Tool design [2-9]

• size, complexity and dimensional tolerances
• surface finish
• thermal expansion, conductivity etc
• holes, bosses and ribs
• inserts and fasteners
• re-entrants/multi-part moulds
• number of components to be produced
• durability, ease of modification and repairability

Tool materials

• CNC steel
• CNC aluminium
• monolithic graphite
• carbon foam
• syntactic foam
• electroform nickel (EFN)
• prepreg carbon fibre composite
• wet lay-up glass reinforced plastics
   
• backing structures

Novel concepts

• MIT^TM: multiple insert tooling (Magnum Venus Plastech)
• PCT: porous cavity tooling (BAE Systems/EPSRC FLAVIIR project)
• RTC: reconfigurable tooling concept (BAE Systems/EPSRC FLAVIIR project)
• VCT: variable cavity tooling (BAE Systems/EPSRC FLAVIIR project)

Decision matrix [9]

• Nick Tiffin's Tooling Selection matrix    Download 20KB .xls file
• Blank Tooling Selection Matrix spreadsheet Download 20KB .xls file

Tracking [10]

• barcodes or RFID inserts may be attached to mould tools to permit integration, e.g. with resin delivery systems, and automation.

Clamping

• bolts
• hydraulics
• vacuum

Heating [11]

• fluid in pipes

Table 1: Heating (and cooling) by fluid circulation
(adapted from Rzgar Abdalrahman's interpretation [12] of Marsh [13])

• embedded electrical heaters [14, 15]
• ovens and autoclaves
• microwave heating [16-20] may require microwave transparent mould tools, e.g. alumina (Mu-Tool), composites, glass ceramics or PTFE.

Cooling

• fluid in pipes

Lost cores

• rubber/elastomers [21-23].
• inflatable mandrels [21].
• low melting point alloys [24-26].
• shape memory polymers (18 minute Smart Tooling video)
• candle or paraffin wax (melting points typically 50-90ºC) [27].
• soluble salts or plaster (subsequently washed or machined out) [28].
• Plastech SmartCore (proprietary particles enclosed in a bladder within the mould tool.  Vacuum in the bladder holds shape while leaving resin flow channels for LCM at the surfaces.  After injection, the SmartCore is pressurised to consolidate the preformed laminate), then when pressure is released the particles can be extracted from the core of the moulding) [29-31].

Ancillary materials

• mould release (coatings and films)
• bagging films
• sustainable reusable membranes [32, 33]
• breather and bleeder cloths
• flow media
• tacky tape - edge dams - breach units
• pressure intensifiers
• preforming supports

Surface finish

The surface finish on a component when taken from the mould will never be better than the surface of the mould tool from which it has been taken.  Further, it is possible that resin shrinkage during the cure of thermosetting matrix composites will reveal the topology of the reinforcement fabric - this is known as "print-through". The automotive industry dedicates considerable effort to producing vehicles which have a high gloss, consistent colour finish with minimal defects where the surface reflects a grid under controlled lighting conditions without significant distortion.  This is generally referred to as "Class A" finish, but there is no rigorous definition for this parameter and hence each potential customer may have different specifications.  Wood [34] has recently considered these requirements.  Key parameters are bond-line read-through, distinctness of image (DOI), fibre print-through, orange peel, pinholes and texture.  A variety of instruments are available to "measure" the finish including the Ashland Laser Surface Analyzer (ALSA, which superseded the Laser Optical Reflected Image Analyzer (LORIA)) and the BYG-Gardner Wavescan DOI, ISRA Vision CPV (Car Paint Vision), Micro-Epsilon reflectControl and Visuol Ondulo deflectometry technology.  Further, the use of fractal dimension [35] or wavelet texture analysis [36] have been considered.

References:

1. N Keen, R Bland and S Job, Mould Tooling for fibre-reinforced polymer composites, Composites UK/National Composites Centre, 13 July 2023.
2. G J Gibbons, J J Segui-Garza, R G Hansell , Low-cost resin infusion mould tooling for carbon fibre composites manufacture [FLAVIIR project], Journal Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2010, 224(4), 511-518.
3. MS Anghelescu and AK Alam, Carbon foam tooling for aerospace composites manufacturing, SAMPE Journal, January/February 2008, 44(1), 6-13.
4. DJ Merriman and R Lucas, Carbon foam tooling: self-heating concept, evaluation and demonstration, SAMPE Journal, Nov/Dec 2006, 42(6), 42-49.
5. JJ Morena, Mold fabrications, in International Encyclopædia of Composites, VCH Publishers, New York, 1990, volume 3, pp 394-420.  PU CSH Library
6. JJ Morena, Advanced composite mold making, Van Nostrand Reinhold, New York, c1988. ISBN 0-442-26414-3.  PU CSH Library.
7. John Murphy, Moulds and mould design, Chapter 3 in John Murphy, Reinforced Plastics Handbook, Elsevier Advanced Technology, Oxford, 1994.  ISBN 1-85617-217-1.  PU CSH Library.
8. Chris Ridgard, New moulding methods cut component costs, Advanced Composites Engineering, September 1986, 1(1), 16-17. Good diagram of key stages in making mould tools.
9. Nicholas Tiffin, Choosing better tooling, Advanced Composites Engineering (supplement to Engineering), Autumn 1988, 3(3), 18-19.
10. H Mason, Streamlining aerospace cpomposites operatios with RFID tracking, CompositesWorld, October 2024, 10(10), 30-36.   
11. MW Arney, S Grove, I Progoulakis, T Searle, D Short, J Spooner and J Summerscales, Integrally-heated tooling for the manufacture of fibre-reinforced composites, Composites Processing 2004, Composites Processing Association, Bromsgrove, 23 April 2004.  MooDLE
12. R Abdalrahman, Numerical studies of integrally-heated tooling, Plymouth University Engineering Research Seminar, Wednesday 26 November 2014.
13. G Marsh, Mould tool heating – the oven-free alternative, Reinforced Plastics, December 2003, 47(11), 38–41.
14. J Lee, IY Stein, SS Kessler and BL Wardle, Aligned carbon nanotube film enables thermally induced state transformations in layered polymeric materials, ACS Applied Materials & Interfaces, 2015, 7(16), 8900–8905.
15. G Gardiner, Heated Composites, CompositesWorld, 13 May 2015.
16. J Jacob, LHL Chia and FYC Boey, Thermal and non-thermal interaction of microwave radiation with materials, Journal of Materials Science, 1 November 1995, 30(21), 5321-5327.
17. MS Johnson, The application of microwave preheating in Resin Transfer Moulding, PhD thesis, University of Nottingham, July 1995.
18. ET Thostenson and T-W Chou, Microwave processing: fundamentals and applications, Composites Part A: Applied Science and Manufacturing, 1999, A30(9), 1055-1071.
19. T Wang and J Liu, A review of microwave curing of polymeric materials, Journal of Electronics Manufacturing, 2000, 10(3), 181-189.
20. Y Li, N Li and J Gao, Tooling design and microwave curing technologies for the manufacturing of fiber-reinforced polymer composites in aerospace applications, International Journal of Advanced Manufacturing Technology, January 2014, 70(1-4), 591-606.
21. G Musch and W Bishop, Tooling with reinforced elastomeric materials, Composites Manufacturing, 1992, 3(2), 101-111.  Notable for intensifiers and inflatable mandrels.
22. Specialized Elastomeric Tooling^TM, accessed at 09:26 on 02 October 2015.
23. Specialized Elastomeric Tooling (3'11" Vistex Composites on YouTube)
24. RC Haines, Volume production with carbon fibre reinforced thermoplastics, Plastics and Rubber Processing and Applications, 1985, 5(1), 79-84.
25. K Fischer, Materials for the fusible-core technique and half-shell technique, publication and date not given (alternative URL).
26. JH Schut, Close-up on 'lost-core': a puzzle with many pieces (injection molding technique), Plastics Technology, 01 December 1991.
27. M Brierley, M Prest and C James, Composite coil over spring, BEng MEC MATS320 assignment, University of Plymouth, April 2014 (N/A outside PU).
28. R Blackburn, The manufacture and testing of perforated composite acoustic panels, MPhil thesis, University of Plymouth, 2009.
29. Anon., RTM hollow mouldings: from fiction to fact, Reinforced Plastics, April 1994, 38(4), 34-37.
30. Anon., Hollow RTM becomes a booming business, Reinforced Plastics, January 1995, 39(1), 20-23.
31. T Kruckenberg and R Paton (editors), Resin Transfer Moulding for Aerospace Structures, Kluwer Academic Publishers, Dordrecht NL, 1998. ISBN 0-412-73150-9.  Google Books extract.
32. Alan R Harper and John Summerscales, Industrialization of the composite infusion moulding process, Composites Sustainability Report 2022 (JEC Group), 4 November 2022, 141-145.
33. Alice Harper/Mike Richardson, A smart and sustainable approach, Composites in Manufacturing (CiM), September/October 2024, 8-9. Online 27 August 2024.
34. K Wood, Taking subjectivity out of Class A surface evaluation, Composites Technology, August 2008, 14(4), 67-70.
35. Q Labrosse, CP Hoppins and J Summerscales, Objective assessment of the surface quality of coated surfaces, Insight, January 2011, 53(1), 16-20.
36. S Palmer, W Hall and J Summerscales, Ranking of fibre-reinforced composite plate surface finish quality by wavelet texture analysis, Insight, June 2016, 58(6), 318-323.

Further information:

• GJ Gibbons, RG Hansell, G Thacker and G Arnett, State of the art in low-cost, rapid composite forming tooling technologies, Journal of Advanced Materials (Covina), 2009, 41(2), 5-19.
• PD Christiou, High temperature resistant tools and master models: seamless molding paste (SMP) technology, SAMPE Journal, Nov/Dec 2006, 42(6), 7-13.
• SW Beckwith and LC Dorworth, Tooling materials: typical properties and characteristics, SAMPE Journal, November/December 2006, 42(6), 53.
• B Boursier, R Callis and J Porter, New composite tooling: material and concept for aerospace composite structures, SAMPE Journal, Nov/Dec 2006, 42(6), 60-66.
• LL Clements, JL Crowley and T Jacobsen, Innovative uses of reconfigurable tooling for rapid, low-cost composite manufacturing, repair and replication, SAMPE Journal, November/December 2006, 42(6), 70-75.