| abstract |
Breathable microporous films (12) are provided having controlled regional breathability with thick high WVTR regions (24, 29) and thinner low WVTR regions (26, 27). The zoned breathable microporous films can be made by selectively applying heat and/or pressure to specific regions the microporous film such as by feeding a microporous film through a pair of heated nip rollers (18, 19, 20) with one of the rolls (18, 19) having a raised surface area (22, 23) or by applying a focused stream of hot air (110). Monolayer microporous films and multilayer films having at least one microporous layer can be treated to impart zoned breathability to the film. |