Iranian Journal of Polymer Science and Technology

Iranian Journal of Polymer Science and Technology

An Evaluation and Comparison of Mechanical Properties of Phenolic-Glass Fabric Composites Prepared by Vacuum Bag-Only and Autoclave Processes

Document Type : Research Paper

Authors
Faezeh Rafieyan
Amir Masood Rezadoust
Alireza sabet
Iran Polymer and Petrochemical Institute, Additive Manufacturing Laboratory, P.O. Box 14975-112, Tehran, Iran
10.22063/jipst.2023.3393.2234
Abstract
Hypothesis: The curing process for phenolic resin composites is always carried out under press or autoclave pressure, as water by-products are released during curing process. As a result, when phenolic composite parts are formed using the vacuum bag-only method, the costs of the mold and challenges of the pressure vessels would be eliminated, and a significant step is taken in easier manufacture of these parts.
Methods: For the purpose of comparing the two methods, phenolic laminates were prepared using 3 bar pressure autoclave and vacuum bag-only methods. In order to investigate the effects of thickness on different properties, the samples were subjected to bending tests, short beam strength tests, void percentage tests, and fractured surface morphology tests.
Findings: As the sample’s thickness increases, the flexural modulus increases while the flexural strength and short beam strength decrease. Furthermore, the modulus, bending strength, and strength of the short beam in the autoclave sample have increased by 27%, 17%, and 17%, respectively, compared to the vacuum bag-only sample. Morphological studies also showed that more void content was formed in the vacuum bag samples and the resin-fiber interaction was reduced compared to the autoclaved samples. A decrease in the bonding between resin and fibers and in the penetration of resin between fiber strands has also been observed with increasing thickness. Samples with a thickness of 1 mm had a void content of 3.5 ± 1% and in samples with a thickness of 9 mm, it was 15% ± 1%.
Keywords
composites process
phenolic composites
vacuum bag-only
autoclave
mechanical properties
  1. Ekuase O.A., Anjum N., Eze V.O., and Okoli O.I., A Review on the Out-of-Autoclave Process for Composite Manufacturing, Compos. Sci., 6.6, 172, 2022.
  2. Babukiran B.V. and Harish G., Influence of Resin and Thickness of Laminate on Flexural Properties of Laminated Composites, J. Innov. Sci. Eng. Technol., 3, 279–287, 2014.
  3. Tracy J.J and Pardoen G.C., Effect of Delamination on the Flexural Stiffness of Composite Laminates, Thin-Walled Struct., 6, 371–383, 1988.
  4. Kratz J., Hsiao K., Fernlund G., and Hubert P., Thermal Models for MTM45-1 and Cycom 5320 Out-of-Autoclave Prepreg Resins, Compos. Mater., 47, 341-352, 2013.
  5. Agius S.L. and Fox B.L., Rapidly Cured Out-of-Autoclave Laminates: Understanding and Controlling the Effect of Voids on Laminate Fracture Toughness, A: Appl. Sci., 73, 186-194, 2015.
  6. Kheirkhah Barzoki P., Latifi M., and Rezadoust A.M., The Outstanding Effect of Nanomat Geometry on the Interlaminar Fracture Toughness Behavior Out of Autoclave Made Glass/Phenolic Composites under Mode-I Loading,  Fract. Mech., 205, 108-119,2019.
  7. Kim J.W., Kim H.G., and Lee D.G., Compaction of Thick Carbon/Phenolic Fabric Composites with Autoclave Method, Struct., 66, 467–477, 2004.
  8. Tavares S.S., Michaud V., and Månson J.A.E., Assessment of Semi-impregnated Fabrics in Honeycomb Sandwich structures, A: Appl. Sci., 41, 8-15, 2010.
  9. Centea T. and Hubert P., Measuring the Impregnation of an Out-of-Autoclave Prepreg by Micro-CT, Sci. Technol., 71, 593-599, 2011.
  10. de Almeida S.F.M. and dos Santos Nogueira Neto Z., Effect of Void Content on the Strength of Composite Laminates, Struct., 28, 139-148, 1994.
  11. Hyun D.K., Kim D., Hwan Shin J., Lee B.E., Shin D.H., and Hoon Kim J., Cure Cycle Modification for Efficient Vacuum Bag Only Prepreg Process, Compos. Mater., 55, 1039-1051, 2021.
  12. Mujahid Y., Sallih N., and Abdullah M.Z., A Comparison of Single-Vacuum-Bag and Double-Vacuum-Bag Methods for Manufacturing High-Quality Laminated Composites, Ind. Manuf. Eng., 457-467, 2020.
  13. Mujahid Y., Sallih N., Mustapha M., Abdullah M.Z., and Mustapha F., Effects of Processing Parameters for Vacuum-Bagging-Only Method on Shape Conformation of Laminated Composites, Processes, 8, 1147, 2020.
  14. Edwards W.T., Martinez P., and Nutt S.R., Process Robustness and Defect Formation Mechanisms in Unidirectional Semipreg, Manuf.: Polym. Compos. Sci., 6.4, 198-211, 2020.
  15. Maguire J.M., Nayak K., and Brádaigh C.M.Ó., Novel Epoxy Powder for Manufacturing Thick-Section Composite Parts under Vacuum-Bag-only Conditions. Part II: Experimental Validation and Process Investigations, A: Appl. Sci., 136, 105970, 2020.
  16. Cender T.A., Gangloff J.J.J., Simacek P., and Advani S.G., Void Reduction During Out-of-Autoclave Thermoset Prepreg Composite Processing, SAMPE Int. Symp., 2013.
  17. Anandan S., Dhaliwal G.S., Samaranayake V.A., Chandrashekhara K., Berkel T.R., and Pfitzinger D., Influence of Cure Conditions on Out-of-Autoclave Bismaleimide Composite Laminates, Appl. Polym. Sci., 133, 2016.
  18. Centea T. and Hubert P., Out-of-Autoclave Prepreg Consolidation under Deficient Pressure Conditions, Compos. Mater., 48, 2033-2045, 2014.
  19. Nettles A.T. and Jackson J.R., Compression after Impact Strength of Out-of-Autoclave Processed Laminates, Reinf. Plast. Compos., 32, 1887-1894, 2013.
  20. Kay J. and Fernlund G., Processing Conditions and Voids in Out of Autoclave Prepregs, Proceedings of the SAMPE 2012 Conference of the Society for the Advancement of Materials and Process Engineering, Baltimore, MD, United States, 21-24, 2012.
  21. Mahmood A.S., Summerscales J., and James M.N., Resin-rich Volumes (RRV) and the Performance of Fibre-Reinforced Composites: A Review,  Compos. Sci., 6, 53, 2022.
  22. Beheshty M.H., Kadkhodaei M.A., and Vafayan M.. The Effect of Co-cure and Counter Cure Methods on the Properties of Phenolic Sandwich Structures, J. Polym. Sci. Technol. (Persian), 18, 157-151, 2005.
  23. Khalaf N., Hanoosh W.S., and Hadad A.I. Thermal, Flexural, and Impact Strength Studies on Phenolic Novolac Resin/Acrylonitrile–Butadine Rubber Blends, Compos. Interfaces, 19, 453-460, 2012.
  24. Rathnakar G. and Shivanand H.K., Effect of Thickness on Flexural Properties of Epoxy Based Glass Fiber Reinforced Laminate, J. Sci. Technol., 2, 409-412, 2012.
  25. Crawford Roy J., Plastics Engineering, 3rd ed., Elsevier, Butterworth-Heinemann, 1998.
  26. Greenhalgh E., Failure Analysis and Fractography of Polymer Composites, Elsevier, 2009.
  27. Khatri S.C. and Koczak M.J., Thick-Section AS4-Graphite/E-Glass/PPS Hybrid Composites: Part II. Flexural Response, Sci. Technol., 56, 473-482, 1996.
  28. Budiansky B. and Fleck N.A., Compressive Failure of Fibre Composites, Mech. Phys. Solids, 41, 183-211, 1993.
  29. Han S. and Chung D.D.L., Increasing the Through-Thickness Thermal Conductivity of Carbon Fiber Polymer-Matrix Composite by Curing Pressure Increase and Filler Incorporation, Sci. Technol., 71, 1944-1952, 2011.
  30. Grellmann W. and Seidler S., Deformation and Fracture Behaviour of Polymers. Berlin, Heidelberg, Springer Berlin Heidelberg, 2001.
  31. Davies P., Sohier L., Cognard J.Y., Bourmaud A., Influence of Adhesive Bond Line Thickness on Joint Strength, J. Adhes., 29, 724-736, 2009.
  32. Chong H.M., Liu S.L., Subramanian A.S., Ng S.P., Tay S.W., Wang S.Q., and Feih S., Out-of-Autoclave Scarf Repair of Interlayer Toughened Carbon Fibre Composites Using Double Vacuum Debulking of Patch, A: Appl. Sci., 107, 224-234, 2018.
  33. Agarwal B.D., Broutman L.J., and Chandrashekhara K., Analysis and Performance of Fiber Composites, John Wiley and Sons, 2006.
  34. American Society for Testing and Materials, Standard Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates, ASTM International, 2006.

 

Iranian Journal of Polymer Science and Technology
Volume 36, Issue 3 - Serial Number 185
September and October 2023
Pages 281-294