3D Model for Powder Compact Densification in Rotational Molding
Article dans une revue avec comité de lecture
Date
2012Journal
Polymer Engineering and ScienceAbstract
During rotational molding, a loosely packed, low-density powder compact transforms into a fully densified polymer part. This transformation is a consequence of particles sintering. Powder compact density evolution of the polymer powder is measured experimentally. Obtained results show that the powder densification process consists of two stages, and its mechanism during these two stages is not the same. During the first stage, densification occurs by grains coalescence, and air between the grains escape by open pores between particles. These open pores close in time by particles coalescence progress, and remaining air entrapped in polymer melt becomes air bubbles. Surface tension, viscosity, grains size, and temperature are the controlling parameters during first stage. A three-dimensional model is proposed for the densification of polymer powder during first stage. Second stage starts after bubble forming. Diffusion is the controlling phenomena during this stage. A diffusion-based model is used for the second stage of densification. By comparing with the other models, proposed model exhibits several advantages: it is proposed in three-dimensional and takes into account the nature of layer-by-layer powder densification. Model verification by experimental data obtained for densification of two different polymers shows a close agreement between model prediction and experiments.
Files in this item
Related items
Showing items related by title, author, creator and subject.
-
Article dans une revue avec comité de lectureHAMIDI, A; ILLOUL, Lounès; SHIRINBAYAN, Mohammadali; TCHARKHTCHI, Abbas; BAKIR, Farid; KHELLADI, Sofiane (ELSEVIER, 2015)Reactive Rotational Moulding (RRM) is the best process for producing large hollow plastic parts without weld lines. Constant quality in technical parts requires the process to be mastered by controlling on-line the main ...
-
Article dans une revue avec comité de lectureRIVIERE, Sylvain; FARZANEH, Sedigheh; TCHARKHTCHI, Abbas; BAKIR, Farid; KHELLADI, Sofiane (Wiley-Blackwell, 2013)Reactive rotational molding (RRM) is a process to manufacture hollow plastic articles. Comparing to rotational molding of thermoplastics, it decreases the process cycle time due to the reactivity of the system. However, ...
-
Article dans une revue avec comité de lectureHAMIDI, A.; FARZANEH, Sedigheh; NONY, Fabien; ORTEGA, Zaida; MONZON, M.; TCHARKHTCHI, Abbas; BAKIR, Farid; KHELLADI, Sofiane (Springer Verlag, 2015)This paper concerns the study of sintering phenomenon during rotational molding of polypropylene(PP),Polyvinylidenefluoride (PVDF) and Polymethyl methacrylate (PMMA). First, the coalescence (first step of sintering) of two ...
-
Article dans une revue avec comité de lectureHAMIDI, A.; ILLOUL, A.; SHIRINBAYAN, Mohammadali; TCHARKHTCHI, Abbas; BAKIR, Farid; KHELLADI, Sofiane (Springer Verlag, 2015)During Reactive Rotational Molding (RRM), it is very important to predict the fluid flow in order to obtain the piece with homogeneous shape and high quality. This prediction may be possible by simulation the fluid flow ...
-
Article dans une revue avec comité de lectureAn experimental study of simultaneous sintering of several particles has been carried out using spherical polymer grains. Considering rotational molding condition, coalescence of several grains in contact, happens ...