Mohammad Iqbal

RFID Configuration for Part Monitoring in Job Shop Production System

Job-shop production system produces several types of product at the same time. The work parts are transported among the stations following the routing according to the type of the product. Some of the stations are shared by different product. Consequently the production line has a set of complex process flows and material handling process become difficult. The setup time is required whenever type of product is change at a station which results with the increasing of waiting time and workin-process inventory. This situation makes the monitoring of part flow is essential as the information for production management and control. This paper discusses the work part monitoring system in job-shop production line by using Radio Frequency Identification Device (RFID). The system was developed under Microsoft Visual Studio software and built using CSL High Level API Manual software for CSL CS-461 RFID. RFID chip was attached at each work part and antennas are installed at several locations in the production line. A set of experiment were conducted to investigate the effect of chip orientation at the work part to the reading performance of the antenna. The result shows that the system is able to detect the number and location of the work part. The information could be used to monitor the current waiting time and number of work-in-process in the production line.

Effect of Cutting Parameters on Cutting Forces for Different Profile of Cutting

In machining operation of mould cavities, the tool travels in various straight and corner profiles following predetermined toolpath. Such condition results in a fluctuation of cutting forces that may produce bad surface finish. The objective of this study is to investigate the most influential parameters on cutting operation for both straight and corner profiles of pocketing operation. Cutting speeds of 150, 200 and 250m/min, feedrates from 0.05, 0.1, 0.15 mm/tooth and depths of cut of 0.1, 0.15 and 0.2 mm were selected for the cutting processes. Taguchi L9 orthogonal array with Pareto ANOVA analysis was employed to analyze the effects of the selected parameters. The result demonstrates there are different effects of cutting parameters on cutting forces for straight and corner profiles. Furthermore, it was found that cutting speed and feedrate are prevailing factors that affected cutting forces for both types of profile.

Surface Quality of High Speed Milling of Silicon Carbide by Using Diamond Coated Tool

The high speed milling of silicon carbide was discussed by using flat end-mill 2 mm in diameter diamond coated tool. Ultra-precision high speed spindle attachment was used to achieve cutting tool rotation speed as high as 50,000 rpm. Special fixture was designed to minimize the chatter on work-piece surface during the machining process. Three cutting parameters were selected as independent variables of the experiments. They were spindle speed, depth of cut and feed rate. The arithmetic mean value of roughness (Ra) was measured on the work-piece surface as the response of the experiment. Result of the experiment shows that the value of surface roughness can be achieved as low as 0.150 μm. Statistical analysis was provided to study the significant of the model, interaction among the cutting parameters and their effects to the surface roughness value.

Economic Scenario of Cellulase Enzyme Production Using Palm Oil Mill Effluent (POME)

This paper presents an analysis on the economic suitability of a large scale plant for the production of cellulase enzyme from Palm Oil Mill Effluent (POME). Based on the data and other relevant information gathered from indigenous operation of a lab and a pilot scale bio-reactors (30L and 300L capacities), a predicted evaluation of economic aspects of enzyme production with a 3000L bioreactor has been made. Factors such as the initial price and installation cost, the expenses for raw materials, operation and maintenance of the plant, overhead, utilities, logistics etc. were considered. Enzyme output from the proposed bioreactor was estimated depending on the optimum operational conditions established by the small scale investigation. Net present value (NPV) of the project was evaluated by using the discounted cash-flow analysis. With a conservative view of 5% escalation of recurring costs and a target of 70% capacity utilization an NPV of MYR 2,5 million was found to be achievable for a 10% discount rate and a plant life of 10 years,. Economic scenario developed for 50-100% range capacity utilization indicating the NPV can be helpful in making decisions for implementation of such plants. Thus production of cellulase enzyme from POME using a 3000L bioreactor is found to be economically attractive.

High Speed Milling of Silicon Carbide with Diamond Coated End Mills

The primary applications of silicon carbide SiC-based materials, which include include micro-structures, optoelectronic devices, high temperature electronics, radiation hard electronics and high power/high frequency devices to name a few have necessitated the need for machining SiC. The paper presents the outcome of milling of silicon carbide using diamond coated end mill under different machining conditions in order to determine the surface roughness parameter after the machining processes. Relationship between the machining parameters and response variables has been established and a mathematical model has been predicted, the minimum roughness value, Rz being 0.19 µm.

Solving Multiple Routes Travelling Salesman Problem Using Modified Genetic Algorithm

The multiple routes travelling salesman problem (mrTSP) is an extension of the well-known travelling salesman problem (TSP), where there are several points clusters to be visited by salesman. The problem to be solved is how to define the best route in every cluster and initial position of each routes as interconnection points for the salesman. In this paper, modified genetic algorithm (mGA) is proposed in order to solve the mrTSP problem. In the proposed mGA, new heuristic algorithm for crossover and mutation operator based on local shortest path algorithm is proposed in order to assist the mGA to improve best solution so far. Numerical examples are also given to test the performance of proposed mGA when solving mrTSP. The result of the study shows that the mGA is superior compared to conventional GA.

Diamond Coated End Mills in Machining Silicon Carbide

Silicon Carbide (SiC) is a type of ceramic that belongs to the class of hard and brittle material. Machining of ceramic materials can result in surface alterations including rough surface, cracks, subsurface damage and residual stresses. Efficient milling of high performance ceramic involves the selection of appropriate operating parameters to maximize the material removal rate (MRR) while maintaining the low surface finish and limiting surface damage. SiC being a ceramic material, its machining poses a real problem due to its low fracture toughness, making it very sensitive to crack. The paper discusses milling of silicon carbide using diamond coated end mill under different machining conditions in order to determine the surface roughness parameter, Rt after the machining processes and to establish a relationship between the machining parameters and response variables. Based on the surface roughness carried out the lowest Rt obtained is 0.46 µm.

The Study on Production Performances of Part Transporter in Flexible Manufacturing System by Using Simulation Method

Material handling is one of major components in Flexible Manufacturing System (FMS). Any improvement of material handling capability is to affect the performance of the whole system. This paper discusses the simulation study on the effect of part arrival rate and dispatching rules to the average waiting time and production rate of the FMS. The facilities of the system were modeled into simulation environment by using Arena Simulation Software. The production parameters such as machine processing times, part transportation speed and type of products were put into the model to represent the behaviors of the real system. Two rules have been considered in the study, i. e. first come first served (FCFS), and shortest processing time (SPT). Average waiting time and productivity were taken into account as performance measures of the system. The result of the study showed that SPT rule gives shorter average waiting time and higher productivity. Based on this result, the SPT rules would be used to control part transporter in order to have a better performance of the FMS.