Study on the selective laser sintering of a low-isotacticity polypropylene powder
Abstract
Purpose
Semi-crystalline polymers such as polyamide-12 can be used for selective laser sintering (SLS) to make near-fully dense plastic parts. At present, however, the types of semi-crystalline polymers suitable for SLS are critically limited. Therefore, the purpose of this paper is to investigate the processibility of a new kind of semi-crystalline polypropylene (PP) with low isotacticity for SLS process.
Design/methodology/approach
The SLS processibility of the PP powder, including particle size and shape, sintering window, degree of crystallinity and degradation temperature, was evaluated. Effects of the applied laser energy density on the surface micromorphology, density, tensile strength and thermal properties of SLS-built PP specimens were studied.
Findings
The results show that the PP powder has a nearly spherical shape, smooth surfaces, an appropriate average particle size of 63.6 μm, a broad sintering window of 21 oC and low crystalline degree of 30.4 per cent comparable to that of polyamide-12, a high degradation temperature of 381.8°C and low part bed temperature of 105°C, indicating a very good SLS processibility. The density and the tensile strength first increase with increasing laser energy density until they reach the maximum values of 0.831 g/cm3 and 19.9 MPa, respectively, at the laser energy density of 0.0458 J/mm2, and then decrease when the applied laser energy density continue to increase owing to the degradation of PP powders. The complex PP components have been manufactured by SLS using the optimum parameters, which are strong enough to be directly used as functional parts.
Originality/value
This paper provides a new knowledge for this field that low-isotacticity PPs exhibit good SLS processibility, therefore increasing material types and broadening the application of SLS technology.
Keywords
Acknowledgements
The study was supported by the National Natural Science Foundation of China (Grant No. 51375188, Grant No. 51375189), the Guangdong Innovative and Entrepreneurial Research Team Program (No. 2013C071), the National Science and Technology Pillar Program of China (Grant No. 2012BAF08B00), the independent R&D subjects of Huazhong University of Science and Technology (Grant No. 2013TS065) and the State Key Laboratory of Materials Processing and Die and Mould Technology (Grant No. 2013-09). The author also greatly acknowledges the Analysis and Testing Center of HUST for the measurement.
Citation
Zhu, W., Yan, C., Shi, Y., Wen, S., Han, C., Cai, C., Liu, J. and Shi, Y. (2016), "Study on the selective laser sintering of a low-isotacticity polypropylene powder", Rapid Prototyping Journal, Vol. 22 No. 4, pp. 621-629. https://doi.org/10.1108/RPJ-02-2015-0014
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited