A Study on the Resin Flow through Fibrous Preforms in the Resin Transfer Molding Process

수지이동 성형공정에서 섬유직조망내의 수지유동에 관한 연구

  • 김성우 (경기대학교 화학공학과) ;
  • 이종훈 (서울대학교 응용화학부) ;
  • 이미혜 (부산/울산 지방중소기업청) ;
  • 남재도 (성균관대학교 고분자 공학과) ;
  • 이기준 (서울대학교 응용화학부)
  • Published : 1999.04.01

Abstract

Resin transfer molding(RTM) as a composite manufacturing process is currently of great interest in the aerospace industry requiring high performance composite parts. In this study, an analysis of mold filling in the RTM process was carried out by numerical simulation using finite element/control volume technique. Experimental work for the visualization of resin flow through fibrous preform was also conducted in order to quantitatively measure the permeabilities of the fiber mats and to evaluate the validity of the developed numerical code. The different types of fiber mats and silicon oils were selected as reinforcements and resin materials, respectively. The effects of fibrous preform structure, mold geometry, and preplaced insert on the flow front patterns during mold filling were examined by integrating the model predictions and experimental results. The flow fronts predicted by numerical simulation were in good agreement with those observed experimentally. However, according to the regions of the mold, some deviations between predicted and observed flow fronts could be found because of non-uniform fiber volume fraction. Weldline locations for the resin flow through round insert preplaced in the mold could be qualitatively deduced based on predicted flow fronts.

고분자 복합재료 제조공정인 수지이동성형(RTM) 공정은 최근 들어서 고성능 재료를 필요로 하는 항공산업분야에서 관심의 대상이 되고 있다. 본 연구에서는 유한요소/관할부피 기법을 도입한 수치모사를 통해서 수지이동 성형공정에서의 금형충전단계를 해석하였다. 섬유직조망의 투과계수를 정량적으로 측정하고, 또한 수치모사에 이용된 프로그램을 검증하기 위하여 유동가시화 실험을 수행하였다. 실험에 사용된 강화섬유와 수지물질로는 여러 가지 형태의 섬유직조망과 실리콘 기름을 선택하였다. 수치모사와 유동가시화 실험을 병행함으로써 섬유직조망의 구조, 금형의 구조, 금형삽입체가 금형충전단계에서의 수지 유동선단의 형태에 미치는 영향을 살펴보았다. 모델링에 의해 예측된 유동선단은유동가시화 실험을 통해 관찰된 결과와 잘 일치한 것으로 나타났으나, 금형내 불균일한 섬유부피분율로 인해 섬유조직망의 투과계수가 전 영역에서 일정한 값을 가지지 못하기 때문에 약간의 차이를 보여주었다. 원형의 구조물이 금형내에 삽입되어 있는 경우, 월드라인의 위치를 예측된 유동선단으로부터 정성적으로 추정할 수 있었다.

Keywords

References

  1. Textile Res. J. v.57 In-Plane Flow of Fluids in Fabrics : Structure/Flow Characterization Adams, K. L.;Rebenfeld, L.
  2. J. Compos. Mater. v.21 Consolidation Experiments for Laminate Composites Gutowski, T. G.;Cai, Z.;Bauer, S.;Boucher, D.;Kingery, J.;Winwman, S.
  3. Polym. Eng. Sci. v.14 Liquid Flow through Aligned Fiber Beds Williams, J. C.;Morris, C. E. M.;Ennis, B. C.
  4. Int. J. Multiphase Flow v.14 Radial Penetration of a Viscous Liquid into a Planar Anisotropic Porous Medium Adams, K. L.;Russel, W. B.;Rebenfeld, L.
  5. Polym. Compos. v.12 Simultaneous Measurements of Permeability and Capillary Pressure of Thermosetting Matrices in Woven Fabric Reinforcements Ahn, K. L.;Seferis, J. C.
  6. J. Compos. Mater. v.24 A Unified Approach to Modeling Resin Flow during Composite Processing Dave, R.
  7. Proceedings. 2nd Technical Conference American Society for Composites Experimental and Numerical Analysis of Resin Impregnation During the Manufacturing of Composite Materials Coulter, J. P.;Smith, B. F.;G ceri, S. I.
  8. Polym. compos v.11 A finite Element/Control Volume Approach to Mold Filling in Anisotropic Porous Media Bruschke, M. V.;Advani, S. G.
  9. Polym. Eng. Sci. v.31 Modeling of the Impregnation Process During Resin Transfer Molding Chan, A. W.;Hwang, S. T.
  10. Journal of the Korean Society for Composite Materials v.11 Studies on the Mold Filling in the Resin Transfer Molding Process: Ⅰ. Numerical Simulation Choi, M. A.;Lee, M. H.;Lee, K. J.;Lee, S. J.
  11. Polym. Compos. v.12 Permeability Characteristics of Multilayer Fiber Rein-forcements. Part Ⅰ:Experimental Observations Adams, K. L.;Rebenfeld, L.
  12. Polym. Compos. v.12 Perme-ability Characteristics of Multilayer Fiber Rein-forcements. PartⅡ: Theoretical Model Adams, K. L.;Rebenfeld, L.
  13. Ph.D Thesis, Cornell University Dynamic simulation with Graphics for the Injection Molding of Three-Dimensional Thin Parts Wang, V. W.
  14. Polym. Eng. Sci. v.14 Flow Analysis Network(FAN) - AMethod for Solving Flow Problems in Polymer Processing Tadmor, Z.;Broyer, E.;Gutfinger, C.
  15. Trans. Soc. Rheol. v.19 A Theoretical Model for the CavityFilling Process in Injection Molding Broyer, E.;Gutfinger, C.;Tadmor, Z.