Kevlar fabric ballistic performance affected by plasma treatment

In this study, non-polymerising reactive plasma gas N2 and chemical vapour (CH3)2 Cl2 Si were employed to modify Kevlar fabric surface for the application of ballistic impact material. SEM observations yield information about the surface effect of the fabrics after plasma treatment. The surface morphology of the treated fabrics was studied. EDX (Energy Dispersive X-ray) analysis was used to analyse the surface chemical properties of the treated samples. Yarn pulling out test shows that the resistance to pull out a yarn from N2 and (CH3)2 Cl2 Si plasma treated fabric is increased 18% and 300% respectively, compared to the untreated Kevlar fabric. A 3D FE model is developed to simulate the projectile-fabric impact process and predict how the surface friction of Kevlar fabric affects the energy absorption and back face deformation of the impacted fabric. It shows that fabric with higher surface coefficient of friction absorbs more energy by allowing the strain wave propagates in a larger area. In the meantime, the depth of back face deformation decreased with the increase of surface friction which will help to prevent from trauma and improve ballistic performance.