opening length t2 of this yarn g is determined in the same way as described above the knot strength is hence determined as the quotient of t2 to t1 since generally by means of the dynamic stress applied to the yarn via pins 11 the opening length t2 of the yarn g is larger than the opening length t1 prior to treatment values for the knot strength larger than 1 are generally obtained however it has also been observed that by means of the grazing stress of the ceramic pins 11 a shortening albeit a slight one of opening length t2 relative to t1 can occur thus generally values of more than 1 and in exceptional cases values of 1 or less were determined in the measurement of the knot strength in the experiments conducted to date values of 0 8 or more were obtained knot strength values of less than 1 0 such as 0 9 or 0 8 show clearly that among the yarns of the invention there are also yarns whose filament cohesion even improves during subsequent processing for example during weaving values of 1 0 for knot strength mean that the yarns behave in an extremely stable fashion during weaving while the higher the knot strength value the more the stability of the yarns increases and the lower the frequency of disruptions becomes it was surprising to discover that when weaving the yarns according to the invention which are preferably used as warp.