When a high-speed rotating grinding wheel breaks during grinding operations, abrasive fragments are scattered at high speed. Generally, the windows of work zone enclosures are made of a transparent polycarbonate plate to allow observation of grinding conditions. However, the collision mechanism of abrasive products against polymer materials, such as polycarbonate, have not been clarified. Here, we performed collision experiments and the finite element method (FEM) of an abrasive projectile (WA46O8V) against the polycarbonate plate and investigated the collision mechanism. The results indicated that the impact resistance of the polycarbonate plate is proportional to the square of the plate thickness, similar to rolled steel plate. On the other hand, the deformation of the polycarbonate plate by the collision of a projectile is dominated by viscoelasticity, which is different from rolled steel plate in which it is dominated by plasticity.