Applied Mechanics and Materials Vol. 679

Abstract: This paper describes the harmonic current effect at T-joint and corner joint on 3 phase 100kVA transformer model. The methodology that used to measure a harmonic current is using search coil connected to oscilloscope. The experiment is conducted by changing input voltage with different flux density. From the results obtained, the 3^rd order harmonic current shows the highest for both T – joint and corner joint. The highest harmonic occurred at T – joint. For in plane, the harmonic current is 0.237A at corner joint and 0.389A at T - joint. At normal condition, the harmonic current were 0.250A and 0.769A at corner joint and T – joint respectively. This happened because of more energy required for transferring the flux to the left and right of the core. The corner joint of harmonic is less since the flux direction is 90° thus smaller amount of energy is required for the movement.

Abstract: This paper describes the harmonic current effect under static and dynamic load on 3 phase 100kVA transformer model. The methodology that used to measure a harmonic current is using power analyzer with different excitation. The experiment is conducted by changing input voltage with different flux density. A waveform can be obtained by using the data collected. 3^rd order of harmonic gives a high impact to the complex waveform. At 0.6 Tesla, 50 Hz, the 3^rd order of harmonic current under static load and dynamic load is 0.00196A and 0.26746A respectively. Therefore, both static and dynamic load were give an effect to harmonic current effect on transformer. This is because when the transformer connected to the load, more current and voltage induced in order to energize the load. Moreover, the loads itself have their own harmonic effect because of the functional mechanism.

Abstract: The effects on the properties of recycled latex glove (RL-G) filled Epoxidized Natural Rubber (ENR 50) were studied. Both compounds were prepared by two roll mill at five different compositions of RL-G (5, 15, 25, 35 and 50 phr). The size range of RL-G particles i.e., S₁ (300μm-700μm) and S₂ (3cm-5cm) were used. The properties such as tensile properties (tensile strength, elongation at break, and stress at 100% elongation) and morphology studies were determined. The results indicated that the both size, S₁ and S₂ of recycled latex glove filled ENR 50 blends exhibited an increased in tensile strength and elongation at break for increasing weight ratio of RL-G. Scanning electron microscopy (SEM) of the fracture surfaces shows that the fine size, S₁ RL-G/ENR50 exhibited high surface roughness and matrix tearing lines than the coarse size, S₂ thus improving the compatibility of RL-G/ENR50 compounds. The results overall indicated that the fine size, S₁of RL-G filled ENR50 contributed to the better properties such as tensile strength and surface morphology compared to the coarse size, S₂ mainly at 15 phr of RL-G content.

Abstract: Synthetic polymers are important in many branches of industry, particularly in the packaging industry. However, it has an undesirable influence on the environment and causes problems with deposition of waste and consumption. Therefore, there is a tendency to replace the polymer with biodegradable polymer that undergoes a process. This review summarizes the data on consumption, the level of biodegradation, the reliability of commercialization and production from renewable sources. Some biodegradable plastics that have been commercialized are starch based plastics, bacteria based plastics, soy based plastics, cellulose based plastics, lignin based plastics and natural fiber reinforced plastics. Production of this kind of material and its introduction to the market is important for the natural environmental.

Abstract: The effects of different particle sizes of recycled latex glove (rLG) on curing characteristics of SMR L were examined. Two different size ranges of rLG particles, i.e., 100-300μm, 2-3 cm were used in this study. The SMRL/rLG composition of 100/0, 100/5, 100/15, 100/25, 100/35 and 100/50 were prepared using a two roll-mill at room temperature. The characterization results of the blends shows that scorch time, t₂, and cure time _t90 of the SMRL/rLG blends decreased with increased rLG content as well as decreasing sizes of rLG particles due to the existence of cross-linked precursors and unreacted curative in the recycled rubber. Among all blend ratios, the SMRL/rLG blends with fine size of rLG particles exhibit lowest minimum torque (M_L) compared with the coarse size of it in SMRL/rLG compound which resulted in more efficient processing. The maximum torque (M_H) of SMRL/rLG compound shows a declining trend with increasing rLG content probably due to the poor interactions in SMRL/rLG compound. As the particle size decreased, the contact surface area increased which provided more efficient interfacial bonds, leading to better properties. Results indicated that the fine size of rLG filled SMR L contributed to the better properties compared to coarser size of rLG filled SMR L mainly at 15 phr of rLG.Key words: Recycled – rubber – latex – glove – SMR L

Abstract: Blends of styrene butadiene rubber/recycled chloroprene rubber (SBR/CRr) with and without of trans-polyoctylene rubber (TOR) were prepared and the effects of tensile and morphological properties were determined. Both uncompatibilised and compatibilised SBR/CRr blends were prepared using a two roll mill at room temperature with blend ratios 95/5, 85/15, 75/25, 65/35 and 50/50. Compatiblized SBR/CRr blends with TOR enhanced the tensile strength and M100 but reduced the E_b and rebound resilience compared to uncompatibilized SBR/CRr blends. The scanning electron microscopy (SEM) of the tensile fractured surface of compatibilised SBR/CRr blend at 15 and 50 blend ratios illustrated a stronger interfacial adhesion and better dispersion of CRr-SBR matrix.

Abstract: Effects of citric acid on the mechanical properties of thermoplastic tapioca starch/high density polyethylene/natural rubber (HDPE/NR/TPS) blends were investigated. The ratio between HDPE/NR was fixed at 70/30 and used as a matrix system. TPS loadings with and without modification with citric acid (CA) were varied from 0% to 30wt%. Mechanical and physical properties of blends were evaluated as a function of TPS loadings modified with and without CA. The tensile strength, Young’s modulus and elongation at break were found to decrease with increasing TPS content. However an improvement in the tensile strength for TPS modified with CA at 5%, 10% and 20% TPS loadings was observed. The degree of TPS adhesion and dispersion in HDPE/NR blends were determined by scanning electron microscope (SEM).Keywords; HDPE/NR/TPS, citric acid, tensile properties, morphology.

Abstract: The effects on properties of recycle nitrile glove (NBRr) filled Epoxidised Natural Rubber (ENR 50) was studied. Compound was prepared by two roll mill at five different compositions of NBRr (5, 15, 25, 35 and 50 phr). Two different size ranges of NBRr particles i.e., 300μm-700μm (fine) and 3cm-5cm (coarse) were used. The properties of cure characteristics (cure time, scorch time, minimum torque, and maximum torque) and swelling test were determined. Results indicated that the incorporation of fine size NBRr loading on ENR 50 provides better improvement both on cure characteristics and swelling behaviour mainly at 15 phr of NBRr compared to the coarser size NBRr particles.

Abstract: Tensile test and morphology studies were performed to determine the influences of Trans-polyoctylene Rubber (TOR) as compatibilizer of NBRr filled ENR 50 with composition of 15 phr. Fine size (300μm-700μm) of NBRr was used as fillers. Both uncompatibilized and compatibilized NBRr/ENR 50 were prepared using two roll mill at room temperature with different php of 1.0, 1.5, 2.0, 2.5 and 3.0. It can be observed that tensile strength and modulus of elasticity were decreased as increased in TOR loading before started to increased at 1.5 up to 3.0. Meanwhile, the increment in the value of elongation at break when increased in the addition of TOR. The scanning electron microscopy (SEM) of the tensile surface fracture of increased TOR loading illustrated a better adhesion and dispersion in comparison of low amount of TOR loading.