Abstract: A method for manufacturing a novel air permeable composite film is disclosed. The air permeable composite film has a polymer layer with a top face and a bottom face and a sealing layer covering the top face. The polymer layer is first perforated by virtue of an impression process to form a plurality of tiny gaps in it for air permeation. Then the sealing layer is coated on the top face of the polymer layer to fill the gaps. The differential pressure between the top face and bottom face of the polymer layer enlarges the gaps and makes the gaps become air permeable.

Abstract: A steam heated web processing roll includes a fully enclosed steam and condensate flow-through system which maintains the roll end walls at approximately the same operating temperature as the functional cylindrical outer roll shell at normal rotational speeds. The closed loop system also assists in purging non-condensible gases from the steam path. At low roll speeds or when the roll is stopped, a valving system closes all of the condensate return paths except one or more of the lowermost paths from which condensate pooling in a sump at the bottom of the roll is withdrawn. This prevents undesirable cooling of the lower portion of the roll as compared to the remaining portion, thereby reducing the possibility of bowing of the roll by thermal distortion.

Abstract: A gas burner for a water heater and comprising a base having central passage. Gas fuel is supplied to one end of the passage and an orifice is removably connected to the other end of the passage. An inverted cup-shaped head has an inner end threaded to the base and defines a closed chamber disposed in communication with the orifice. A plurality of ports are formed in the head and provide communication between the chamber and the exterior of the burner. The ports have a greater axial length than diameter and aid in controlling the flame configuration.