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Abstract

An experimental and modeling study is conducted on the vacuum consolidation of commingled glass/thermoplastic composites as part of a larger project on manufacturing large monolithic structures from these precursors. Two polyethylene terephthalate (PET) matrices are employed: semicrystalline PET and an amorphous PET copolymer. Samples of commingled fabric are processed into consolidated composites by means of both a convective oven, as will be used in practice, and a small-scale experimental characterization rig, designed to measure consolidation accurately. The samples are then cooled to room temperature. In this article, the thermal and consolidation characterization of these fabrics is reported. Thermally induced consolidation is observed to occur in two stages: a low temperature solid state de-bulking near to T_g, followed by full melt impregnation at a higher temperature. Both stages are modeled separately using an empirical model based on the Kamal equation. The measured consolidation versus time profiles suggest a rapid impregnation and wetting of the fibers, occurring near to the melting point of the semicrystalline polymer. The PET melting endotherm and crystallization exotherm have little effect on the observed thermal profiles, suggesting that these effects can possibly be neglected when modeling the process.

Keywords

commingled preforms PET consolidation thermoplastic processing

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References

Hamada, H. , Maekawa, Z. , Fujita, A. , Matsuda, M. and Hokudoh, T. (1994). Impregnation and Mechanical Properties of Carbon Fiber Reinforced Thermoplastic Composites with Commingled Spun Yarn , 39th International SAMPE Symposium, Anaheim CA, USA, April 11–14, pp. 1507–1520 .

Shonaike, G.O. , Matsuda, M. , Hamada, H. , Maekawa, Z. and Matsuo, T. (1994). The Effect on Impregnation Technique on Bending Properties of Glass Fiber Reinforced Polyethylene Terephthalate Composites , Composite Interfaces, 2(2): 157–170 .

Lystrup, A. and Andersen, T.L. (1998). Autoclave Consolidation of Fiber Composites with a High Temperature Thermoplastic Matrix , Journal of Materials Processing Technology, 77(1–3): 80–85 .

McDonnell, P. , Mcgarvey, K.P. , Rochford, L. and Bradaigh, C.M.O (2001). Processing and Mechanical Properties Evaluation of a Commingled Carbon-fiber/PA-12 Composites , Composite Part A, 32(7): 925–932 .

Bernhardsson, J. and Shishoo, R. (2000). Effect of Processing Parameters on Consolidation Quality of GF/PP Commingled Yarn Based Composites , Journal of Thermoplastic Composite Materials, 13(4): 292–313 .

Wakeman, M.D. , Cain, T.A. , Rudd, C.D. , Brooks, R. and Long, A.C. (1998). Compression Molding of Glass and Polypropylene Composites for Optimized Macro and Micro Mechanical Properties–I Commingled Glass and Polypropylene , Composites Science and Technology, 58(12): 1879–1898 .

van West, B.P. , Pipes, R.B. and Advani, S.G. (1991). The Consolidation of Commingled Thermoplastic Fabrics , Polymer Composites, 12(6): 417–427 .

Ye, L. , Friedrich, K. and Kastel, J. (1995). Consolidation of GF/PP Commingled Yarn Composites , Applied Composite Materials, 1(6): 415–429 .

Ye, L. , Friedrich, K. , Kastel, J. and Mai, Y.-W. (1995). Consolidation of Unidirectional CF/PEEK Composites from Commingled Yarn Prepreg , Composites Science and Technology, 54(4): 349–358 .

10.

Klinkmuller, V. , Um, M.-K. , Steffens, Friedrich, K. and Kim, B.S. (1995). A New Model for Impregnation Mechanism in Different GF/PP Commingled Yarns , Applied Composite Materials, 1(5): 351–371 .

11.

Cain, T.A. , Wakeman, M.D. , Brooks, R. , Long, A.C. and Rudd, C.D. (1997). Towards an Integrated Processing Model for a Commingled Thermoplastic Composite , ICCM-11, V: V-366-V-366, V-375-V-375 .

12.

Bernet, N. , Michaud, V. , Bourban, P.E. and Manson, J.-A. E. (1999). An Impregnation Model for the Consolidation of Thermoplastic Composites made from Commingled Yarns , Journal of Composite Materials, 33(8): 751–772 .

13.

Gibson, A.G. , Ijaz, M. , Dodds, N. , Sharpe, A. and Knudsen, H. (2003). Vacuum Bag Molding of Large Thermoplastic Parts in Commingled Glass/PET , Plastics, Rubbers and Composites, 32(4): 160–166 .

14.

Ijaz, M. (2005). Vacuum Consolidation of Commingled Thermoplastic Matrix Composites, PhD Thesis, University of Newcastle upon Tyne, UK.

15.

Kamal, M.R. and Sourour, S. (1973). Kinetics and Thermal Characterization of Thermoset Cure , Polymer Engineering & Science, 13(1): 59–64 .

16.

van Wyck, C.M. (1946). Note on the Compressibility of Wool , Journal of Textile Institute, 37: T285–T292 .

17.

Toll, S. (1998). Packing Mechanics of Fiber Reinforcements , Polymer Engineering and Science, 38(8): 1337–1350 .