Fiber Testing

These factors must always be considered when comparing properties from various groups of fibers and the data shown in the following sections is to be viewed with this in mind.P I 

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Fig. 5. The effect of dry heat exposure on acetate and triacetate fibers. Tested at 65% rh, 21°C after exposure. A, acetate, 100°C B, triacetate, 130°C and C,...

From the results of fiber testing for different cramped lengths one determines A and B (cf. [147]). The composite containing this particular fibrous filler is then tested under tension or bending to determine t. Then the attained strength is compared with the limiting one calculated by Eq. (18) and the coefficient k is found then one can predict k for any t value. 

The microindentation technique (or push-out test as opposed to the pull-out test) is a single fiber test capable of examining libers embedded in the actual composite. The... 

DiAnselmo, A., Accorsi, M.L, and DiBenedetto, A.T, (1992). The effect of an interphase on the stress and energy distribution in the embedded single fiber test. Composites Sci. Technol. 44, 215-225. 

On the other hand, the type of fiber was only important for the lighter PCBs, mainly for PCB-28 and PCB-52. For these compounds, the PDMS-DVB fiber is more efficient than the PDMS fiber. The effect of the fiber factor appeared negative (Figure 2) because PDMS-DVB was selected as its low level (Table 1). For the highly chlorinated PCBs, the two fibers tested seem to have similar performance, and this factor lacks statistical significance. 

Strength properties of rayon-polystyrene graft copolymers (single fiber tests) (108)... 

Fig. li. The change in failure at the single-fiber level as shown by the embedded single-fiber test is mirrored by the failure behavior at the macroscopic level. The increase in adhesion also tracks the same between the ITS results and 0° flexure data. 

Metabolism of pectin. Pectin has only recently come, to be considered a part of the dietary fiber complex. Previously it was excluded because 1) it is not fibrous (except at the molecular level), 2) it escapes detection in standard fiber tests owing to its solubility, and 3) it usually does not survive intestinal passage. In a reassessment of which dietary components should be considered fiber, Trowell (49) proposed that dietary fiber include those constituents of food resistant to hydrolysis by man s alimentary enzymes. Spiller (50, 51) suggested that confusion surrounding the term "fiber" be avoided by using the term "plantix" to denote those plant materials of polymeric nature not attacked by human digestive enzymes. 

When the uncrosslinked self-assembled collagen fibers tested above were crosslinked by removal of water (dehydration) the resulting incremental stress-strain curves approached those observed for tendons (see Figure... 

In Sudan [607], cotton is classified twice, as seed cotton before the gin and as lint at the port of shipment. The handpicked cotton is piled up on covers where trash and other contaminants are removed. Grades are assigned to the piles and the graded cotton is transported to the gin. The field classification system is felt to be key to implementing quality control measures such as timely and early picking, which can reduce stickiness. The ginned cotton is baled and transported to Port Sudan where the lint is reclassified and samples are taken for fiber testing. 

Figure 5. Apparatus elevation A, microscope objective B, bar support C, magnetic clamp D, platform Ey pulley F, fiber tested G, glass fiber H, heater I, walls J, optical fiber K, lever L, load and M, magnetic...

Scanning Electron Photomicroscopy. At 190 and 160 °C, samples aged in nitrogen were significantly less yellowed and stronger than those aged in air. The distinctively different modes. of fractures in fibers tested in the different environments are visually apparent in Figures 19-21 (40). 

Single fiber tests were used to evaluate the fiber-matrix adhesion. Acid/base interactions do play a role in this adhesion but are not exclusively responsible for improvements at the interface. Treatment with a siloxane coupling agent was proven to be effective in lowering the dispersive component of the carbon fibers and altering their acid/base properties, producing poorer adhesion. 

Inspection of the graph suggests that the across the fiber and parallel to the fiber tests may fall on different curves. Calculating separate correlations for the two sets of data, we get the equations... 

Figure 10. Weibull plots of tensile-strength distribution for kilometer lengths of fibers tested in 20-m gauge lengths. In each case one variable was intentionally altered and all others were optimized. (Reproduced with permission from Ref. 6. Copyright 1980 IEEE.)...

The linear density of the fibers tested is determined in accordance with ISO 1973 (see earlier in Section 3). 

ASTM D 5103 95 Length and length distribution of man-made staple fibers (single-fiber test). 

Since the completion of the first edition of Fiber Chemistry, remarkable progress has taken place in the industrial applications of vinylon. The health hazards of asbestos, which had been used as reinforcement materials in cement, led to the search for an alternative cement-reinforcement fiber. Among the many fibers tested, vinylon showed the most superior performance. Figure 4.34 shows the flexural strengths of the slate in the presence... 

Rat-tail collagen type I extruded fibers tested after stretching from 0 to 50%. 

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