| 摘要 |
PROBLEM TO BE SOLVED: To reduce stress, which causes to produce strain in a product, by a method wherein thermal actuators make limiting rods positioningly controlling the surface of a fluid flow in the impression, which is formed by combining die main body portions into one, selectively actable. SOLUTION: This extrusion die 20 comprises a first and a second die main body portions 24 and 26 and further includes a die outlet 40 opposing to a die inlet 22 so as to pass sheet-like molten thermoplastic plastic material there through. A plurality of thermal actuators, which are arranged along the longitudinal direction of the first die main body portion 24 and fixed to the portion 24, are provided so as to be connected to limiting rods 100 extending over the whole width of the die. For example, when an electric current is applied to the input lead 48-15 of the thermal actuator 42-15, a heating element 70 emits heat so as to extend a transducer 76, resulting in extending the flow surface 126 of the limiting rod 100 in a flow passage. When an electric current is not applied, the flow surface 126 of the limiting rod retreats. Thus, the flow surface can be locally deformed, resulting in allowing to precisely control the flow of the plastic material. |
