Tensile Testing of Single Regenerated Cellulose Fibres

Abstract

A tensile testing set-up was developed for the determination of the elastic modulus, tensile strength, and failure strain of single regenerated cellulose fibres. Since the accuracy of strain measurement is crucial for the measured elastic modulus and failure strain, strain measurements were performed mechanically and with a non-contacting optical method in parallel. The optical validation of mechanical strain measurement showed an agreement of measured strain >99%, confirming the accuracy and usefulness of the set-up and sample geometry developed for the test series.

Shear strength of the lyocell fiber/polymer matrix interface evaluated with the microbond technique

“…Tensile test specimens were prepared as per the ASTM D3379-75 standard. 8,25 Prior to tensile tests, fiber diameter was measured at three different locations along the fiber length using an optical microscope. Since the diameter values were found to be consistently underestimated when compared to the diameter values from linear density measurements (internal report), the corrected values of the optical microscopic measurements were taken as input parameters for stress calculations.…”

“…Strain was calculated from the cross-head movement, which is found to be accurate and published elsewhere. 25 Specimens for each kind of fiber were tested and the results are listed in Table 1 and Figure 2. All tensile tests were carried out at 23 C and 55% relative humidity (RH).…”

Anisotropy of the modulus of elasticity in regenerated cellulose fibres related to molecular orientation

“…[25] and tested until failure at a speed of 1 mm min À1 . For the mechanical characterisation of cellulose films, strips with a width of 5 mm and a length of 50 mm were cut.…”

“…In the case of those films, which were stretched to introduce preferred orientation, the strips for tensile testing were cut with their length transverse to the direction of stretching, in order to obtain data points for cellulose with preferred orientation transverse to the direction of straining and thus very low modulus. While the calculation of strain from the tested free length and the recorded machine cross-head displacement is sufficiently accurate for cellulose fibres [25], direct deformation measurement was performed for all tested cellulose films using Zwick Macrosence clip-on displacement sensors.…”

Effect of scalp position on tensile properties of single hair fibers

“…SEM was used after sputter coating and macrofibril diameters were measured using Image J software (http://imagej.net/Help#Ways_to_get_help). [16]…”