The objectives of this research are to study the rate of deterioration of tyre friction coefficient and investigate the quality of new and old tyres that are currently in use. A set of the rolling resistance testing was designed and set up to work with the single dynamometer according to speed 80 km/h tire load 4660 N and inflation pressure 30 psi. There were three tire samples new tire one year used tire and two year used tire to find the rolling resistance coefficients. The finding shows that the rolling resistance was inverse variation with tire aging. For instance the new tire (1st sample) had the highest rolling resistance on the other hand the two year used tire (3th sample) had the lowest rolling resistance. Moreover the rolling resistance coefficients were inverses variation with tire aging. Besides the one year used tire had the average of the decreasing rate of the rolling resistance coefficient at 0.03689 N/kN per a week while the two year had the average of the decreasing rate of the rolling resistance coefficient at 0.03671 N/kN per a week. Furthermore the result also revealed that the rolling resistance coefficients nonlinearly decreased comparing to the tire aging.

In this research zeolite NaY is successfully synthesized from rice husk silica as agricultural waste material. Iron catalysts on zeolite NaY from wet impregnation Fe/NaY with Fe loading 0.5-10.0 wt% are characterized and investigated for the oxidation of styrene to benzaldehyde. The characterization with wide angle X-ray scattering (WAXS) suggest that loaded iron dispersed on external surface and inside pore of NaY. Moreover the formation of g-Fe2O3 phase is observed on NaY as indicated by soft X-ray absorption spectroscopy. TGA and FTIR measurements of the Fe/NaY also show the formation of nitrate ion. Over the catalysts the oxidation of styrene is enhanced with benzaldehyde being the major whereas styrene glycol acetophenone phenylacetaldehyde styrene oxide and benzoic acid being the minor products. The 2.5wt%Fe/NaY show the good catalytic selectivity in catalytic oxidation of styrene using H2O2 and reaction time at 6 h and the selectivity of the benzaldehyde reached 75%.

The shrinkage of plastic was caused by the shape of the product and the type of plastic used in the injection. The plastic shrinkage difference was resulted from the temperature used in melting the injection speed mold cooling and different injection surroundings. These led to unknown exact value of plastic shrinkage and the trial and error work has been done. As a result of trial and error work the injection products were not in the determined size. This research aims to find the percentage of plastic shrinkage according to standard test ASTM D955 from (Amorphous Thermoplastic) (Acrylonitrile Butadiene Styrene ABS). The findings showed that square specimen size 60x60x2 mm measured from vertical perpendicular to flowing direction the shrinkage was at 0.86% the shrinkage was at 0.59% when measured from flowing direction and the thickness expanded at 20%. For the rectangular specimen size 12.7x127x3.2 mm measured from vertical perpendicular to flowing direction the expanding was at 0.16% the shrinkage was at 0.88% when measured from flowing direction and the thickness expanded at 14.86%. The circular specimen size 100x3.2 mm the shrinkage was at 1.26 when measured from vertical perpendicular to flowing direction the shrinkage measured from flowing direction was at 0.82% and the thickness expanded at 13.23%

This research aims to reduce waste in the production process to meet the target to find ways to prevent defects occurring in the curing process and to improve preventative measures available today. The waste found in the curing process label the edges are blamed blistering edge under inflated tires cover on low. After brainstorming to find factors that affect the defect by using techniques Six Sigma (Six Sigma).The work five main steps in performing a job defining the problem measuring analyzing problems improved control and severity surveillance and monitoring disorders of the process. It was found that the raw materials are the main parameters that cause much waste as possible. Therefore we have developed an approach to improve the material by adding a preliminary inspection and design documents to determine work procedures. The benefits of this research can reduce the waste that occurs in the curing process of the target by reducing the rate of 8.0 % an average of 7.3% in a survey from January to May 2557 is an average rate of 6.0% In a survey in June 2557 equivalent to saving manufacturing cost 135045 baht per month. The rate of decline is likely to be quite good that make employees feeling and effort to cooperate in the reduction of waste in the production process.