Method and apparatus for preheating sheets

摘要

An oven 10 for preheating plastic sheet material 20 prior to moulding, the oven 10 including at least two separate heating chambers 11 - 14 which each include a drawer 15 having supporting means 14 for supporting a sheet 20 and being movable into and out of the chamber 11 - 14. Each chamber is associated with heating means 30 for heating a sheet 20 within the chamber 11 - 14. Each drawer 15 being movable into and out of a chamber 11 - 14 for loading and unloading a sheet 20 and the chamber 11 - 14 being closed for heating a sheet 20 wherein the temperature within one of the chambers 11 - 14 which is closed is substantially unaffected when another of the chambers 11 - 14 is opened.