Patent ID: 7425369

Claim:
A high-impact, transparent sheet comprising: a base sheet of transparent polycarbonate material having a glass transition temperature and a melt temperature, the base sheet having a non-planar shape comprising a first portion and a second portion; wherein the first portion has a shape created by a non-contact forming operation occurring at a temperature above the glass transition temperature and below the melt temperature of the transparent polycarbonate material; and wherein the second portion is a peripheral portion, said second portion has a non-planar shape at its outermost edge created by a contact forming operation occurring at a temperature above the glass transition temperature and below the melt temperature of the polycarbonate material, said second portion non-planar outermost edge having a non-planar contour; and wherein when said sheet rests on a plane, said second non-planar portion contour is spaced away from said plane such that portions of the periphery including said second non-planar portion contour are raised above and not in contact with said plane.