Abstract: A manufacturing method of a laminated plate (19) includes: a first step of supporting, by a support member (9), a thermoplastic resin-made laminated material (1) in which a pair of plate-like members (3, 4) are laminated to each other while interposing a longitudinal wall portion (2b) so that a peripheral edge portion (1a) of the laminated material (1) can be exposed, and heating and softening the peripheral edge portion (1a) by blowing a hot air to the peripheral edge portion (1a); and a second step of pressing the plate-like member (4) as one of the pair of plate-like members (3, 4) against other plate-like member (3) by thrusting a cutting blade (17a) of a cutting die (17) against the heated and softened peripheral edge portion (1a), thereby bringing the pair of plate-like members (3, 4) into contact with each other and welding the plate-like members (3, 4) to each other, and then cutting the laminated plate (19) out of the laminated material (1).

Abstract: A manufacturing method of a laminated plate (19) includes: a first step of supporting, by a support member (9), a thermoplastic resin-made laminated material (1) in which a pair of plate-like members (3, 4) are laminated to each other while interposing a longitudinal wall portion (2b) so that a peripheral edge portion (1a) of the laminated material (1) can be exposed, and heating and softening the peripheral edge portion (1a) by blowing a hot air to the peripheral edge portion (1a); and a second step of pressing the plate-like member (4) as one of the pair of plate-like members (3, 4) against other plate-like member (3) by thrusting a cutting blade (17a) of a cutting die (17) against the heated and softened peripheral edge portion (1a), thereby bringing the pair of plate-like members (3, 4) into contact with each other and welding the plate-like members (3, 4) to each other, and then cutting the laminated plate (19) out of the laminated material (1).