Measurements on Fibres and Monofilaments

Dynamic mechanical measurements have been used to study the influence of molecular orientation on the extensional moduli of fibres drawn to different draw ratios and also to compare the extensional moduli for a wide range of textile fibres produced by conventional manufacturing processes. The most extensive studies of this type are those of Wakelin et al. [22] and Meredith [23], 

Detailed measurements of the extensional modulus of monofilaments have been made by longitudinal wave-propagation methods, where the relationship of the extensional modulus to molecular orientation and crystallinity has been examined. Early investigations using this technique were made by Hillier and Kolsky [24], Ballou and Smith [25], Nolle [26] and Hamburger [27]. 

The measurement of the extensional modulus was re-examined as a possible method for the measurement of molecular orientation in textile yarns by Charch and Moseley [28], Moseley [29] and Morgan [30], Morgan has developed Hamburger s pulse-propagation method. 

A convenient dynamic method for measuring the torsional modulus of synthetic fibre filaments was developed by Wakelin et al. [22]. 

A simpler method is that adopted by Meredith [23], where the fibre undertakes free torsional vibrations supporting known inertia bars at its free end. 

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