Preparation of body armour material of Kevlar fabric treated with colloidal silica nanocomposite

Abstract

To safeguard bodies of soldiers better, including their necks and joints, a novel armour material was exploited using nanocomposite. Compared with traditional armour materials, this new material possessed superior barrier property and more comfortable characteristics. The new armour material was made of Kevlar cloth and shear thickening fluid (STF). Colloidal silica particles were first synthesised via the Stö ber synthesis method and then they were used to prepare a suspension with solvent of polyethylene glycol 200. At last, Kevlar cloth was treated with the suspension and the resultant was named as STF-Kevlar nanocomposite. In this process, the particle sizes were characterised with scanning electron microscopy. The rheological properties were measured with a Physica MCR301 stress controlled rheometer. The results showed that the silica particles could be determined to be monodispersed spherical particles. The suspension, named the shear thickening fluid, had shear thickening characteristic. The property of multilayer STF-Kevlar nanocomposite targets was compared to that of the neat Kevlar cloth and the results indicated that the STF-Kevlar nanocomposite had an improvement in barrier property and was more flexible and comfortable. The mechanism that could improve the barrier property of STF-Kevlar was briefly explained.

Application of shear thickening fluid in ultra high molecular weight polyethylene fabric

“…When impact force is disappeared, STF is back to liquid form. Therefore, the shear response of the STF displays reversible transition and STF can be stable on the fabrics 2, 3. Personal body armor was used to protect the human body from the injury of the knife, dagger, and other sharp instrument 4, 5.…”

Effect of particle size of fumed silica on the puncture resistance of fabrics impregnated with shear thickening fluid

“…[12][13][14] However, the mass fraction of the colloidal silica needs almost twice amount to get the same shear thickening effect. [15][16][17] The fumed silica based STFs exhibit rapid thickening in comparison to colloidal based STFs. 18 Therefore, the fumed silica based STFs have the potential to produce lighter stabbing resistance body armor.…”

Fabrication and Characterisation of Magnetorheological Shear Thickening Fluids

“…In the past decade, STFs made from silica nanoparticles loaded in carrier fluids, such as polyethylene glycol, and impregnated in a fabric, have gained attention by military and law enforcement agencies to have potential for usage in liquid body armour and bulletproof vests. The most common application focuses on impregnating Kevlar fabrics with STFs in order to improve its stab resistance and to reduce the number of layers required for maximum penetration resistance (Li et al, 2008;Petel et al, 2015;Wagner and Wetzel, 2007;Grover et al, 2020). STFs can also be used in smart structures due to their unique shear thickening properties (Zhou et al, 2016).…”