Spiral die and laminate production method using same

摘要

A spiral die (21) for forming a laminate includes an outer die ring (22b), an inner die ring (22a) inserted into the outer die ring (22b) with a fit clearance therebetween, a plurality (m, a positive integer greater than 1) of spiral grooves (24a,24b) each having a gradually decreasing depth disposed between the outer (22b) and inner (22a) die rings, and distribution paths for distributively introducing melted resin streams of a plurality (n, a positive integer satisfying n < m) of resin species (A,B) in a prescribed order into said plurality (m) of spiral grooves (24a,24b). The individual resin streams distributed to the spiral grooves proceed along the spiral grooves to gradually overflow the respective spiral grooves and overlie each other in a prescribed order before the individual resin streams form a uniform tubular stream in a die axial direction.