Materials selection analysis for vibration isolator pads

Isolator pads which also called as vibration pads are used in many applications to isolate vibration, extend machine life, reduce maintenance costs and reduce excessive wear. It is the process of isolating objects such as equipment from harmful vibration sources. In this study, two types of isolator pad materials; neoprene and sorbothone were analyzed in order to be used for stackable washing and dryer machine. In this case, the stackable washing and dryer machine together with the isolator pads were simplified into two degree of freedom system, where the first and the second natural frequencies for each material of isolator pad were determined by using matrix iteration method, in which later were validated by a modern tool such as Matlab. For neoprene material, the first natural frequency obtained was 44.2 rad/s and the second natural frequency is 107.7 rad/s. By contrast, sorbothone material shows slightly higher for both first and second natural frequencies compared to neoprene, which were 57.9 rad/s and 141.0 rad/s respectively. From this result, it shows that neoprene is suitable to be used as the coupling (spring) material since it has lower natural frequency value compared to sorbothone, besides the second natural frequency of sorbothone material is near to the forcing frequency 140 rad/s, thus could amplified the vibration due to resonance

Composition and Type of a Binder Effects on the Stainless Steel Foam Microstructure Prepared by Sponge Replication Method

Biomaterials with a porous structure are beneficial for a wide range of medical engineering applications such as filtration, bone replacement and implant development. Stainless Steel 316L (SS316L) foam has been fabricated by foam replication method at different SS316L powder composition which is 60 wt%, 65 wt%, and 70 wt%. The binders used were Polyethylene Glycol (PEG), Carboxymethyl Cellulose (CMC) and Polyvinyl Alcohol (PVA), while distilled water was used as a solvent. The effects of using different composition of SS36L powder, binders and sintering time to the SS316L foam properties was studied. The materials were mixed by using a mechanical stirrer at 250 rpm for 1 hour. Polyurethane foam (PU) which was used as a sacrificial template was dipped into the SS316L slurry until fully coated. The coated samples were then dried in a drying oven within 24 hours before being sintered in an argon gas environment at 1200°C. The samples were characterized to observe the microstructure of the SS316L foam produced. As expected, the viscosity of the SS316L slurry was increased as the SS316L composition increases. The viscosity of SS316L slurry prepared by using PVA as a binder is higher than the SS316L slurry prepared with CMC and PEG as binder. The SS316L foam produced consisted of a large volume of open and interconnected pores especially at higher SS316L composition

The potential of coconut waste element as an alternative material for roof ceiling purpose

Nowadays, number of people diagnosed with mesothelioma (disease that could cause death) due to exposure of asbestos increased year by year. To overcome this issue, a study was conducted to investigate the potential of natural fibers that could be used to replace the usage of asbestos in ceiling application. Mixture of coconut shells, coconut fibers and sodium silicate (Na2O3Si) under different composition were analysed to assess its potential to replace the used of asbestos ceiling. The analysis which consist of Bending Test (mechanical properties), Thermal Analysis (thermal absorption rate), and Porosity Test (sound absorbtion coeeficient) were conducted on the natural fibre samples and comparison was made with the asbestos ceiling samples. From the results, it was found that sample with the composition of 70% sodium silicate, 15% coconut fiber and 15% powder coconut shell is the best and most suitable materials to be used as natural fiber ceiling purpose

Intercity Rail Maintainability Analysis: A Case Study on Rolling Stock Maintenance Compliance

Compliance to organizational standard is essential for maintaining high work performance within the appropriate timescale which can result in reduction of maintenance expenses. The purpose of this study was to analyze the compliance level of preventive maintenance activities based on job frequency and its working hours. Historical data of preventive maintenance from 2019 - 2020 obtained from a field study at Keretapi Tanah Melayu Berhad (KTMB) Depot Batu Gajah, Perak, was analyzed to investigate the frequency, manhours, and the cost involved for each type of preventive maintenance activities namely Exam A, B C and D involving ETS Class 91. From the results, Exam A contributed to the highest non-compliance practice compared to the other Exam where the highest non-compliance percentage (62%) was recorded in 2020 which results in losses of RM RM2,552.82. This study is beneficial for the organization as it determine irregular downtime and manhours compliance for rolling stock system maintenance in order to shape for a better future maintenance plan that will results in efficient operation and higher revenue