1. Resin Infusion under Flexible Tooling (RIFT)
John Summerscales
Advanced Composites Manufacturing Centre
School of Marine Science and Engineering - University of Plymouth
Plymouth, PL4 8AA, United Kingdom

2. Outline of presentation
other manufacturing processes
four variants on resin infusion
advantages and disadvantages
applications using the process
notional cost comparisons
brief summary

3. Manufacturing processes
spray
hand lamination
hot press
Resin Transfer Moulding (RTM)
Resin Infusion under Flexible Tooling (RIFT)
vacuum bagging and autoclave cure
filament winding
pultrusion

4. Manufacturing processes
Resin transfer moulding (RTM)
long-range flow of resin into a dry fibre pack preloaded into a defined mould cavity.
Resin infusion (RIFT)
A range of intermediate techniques
Vacuum bagging and autoclave cure
wet resin or prepreg lamination followed by bagging and cure under pressure

5. Change from hand lay-up ?
Increased consolidation pressure
1 atmosphere = full vacuum = 105 N/m2 (10 tonnes/m2)
Occupational Exposure Levels
Germany/Sweden 20 ppm
France/Spain 50 ppm
United Kingdom 100 ppm
EU harmonisation via SPA recommendation for end 2013
Pollution Prevention and Control Act 1999
styrene has an odour threshold of ppm i.e 630 µg/m3

6. Why resin infusion ? Resin transfer moulding (RTM)
as mouldings increase in size, mould clamping forces become excessive
Vacuum bagging and autoclave cure
premium price for pre-impregnation of reinforcements
long cycle times
capital cost of equipment

7. Resin infusion Muskat patent application, 1945
the fibrous base to be impregnated … preferably in a substantially dry state
drive the resin into the base to impregnate it
one tube being connected to a source of resin and the other to a vacuum pump
complementary moulds appear to be free to move together under vacuum
process introduced to UK by Scott Bader in 1946

8. “Acronym” anarchy ! CIRTM: co-injection RTM
Crystic VI: vacuum infusion (Scott Bader)
DRDF: double RIFT diaphragm forming (University of Warwick)
LRI: liquid resin infusion
MVI modified vacuum infusion (Airbus)
* Quickstep * use of liquids for enhanced heat transfer in infusion
RFI: resin film infusion
RIFT: resin infusion under flexible tooling (ACMC Plymouth)
RIRM: resin injection recirculation moulding
SCRIMP Seeman Composites Resin Infusion Molding Process (TPI)
VAIM: vacuum-assisted injection moulding
VAP vacuum assisted processing (patented by EADS)
VARI: vacuum assisted resin injection system (Lotus Cars)
VARIM: vacuum assisted resin injection moulding
V(A)RTM: vacuum (-assisted) resin transfer moulding
VIM: vacuum infusion moulding.
VIMP: vacuum infusion moulding process
VM/RTM Light: a hybrid RIFT/RTM (Plastech)
VIP: vacuum infusion process

9. Resin infusion
RTM with one tool face replaced by a flexible film or a light splash tool
flow of resin results only from vacuum and gravity effects
mould cavity varies with local pressure
thickness of the part depends on pressure history

10. Resin Infusion under Flexible Tooling (RIFT 1 of 4)
Basic RIFT process:
resin flows in the plane of the fabric between the mould and the bag
slow process due to limited pressure gradient
Only good for
low fibre volume fraction/high loft fabrics
reinforcement with flow enhancement tows
Resin feed
Vacuum
KEY
Reinforcement

11. RIFT 1: slow flow in the process
Special fabrics
Commercial process needs flow-enhancing tows, e.g.
Brochier Injectex
Carbon fabrics from Carr Reinforcements
Glass fabrics experimental programme with Interglas-Technologies

12. Potential advantages 
Process
use most resin systems.
use most forms of reinforcement fabrics.
large structural components can be fabricated.
relatively low tooling costs for high-performance components.
better than wet-laid components with little modification of tooling.
heavy fabrics more easily wetted than by hand lamination.
lower material costs than for prepreg and vacuum bagging.

13. Potential advantages 
Performance
higher fibre volume fraction gives improved mechanical performance.
minimal void content relative to hand lamination.
more uniform microstructure than hand lay-up.
cored structures can be produced in a single flow process.
hand-lamination resin infusion

14. Disadvantages  Process
complex process requires different skills to hand-lamination.
emphasis on preparation, not on the actual moulding process.
sensitive to leaks (air paths) in the mould tool and the bag.
quality control of the resin mixing is "in-house".
slow resin flow through densely packed fibre
uneven flow could result in unimpregnated areas/scrap parts.
not easily implemented for honeycomb core laminates.

15. Disadvantages  Performance only one moulded surface
low resin viscosity means lower thermal and mechanical properties.
thinner components have lower structural moduli
laminate thickness dependent on flow history (next slide)
licensing costs where aspects of the process patented in the USA

16. Fabric compressibility in RIFT
A B C
2.2 mm
2.0 mm
1.8 mm
Time (s)
nine layers of plain weave E-glass/UPE resin
compression by vacuum
lubrication by resin front at A
relaxation as pressure gradient falls
resin inlet closed at C

17. Comparison of HL and RI resins
SP resin systems hand lamination infusion
Ampreg 20 Prime 20
Property Units
Viscosity mPa.s
Tg (50C post-cure) °C
Tensile strength MPa

18. RIFT vacuum forming Known as
DRDF: Double RIFT Diaphragm Forming, or
RIDFT: Resin Infusion between Double Flexible Tooling
dry fabric is placed between two elastomeric membranes;
resin is infused into the fabric;
the ‘sandwich’ is vacuum-formed over the mould shape.

19. RIFT vacuum forming NB: an alternative RIFT I route to complex shapes
RIDFT image from JR Thagard, PhD thesis,
Florida State University, 2003.

20. RIFT with flow medium RIFT 2 of 4
A high permeability fabric allows resin to flood one surface followed by through-thickness flow
commonly referred to as either:
V(A)RTM
Vacuum (assisted) resin transfer moulding
SCRIMPTM
Seeman Composites Resin Infusion Manufacturing Process
patented in the USA but prior-art exists in Europe
Resin feed
Vacuum
KEY
Flow medium
Reinforcement

21. EADS VAP® process
Membrane = Gore Composite Manufacturing Membrane (GCM) Image reproduced with permission from EADS

22. 2m diameter CFRP sonar dome
non-crimp carbon fibre fabric monolithic composite
from 9 mm to 50 mm thick, Vf = 60%, Vv = negligible

23. CFRP catamaran forward beam 60v/o NCF (6000 x 300 x 50 mm)
Manufactured by Julian Spooner
Channel section to form box with a second joggled moulding - integral top hat supports
Web: 600gsm triax / 9mm balsa / 600gsm carbon triax
Flanges: 600gsm triax / 4mm UD / 600gsm triax
Sicomin SR8100 resin system
Layup: 7 man hours,
Infusion: 25 minutes,  20ºC / 20mB
Postcure: 50ºC

24. Manufactured by the SCRIMPTM process
J-boats Poma-Otis mass transit
Images from
Reitnouer flat bed trailer NABI 30-foot bus

25. Benefits of SCRIMPTM Vosper Thornycroft state:
resin infusion into tows is independent of fabric weight.
reduced costs and greater efficiency in production: fewer layers of heavier fabric compared to 35 separate plies of 800 gsm woven roving glass used in hand lamination.
reduced component weight (up to 72% fibre by weight).
void content down from 5% by HL to <1% by SCRIMPTM.
increased laminate strength due to the higher fibre fraction and reduced void content.
reduced styrene emissions and waste resin.

26. The NEG-Micon 40 m radius AL40 carbon-wood epoxy wind turbine blade
Resin infusion manufacturing process developed with ACMC

27. Advanced Composite Armoured Vehicle Platform (ACAVP)
demonstrator manufactured by “VARTM”
reinforcement is quasi-isotropic non-crimp E-glass fabric
bare hull weight is around 6000 kg
Image from

28. Civil engineering structures
DML Composites rehabilitate fractured structures for London Underground

29. CFRP infusion vs welded steel repair
London underground
~£40K/day lost revenue for closing the line between two stations
Offshore exploration and exploitation
~£500K/day of crude oil through small platform
need to drain down before hot work (welding)!

30. Resin Film Infusion (RFI) RIFT 3 of 4
B-stage “prepreg” resin film without fibres
interleaved with reinforcement or grouped film layers in dry laminate
unlike prepreg, there are air channels within the bagged laminate
Vacuum
KEY
Resin film
Reinforcement

31. RFI (RIFT 3) for aerospace
T-beams, aileron skin, swaged wing rib, three-bay box
Kruckenberg et al , SAMPE J, 2001
fuselage skin panel for the Boeing 767 aircraft was moulded as a demonstrator with integral stiffeners
Cytec RTM bismaleimide resin (100 mPa.s at 100°C)
880 x 780 mm woven 5-axis 3-D fabric preform
Uchida et al , SAMPE J, 2001
fuselage panels in TANGO Technology Application to the Near-term business Goals and Objectives of the aerospace industry
skins will be non-crimp fabric preforms
integrated stringers to be triaxial braids with unidirectional fibres
Fiedler et al, SAMPE J, 2003

32. “Semi-preg” infusion RIFT 4 of 4
fabric partially pre-impregnated with resin
Commercial systems include
Cytec Carboform
resin impregnated random mat between the two fabric layers
Hexcel Composites HexFITTM
film of prepreg resin combined with dry reinforcements
SP Systems SPRINT®: SP Resin Infusion New Technology
resin between two fabric layers
Umeco (ACG) ZPREG
resin stripes on one side of fabric
Vacuum
KEY
Resin stripes
Reinforcement

33. Comparisons ( debateable! )
In-plane
Flow medium
RFI
Semi-preg
Material costs
Consumables
Process time
Quality 

£€$
£€$
£€$
£€$
£€$
£€$
£€$
£€$

34. Summary
reviewed the four major variants of the Resin Infusion under Flexible Tooling process.
considered the application of these techniques to the manufacture of large composite structures.
recommend this route for the manufacture of large composite structures.

35. ACKNOWLEDGEMENTS
Higher Education Funding Council of England (HEFCE) Development of Research for funding early research into resin infusion
Christopher Williams and Jim Craen for their respective contributions to the project.
David Cripps at SP Systems Limited for most helpful discussions of an earlier version of this paper.
Paul Hill at DML Composites for permission to use his Figure.
Use of trade names/trade marks in the text of this chapter does not imply endorsement by the authors of any specific product. Such descriptions are provided simply in the interest of traceability.

36. Publication
The content this presentation has been refereed and is published as
John Summerscales and TJ Searle Low pressure (vacuum infusion) techniques for moulding large composite structures
in Proceedings of the Institution of Mechanical Engineers Part L - Journal of Materials: Design and Applications, February 2005, L219(1),

37. Based on earlier PowerPoint
previously presented at:
Universiti Putra Malaysia, Bangi, Sept 2004
Imperial College London, Dec 2004
SAMPE out-of-autoclave symposium, Feb 2005
Forum for Plastkompositter – Norway, Nov 2005
Composite Innovations – Barcelona, Oct 2007
ICMAC – Belfast, March 2009
RINA – London, February 2010
SWCG – Plymouth, September 2012.

38.  .. to contact me Dr John Summerscales jsummerscales@plymouth.ac.uk
School of Engineering Reynolds Building RYB University of Plymouth Devon PL4 8AA England