| 摘要 |
PURPOSE:To easily form coatings of different thickness on both faces of a core member and change the coating thickness in the flow direction by a method wherein a rotatable roll or rolls are arranged at the outlet portion of die main bodies, and a molten plastic is coated on both faces of a core member passed between the die main bodies. CONSTITUTION:A molten plastic 4 fed from manifolds A in die main bodies 1, 1' into pools C through restrictors is stored in the pools C, before coated on both faces of a core member 3 passed between die lips D of which at least one is a rotatable roll 2. By changing the rotation speed of the roll 2, it is possible to change plastic flow velocity distribution and hence coating thickness. When the rotation of the roll 2 is interlocked with the mechanism for volume change (in the direction of sheet width) of the manifolds A, restrictors, and pools C, the coating thickness can be changed also in the flow direction. |
