This study presents a combined carbon footprint (CF) and environment damage assessment with a cradle-to-gate approach for an ignition coil. The process considers a data flow of product as the phases: raw materials preparation, part processing, final-product finishing, and packaging. The assessment was performed to explore an automotive ignition pencil coil during its developing phase. This study illustrated that a green product problem could be evaluated as a carbon footprint and environmental hazard. By using the conceptual flow to set up the assessment procedure, a product can be decomposed into several material ingredients to specify the input parameters in a Life Cycle Assessment. A total CF of an ignition coil can be investigated individually by each of the materials. The total CF of an ignition pencil coil equal to 0.5254 kgCO₂eq was calculated. The insulated filling and copper winding of an ignition coil generated the two most impacting processes in terms of CF (21.83% and 17.50%, respectively). EPS (Environmental Priority Strategies) methodology evaluates the environmental damage of the product in the product design process. As a result, the metal material has a seriously damaging impact on human health and inanimate resources, especially inanimate resources. The total CF generated by the newly devised ignition coil is over 39~62 percent less than a general type one that exists in the current market. The new ignition pencil coil also uses fewer raw materials and therefore reduces environmental damage to the Earth.

Epoxy with low viscosity and good fluidity before curing has been widely applied in the packaging of electronic and electrical devices. Nevertheless, its low flexibility and toughness renders the requirement of property improvement before it can be widely acceptable in dynamic loading applications. This study investigates the possible use of 2-hydroxyethyl methacrylate (HEMA) toughening agent and nano-powders, such as alumina, silicon dioxide, and carbon black, to form epoxy composites for dynamic property improvement. Considering the different combinations of the nano-powders and HEMA toughener, the Taguchi method with an L9 orthogonal array was adopted for composition optimization. The dynamic storage modulus and loss tangent of the prepared specimen were measured by employing a dynamic mechanical analyzer. With polynomial regression, the curve-fitted relationships of the glass transition temperature and storage modulus with respect to the design factors were obtained. It was found that although the raise in the weight fraction of nano-powders was beneficial in increasing the rigidity of the epoxy composite, an optimal amount of HEMA toughener existed for its best damping improvement.

The jaw coupling with a flexible spacer is frequently used in the torque transmission between shafts with misalignment for machinery. Its torsional stiffness and limit torque closely determine the operational capacity and the dynamic characteristics of the system because the coupling is usually the most flexible link in the driving chain. In this study, the optimal design of a jaw coupling with an elastomeric spacer was investigated using the Taguchi method by considering four design factors: the tightening method of the clamping bolts, the tightening torque of the clamping bolts, the hardness of the thermoplastic polyether ester elastomer spacer and the installation angle between the two end blocks of the coupling. All specimens were tested by using an in-house torsion tester to record the torque-angular deformation responses. The results showed good reliability and repeatability, with a coefficient of variance within 5%. Spacer's hardness was found to be the most significant factor regarding the torsional stiffness, while the magnitude of the clamping torque had the most critical role in the limit torque. The estimation formulae for the torsional stiffness and limit torque of the jaw coupling were obtained by using the statistical regression of the measured data, respectively. Both formulae predicted the performance of the optimal designs within 5% of error compared to the confirmation tests.

The performance improvement of advanced electronic packaging material is an important topic to meet the stringent demands of modern semiconductor devices. This paper studies the incorporation of nano-alumina powder and thermoplastic elastomer (TPE) into thermoplastic polystyrene matrix to tune the thermal and mechanical properties after injection molding process. In the sample preparation, acetone was employed as a solvent to avoid the powder escape into surrounding during the mechanical mixing in a twin-screw mixer. The pressure and shear force were able to mix the composite with good uniformity in compositions. The samples with different compositions were fabricated using injection molding. The measured results showed that adding 5 wt.% of TPE into the simple polystyrene was able to raise the melt flow index from 12.3 to 13.4 g/10 min while the thermal decomposition temperature remained nearly unchanged. Moreover, the addition of small amount of nano-alumina powder could quickly improve the mechanical property by raising its storage modulus. For example, the addition of 3 wt.% of nano-alumina powder had an increase of 7.3% in storage modulus. Over doping of nano-alumina powder in the composite, such as 10 wt.%, on the other hand, lowered the storage modulus from 2404 MPa to 2069 MPa. The experimental study demonstrated that the tuning in the polystyrene’s thermal and mechanical properties is feasible by composition modification with nano-alumina powder and TPE. The better concentration of the additives should be determined according to the specific applications.

The study attempted to observe the surface characteristics of the flank lock type precision locknut which was assembled in a vertical type and operates under different tightening speed. The speed setting was in according with the specifications of 4rpm, 6rpm and 8rpm conditions to set up this experiment. A type of 2TML lubricant was used. The experiment investigated the surface characteristics of a locknut, including contact surface flatness, contact surface roughness, and thread surface roughness before and after the designed test. According to the contact surface flatness of the locknut obtained from this study, it was found that the surface of the locknut contacting with the bearing resulted into a deterioration of the surface flatness and surface roughness during the tests. Furthermore, the thread surface roughness has been changed at different thread for different tightening speed during the test, especially at threads 1, 2, 7 and 8. The study found that some of variations occurred in the values of Ra, Rz and Rmax at different thread of a locknut. The variation of Rmax is the most among them.