Journal of Engineering Research and Reports

In this study, an extrusion process was studied in a cable manufacturing company located in Southeastern Nigeria. The critical-to-quality (CTQ) characteristic considered in the study was the cable diameter and the design effort was to reduce the possibilities of having cables with inconsistent dimensions. Taguchi Orthogonal Array Design L16 (4˄2) was used to achieve the optimum parameter settings after statistically investigating the assumed correlations between the process parameters in relation to cable dimension. Thereafter, an appropriate engineering tolerance interval for the improved process was designed to tighten the existing tolerance of the process from T±0.185 to T±0.032, thus reducing the engineering tolerance by 82.7% from the initial tolerance limit. After the process improvement, the Taguchi loss function approach was used to estimate cost attributed to deviations. The loss function estimation result has shown that the cost attributed to cable diameter deviations from the nominal value reduced from the initial value of ₦7.34/coil to a reduced cost of ₦2.08/coil. The sigma level increased from 0.6 to 5.2 at the project termination stage and the estimated annual loss decreased by 72% from the baseline value.

This paper studies the challenges and behavior of epoxy material between the roughened Leadframe during the Die Attach process. Die bond on the roughened die-attach paddle (DAP) of epoxy has been a challenge for its manufacturability in terms of maintaining the target epoxy volume. The study on the roughened Leadframe utilizing the Pre-bond inspection parameter causing machine inspection cannot fully detect the epoxy pattern. The uneven contrast of pad’s, causing pre-bond inspection problem. Hard to teach / set-up epoxy inspection due to the contrast between leadframe die pad vs. epoxy. The roughened leadframe property has different surface contrast causing Frequent “Bond Align” and epoxy inspection error on the Roughen leadframe. This occurrence leads to risks of insufficient epoxy which is detrimental to product reliability (delamination on die bottom) and can cause manufacturing yield loss due to insufficient epoxy coverage. Using the Design of Experiment (DOE) methodology and its applicable statistical tools, the author to come up with error-proofing solutions to resolve and reduce the Insufficient Epoxy. The innovative and breakthrough solutions implemented were the installation of ultra-bright light with double sidelights in pre-bond inspection which is the key in reducing defects rate.

In this preliminary study, kenaf core fiber (KCF) was utilized as a natural filler for the preparation of the gellan gum/KCF biocomposite films. The films were prepared by casting gellan gum solutions containing glycerol and KCF, followed by gelation and drying. The weight ratio of gellan gum and glycerol was fixed at 2:3, while the content of KCF varied from 6 to 15 wt.% relative to the weight of gellan gum. The tensile properties of the prepared films have been determined by using a universal testing machine. The tensile test results demonstrated that the tensile extension and tensile energy at break of the biocomposite films have significantly increased with the incorporation of KCF. Nevertheless, the tensile stress and tensile modulus at maximum load have drastically decreased with the increase of KCF content. This study implied that the incorporation of KCF had enhanced the ductility of the gellan gum/KCF biocomposite films and at the same time, reduced the stiffness of the films.

This paper aims to identify the causes of package thickness related defects in compression mold process. Related defects include wrong package thickness, exposed wire and/or die and mold bleed out.

There are three scenarios why package thickness problem is encountered in compression molding. These include wrong mold recipe selected against the actual lot, wrong lot loaded against the current recipe loaded and product input to mold having irregularities such as presence of stray die or damage on strip side rails and end rails. Applying artificial intelligence (AI) the mold machine to detect all abnormalities identified at input and prevent it from proceeding to molding.

Applying AI was able to eliminate occurrence of all package thickness related defects and machine related downtimes.

Exhaust emissions from vehicle traffic refers to the particles released into the air due to combustion of fuels, additives and wear of engine parts in the system during vehicle use. These emissions occur depending on the type of vehicle, type of fuel, combustion process and environmental conditions. In this study, microstructure and chemical characterization of particulate matter (PM) released from gasoline-fuelled vehicles were examined using electron microscopy techniques. As a result, much solid soot, metalloids, heavy metals, ash, sulphates, phosphates, minerals, volatile organic and inorganic pollutants were found to be present in gasoline exhaust emission. These toxic structures still pose a danger to environmental safety and human health.

Aim: In study, microstructure characterization of emissions released from gasoline-fuelled vehicles exhaust were investigated using electron microscopy techniques. Study design: SEM, EDS, XRD and FTIR electron microscopy techniques were used for characterization.

Place and Duration of Study: Material Characterization Laboratory of Karamanoğlu Mehmetbey University, Scientific and Technological Research Application and Research Center, between Junuary 2020 and July 2020.

Results: The vehicles still continue to spread toxic pollutants.

Conclusions: The chemical structure of PM contains 20 elements including C, F, N, Na, O, Mg, Br, Si, Hg, S, P, Pb, Ca, Cr, Mn, Fe, Ni, Co, Cu, Zn. There are pollutant functional groups such as OH, CO, SO in the structure. Hydrocarbons, metalloids, heavy metals, different minerals, phosphates, sulfates, many volatile organic and inorganic compounds pollute the air in PM structure. These toxic pollutants harm the environment and human health.