| 摘要 |
<p>Equipment used in the processing of plastic, such as molds and extrusion screws, is cleaned of plastic residue by a combination of thermal cycling and agitation without impact cleaning. A chamber (102) can be heated by an electric radiant heater (308) and cooled by the introduction of liquid nitrogen (312). A fixture (200) in the chamber (102) receives the equipment to be cleaned and is agitated by a drive motor (216). The chamber is heated and cooled in the following cycle in which the drive motor agitates the fixture: first to 250-300 °F, then to -315 °F, then cycled between -50 °F and -10 °F, then to 150 °F, then to -200 °F, then to 100 °F, then to ambient temperature. The chamber (102) is controlled by a computer (400) that prompts the operator for the kind of plastic to be cleaned off of the equipment and then controls the heating and cooling automatically.</p> |
