จำนวน Repository ( 64 )

การวิเคราะห์แนวโน้มและพยากรณ์ปริมาณการส่งออกยางแผ่นรมควันชั้น 3 เพื่อการตลาดของประเทศไทย
การวิเคราะห์แนวโน้มและพยากรณ์ปริมาณการส่งออกยางแผ่นรมควันชั้น 3 เพื่อการตลาดของประเทศไทย

This study examines Thailands domestic and export market situation with regard to rubber smoked sheet no.3 (RSS3). Time series analysis is used to estimate trends in order to forecast the export of RSS3 during January 2557 – December 2561 using monthly data from 2542 – 2556. The results show that export volume of RSS3 is likely to increase every year in the same month. The volume of exports in December in every year is the most abundant. However as the volume of product increases every year the rubber price keeps falling. As a result farmers and entrepreneurs would benefit from government expansion of the market by the establishment of a domestic industry as an alternative support for output rather than sole reliance on export.

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การผลิตวัสดุดูดซับเสียงจากวัสดุผสม ยางโฟมธรรมชาติและเส้นใยธรรมชาติ
การผลิตวัสดุดูดซับเสียงจากวัสดุผสม ยางโฟมธรรมชาติและเส้นใยธรรมชาติ

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.

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การลดของเสียจากกระบวนการผลิตยางนอกรถจักรยานโดยเทคนิคซิกส์ซิกม่า
การลดของเสียจากกระบวนการผลิตยางนอกรถจักรยานโดยเทคนิคซิกส์ซิกม่า

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.

2559
การใช้แผ่นยางแทนกำมะถันเคลือบผิวในการทดสอบกำลังอัดของคอนกรีต
การใช้แผ่นยางแทนกำมะถันเคลือบผิวในการทดสอบกำลังอัดของคอนกรีต

This research aims to study the using a rubber sheet instead of the sulfur-capping accordance with ASTM C 617 in the compressive strength of concrete testing. The three of the compressive strength of concrete i.e. 180 240 and 320 ksc were the scope of study. The test results showed that the concrete with using a rubber sheet (fc (3)) had higher compressive strength than the standard concrete with sulfur-capping (fc (2)) at 7.7%. Therefore the adjustment factor from using a rubber sheet instead of the sulfur-capping in the compressive strength of concrete testing was 0.923; the compressive strength of concrete is equivalent to the standard testing. The relationship of compressive strength of concrete between fc (2) and fc (3) is fc (2) = 0.88 fc (3) + 12.04 with a correlation coefficient (r) of 0.988.

2559
การใช้ขุยมะพร้าวเพื่อเสริมความต้านทานแรงดึงของผลิตภัณฑ์แผ่นยางธรรมชาติ
การใช้ขุยมะพร้าวเพื่อเสริมความต้านทานแรงดึงของผลิตภัณฑ์แผ่นยางธรรมชาติ

This research aims to study the properties of natural rubber STR 20 at 100 phr with various contents of coir (e.g. 0 5 10 20 40 and 80 phr) and then mixed with chemical substance at constant ratio. After that the samples are ground by two-roll mill and formed by compression molding at 150 degree Celsius. This leads into the coir reinforcement natural rubber plate of dimension 30x30x0.5 cm. The properties of the natural rubber plates are tested under ASTM standard. From the results it is found that increasing in coir then the properties of resilience and density are improved at every mix ratio. However the tensile strength tear strength and wearing are increased at some certain value of coir. The samples give no water absorption at every mix ratio. The results from this research indicate that it can develop into the rubber floor tiles and rubber wall tiles for furnishing the buildings in natural style.

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