This work aimed to study the improvement of mechanical properties and cost reduction of biodegradable packaging made from polylactic acid (PLA) by using sisal fiber. Because sisal fiber as natural fiber is good mechanical properties biodegradable material and low cost. The variables studied were the addition of sisal fiber surface treatment with epoxy silane and fiber direction. Their effects were investigated by tensile flexural and impact testings and morphology analysis. The results suggested that the addition of sisal fiber increased Young’s modulus Flexural modulus and ultimate tensile stress whereas elongation at break and impact strength tended to decrease. For the effect of surface treatment it was found that tensile and flexural moduli increased with epoxy silane treatment but tensile flexural and impact strengths slightly changed. Surface treatment by epoxy silane led to good interfacial bonding by hydrogen bonding between oxirane ring of epoxy silane and hydroxyl group of PLA. The effect of fiber direction revealed that tensile properties of composite in fiber direction of 0o were higher than those of composite in fiber direction of 45o. Fiber direction did not affect flexural and impact properties.

This research aims to develop the natural rubber and ethylene vinyl acetate (EVA) plastic floor tile with flame resistance property. The 6 ratios of natural-rubber STR 20: zinc oxide: stearic acid: sulfur: mercaptobenzothiazole: diphenyl guanidine: EVA plastic: antimony trioxide were equal to 100: 5: 2: 3: 0.5: 0.2: 20: 0 100: 5: 2: 3: 0.5: 0.2: 20: 20 100: 5: 2: 3: 0.5: 0.2: 20: 40 100: 5: 2: 3: 0.5: 0.2: 20: 60 100: 5: 2: 3: 0.5: 0.2: 20: 80 and 100: 5: 2: 3: 0.5: 0.2: 20: 100 by weight or phr. The samples are ground by two-roll mill and formed by compression molding at 150 degree Celsius with 30x30x0.2 cm of dimension for 4: 29 to 5: 19 minutes. The properties of the natural-rubber floor tiles were tested under ASTM standard. From the results it was found that the natural rubber and ethylene vinyl acetate plastic floor tile with flame resistance property was the suitable ratio for using as the rubber floor tiles in building and extinguished a fire by themselves. The antimony trioxide effected to increase the density hardness and thermal conductivity and decrease the tensile strength tear strength and wear resistance properties of the natural rubber and EVA plastic floor tiles

The aims of this research work were to enhance the impact resistance and processibilty of wheat gluten (WG) by the addition of epoxidized natural rubber (ENR) compared to glycerol. This work was divided into two parts: to study the optimum ENR content for improvement of WG and the effect of together functions between ENR and glycerol on the properties of WG. Tested specimens were mixed and prepared by internal mixer and compression molding machine respectively. ENR and glycerol were varied from 10 to 40 phr. The effects of modifier types and contents on WG were evaluated by tensile impact and water absorption testing and thermal analysis. Fracture behavior and rubber dispersion were investigate with scanning electron microscope (SEM). The result revealed that the increase of ENR or Glycerol contents led to the decreases in tensile modulus and strength except for modifier content of 10 phr whereas elongation at break and impact strength increased. Glass transition temperature (Tg) of modified WG tended to decreased with the increase of ENR or glycerol contents especially for glycerol. The presence of glycerol affected on the decomposition temperature (Td) values but those were unchanged for case of ENR. Water resistant of WG specimen was improved by the presence of ENR whereas the increase of glycerol led to weight loss at immersion time of 2880 min. For the effect of ENR : glycerol ratios it indicated that glycerol enhanced tensile resistances but suppressed impact and water resistances of modified WG by ENR. Sizes and dispersion of ENR particles were improved by the addition of glycerol. Tg and Td values of modified WG by ENR and glycerol increased when ENR fractions were increased.

One of important equipment in reforestation or tree planting is a pot for mulching tree saplings. Originally pots were made of clay but they were too strong. When the trees grow up the pots must be smashed in order to let the roots and the stems grow up. Plastic pots are a popular alternative to be potted tree saplings due to their longer usability flexibility keeping and easy cleaning. In addition they are light and easy to move or transport. Typical pots usually have holes at the bottom which make poor ventilation that caused the slow tree saplings growth. Pots with holes in the side let the air comfortably flow and the roots do not go to the bottom of the pot. When the pots are moved the tree sapling roots are not ragged this help reducing the mortality rate of tree saplings. To Construct and find out the efficiency of plastic pot injection molded with 7.7 cm. in size 8 cm. high 0.10 cm. thick and the weight of 20 grams in the specification form the work-piece can be injected. For Construction and finding out the efficiency of holes for putting the plastic pot injection molded with 41 cm. wide 51 cm.long0.20 cm. thick and the weight of 330 grams in the specification form every work piece can be injected. There are 18holes for putting the plastic pot and all 18 holes are in the same size. Asst. Prof. Prasong KanKaew

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%