A First Study of the Sintering Behaviour of Natural Fibre Reinforced Polymer Systems
Fernando G. Torres, M. Cubillas, C. Aragon
POLYCOM - PUCP / Catholic University of Peru
PERU

Keywords: rotomoulding, composites, sintering


Polymer sintering has not been the subject of many studies during the past 50 years. For a long time the Frenkel-Eshelby model had been the only theoretical framework considered, when analysing the sintering of polymer powders. Moreover, the sintering of multiphase polymer systems has not been studied yet in detail. In a previous work, we introduced the process of rotomoulding of natural fibre reinforced thermoplastics (1). Since sintering is considered to be the prevailing mechanism in rotational moulding, it is important to understand the governing mechanisms when a multiphase polymer system is involved.
In the present work we study the different sintering stages in the rotomoulding process of natural fibre reinforced thermoplastic powders. The polymer powders used in the experiments have been different grades of high density polyethylene (HDPE). The powder morphology was in all cases highly non-spherical. The reinforcing fibres used were sisal, jute and cabuya. Wood and rice-shell flour were also used as fillers for the present study. The sintered bodies density has been studied as a function of the sintering time. Morphological characterisation techniques have been used to determine the effect of fibre/filler content on the sintered bed structure. It has been found that at relatively low fibre concentrations, the sintering behaviour of the polymer particles was in agreement with that one found for the unreinforced polymers studied. Moreover, the presence of fillers in flour form, was more detrimental to the sintering of the polymer bed than the presence of natural fibres.


References

1. Torres, F.G., Aguirre M. y Aguila, G., Powder Processing and Rotational Moulding of Natural Fibre Reinforced Thermoplastics, Polymer Processing Society 18th Annual Meeting, PPS-18, Guimaraes, Portugal, 2002