| 摘要 |
<p>The feed of the threads (1) to the substrate (2) provided for receiving them is ensured independently of the welding operation, by acoustic fusion; the said threads are subjected, before the said welding operation to the action of jets of compressed air imparting to them a looped appearance and the base of the loops (16) is subsequently attached to the substrate by insertion determined by the location of the welding heads. In the device for carrying out the process, the means for directing the sheet of threads (1) into the welding zone are independent of the acoustic welding means and supply, at each welding cycle, a determined length of thread to a thread-guide (9) provided in the rear of the welding head (17); the position of the welding heads (17) determines the point of insertion of the loops (16) on the substrate (2), a pneumatic injection device (14) being moreover provided behind the welding heads in order to form the loops. <IMAGE></p> |
