| 摘要 |
<p>Heating apparatuses for packaging materials operating with hot air are often employed for heating thermoplastic packaging materials in connection with heat-sealing, forming or the like. The heating apparatuses are energy-intensive and suffer from a relatively low degree of efficiency, which primarily relates to a considerable waste flow of heated air. A heating apparatus in which these drawbacks have been obviated displays a suction box provided with apertures, the box being located adjacent a nozzle for the hot air and connected, by the intermediary of a recirculation duct, to the intake side of means generating an air current.</p> |
