This research work was to study the effect of moisture on mechanical properties of wood/polyvinylchloride composites (WPVC). WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for WPVC specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The moisture effect was investigated by measuring flexural properties and hardness of WPVC as comparing with case of PVC specimen. The result suggested that flexural modulus of WPVC tended to decrease with increasing time of water immersion and then remained unchanged at immersion time of more than 72 and 48 h for water temperature of 30 and 70 oC respectively. The decrease rate in flexural modulus enhanced when water temperature increased. Flexural modulus of PVC slightly changed with increasing both immersion time and water temperature. Flexural strength for both PVC and WPVC specimens were found the change at water temperature of 70 oC only. Flexural strength of PVC tended to slightly increase with increasing immersion time whereas flexural strength of WPVC slightly decreased with increasing immersion time. Hardness of PVC specimen in cases of both water temperature of 30 and 70 oC slightly increased with increasing immersion time. For WPVC hardness tended to decrease with increasing immersion time and water temperature.

This research work was to study the effect of surface treatment of natural fiber and the effects of type and content of natural fiber on the development of acoustic material from natural rubber foam /natural fiber composites. The surface treatment used for this research work was sodium hydroxide (NaOH) treatment. NaOH Concentrations and treatment times were varied from 0 to 15 %wt. and 0 to 30 min respectively. Natural fibers used for this work were bagasse fiber (BF) and oil palm fiber (OPF). The suitable condition for surface treatment was estimated by fiber length and diameter (L/D) ratio and morphology of natural fiber. The result suggested that L/D ratios tended to increase when NaOH concentrations and/or treatment times increased except for NaOH concentration of 15 %wt. L/D ratios of OPF after surface treatment were changed more than those of BF. The suitable conditions of NaOH treatment for BF and OPF were NaOH concentration of 10 %wt. and surface treatment times of 30 and 10 min respectively. The effects of fiber type and content on sound absorption properties of natural rubber foam /natural fiber composites were investigated by cell characteristics sound absorption coefficient DMA analysis and bulk density. Both treated BF and OPF with suitable treatment condition were varied from content of 0.0 to 10.0 %wt. The result showed that the cell size of composites tended to decrease with addition of natural fiber whereas number of foam cell per unit volume increased. After adding natural fiber more than 2.5 %wt. cell size of composite foam and number of foam cell per unit volume tended to change the inverse direction. Natural fiber in composites enhanced the sound absorption efficiency. Sound absorption coefficient of composites adding BF was more than that of composite adding OPF. The addition of natural fiber enhanced the elasticity of composites and that increased sound absorption efficiency. NaOH treatment led to creation of strong interfacial bonding between natural fiber and natural rubber and enhanced the sound absorption efficiency. Density of NR composite foam increased with increasing natural fiber content.

The study was aimed to investigate the production of banana fiber that was suitable for decorating handicraft basketry examine its effectiveness develop decorative handicraft materials for basketry from fibrous layer on the trunk of the banana tree and promote the obtained knowledge in the community of Plasticseeroong Baanmor Promburi District Singburi Province. The research result could be summarized that the most appropriate production process of dry fibrous layer on the trunk of the banana tree mixed with fibrous layer of paper mulberry was done through mechanical process. After bleaching the mixed fibrous layer was stirred by Hollander beater with the proportion of wet fibrous layer and water at 1:40; 10% of dry of paper mulberry was boiled for three hours in sodium hydroxide at 100 degree Celsius then bleached with 1.5% of hydrogen peroxide with 4% of the dry fibrous layer weight at 90 to 95 degree Celsius for two hours. The mixture of wet fibrous layer on the trunk of the banana tree with wet fibrous layer of paper mulberry was 70:30 which was considered appropriate for decorating handicraft basketry. Concerning the examination of mechanical properties of banana tree fibrous layer according to the standard of TAPPI T it was found that the folding endurance of paper value was 144 (N. m/g); the tensile strength value was 32.16 (N. m/g); the tear resistance value was 26.56 (mN.m2/g); and the bursting strength value was at 1.94 (KPa.m2/g). The fibrous layer obtained from on the trunk of the banana tree was fabricated into decorative basketry materials for example flowers palm leave hats flower key chains bags and paraffin coated flowers for bamboo boxed. The attendants’ satisfaction on the training of the production of decorative handicraft materials of basketry from fibrous layer on the trunk of the banana tree to 30 members of the community of Plasticseeroong Baanmor Promburi District Singburi Province concerning the training service speakers training procedures facilities and training benefits was at high level (90.67%) and at average level (9.33%).

This study aims to development of production process of hard metal by tungsten carbide powder with the particle sized of 0.1 - 0.35 µm. This carbide powder were made of recycling cemented carbide tool scraps so it is mixed with Ta = 2.82 % Mo = 0.45 % Nb = 1.22 % Ti = 4.56 % Zr = 0.37 % The shape of the carbide powder are roughly round due to ball milling for 300 hours. It was mixing cobalt 10 % and Paraffin wax 2 % which is found the work piece that running through the process of sintering with a temperature of 1400 °c and 1430 °c have the hardness of 1368.5 and 1346.3 HV respectively. In one hour of holding time process the work piece with 1430 °c of the sintering causes less wear. After the test of turning operation it can be concluded that the tungsten carbide cutting tool provides the equivalent quality as a standard cutting tool.

This research presents a study of the compressive strength chloride penetration and resistance to corrosion of concrete containing bottom ash. Fine and coarse aggregate is partially replaced with bottom ash 25 50 75 and 100% by weight of the aggregate. The results show that the compressive strength and low chloride penetration of concrete improves substantially with partial replacement of aggregate with bottom ash. Concrete mix cement containing 25 and 50% of bottom ash can be used to make coarse aggregate. In addition Concrete mix cement containing 100% of bottom ash can be used to make fine aggregate. The use of bottom ash produces concrete mix with good compressive strength and resistance to chloride and corrosion.