By using a reduced pressure chamber, and enables the film-forming a sheet having a uniform crystallization speed, even if the cast cooling apparatus stably, the thickness uniformity and surface quality at the same time also provides a method for producing superior microporous polyolefin resin sheet.
Microporous polyolefin resin sheet manufacturing device of the present invention the conveying direction upstream of the cast cooling device and the cast cooling device than detention to solidify by cooling while conveying the sheet being extruded from the detention and detention for extruding a molten resin into a sheet It is installed on a side, and having a pressure chamber for sucking air between the sheet and the casting cooling system is extruded from the detention, further including a current plate provided so as to block the gap between the sheet and the casting surface to be discharged from the spinneret. Pressure chamber provided in the microporous polyolefin resin sheet made of the invention apparatus, cast cooling unit and the opposite side at least a sealing member to come to the peripheral portion in physical contact with the cast cooling unit, the sheet width at the opening near the opposite to the custody of the surface provided with a partition plate is installed over the direction.