초록 ▼

A method of forming a duct liner from a duct insulation board includes cutting a plurality of parallel grooves into duct boards with a plurality of rotary saw blades which are spaced on 1.57 inch or 3.14 inch centers. The saw blades have peripheral teeth which project outwardly on both sides of the

A method of forming a duct liner from a duct insulation board includes cutting a plurality of parallel grooves into duct boards with a plurality of rotary saw blades which are spaced on 1.57 inch or 3.14 inch centers. The saw blades have peripheral teeth which project outwardly on both sides of the saw blades to form grooves in a first major surface of a duct board which are wider than the saw blades. The grooves have sidewalls which extend perpendicular to the first major surface of the duct board and have a depth from 70% to 90% of the thickness of the duct board. The first major surface is typically coated and a second major surface of the duct board normally has a facing adhered thereto. After the duct board is grooved, the duct board can be curved to conform to the curvature of a tubular metal shell, with the parallel grooves of the duct board extending parallel to the axis of curvature, and placed in the tubular metal shell as a liner to form an insulated air duct.

대표청구항 ▼

[ What is claimed is:] [1.] A method of forming a duct insulation board for forming a tubular duct having a diameter of at least thirty inches comprising: providing a duct insulation board having a first major surface, a second major surface and a thickness; and cutting a plurality of parallel groov

[ What is claimed is:] [1.] A method of forming a duct insulation board for forming a tubular duct having a diameter of at least thirty inches comprising: providing a duct insulation board having a first major surface, a second major surface and a thickness; and cutting a plurality of parallel grooves in said first major surface of said duct insulation board which are spaced on 3.14 inch centers across said first major surface and have a depth from 70% to 90% of the thickness of said duct insulation board.