Heat Transfer and Crystallization Modeling during Compression Molding of Thermoplastic Composite Parts

Abstract:

We present in this paper, the coupling of heat transfer to the crystallization of composite in a closed mold. The composite is based on thermoplastic resin (low viscosity PA 66) with glass fiber (50% volume fraction). In order to realize this coupling, an accurate characterizationof thermo physical properties in process conditions, especially in the molten and solid state is needed. In addition, theidentification of the parameters of crystallization kinetics is required. Therefore, we present the methods that were used to study the thermo physical properties as the thermal conductivity, heat capacity and the specific volume. Moreover, the kinetic of crystallization was estimated over a large temperature range by using Flash DSC and classical DSC. In order to validate the measurements, the whole process was modeled by finite elements. The model includes the resolution of the strong coupling between the heat transfer and crystallization. Finally, the experimental and numerical results were compared.

• Periodical: Key Engineering Materials (Volumes 651-653)
• Pages: 1507-1512
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.651-653.1507
• Online since: July 2015
• Authors: Jalal Faraj*, Baptiste Pignon, Jean Luc Bailleul, Nicolas Boyard, Didier Delaunay, Gilles Orange
• Keywords: Crystallization, Heat Transfer, PA 66, Thermophysical Properties, Thermoplastic Composite

References

[1] 'Isolation thermique - détermination de la résistance thermique et des propriétés connexes en régime stationnaire - méthode de la plaque chaude gardée, ', ISO8302, (1991).

DOI: 10.1007/bf02474022

[2] J. Mchugh, P. Fideu, A. Herrmann, and W. Stark, Determination and review of specific heat capacity measurements during isothermal cure of an epoxy using TM-DSC and standard DSC techniques, Polymer Testing, vol. 29, no. 6, p.759–765, (2010).

DOI: 10.1016/j.polymertesting.2010.04.004

[3] X. Tardif, N. Boyard, V. Sobotka, and N. Lefèvre, A new PvT device for the thermoplastics characterization in extreme thermal conditions ., Key Engineering Materials, vol. 557, p.1619–1627, (2013).

DOI: 10.4028/www.scientific.net/kem.554-557.1619

[4] S. Van Herwaarden, E. Lervolino, F. van Herwaarden, T. Wijffels, A. Leenars, and V. Mathot, Design , performance and analysis of thermal lag of the UFS1 twin-calorimeter chip for fast scanning calorimetry using the Mettler-Toledo Flash DSC 1, Thermochimica Acta, vol. 522, no. 1–2, p.46–52, (2011).

DOI: 10.1016/j.tca.2011.05.025

[5] V. Mathot, M. Pyda, T. Pijpers, G. Vanden Poel, S. Van Herwaarden, F. van Herwaarden, and A. Leenaers, The Flash DSC 1 , a power compensation twin-type , chip-based fast scanning calorimeter ( FSC ): First findings on polymers, Thermochimica Acta, vol. 522, no. 1–2, p.36–45, (2011).

DOI: 10.1016/j.tca.2011.02.031

[6] N. Boyard, M. Vayer, C. Sinturel, R. Erre, and D. Delaunay, Analysis and modeling of PVTX diagram of an unsaturated polyester resin, thermoplastic additive, and mineral fillers blend, J. Appl. Plym. sci, vol. 88, p.1258–1267, (2003).

DOI: 10.1002/app.11830

[7] M. Avrami, Kinetic of phase change I, chemical physics, vol. 7, (1939).

[8] M. Avrami, Kinetic of phase change II, chemical physics, vol. 8, (1940).

[9] M. Avrami, Kinetics of Phase Change III: Granulation, Phase Change, and Microstructure., Medical physics, vol. 9, p.177–184, (1941).

DOI: 10.1063/1.1750872

[10] K. Nakamura, Some aspect of nonisothermal crystallization of polymers. I. Relationship between crystallization temperature, crystallinity and cooling conditions, Journal of applied Polymer Science, vol. 16, p.1077–1091, (1972).

DOI: 10.1002/app.1972.070160503

[11] K. Nakamura, Some aspect of nonisothermal crystallization of polymers. II. Consideration of the isokinetic condition, Journal of applied science, vol. 17, p.1031–10411973, (1973).

DOI: 10.1002/app.1973.070170404

[12] P. Le-Bot, Comportement thermique des semi-cristallins injectes Application à la prediction des retraits, (1998).