| 摘要 |
<p>PURPOSE:To peel and remove completely XLPE sticked and remained on the inner wall of a resin path by a method wherein a heating process for raising resin temp. in the resin path of polyethylene to a specified temp., an extruding process extruding the resin the resin path and a cooling process cooling the polyethylene in such a way that the resin temp. becomes to a specified temp. or lower are repeated a plurality of times. CONSTITUTION:A PE resin batch is fed in a small hopper 2 and a temp. elevating switch is turned on to elevate the temp. of a resin path. Then, when the temp. of PE reaches 120 deg.C, a switch for a motor 4 is turned on to rotate a screw 5 and to start kneading and extrusion of PE. After 30min, the switch of the motor is turned off to stop rotation of the screw 5 and when the temp. elevating switch is simultaneously turned off, the temp. of PE in the resin path is returned to 25 deg.C after 30min. As the linear expansion coefficient of the inner wall of the resin path is different from that of XLPE sticked on the inner wall, heating and cooling of the resin path are repeated several times. As the upper limiting temp., a proper temp. which is at least 110 deg.C and at most 140 deg.C is selected and as the lower limiting temp., a proper temp. which is at 90 deg.C or lower can be selected.</p> |
