摘要 |
Thermoplastic filamentary material is continuously formed into a row of helically coiled or zigzag coupling elements for slide fasteners. One of the coupling elements as thus formed is measured for a dimension thereof. The measured dimension is compared with a reference value to detect a dimensional error, if any, of the measured one of the continuous coupling elements. The tensioning of the thermoplastic filamentary material prior to being formed into the row of coupling elements is adjustably controlled on the basis of the dimensional error so as to remove the latter from subsequently formed coupling elements. The measurement of the coupling element may be effected while the row of coupling elements as formed is being held at rest. |