| 摘要 |
An apparatus for reheating and conditioning an elongate preform for forming a blow moulded container such as a PET bottle comprises a heated receiver 4 with an elongate annular non-cylindrical inner surface 6. The surface 6 defines a cavity and is adapted to engage with, and transfer heat by conduction to, an elongate outer surface of a preform. The surface 6 includes a three-dimensional relief to provide substantially non-uniform contact between the receiver and the elongate preform. The non-uniform contact provides for non uniform heating of the preform. The relief depth may be from 0.01 to 1.5mm and may result in a temperature which is 5 to 15 degrees C higher in areas of the preform in contact with the surface compared with non-contacted areas. The surface may be eliptical and may be used to heat preforms used for forming eliptical bottles. The end of the cavity may be closed by a concave surface 15 into which opens a vacuum duct 30 for applying a negative pressure to hold a preform in the cavity. Alternatively, preforms may swell upon heating in the cavity and consequently may be held in the cavity. |
