| 摘要 |
A tube of thermoplastic netting is drawn through a work station in a radially collapsed, condensed condition. At the work station, the netting is angularly twisted to rope-like form, to increase its bulk density and, in such condition, is drawn between the die and platen of an ultrasonic welding horn. Periodically, the die and platen momentarily bear against a succeeding short length of the twisted, condensed rope-like form making a fused seal nugget integrating all strands of the netting at that site. The resulting product may be a long length of such tubing, having such a seal every so often, or a plurality of bags formed from the intermediate product by making one transverse cut through the netting tube beside each seal nugget.
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