International Science and Technology Journal

This research was conducted to investigate the powder degradation behavior of Glass-filed GF polyamide (PA3200) GF, nylon 12. And to describing and understanding these reasons to find systematic approach to improve the quality of parts and to reduce the orange peel texture. The thermal behaviour and melt flow rate (MFR) of the virgin and recycled powder were studied by means of differential scanning calorimetry (DSC), and melt flow rate testing (MFR). DSC results indicated that the three transitions temperatures were affected by reprocessing (number of cycles). MFR testing showed that the melt flow rate of glass filled (PA3200) powder was decreased by the temperature, time and reprocessing. The main problem related to this practice is how to choose the right amount of recycled powder to be blended with virgin powder, in order to obtain materials that have good properties, do not show significant variation from the virgin powder, without greatly deteriorate the properties of the final material with respect to the virgin one. However its quality was degraded due long hours expose at elevated temperature caused molecular chain structure and thermal properties have changed. For this reason and according to the EOS and 3D systems companies this investigation used 50% old blended with 50% virgin powder.