| 摘要 |
PURPOSE:To uniformly heat the whole surface of a sealing part of an opening by jetting hot air from small holes with a small diameter on an oven in order to prevent only the internal and external resin surfaces being confronted with the small holes from being heated emphatically when the internal and external surfaces of the opening sealing part of a carton are heated. CONSTITUTION:A center oven 1 and side oven 2 are respectively brought closer to the internal and external surfaces of an opening sealing part C1. Then, both ovens 1, 2 are reciprocated by an appropriate distance along the internal and external surfaces of the opening sealing part C1, once or extending to a plurality of times to heat the internal and external surfaces of the opening sealing part C1. |
