จำนวน Repository ( 96 )
การเปลี่ยนแปลงสมบัติทางกลของวัสดุผสมพีวีซีและผงขี้เลื่อยไม้ ภายใต้สภาวะการใช้งานที่มีความชื้น
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.
การพัฒนาและสร้างเครื่องบีบเยื่อเปลือกออกจากเนื้อเยื่อใบสับปะรด
Normally bast fibres were removed from pineapple web by wrapping the boiled pineapple leaf with nylon web and stamp on it. If using this method it will take 24 hours to stamp on 40 kilograms of boiled leaf in order to obtain clean pineapple web that is suitable for producing paper. Apart from that when pressing the fiber we need to get rid of the water as much as we can because the fiber will be weight before using to produce paper. If the water pressed out each time is not equal there may be an error about paper thickness. Moreover stamping on boiled leaf may be dangerous because the chemical substance used when boiling the leaf may burn the feet and cause wound. Currently there is a Pressing machine to separate water from pineapple fiber Rachadasak Supengcum 2010 to fix the problems mentioned above. However there is a weak point because the pressing tube is small so it can press only 1 kilogram of leaf per one time. Therefore the new machine is designed to have a pressing tube sized 30 centimeters wide and 30 centimeters long. The pressing period is 30 centimeters and the pressure for pressing is 70 bars. It takes 1 minute 15 second for one squeeze which contains 6 kilograms of pineapple leaf. It can decrease the time for pressing from the old machine by 6 times. In addition the machine is designed to have the open-close channel to bring the pressed fiber out from the machine more easily. According to the experiment to remove the bast fibres from pineapple web the most appropriate amount for each pressing is 6 kilograms. The pressing process takes 1 minute 15 second. The remaining pineapple web after the pressing is 3 kilograms
A study of chemical release of wook/PVC composites affecting on the physical and chemical water qualities
This research work was to study the chemical release of wood/polyvinylchloride composites (WPVC) affecting the physical and chemical properties of water. WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The water quality was estimated by measuring pH electrical conductivity turbidity and color of water after immersion of WPVC specimen as comparing with case of PVC specimen. The result suggested that pH values of water slightly decreased with increasing specimen immersion time whereas the change of temperature of water did not affect the pH value. The electrical conductivity remained unchanged with increasing specimen immersion time or temperature except for immersion of WPVC specimens at 70 oC. This might be attributed the weak interfacial bonds between PVC and wood and this led to more easily release the metal ions from additives of PVC. The turbidity and color of water for case of WPVC increased with increasing specimen immersion time whereas those for case of PVC did not change. From the results of water quality testing it indicated that WPVC applications which contact with water are safety. This was because water quality after immersion of WPVC specimen is within the effluent standards of pollution control department.
The application of kaolin with coconut meal, plywood from corncobs and durian peel in concrete masonry unit wall for increasing effective heat protection and lightweight
This research aims to study the application of kaolin with coconut fiber corncobs fiber and durian peel in concrete masonry unit wall for increasing effective heat protection and lightweight. The ratio of cement type 1: kaolin is equal to 1: 60 by weight. The kaolin is replaced by fiber include coconut fiber corncob fiber durian peel fiber with 1.67% 3.33% and 5% by weight of kaolin. The kaolin concrete block mixed with fiber sample size is formed to 6.9 x 39 x 19 centimeter with the hydraulic compactor. The samples tested in physical and mechanical properties follow the TIS 58-2533 standard. Resulting their fibers can reduce the density thermal conductivity and compressive strength and increase the changing length and water absorption of kaolin concrete blocks. The kaolin concrete block without fiber has highest compressive strength followed by the kaolin concrete block mixed with corn cob fiber the kaolin concrete block mixed with coconut meal fiber and the kaolin concrete block mixed with durian peel fiber has lowest compressive strength respectively. However their fibers have possibility to be composite materials to reduce weight of kaolin concrete blocks
การใช้ดินขาวผสม กากมะพร้าว เส้นใยจากต้นข้าวโพดและเส้นใยจากเปลือกทุเรียนเพิ่มประสิทธิภาพการป้องกันความร้อนและลดน้ำหนักในผนังคอนกรีตบล็อก
This research aims to study the application of kaolin with coconut meal plywood from corncobs and durian peel in concrete masonry unit wall for increasing effective heat protection and lightweight. The ratio of cement type 1: kaolin is equal to 1: 60 by weight. The kaolin is replaced by fiber include coconut meal fiber corn cob fiber durian peel fiber with 1.67% 3.33% and 5% by weight of kaolin. The kaolin concrete block mixed with fiber sample size is formed to 6.9 x 39 x 19 centimeter with the hydraulic compactor. The samples tested in physical and mechanical properties follow the TIS 58-2533 standard. Resulting their fibers can reduce the density thermal conductivity and compressive strength and increase the changing length and water absorption of kaolin concrete blocks. The kaolin concrete block without fiber has highest compressive strength followed by the kaolin concrete block mixed with corn cob fiber the kaolin concrete block mixed with coconut meal fiber and the kaolin concrete block mixed with durian peel fiber has lowest compressive strength respectively. However their fibers have possibility to be composite materials to reduce weight of kaolin concrete blocks.