Title: INVESTIGATING THE EFFECTS OF RELEASE COATING ON TOOL-PART INTERACTION AND PROCESS-INDUCED DEFORMATIONS IN COMPOSITES MANUFACTURING
Authors: Caleb Schoenholz, Navid Zobeiry
Abstract: Although modern-era composites manufacturers possess advanced processing capabilities, several production challenges remain prevalent. One such challenge is mitigating residual stresses and process-induced deformations (PIDs) in composite parts while maintaining a cost-efficient manufacturing workflow. For example, applications and touch-ups of release coatings are labor-intensive process steps and generate high recurring production costs, yet are critical to minimize tool-part interaction and PIDs. One intuitive approach to reduce the frequency of disruptive tool coatings or cleanings may be to apply greater quantities of fresh release coats to a tool surface before completing successive cure cycles. However, the consequential effects of such an approach on tool-part interaction and PIDs are currently undetermined and neglected. This paper first investigates the relationship between release coating quantity and tool surface physicochemical properties using laser microscopy and contact angle goniometry. Then, a novel test fixture installed in a Dynamic Mechanical Analyzer (DMA) is presented and used to quantify tool-part stress developments as a function of fresh release coating quantity applied on a tool surface. Lastly, findings from tool surface characterization and DMA testing were validated by curing long symmetric laminates on tools treated with different release coating quantities in an autoclave and measuring warpages. The results in this paper can be used to expand the current understanding of tool-part interaction and improve the efficiency of tool preparation in composites manufacturing.
References:  Zobeiry N, Poursartip A. The origins of residual stress and its evaluation in composite materials. Structural Integrity and Durability of Advanced Composites: Innovative Modelling Methods and Intelligent Design 2015:43–72. https://doi.org/10.1016/B978-0-08-100137-0.00003-1.  Zobeiry N, Forghani A, Li C, Gordnian K, Thorpe R, Vaziri R, et al. Multiscale characterization and representation of composite materials during processing. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2016;374. https://doi.org/10.1098/RSTA.2015.0278.  Fernlund G, Mobuchon C, Zobeiry N. 2.3 Autoclave Processing. Elsevier; 2018. https://doi.org/10.1016/B978-0-12-803581-8.09899-4.  Li C, Zobeiry N, Keil K, Chatterjee S, Poursartip A. Advances in the Characterization of Residual Stress in Composite Structures. SAMPE 2014 - SEATTLE, 2014.  Twigg G, Poursartip A, Fernlund G. Tool–part interaction in composites processing. Part I: experimental investigation and analytical model. Compos Part A Appl Sci Manuf 2004;35:121–33. https://doi.org/10.1016/S1359-835X(03)00131-3.  Twigg G, Poursartip A, Fernlund G. Tool–part interaction in composites processing. Part II: numerical modelling. Compos Part A Appl Sci Manuf 2004;35:135–41. https://doi.org/10.1016/S1359-835X(03)00132-5.  Potter KD, Campbell M, Langer C, Wisnom MR. The generation of geometrical deformations due to tool/part interaction in the manufacture of composite components. Compos Part A Appl Sci Manuf 2005;36:301–8. https://doi.org/10.1016/J.COMPOSITESA.2004.06.002.  Twigg G, Poursartip A, Fernlund G. An experimental method for quantifying tool–part shear interaction during composites processing. Compos Sci Technol 2003;63:1985–2002. https://doi.org/10.1016/S0266-3538(03)00172-6.  Ersoy N, Potter K, Wisnom MR, Clegg MJ. An experimental method to study the frictional processes during composites manufacturing. Compos Part A Appl Sci Manuf 2005;36:1536–44. https://doi.org/10.1016/J.COMPOSITESA.2005.02.010.  Zappino E, Zobeiry N, Petrolo M, Vaziri R, Carrera E, Poursartip A. Analysis of process-induced deformations and residual stresses in curved composite parts considering transverse shear stress and thickness stretching. Compos Struct 2020;241:112057. https://doi.org/10.1016/J.COMPSTRUCT.2020.112057.  Kaushik V, Raghavan J. Experimental study of tool–part interaction during autoclave processing of thermoset polymer composite structures. Compos Part A Appl Sci Manuf 2010;41:1210–8. https://doi.org/10.1016/J.COMPOSITESA.2010.05.003.  Albert C, Fernlund G. Spring-in and warpage of angled composite laminates. Compos Sci Technol 2002;62:1895–912. https://doi.org/10.1016/S0266-3538(02)00105-7.  Schoenholz C, Slade D, Zappino E, Petrolo M, Zobeiry N. Representation, Characterization and Simulation of Tool-Part Interaction and Its Effects on Process-Induced Deformations in Composites. Proceedings of the American Society for Composites—Thirty-Sixth Technical Conference on Composite Materials, vol. 0, DEStech Publications; 2021, p. 1204–16. https://doi.org/10.12783/ASC36/35832.  Schoenholz C, Moomaw J, Zobeiry N. Investigating the Effects of Cure Pressure on Tool-Part Interaction and Process-Induced Deformations in Composites. PROCEEDINGS OF THE AMERICAN SOCIETY FOR COMPOSITES-THIRTY-SEVENTH TECHNICAL CONFERENCE, vol. 0, DEStech Publications Inc.; 2022. https://doi.org/10.12783/ASC37/36383.  Stefaniak D, Kappel E, Spröwitz T, Hühne C. Experimental identification of process parameters inducing warpage of autoclave-processed CFRP parts. Compos Part A Appl Sci Manuf 2012;43:1081–91. https://doi.org/10.1016/J.COMPOSITESA.2012.02.013.  Schoenholz C, Li S, Bainbridge K, Huynh V, Gray A, Chen X, et al. An Automated Evaluation Method of Tool Surface Condition in Composites Manufacturing Using Machine Learning and Sparse Sensing. SAMPE Journal: Tooling Technology Advancement/Applications 2023;59:10–23.  Bainbridge K, Schoenholz C, Zobeiry N. Investigating the aging of release coating in aerospace composites manufacturing. University of Washington Undergraduate Research in MSE 2021;2:7–11. https://doi.org/10.6069/ssywg443.  Schoenholz C, Li S, Bainbridge K, Huynh V, Gray A, Chen X, et al. A Machine Learning-Based Portable Inspection Method for Evaluation of Tool Surface Condition and Release Coating in Composites Manufacturing. SAMPE 2022 2022. https://doi.org/10.33599/NASAMPE/S.22.0740.  Blass D, Dilger K. CFRP-Part Quality as the Result of Release Agent Application – Demoldability, Contamination Level, Bondability. Procedia CIRP, vol. 66, Elsevier; 2017, p. 33–8. https://doi.org/10.1016/J.PROCIR.2017.03.219.  Critchlow GW, Litchfield RE, Sutherland I, Grandy DB, Wilson S. A review and comparative study of release coatings for optimised abhesion in resin transfer moulding applications. Int J Adhes Adhes 2006;26:577–99. https://doi.org/10.1016/J.IJADHADH.2005.09.003.  LOCTITE FREKOTE 710NC - Release Agent - Henkel Adhesives 2015. https://www.pccomposites.com/product/frekote-710nc/ (accessed September 1, 2022).  Markatos DN, Tserpes KI, Rau E, Markus S, Ehrhart B, Pantelakis S. The effects of manufacturing-induced and in-service related bonding quality reduction on the mode-I fracture toughness of composite bonded joints for aeronautical use. Compos B Eng 2013;45:556–64. https://doi.org/10.1016/J.COMPOSITESB.2012.05.052.  3900 Prepreg System | Toray Composite Materials America, Inc. 2020. https://www.toraycma.com/3900-prepreg-system/ (accessed September 1, 2022).  Brosius D. Boeing 787 Update. CompositesWorld 2007. https://www.compositesworld.com/articles/boeing-787-update (accessed November 13, 2022).  Steel Feeler Gage 1/2" x 12" Blades - Precision Brand n.d. https://www.precisionbrand.com/product-category/1-2-x-12-blades-steel-feeler-gage/ (accessed December 28, 2022).  ISO - ISO 1302:2002 - Geometrical Product Specifications (GPS) — Indication of surface texture in technical product documentation 2002. https://www.iso.org/standard/28089.html (accessed September 28, 2022).  LOCTITE FREKOTE PMC - solvent-based post mould cleaner - Henkel Adhesives n.d. https://www.henkel-adhesives.com/us/en/product/mold-release-cleaners/loctite_frekote_pmc.html (accessed December 28, 2022).  Owens DK, Wendt RC. Estimation of the surface free energy of polymers. J Appl Polym Sci 1969;13:1741–7. https://doi.org/10.1002/APP.1969.070130815.  FlexiForce HT201 Sensor | Tekscan n.d. https://www.tekscan.com/products-solutions/force-sensors/ht201 (accessed December 28, 2022).  de Gennes P-G, Brochard-Wyart F, Quéré D. Capillarity and Wetting Phenomena. Springer New York; 2004. https://doi.org/10.1007/978-0-387-21656-0.  Wenzel RN. Surface roughness and contact angle. Journal of Physical & Colloid Chemistry 1949;53:1466–7. https://doi.org/10.1021/J150474A015/ASSET/J150474A015.FP.PNG_V03.  Chen C, Poursartip A, Fernlund G. Cure-dependent microstructures and their effect on elastic properties of interlayer toughened thermoset composites. Compos Sci Technol 2020;197:108241. https://doi.org/10.1016/J.COMPSCITECH.2020.108241.  Persson BNJ. On the theory of rubber friction. Surf Sci 1998;401:445–54. https://doi.org/10.1016/S0039-6028(98)00051-X.  Otsuki M, Matsukawa H. Systematic Breakdown of Amontons’ Law of Friction for an Elastic Object Locally Obeying Amontons’ Law. Scientific Reports 2013 3:1 2013;3:1–6. https://doi.org/10.1038/srep01586.
Conference: SAMPE 2023
Publication Date: 2023/04/17
Price: $32.00Get This Paper