the interlacing of the yarn was measured as a function of this pressure the operation as repeated for different speeds and the pressure read on a manometer and expressed in bars the cohesion factor of the interlacing was measured on an 34 entanglement tester r 2040 34 rothschild zurich this entanglement tester works on the principal of automatic detection of the distance between points of interlacing by utilizing a needle that penetrates between the filaments of a moving yarn and retracts as soon as it encounters a point of resistance the point of resistance being an interlace point the yarn being tested is first subjected to a known adjustable pretensioning since the threshold of tension that corresponds to disengagement of the needle from the yarn is known and adjustable the cohesion factor can be expressed by the relationship f 100 d wherein d is the average distance between interlace points expressed in centimeters and is the average of at least 100 measurements the values of the interlace factor are presented in the following table in which p i is the injection pressure of the principal fluid p t is the injection pressure of the auxiliary fluid used to create the turbulence and v is the yarn speed in meters per minute table i______________________________________p i p t 0 5 1 1 5 2 3 4 5 6v fil______________________________________200 10 6 24 3 27 1 38 6 47 4 48 8 65 5 58 5300 9 68 20 1 25 4 35 5 45 5 56 9 50 7 55 6400 11 9 16 8 26 2 26.