Investigation on the use of mask in waterjet surface texturing of stainless steel

Surface texturing has been applied to diverse mechanical mechanisms to improve performances in various fields related to friction, lubrication and resistance to wear. The present study investigates the application of mask in prouducing circular craters during the abrasive waterjet surface texturing of stainless steel. In the experiment, the mask with parallel slots was placed above the surface of the specimen and the waterjet nozzle moved along the mask. The effect of feed rate was studied in terms of crater characteristic produced. The results showed that with increasing traverse rate a shallower crater depth was produced. Increasing the traverse rate also produced a narrower circular crater with improved inner surface roughness. It can be concluded that a proper selection of parameters can produce a shallow and small circular crater during the waterjet surface texturing process

Optimisation of paint removal operation using waterjet cleaning process

The need of cleaning automotive paint without secondary pollution has recently become a major concern globally. The waterjet technology has extended its application to include surface treatment, machining, cleaning and cutting of materials. Plain waterjet is frequently used for cleaning since its offers environmentally friendly concept which results near zero pollution to the surroundings. This research aims to analyse and optimise the use of multiple passes in waterjet cleaning process for removal of automotive paint using response surface method (RSM). The effect of surface roughness (Ra) and its topography were analysed. RSM, analysis of variance (ANOVA), fractional factorial at two levels were utilized to optimize the plain waterjet process parameters for effective cleaning of paint. It was found that the lateral feed and pressure were the most significant control factors in influencing the cleaning performance criteria. Mathematical model was developed using linear regression analysis to predict the surface roughness in terms of cleaning parameters of plain waterjet process. The model had successfully predicted the Ra of the plain waterjet cleaned automotive parts within the limit of this study. The recommended optimal parametric combinations for better Ra were found to be waterjet pressure of 34.0 MPa, traverse rate of 500 mm/min, standoff distance of 10 mm, number of passes of 1 and lateral feed of 0.6 mm

Investigation on the effect of multiple passes in plain waterjet cleaning of paint

Paint removal process in automotive coating is widely used in vehicle component recycling industry. The need of utilization and recycling the automotive component without producing secondary pollution from the paint removal process is recently become a major concern globally. Water jet cleaning is a new method for paint removal and getting recognition because of environmental friendly and it is better than mechanical cleaning such as sand blasting, brushing with water, hydropneumatic cleaning, controlled dry sanding, low pressure water projection and low pressure water spray. The present study focuses on the investigation of effect of multiple passes in plain water jet cleaning on paint removal process. A new method of multiple passes treatment is applied in plain water jet cleaning to access its effect on surface roughness and paint removal rate. It was found that, with increasing of number of passes, the surface roughness and paint removal rate is slightly increase. It is also found that the increase in water jet pressure will increase the surface roughness and paint removal rate. This is probably because increasing pressure will leads to more energy to remove the paint. It is found also that the increase in traverse rate increase the surface roughness and decrease paint removal rate. Based on the present study, it is a high prospect to apply multiple passes of paint removal using plain water jet in automotive industry

The effect of cryogenic cooling in machinability of stainless steel during turning

A high cutting temperature inherently characterizes high production machining. Such a high cutting temperature adversely effects tool life, dimensional and form accuracy and surface integrity of the product. Currently, an effort is being made to control this problem by reducing heat from the cutting zone through proper selection of machining parameters, cutting fluid application and heat resistant tools. The objective of this project is to investigate the effect of cryogenic cooling in machinability of stainless steel during turning. Cryogenic cooling is a promising new technology, which economically addresses the current processes environmental, and health, concerns. Cooling the cutting tool with liquid nitrogen (-320°F) is expected to maintain tool hardness and life. Cooling the chip makes it brittle and aids removal. Because nitrogen is an abundant atmospheric constituent and the quantities used are small, there is no unfavorable environmental effect or health impact or coolant disposal cost, and the chips are readily recycled. It was assumed that using cryogenic cooling during turning operation would discover some improvement in machinability of stainless steel by using cryogenic cooling during turning operationLarge number of research works performed in the area of metal cutting has contributed towards understanding the basic principles of improving machinability. It is therefore worthwhile to explore the possibility to strengthen the continuity of these works. This research intends to emphasize on chatter analysis to establish a co-relation between chatter and machinability, which is seldom highlighted by scientists and researchers. Chatter is an unwanted phenomenon in machining due to its adverse effects on the product quality, operation cost, machining accuracy, tool life, machine-tool bearings, and machine-tool life. The term defines the self-excited violent dynamic motion between the cutting tool and work piece [1]. Chatter analysis could be another accurate, precise, effective and efficient method to analyze instantaneous cutting environment and performance. Cryogenic cooling is the cooling approach to replace conventional coolant by liquefied gas in machining process [2]. In most cases, the liquid nitrogen (LN2) is chosen because of its availability and cost. There were many research works [3-5] on the application of cryogenic cooling to improve the machinability of the hard to cut materials. Liquid nitrogen (LN2) as a cryogenic coolant has been widely investigated, especially for machining hard to cut material [6,7]. Cryogenic cooling is being looked at as a potential replacement of conventional mineral oil based coolants because the latter is being rejected on grounds on serious environmental and health problems that it causes [8]. It is therefore essential to design efficient cryogenic cooling systems for high speed machining applications of hard-to-machine materials. The impact of cryogenic cooling on chip breaking and tool wear intensity during end milling and turning has been investigated by various researchers [9] but there has not been any study on the impact of cryogenic cooling on chip formation and chatter

Kenaf Fibre Composites As Promising Green-Composites For Automotive Car Door Map Pocket Application

The utilisation of natural fibres in composite materials is expanding because of an enactment that constrains automotive makers to reuse and recycle materials,leading to an increase in bio-based materials substances in automotive applications.An experimental investigation was conducted to explore car door map pocket for PROTON Saga FL by using non-woven kenaf (N-W)and hybrid from non- oven/ woven fabric kenaf (HN-W/W).The Hand Lay-up Method followed by vacuum bagging process were used.The results revealed that L2 HN-W/W was the reasonable sample for car door map pocket due to its light weight,good tensile strength and flexural strength as compared to PP.It was also found that the tensile strength and flexural strength were improved by utilising woven kenaf fabric in composites.Result implications and future research directions were also presented

Faktor Utama Vandalisme dalam Kalangan Pelajar di Sekolah

Di Malaysia, tingkah laku merosakkan harta benda di tempat awam dikategorikan sebagai salah laku yang berat dan serius. Objek kajian ini iaitu mengenalpasti faktor berlakunya masalah vandalisme dalam kalangan pelajar sekolah, menjelaskan kesan-kesan vandalisme kepada pelajar dan pihak sekolah, mengenalpasti langkah-langkah yang diambil oleh pihak sekolah dan pihak keluarga untuk mengatasi masalah vandalisme dalam kalangan pelajar sekolah, dan mengenalpasti cabaran yang dihadapi oleh pihak sekolah dalam mengatasi masalah vandalisme ini. Kaedah yang digunakan oleh pengkaji dalam kajian ini adalah dengan menggunakan kaedah temu bual untuk mendapatkan maklumat. Hasil temu bual ditulis semula serta disokong dengan beberapa rujukan daripada jaringan internet dan sumber-sumber ilmiah. Kaedah temu bual yang pengkaji gunakan ialah temu bual semi-struktur. Kesimpulannya, masalah gejala vandalisme dalam kalangan pelajar sekolah mahupun remaja di Malaysia dilihat tidaklah terlalu teruk, namun jika masalah ini tidak dipandang serius ia boleh memberi impak yang besar kepada negara. Masalah vandalisme yang melanda remaja pada masa kini adalah dipengaruhi oleh beberapa faktor. Antara faktor-faktor tersebut ialah masalah institusi keluarga, persekitaran dan sebagainya

Masalah Kecelaruan Tingkah Laku: Ponteng Sekolah

Ponteng sekolah merupakan salah satu masalah disiplin yang semakin ketara. Terdapat pelbagai faktor-faktor yang menyebabkan pelajar-pelajar terlibat dengan gejala ponteng sekolah dimana ianya berpunca daripada guru, sikap pelajar, rakan sebaya dan juga ibu bapa dimana mereka banyak mempengaruhi pelajar-pelajar terlibat dengan gejala ponteng sekolah. Masalah ini perlulah diatasi dengan segera bagi mengelakkan daripada timbulnya pelbagai gejala buruk yang lain rentetan daripada perilaku ponteng. Objektif kajian ini iaitu untuk mengenal pasti apakah punca-punca yang menyebabkan pelajar mengambil tindakan untuk tidak hadir ke sekolah atau dipanggil ponteng, untuk mengenal pasti kekerapan pelajar yang terlibat dalam gejala ponteng sekolah, mengetahui dengan lebih terperinci cara-cara untuk mengatasi gejala ponteng sekolah yang semakin berleluasa di kalangan pelajar sekolah, dan mendedahkan kesan dan akibat yang akan diterima akibat daripada gelaja ponteng sekolah. Dapatan kajian dari hasil temu bual, faktor ibu bapa ialah faktor yang utama sekali dalam mengawal anak – anak mereka. Termasuk guru juga, sebagai pembimbing pelajar – pelajar di sekolah dalam membantu berkaitan tentang pelajaran mahupun masalah keluarga yang dihadapi oleh pelajar tersebut.   Behavioral Disorders Issues: Truant Abstract: School neglect is one of the more important disciplinary issues. There are a number of factors that cause students to experience school dropout symptoms which are caused by teachers, students, peers, and even parents which greatly influence the students involved with school dropout symptoms. This problem needs to be resolved immediately to prevent the emergence of many other adverse symptoms from stray behavior. The objectives of this study were to identify the causes of students' failure to attend school or to be called a skeptic, to identify the frequency of students involved in school dropout symptoms, to know in more detail ways to overcome school dropout symptoms is becoming more prevalent among schoolchildren, and exposes the repercussions and consequences that will come from school drop-offs. According to the findings from the interview, parental factors are the most important factor in controlling their children. Includes teachers as mentors of students in the school to help with the education or family issues faced by the student. Keyword: Behavioral Disorders, Truant Issues, Student

Investigation on the effect of abrasive waterjet parameter on machining stainless steel

Abrasive waterjet machining (AWJM) can perform various machining operations on almost any material including hard to machine materials. However, performance of a process depends on the chosen set of parameters. AWJM has major parameters such as traverse rate, water pressure, standoff distance and abrasive flowrate that will affect its performance. The present study investigates the effects of AWJM parameters (i.e. traverse rate, water pressure and standoff distance) on the width, depth and roughness of a channel produced at the surface of stainless steel. The results showed that by reducing the standoff distance and water pressure, the width of the channel was also reduced. For channel depth, increasing traverse rate produced a shallower channel depth. In contrast, increasing the water pressure produced a deeper channel depth. The surface roughness of the channel showed significant improvement by reducing the water pressure at a lower traverse speed and standoff distance. A proper selection of parameters is required in order to produce a suitable channel during AWJM surface texturing process

Effect of masked abrasive waterjet texturing on surface roughness using Taguchi method

High pressure waterjet technology has received a wider acceptance for various applications involving machining, cleaning, surface treatment and material cutting. Surface texturing is a popular method to improve the wear resistance of a surface. The present study applied a masked abrasive waterjet texturing pro-cess to produce a circular crater on a surface of stainless steel 304. The effect of machining parameters namely traverse rate, water pressure, standoff distance and number of passes on the roughness of the crater surface was analysed. Taguchi method of experimental design was employed by utilizing the L9 orthogonal array. The result shows that the water pressure is the most significant parameter in determining the roughness of the crater surface. Also, based on at the optimum parameters has shown an improvement of surface roughness as compared the initial optimal setting. This shows that the Taguchi method can be conveniently used to analyse the surface roughness during the AWJ texturing process of stain-less steel 304