| 摘要 |
<p>An extrusion method for obtaining a long phenolic resin pipe (7) having excellent heat resistance by using an extruder comprising a screw (4), a cylinder (2), a die (5) and a mandrel (6), the mandrel being inserted into a through-hole formed in the screw along the screw axis and protruding into the die along the screw axis, the die satisfying the following formulas <MATH> <MATH> where R1 is an outside diameter of the die flow path at the die outlet, S1 is a cross-sectional area of the die flow path at the die outlet, R2 is an outside diameter of the die flow path at the die inlet, and S2 is a cross-sectional area of the die flow path at the die inlet, and the inclination of the outer periphery of the die flow path portion from the die inlet to the starting point of the uniform flow path portion having the same cross section as the die outlet is not larger than 35 DEG to the axis of the screw, and by shaping and extruding a phenolic resin material in a state that the material after extrusion is cured so as to be able to retain its own shape, by controlling the temperature of the heating zone of the cylinder communicating with the die inlet at 120-145 DEG C and the temperature of the die at 150-200 DEG C; an extruder used for effecting said method; and an extruded article obtained by using said method and said extruder. <IMAGE></p> |
