Final Poster Presentation for the 2012 SURE Project

1. • Impregnation of shear thickening fluids (STFs) into
traditional ballistic fabrics, such as Kevlar, to create
lighter, less constraining, and more effective body
armor [1]
• Ballistic performance increase in STF-Kevlar
systems is comparable to that of Kevlar systems
treated with dry particles [2]
• Since the fluid is not of primary importance, we
investigated different particle integration techniques
involving a variety of polymers
• Shear thickening fluids are currently built-into some
sporting and personal protection equipment (D3O
Labs)
• The integration of STFs in ballistic fabrics has shown
promise in increasing the protective characteristics
offered by the fabrics in stabbing incidents [2].
• Treatment of ballistic fabrics to improve their ballistic
characteristics through the integration of particles
within the fabrics through the use of various coating
methods.
• Knife-over-roll coating applies the coating directly to
the fabric which is then passed between a `knife`
and roller in order to achieve the desired thickness of
coating
• Roll-to-roll coating passes the fabric and coating
through two rotating rollers and uses the application
of great pressure for improved coating integration.
• Kevlar fabric was chosen as the base fabric to which
the particles would be applied. Both satin and plain
weave Kevlar were examined.
• 𝛼-silicon carbide particles of irregular morphology
and a dmean = 5 𝜇m were integrated into Kevlar
fabrics
• Neat coatings and coatings mixed with varying
percentages of particles were tested
• Dow Corning Sylgard - Two part, silicone elastomer
which cures at room temperature
• White Glue – multi-purpose, water soluble adhesive
with a polyvinyl acetate base
• Dow Corning 732 Multi-Purpose Sealant – One part,
silicone elastomer with fast acting room-temperature
vulcanizing moisture cure
• Sylgard coatings resulted in incomplete curing.
Application of Sylgard in thin layers in the presence of
excessive manipulation has been known to result in
poor curing.
• White glue coatings resulted in a non-flexible, brittle
layer on the surface of the fabric. Movement of the
fabric caused flaking of the coating.
• Inclusion of particles in the multi-purpose sealant
coating resulted in rapid curing. Inclusion of a non-
polar solvent, such as ethanol, may resolve this issue.
• Examination of low temperature thermoplastics to coat
Kevlar fabrics
• Determining the V50 ballistic limit of the particle
integrated Kevlar to assess the ballistic performance
of the various samples.
The authors would like to thank Simon Ouellet and
Jacques Blais of Defence Research and Development
Canada-Valcartier as well as Hamid Benaddi of Stedfast
Inc. for their support and collaboration on this project
[1] Y.S. Lee, E.D. Wetzel, and N.J. Wagner (2003), J. Mat.
Sci., 38(13):2825-2833
[2] D.P. Kalman, R.L. Merrill, N.J. Wagner, and E.D. Wetzel
(2009), Appl. Mat. & Int. 1(11):2602-2612
Integration of Silicon Carbide Particles into Ballistic Fabrics
Bradley J. Marr, Oren E. Petel, and David L. Frost
McGill University, Montréal, Québec, CANADA
Introduction
Current Applications
Fabric
Methodology Results
Future Research
Coating
References
Figure 2. D3O Olympic ski suit
containing STF technology
http://www.snewsnet.com/cgi-
bin/snews/16368.html
Coating Processes
Particle Inclusions
Figure 4. (a) Plain weave fabric, (b) Satin weave fabric
www.fibermaterialsinc.com/2dws.htm
(a) (b)
Acknowledgments
Objectives
Figure 3. Schematic of Knife-over-roller coating process
www.tciinc.com/Capabilities.aspx
Methodology
• Kevlar sheets were soaked
in solutions of silicon
carbide particles and
ethanol.
• Vibration was introduced to
increase penetration of the
particles into Kevlar fibers.
Figure 8. The coating was first
applied to the Kevlar using a paint
scraper to achieve an even coating
over the fabric
Figure 9. The fabric was then passed
under a roller with great pressure applied
to aid in the elastomers integration
Figure 5. (a) Neat Kevlar, (b) Kevlar with integrated particles
(a) (b)
Particle Inclusions
Figure 11. Typical distribution found in determining V50 ballistic limit
www.bella.waw.pl/index.php?page=32&lang=en
Figure 1. A STF is a non-Newtonian fluid, typically consisting of a
suspension of fine solid particles in a carrier fluid, whose
viscosity increases under increasing shear rates
Viscosity
Figure 10. Satin weave Kevlar coated with
Silicone multi-purpose sealant that has been
mixed with particles
Figure 7. Kevlar sheet in a 15% by mass
silicon carbide and ethanol mixture