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.
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.
Automobile manufacturers have been contributing a large quantity of carbon emission on the earth for decades. This study examined an environmental impact problem of an automobile ignition coil within a supply chain. An assessment based on the methodology of Life Cycle Assessment to certify total carbon emission that a product contributes to the environment at various stages of production, packing and transportation. In this case, a production of every automobile ignition coil will generate a total of 0.8649 kg carbon dioxide equivalents (CO2eq). An analysis exhibits that these constituent parts, including core, insulating filling resin and shell, are the major sources of CO2 emissions, which account for 23.78%, 16.37% and 15.04%, respectively. The major ingredients of these components are iron, epoxy resin and polybutylene terephthalate. A further investigation shows that the carbon emission of the packaging material should be considered in this case, due to paper and wood-containing materials. Also, while setting an environmental impact problem for a product, a generic analysis development can classify into three categories: human health, ecosystem quality and resource consumption. The analysis result showed that both of materials, i.e., polymer and metal, heavily influence the environment, especially metal. For a green manufacturing process, reducing the consumption of these raw materials in manufacturing is essential to achieve sustained economic growth but diminish carbon emission problem in the life cycle of an automobile ignition coil.
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.
2 June 2022 in Journal of Failure Analysis and Prevention