Abstract
The major disadvantage of rotational molding is the cycle time, which is very long compared to other plastic processing methods. A major percentage of the cycle time besides heating and cooling results from the time necessary to remove gas inclusions from the polymer melt, which are trapped while sintering the polymer powder. In this work the formation of gas inclusions is investigated by conducting a cycle time variation on a uniaxial rotational molding machine. The influence of low pressure during melting on the formation of inclusions is investigated by examining sintering experiments with a pressure variation during the melting of the polymer. Sintering experiments are conducted with different melt residence times to investigate the mechanisms of gas inclusion removal. By comparing the time to reach a pore-free polymeric melt, the cycle time reduction potential under low-pressure application while melting the polymeric powder is estimated.
References
[1] Crawford RJ, Spence AG, Cramez MC, Oliviera MJ. Proc. Inst. Mech. Eng., Part B 2004, 218, 1683–1693.10.1177/095440540421801204Search in Google Scholar
[2] Spence AG, Crawford RJ. Polym. Eng. Sci. 1996, 36, 993–1009.Search in Google Scholar
[3] Crawford RJ, Kearns MP. Practical Guide to Rotational Moulding, Rapra Technology: Shawbury, Shrewsbury, UK, 2003.Search in Google Scholar
[4] Crawford RJ. Rotational Moulding of Plastics, Wiley: Chichester, UK, 1997.Search in Google Scholar
[5] Crawford RJ, Thorne JL. Rotational Molding Technology, William Andrew Publishing: New York, 2002.10.1016/B978-188420785-3.50006-XSearch in Google Scholar
[6] Abdullah MZ, Bickerton S, Bhattacharyya D. Polym. Eng. Sci. 2007, 47, 1420–1429.Search in Google Scholar
[7] Abdullah MZ, Bickerton S, Bhattacharyya D. Polym. Eng. Sci. 2007, 47, 1406–1419.Search in Google Scholar
[8] Abdullah MZ, Bickerton S, Bhattacharyya D, Crawford RJ, Harkin-Jones E. Polym. Eng. Sci. 2009, 49, 1846–1854.Search in Google Scholar
[9] Hardt DE, Lustrino ME, Mazzeo AD, Polym. Eng. Sci. 2011, 52, 80–90.Search in Google Scholar
[10] Gogos G. Polym. Eng. Sci. 2004, 44, 388–394.Search in Google Scholar
[11] Kontopoulou M, Vlachopoulos J. Polym. Eng. Sci. 1999, 39, 1189–1198.Search in Google Scholar
[12] Xu L, Crawford RJ. J. Mater. Sci. 1993, 28, 2067–2074.Search in Google Scholar
[13] Kontopoulou M, Vlachopoulos J. Polym. Eng. Sci. 2001, 41, 155–169.Search in Google Scholar
[14] Product datashett Lupolen 4021 K RM Powder, LyondellBasel, 2013.Search in Google Scholar
©2015 by De Gruyter
