-konfigureerbaar is, bekend gestel. Die ontwikkelde vervaardigingstelsel toon die vermoë en potensiaal vir vinnige verandering van die vervaardigingskapasiteit en die vinnige integrasie van nuwe produkte in ’n bestaande produksiestelsel.http://www.journals.co.za/ej/ejour_indeng.htm

Error compensation of complex three-dimensional surfaces machined on computer-numeric-control grinding machine tools

This study discusses the development of a method for compensating profile errors, resulting from the deviation of the actual grinding wheel radius from the calculated one. The study also elaborates on a control strategy that may be followed to minimise the profile error and allow the use of a four-axis grinding machine instead of five-axis one to perform the same machining task. This approach can be completely justified when the reduction in the machining cost is achieved as a result of grinding the gauge profile on a four-axis CNC machine tool instead of the five-axis one. When a number of five segments are chosen, the first control program is established for the first mean radius (170 mm) of the first segment. When the grinding wheel radius reaches 150 mm as a result of wheel dressing, a new control program that will consider a new nominal radius of 160 mm will be activated

Machinability of aluminum nitride ceramic using TiAlN and TiN coated carbide tool insert

This research presents the performance of Aluminum nitride ceramic in end milling using titanium coated carbide insert under dry machining. The surface roughness of the work piece and tool wear was analyzed in this. The design of experiments (DOE) approach using Response surface methodology was implemented to optimize the cutting parameters of a computer numerical control (CNC) end milling machine. The analysis of variance (ANOVA) was adapted to identify the most influential factors on the CNC end milling process. The mathematical predictive model developed for surface roughness and tool wear in terms of cutting speed, feed rate, and depth of cut. The cutting speed is found to be the most significant factor affecting the surface roughness of work piece and tool wear in end milling process

Fourth order torque prediction model in end milling

This study presents the development of mathematical models for torque in end-milling of AISI 618. Response Surface Method (RSM) was used to predict the effect of torque in the end-milling. The relationship between the manufacturing process factors including the cutting speed, feed rate, axial depth and radial depth with the torque can be developed. The effect of the factors can be investigated from the equation developed for first order to fourth order model. The acquired results show that the torque increases with decreases of the cutting speed and increases the feed rate, axial depth and radial depth. It found that the second order is more accurate based on the analysis of variance (ANOVA) and the predicted torque results is closely match with the experimental results. Third- and fourth-order model generated for the response to investigate the 3 and 4-way interaction between the factors. It’s found less significant for the variables

Surface roughness prediction model of 6061-T6 aluminium alloy machining using statistical method

This paper explores on the optimization of the surface roughness of milling mould 6061-T6 aluminium alloys with carbide coated inserts. Optimization of the milling is very important to reduce the cost and time for machining mould. The purposes of this study are to develop the predicting model of surface roughness, to investigate the most dominant variables among the cutting speed, feed rate, axial depth and radial depth and to optimize Surface Roughness Prediction Model of 6061-T6 Aluminium Alloy Machining Using Statistical Method the parameters. Response surface method based optimization approach was used in this study. It can be seen from the first order model that the feed rate is the most significantly influencing factor for the surface roughness. Second-order model reveals that there is no interaction between the variables and response