CLP curves

Fig. 9.4 Possible interpretation of experimental results associated with CLP curves proposed in (a) [36] and (b) Reproduced with the kind permission of the publishers of [45, 46]...

The interfacial shear strength of polymer composites reinforced with lignocellulosic fibers has been evaluated using (9.2) for the critical length obtained in CLP curves. Transformation of this equation provides a simple way to determine the IFSS of a system composed of a given lignocellulosic fiber embedded into a polymeric matrix. 

Figure 9.5 illustrates typical CLP curves for different lignocellulosic fiber embedded in polyester matrices. 

It is relevant to mention that the method of obtaining the IFSS based on the CLP curve provides not only interfacial information but also the critical length 4, which is important for composite design. For instance, fiber for which the natural length is greater than 154 are considered continuous [42]. In this case, the composite equations (rale-of-mixtures) for the strength and stiffness give maximum values. 

Table 9.2 presents the critical length evaluated by CLP curves and corresponding IFSS, calculated by the Kelly and Tyson equation, for different lignocellulosic fibers embedded in thermoset polymeric matrices. 

The TRAACS 800+ is controlled by a personal computer and the features provided include complete interactive control via keyboard or mouse calculation of results as necessary taking into account baseline or sensitivity drift, graphical output of calibration curves for all calibration types—either Hnear or non-hnear, input facility for sample identification data allowing storage on disc and real-time results together with chart traces on a computer printer. The programs allow easy access to input or data files and connection to other computers, and gives system performance verification to CLP standards and built-in QC charts. 

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