| 摘要 |
<p>In a traditional preform the spherical shape of the gate portion causes a variable angle of refraction of infrared light rays, thus resulting in uneven heating of the preform during the re-heating process According to embodiments of the present invention, there is provided a preform (300, 400, 900) and a mold stack (600, 1000) for producing the preform (300, 400, 900) For example, there is provided a preform (300, 400, 900) suitable for subsequent blow-molding The preform (300, 400, 900) comprises a neck portion (302, 402, 902), a gate portion (306, 406, 906), and a body portion (304, 404, 904) extending between said neck portion (302, 402, 902) and said gate portion (306, 406, 906), the gate portion (306, 406, 906) being associated with a substantially conical shape. In an example embodiment, the substantially conical shape is selected such that to substantially homogenize angle of refraction of rays (206) used during a re-heating stage of a blow-molding process.</p> |
