No abstract

Efficiently utilization of rice husk ash (RHA) and waste sludge from cutting glass manufacturer (WSG) as additives to pottery clay would yield positive economic impacts, such as more friendly industrial ecosystems. In this study, The RHA and WSH were used as additives to Angthong pottery clay (APC) and casting and fired properties were examined. Two sets of sample with a mixture consisting of 60% APC, 20% RHA, and 20% WSG (CRG formula) and non-added clay (C100 formula) were prepared by slip casting technique. Samples were fired at temperature 900 °C and 1100°C; then the viscosity of slurry, linear shrinkage, water adsorption, and 3-point bending strength were measured. The results showed that the optimum viscosity for slip casting of CRG and C100 were 1638 cP and 983 cP, respectively. The water adsorptions of all samples decrease while their shrinkage and strength increase with temperature. At 900°C, the water adsorption and the strength of CRG were 32% and 1184 psi, respectively. Comparatively, CRG’s water absorption was 1.5 times higher than C100’s, while their mechanical strength was insignificantly different. This due to the RHA behaves as pore forming and the WSG promotes the sintering of samples.

The objective of this research was to reduce defects in the forming process of fired clay floor tiles by modifying the parameter settings of the influential factors using the Six Sigma approach. The current process had 152,871.16 DPPM (Defect Parts per Million). The main cause of this problem was the rough surface problem in the forming process. The five steps of the Six Sigma quality improvement approach were exercised in this research, i.e. define, measurement, analysis, improvement, and control phases, respectively. This research started by studying in details of the production process to find relevant factors that could cause a rough surface defect. The main factors were selected and analyzed by Failure Mode and Effect Analysis (FMEA). After that, the settings of each factor were discovered by applying the Design of Experiment (DOE) approach. The results showed that the appropriate settings were the sieve size of pan mill setting to 18 Mesh and the size of sieve holes at pan mill setting to be uniformly distributed. It is found that the defect was reduced to 49,151.14 DPPM, which is 67.85% of the defect before the improvement.

In present study, poly (acrylonitrile-co-methyl acrylate) nanofibers were fabricated via electrospinning method and stabilized at elevated temperature in air. Electrospinning processing parameters i.e. solution concentration, solution flow rate and applied voltage were optimized. Fiber morphology and polydispersity index of fiber size was assessed from scanning electron microscope (SEM) images. Selected nanofiber was then used to study effect of stabilization time and stabilization temperature on fiber morphology, change in chemical structure and aromatization index (AI) using Fourier transform infrared spectroscopy and differential scanning calorimetry. SEM images showed drastic morphological change of stabilized fibers compared to the as spun precursor. AI value increased as stabilization time and temperature increased and reaching maximum value of 98%. This indicated high cyclization of the aromatic ring in fiber structure. Current finding is critical for carbonization process and preparation of carbon nanofibers from PAN copolymer in the future.