摘要 |
In mfr. of a plastics barrel the body of the barrel is bonded to lid and bottom by heating an annular zone of the body to optimal heat-deforming temp. whilst keeping the edge of the body cool; compressing the body in presence of an inner template to form a bead and using the latter for fitting bottom and/or lid with the aid of a tensioning ring. The claimed process is much less expensive than blow-moulding of single-piece barrels whose mfr. requires a separate blow-mould for each size and therefore suitable for mass prodn. Also, size of extruder should be appropriate to weight of barrel since the min. throughput of the extruder should correspond to it. |