Patent 7997114 was granted and assigned to Material Sciences Corporation on August, 2011 by the United States Patent and Trademark Office.
A method includes providing a sheet having layers characterized by different softnesses, providing a die component having a leading surface that is generally concave, and causing the leading surface to puncture the sheet thereby to cut a part from the sheet. The method provides improved flatness of parts cut from sheets having layers of varying softness and prevents soft material from exiting the sheet because the peripheral edge of the leading surface applies maximum pressure to the sheet during the puncturing step.