Waste simplification for warehouse using Boolean logic

Warehouse accumulates non-value added or wastes activities consist of inventory, waiting and transportation. The warehouse is a must to prevent any unforeseen events causing failures to implement the Just-In-Time concept. However, the existence of the warehouse will increase the operation expenditure and can lead to the profit losses. Therefore, the manufacturer needs to identify and eliminate the wastes to reduce the consumption of the resources and keep minimum requirement of the activities such as inventory, waiting and transportation in the warehouse. Value Stream Mapping is one of the Lean tools as an approach to eliminate the non-value added or wastes. This tool visualizes the information and material flow of the manufacturing activities. The development of a model based from Value Stream Mapping determined the current state of the wastes existed in the warehouse activities. The model is used to identify and eliminate the waste in the warehouse. From the information flow, the optimum combination of the wastes was determined through Boolean concept. The wastes are simplified and combined by passing through the Boolean operators consist of AND Gate and OR Gate. The expected outcome of this paper is to propose a conceptual model of new value stream mapping to identify and eliminate the waste in the warehouse. From the removal of wastes, the profit can be increased by reduction of the operation expenditure of the manufacturer

Wear Behaviour of Tungsten Carbide in End Milling Process of Aluminium Alloy 6061-T6 with Minimal Quantity of Tri-hybrid Nanofluids

Nowadays, using nanotechnology in science and industry improves the yield of different processes. The machining process using hybrid nanofluids requires further research to better understand the mechanism of tool wear and the fundamental aspects are not yet ventured. In machining, tool wear is common problems that exist for quite some time. In addition, milling process of Aluminium Alloy was challenged due to a strong adhesion particularly in higher temperature. Deposition of chips material during the process at the tool edge may induce several tool failures such as build-up edge, chipping and flaking. Eventually, tool life, manufacturing cost and product quality were the factors that normally effects by tool wear. However, the severity of tool wear can be reduced by applying a cutting fluid to the tool-workpiece interface. This paper intends to discover the effects of tri-hybrid nanofluids in end milling process of Aluminium Alloy 6061-T6 mainly on wear conditions of uncoated and double-layered PVD coated inserts. In this research works, three different nanoparticles SiO2-Al2O3–ZrO2 were dispersed in 60:40 of deionized water and ethylene glycol. The concentration was prepared between 0.06 and 0.12 wt.%. The MQL system with assisted air pressure was employed to deliver newly developed tri-hybrid nanofluids. During metal cutting process, the metal working fluid was supplied intermittently based on flow rate setting in the MQL system to the cutting zone with a very minimal quantity. A single insert was used and changed for every 100 mm of cutting length at different machining parameters. The effects on wear mechanisms were closely examined at the flank area using scanning electron microscope. Through comprehensive investigation, the wear mechanisms consist of attrition, flaking, abrasion and coating delamination. Other phenomenon such as thermal crack was observed in the wear region. The tool failures have a relationship with machining parameters and cutting tool condition itself. It can be concluded that, coating delamination and abrasion quite severe for coated inserts. While, uncoated tools were severe with attrition mode of failures. At extreme machining condition, higher temperature and friction forces at the tool-workpiece interface have a significant effect on the tool failures. For further investigation, the effects of tri-hybrid nanofluids on wear behaviour of tungsten carbide inserts can be examined for other machining process with different workpiece material

Preparation, stability and wettability of nanofluid: a review

Nanofluids possess many advantages over conventional working fluid especially in physical, thermal and rheology properties. Nowadays, nanofluids have been applied extensively in many engineering applications in enhancing the overall performance. Preparation and characterization of nanofluids are vital as the nanomaterials have significant effects on the dispersion and stability of nanofluids. On the other hand, there is a trend to employ more than a single nanoparticle for preparing nanofluid. The hybrid nanofluid receives wide attention due to its capability in improving the thermal-physical properties of single phase nanofluids. In this paper, the flow of formulating nanofluid from preparation method, characterization, wettability analysis and stability techniques are discussed comprehensively. Furthermore, the challenges for obtaining stable suspension and wettability behaviour of nanofluids are discussed as well. The main objective when preparing the nanofluids is to obtain a well-dispersed nanoparticle into the base fluid. Based on the literature review, the impact of surfactant on the stability and the correlation between nanofluids wettability and thermal-physical properties of nanofluids have great potential to discover. There are some aspects that can be considered to expand the knowledge of nanofluids such as the composition ratio of hybrid nanofluid with regards to achieving the best stability and wettability study of hybrid nanofluid with and without surfactant in the suspension. Therefore, a lot of research should be conducted in order to explore the behaviour of nanofluid and the effect of various surfactants in terms of stability as well as its thermal and viscosity effect on the engineering applications

Experimental study on dynamic viscosity of aqueous-based nanofluids with an addition of ethylene glycol

In this study, the effect of adding different nanoparticles in the mixture of deionised water and ethylene glycol on dynamic viscosity is investigated experimentally. In order to prepare for single nanofluids, the dry nanoparticles of SiO2, Al2O3 and ZrO2 were dispersed into 60% volume of deionised water and 40% volume of ethylene glycol as a base fluid using a two-step method. The experiments were performed in the temperature range of 30°C and 70°C and weight fraction ranging between 0.1wt.% and 1wt%. No surfactant used in preparing the nanofluids. The dynamic viscosity data were collected using DV-II+ Pro Brookfield viscometer. The single, dual-hybrid and tri-hybrid aqueous based nanofluids dynamic viscosity results are explicitly presented. From the results, it is exhibited that nanofluid viscosity decreases with increasing liquid temperature and increases with increasing of nanoparticles volume concentration. The viscosity decreases with increasing of deionised water volume percentage in the base fluid. Zirconia single nanofluid at 1wt.% recorded 2.5 times maximum enhancement of viscosity over the base fluid. The results display that single nanofluids have higher dynamic viscosity compared to hybrid nanofluids

Experimental study on dynamic viscosity of aqueous-based nanofluids with an addition of ethylene glycol

In this study, the effect of adding different nanoparticles in the mixture of deionised water and ethylene glycol on dynamic viscosity is investigated experimentally. In order to prepare for single nanofluids, the dry nanoparticles of SiO2, Al2O3 and ZrO2 were dispersed into 60% volume of deionised water and 40% volume of ethylene glycol as a base fluid using a two-step method. The experiments were performed in the temperature range of 30°C and 70°C and weight fraction ranging between 0.1wt.% and 1wt%. No surfactant used in preparing the nanofluids. The dynamic viscosity data were collected using DV-II+ Pro Brookfield viscometer. The single, dual-hybrid and tri-hybrid aqueous based nanofluids dynamic viscosity results are explicitly presented. From the results, it is exhibited that nanofluid viscosity decreases with increasing liquid temperature and increases with increasing of nanoparticles volume concentration. The viscosity decreases with increasing of deionised water volume percentage in the base fluid. Zirconia single nanofluid at 1wt.% recorded 2.5 times maximum enhancement of viscosity over the base fluid. The results display that single nanofluids have higher dynamic viscosity compared to hybrid nanofluids

Effects of SiO2-Al2O3-ZrO2 Tri-hybrid Nanofluids on Surface Roughness and Cutting Temperature in End Milling Process of Aluminum Alloy 6061-T6 Using Uncoated and Coated Cutting Inserts with Minimal Quantity Lubricant Method

In machining, heat concentration is generated at the surface contact between the tool and workpiece. This is the effect of hard frictions at the shear cutting plane to remove hard and brittle materials. The highly adhesive behavior of aluminum alloy 6061-T6 is more severe in higher cutting temperature, which may affect tool failures such as flank wear, tool chip and built-up edge, particularly on the edge of cutting inserts during the process. As a result, this may lead to the rough surface and low-dimensional accuracy of the machined parts. Realizing that metal-cutting industry players are demanding high-quality products with better surface finish and dimensional accuracy led to this study. Aluminum alloy 6061-T6 is a standard alloy used in automotive, aerospace and food packaging due to good hardness, high strength-to-weight ratio, resistance to corrosion and weldability. In order to address this problem, a newly developed metal working fluid which is SiO2-Al2O3-ZrO2 tri-hybrid nanofluid is applied in the cutting zone to achieve a good surface finish of the machined parts and lowering the cutting temperature. This study is the first attempt to enhance machining performance, particularly at high-speed machining, by employing a combination of tri-hybrid nanofluids and a minimum quantity lubricant technique. Industrial standards include uncoated tungsten carbide and CVD TiCN-Al2O3 carbide used during machining of aluminum alloy 6061-T6. The minimum quantity lubricant method is an alternative in supplying the lubricant into the machining zone due to flood machining and conventional fluid possess safety, health, economic and environmental effects. In this study, the experimental data were analyzed statistically using analysis of variance and response surface methodology. The responses studied were reduced significantly when tri-hybrid nanoparticles present at the cutting interface with higher MQL flow rate and concentration. There are two-factor interactions which are significant to the responses studied. Therefore, the combinations of MQL and excellent tri-hybrid nanofluids characteristics have enhanced between 16 and 76% of surface roughness and the cutting temperature, respectively, which is very promising in the future

Evaluation Of Cutting Force in End Milling Process of Aluminum Alloy 6061-T6 Using Tungsten Carbide Inserts with MQL Method Utilizing Hybrid Nanofluid

As an alternative to conventional metal working fluid in the end milling process, a combination of newly developed tri-hybrid SiO2-Al2O3-ZrO2 in aqueous-based nanofluid was delivered to the cutting zone using the MQL technique. The liquid has excellent thermal-rheology properties that can offer effective cooling and lubricating during the process. The tri-hybrid nanofluid application is environmentally safe, thus promoting sustainable manufacturing compared to the conventional working fluid. In this experimental study, the cutting forces were investigated comprehensively. Tri-hybrid nanofluid presents in atomizing conditions using the minimum quantity lubricant (MQL) technique at the cutting zone. Industrial standard inserts, namely uncoated, CVD TiCN-Al2O3 and PVD TiAlTaN tungsten carbide used in the experiments. End milling process variables were cutting speed, feed rate, depth of cut, MQL flow rate and nanofluid concentrations. The response data were analyzed statistically based on the design of experiment and regression models were developed for each response according to response surface methodology. Higher cutting force was observed at extreme machining parameters, which regards to higher material removal rate. During the cutting process of Aluminum Alloy 6061-T6, the cutting force, Fr measured was between 16 Newton and 30 Newton. The cutting force in Y-axes (Fy) demonstrates a higher magnitude than others due to the cutting feed of AA6061-T6 in the Y direction. CVD TiCN-Al2O3 tungsten carbide exhibited higher cutting force (Fy) due to coated hardness and tool failures mechanism on both rake and flank face as the wear phenomenon will increase the land contact area. In summary, the resultant cutting force (Fr) was recorded below 30 Newton, indicating the significant improvement in the end milling process. For future experimental works, the cutting force can be explored by considering different nanofluids, extreme machining conditions and brittle material

Experimental Investigation on Preparation and Stability of Al2O3 Nanofluid In Deionized Water and Ethylene Glycol

Nanofluid has the potential as a cooling medium for the next generation fluid as it possesses many advantages in many engineering applications. However, one of the main challenges is to establish a well-dispersed nanoparticles system in a base fluid. The preparation technique of nanofluid plays an important part as it influences the measurement of thermal conductivity. Therefore, the objectives of this study are to evaluate the nanoparticle dispersion in different base fluid compositions and to determine the optimized suspension sonication time. In detail, 0.2 wt.% of Al2O3 nanofluid stability in the three ratios of base fluid (deionized water:ethylene glycol) 80:20, 70:30 and 60:40 were studied. The studies were based on a visual inspection and spectral absorbance analysis. It has clearly shown that the nanofluids prepared in 60:40 base fluid within 3 hours sonication time was the most stable suspension compared to other nanofluids. The visual inspection indicated nanofluid condition remains stable after 30 days. The spectral absorbance of nanofluids was recorded at 100 % for 5 days after preparation and remains above 95 % compared to the initial value, reflecting stable suspension. Hence the novelty of this work lies in the nanofluid stability based on sonication time and base fluid compositions