Method of aperturing thin sheet materials

A method of forming apertures in a sheet material having a first side and a second side, the method comprising the steps of:

• (a) placing the sheet material on a patterned anvil having a pattern of flattened raised areas wherein the height of the flattened raised areas is equal to or less than the thickness of the sheet material;
• and
• (b) subjecting the sheet material to a sufficient amount of sonic vibrations to aperture the sheet material in the absence of a liquid;
• whereby the sheet material is apertured in a pattern generally the same as the pattern of raised areas on the patterned anvil.

A method of forming apertures in a thin sheet material having a first side and a second side wherein at least one side of the thin sheet material is substantially coated with an adhesive and further wherein the area of each of the formed apertures is generally greater than about 0.05 square millimeters, the method comprising the steps of:

• (a) placing the adhesive-coated thin sheet material on a patterned anvil having a pattern of raised areas wherein the height of the flattened raised areas is equal to or less than the thickness of the thin sheet material and the adhesive;
• and
• (b) subjecting the thin sheet material to a sufficient amount of sonic vibrations to aperture the thin sheet material and the adhesive;
• and
• whereby the thin sheet material and the adhesive is apertured in a pattern generally the same as the pattern of raised areas on the patterned anvil.

A method of forming apertures in a thin sheet material having a first surface and a second surface wherein at least one surface of the thin sheet material is in planar juxtaposition with a liner and an adhesive is optionally coated on the thin sheet material, the thin sheet material and the optional adhesive and the liner together comprising a composite sheet material and further wherein the area of each of the formed apertures is generally greater than about 0.05 square millimeters, the method comprising the steps of:

• (a) placing the composite sheet material on a patterned anvil having a pattern of raised areas wherein the height of the raised areas is less than or equal to the thickness of the thin sheet material and the optional adhesive;
• and
• (b) subjecting the composite sheet material to a sufficient amount of sonic vibrations to aperture the thin sheet material and the optional adhesive;
• and
• whereby the thin sheet material and the optional adhesive is apertured in a pattern generally the same as the pattern of raised areas on the patterned anvil, but the liner is not apertured.

A method of forming apertures in a thin sheet material having a first surface and a second surface wherein at least one surface of the thin sheet material is in planar juxtaposition with a liner and an adhesive is coated on at least one surface of the thin sheet material, the thin sheet material and the adhesive and the liner together comprising a composite sheet material and further wherein the area of each of the formed apertures is generally greater than about 0.05 square millimeters, the method comprising the steps of:

• (a) placing the composite sheet material on a patterned anvil having a pattern of raised areas wherein the height of the raised areas is less than or equal to the thickness of the thin sheet material and the adhesive;
• (b) subjecting the composite sheet material to a sufficient amount of sonic vibrations in the absence of liquid to aperture the thin sheet material and the adhesive but not aperture the liner;
• and
• whereby the thin sheet material and the adhesive is apertured in a pattern generally the same as the pattern of raised areas on the patterned anvil but the liner is not apertured.