| 摘要 |
<p>A process for increasing the crystallization rate of a sheet of amorphous polyester (26) including the steps of raising the temperature of the sheet (26) to or above the glass transition temperature of the polyester, stretching the sheet of material in at least one direction to a length at least 120 % of the length of the sheet (26) in the direction of stretching, and allowing the sheet to return to a fully relaxed state. The temperature of the sheet (26) is raised using an oven (10) having an oven cover (14) which includes heating elements (18) and a fan (20) and having a base (16) which includes two sets of upper (22) and lower (24) clamps for securing the sheet (26). Air cylinder driving means (12) is used for stretching the sheet (26) and is associated with control means (36) for controlling the rate of stretching.</p> |
