Abstract: A method of stamping a part from an elongated strip of multi-layered material. The multi-layered material includes a viscoelastic intermediate layer, and upper and lower layers that are relatively rigid with respect to the intermediate layer. The method includes providing symmetrically aligned top and bottom punches each including a material displacement edge corresponding with a desired shape of the part. Each of the material displacement edges are defined by a rake surface and a part interface surface that combine to form a positive rake angle. The strip is positioned between the top and bottom punches. The top and bottom punches then shear a portion of the upper and lower layers, respectively. More particularly, symmetrical groove patterns are formed in the upper and lower layers, defining a perimeter of the part. The part is then removed from the strip along the perimeter.

Abstract: Microwave oven window having a microwave-blocking screen, an interior plastic film and a pressure-sensitive adhesive layer bonding the plastic film to the screen over the full area of the screen but substantially not penetrating into the openings of the screen.

Abstract: Microwave oven window comprising two transparent panels, an intermediate microwave-blocking screen and a transparent thermoplastic adhesive filling the space between the panels. The interior panel is very thin and the thickness of the thermoplastic adhesive panel barely exceeds that of the screen. The thinness of the interior panel plus adjacent adhesive minimizes the leakage of microwaves.