| 摘要 |
A heat sealing apparatus is disclosed for sealing together two layers of heat softenable plastics material, for example two sides of the top of a bag or sack. A pair of rollers are arranged to nip the layers together to form a seal after they have been softened and means are provided for loading one roller towards the other roller and permitting said one roller to be urged away from said other roller against the load exerted by the loading means on passage of layers of plastics material between the rollers. Stop means are arranged such that said loading means exerts a reduced loading on the rollers in the absence of layers of plastics material to be sealed. |
