จำนวน Repository ( 2 )

Molecular weight polyethylene composites for high wear resistance under temperature changes and lubricant to apply for use in industrial machinery parts
Molecular weight polyethylene composites for high wear resistance under temperature changes and lubricant to apply for use in industrial machinery parts

The objective of this research is a study to determine optimum forming condition of semi-finished bulk UHMWPE by using ram extruder that obtain maximum yield strength and minimum wear rate for apply to use in area of medical and mechanical application. Experimental extrusion specified forming condition consists of the temperature of 140 150 and 160 ºC and pressure of 3 5 8 and 10 MPa with the temperature exposure time of 30 minutes. After known optimum forming condition of UHMWPE powder thus forming UHMWPE filled with different kind of filler to study and determine optimum weight fraction of various types of filler that affect onto wear resistance property of UHMWPE composites. Result extruded condition at the temperature of 1 5 0 ºC under pressure of 5 MPa with exposure time of 30 minutes is an optimum extruded condition due to specimen shown a maximum yield strength ultimate tensile strength and elongation of 20.43 ± 1.21 MPa 28.33 ± 1.53 MPa and 285.60 ± 6.41 % respectively and obtain minimum wear rate of 3.02  10-9 ± 5.27  10-10 mm3/Nm. Its mechanical properties and wear resistance property higher than imported bulk UHMWPE by 23.3 % and 4.75 times respectively due to the formation of cross-linking are occurred in polymer chain and also its degree of crystallinity is high equal to 61.52%. For bulk UHMWPE IR-spectrum shown a variation peak of carbonyl group (C=O) are occurred that that it indicated the oxidation reaction at the end of polymer chain and tis degree of crystallinity is equal to 53.31% which result to decrease strength of polymer. In the case of UHMWPE filled with filler optimum weight fractions of various types of filler are as follows. 1. The filling of 0.3 wt. % Al2O3 particle size 0.05 μm shown yield strength ultimate tensile strength and elongation of 23.17 ± 3.35 MPa 34.78 ± 2.80 MPa and 229.00 ± 6.09% respectively that its mechanical properties was increased by 18.55% (increasing of ultimate tensile strength). For the wear rate is equal to 2.09  10-9 ± 3.39  10-10 mm3/Nm or its wear resistance was increased by 1.44 times in compared with initial bulk UHMWPE. 2. The filling of 0.4 wt. % Al2O3 particle size 0.3 μm shown yield strength ultimate tensile strength and elongation of 21.93 ± 0.51 MPa 25.40 ± 0.69 MPa and 267.67 ± 22.03% respectively that its mechanical properties was increased by 11.54% (increasing of ultimate tensile strength). For the wear rate is equal to 2.32  10-9 ± 4.78  10-10 mm3/Nm or its wear resistance was increased by 1.30 times in compared with initial bulk UHMWPE. ฉ 3 . The filling of 0.4 wt. % Al2O3 particle size 1 μm shown yield strength ultimate tensile strength and elongation of 23.93 ± 1.89 MPa 26.77 ± 1.20 MPa and 296.54 ± 7.51% respectively that its mechanical properties was increased by 5.83% (increasing of ultimate tensile strength). For the wear rate is equal to 2.14  10-9 ± 3.16  10-10 mm3/Nm or its wear resistance was increased by 1.41 times in compared with initial bulk UHMWPE 4 . The filling of 4 wt. % Al2O3 particle size 5 μm shown yield strength ultimate tensile strength and elongation of 22.57 ± 2.01 MPa 26.31 ± 3.11 MPa and 136.66 ± 11.67% respectively that its mechanical properties was increased by 7.68% (increasing of ultimate tensile strength). For the wear rate is equal to 2.37  10-9 ± 5.71  10-10 mm3/Nm or its wear resistance was increased by 1.27 times in compared with initial bulk UHMWPE

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เก้าอี้ปรับระดับสำหรับจักรอุตสาหกรรม
เก้าอี้ปรับระดับสำหรับจักรอุตสาหกรรม

The purpose of this project was to develop a chair for industrial sewing machines to suit the physiology of industrial machine users. And to study the satisfaction of industrial sewing machine users with adjustable chairs. The representative sample was student in Industrial Textile and Fashion Design at RMUTP as 40 samples. By allowing the sample group to sat on the sewing chair for the industrial machine and evaluate it by questionnaire the satisfaction with the use of the adjustable chair for the industrial machine. Statistics were usedfrequency percentage mean and standard deviation. The results of the study showed that the satisfaction assessment that affected the adjustable Industrial sewing machine chair. The most useful aspect was the adjustable chair which could be move to as scored as an average of 4. 13 at a high level. The safety of usage is average 3. 98 at a high level. The highest strength was durability and strength while using with an average of 4.2 in a high level. The highest material aspect was that the strong structure with an average of 4. 13 at a high level. The most beautiful aspect was the color of the adjustable chair which was beautiful and suitable with an average of 3.95 at a high level. And the overall summary of satisfaction was 4. 15 at a high level. Based on the research results using an industrial sewing machine table with a height of 73 cm and a 3 level adjustable chair was level 1 height 45 cm level 2 height 48 cm level 3 height 51 cm. It could be conclude that the level 1 chair was suitable for users with a height of 145-153 cm. The level 2 chair was suitable for users with a height of 154- 161 cm and a level 3 chair suitable for users with a height of 162- 170 cm

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