EXPERIMENTAL STUDY OF LASER PARAMETER EFFECTS ON MECHANICAL PROPERTY OF LASER SINTERED POLYPROPYLENE SAMPLES IN 3D LASER PRINTERS

Original Research Paper Received 21 July 2015 Accepted 23 September 2015 Available Online 17 October 2015 Today, laser 3D printers are one of the ef icient devices for rapid prototyping process. There are large number of studies about quality of samples in these printers. The laser sintering technique is the one of the popular methods for consolidation and shaping of semi-crystalline polymer powders. In this study, we considered the role of laser parameters including laser scanning pattern, laser scanning speed and power in tensile strength and stiffness as the important factors of the mechanical property of samples which are sintered by laser in single layer procedure. Experimental samples were sintered with low power CO2 laser on Polypropylene powder with 200 micrometer grain size. Tensile strength and stiffness had been measured according to ASTM D882 standard and results were reported. In this paper, main effects of factors and interactions were considered via the variance analysis under the imperative conditions that have been passed before. The regression equation was derived. general full factorial method was employed as experimental design. The results show that the laser scanning pattern and laser power have the greatest effects on tensile strength and stiffness of produced samples. The maximum value of responses, 2/9 MPa for mechanical strength and 96 N/mm for stiffness demonstrate that the 2W power of laser with 1650mm/min of scan speed can be the proper value to obtain an optimal response when the selected pattern is No2.