| 摘要 |
<p>A method of pre-heating an extrusion die comprises heating an extrusion die using a first group of heating elements and a second group of heating elements; and then heating the extrusion die using only the first group of heating elements to bring the extrusion die to a desired pre-heat temperature, or heating the extrusion die using the first and second groups of heating elements, the second group of heating elements being operated at reduced power, to bring the extrusion die to a desired pre-heat temperature.</p> |
