Estimate of the nonwoven geotextile mechanical characteristics starting from the fiber characteristics

The study in question is based on the specific industrial experience made on nonwoven lines consisting mainly of the following manufacturing phases: opening of the fiber, carding, pre-punching, needling 1, needling 2, folding, calandering. The raw material considered is made of high tenacity polypropylene (PP) fiber. The study starts from the analysis of the fiber resistance trend in reference to the EN ISO 5079 toughness test, in order to characterize the behavior of a mixture of up to three types of fibers. The specific processing characteristic of the production line is represented by the specific mechanical tensile resistance values obtained on the nonwoven geotextiles with reference to EN ISO 10319. Subsequently, the loss of resistance of the mixture due to the different toughness and elongation of the three components of the mixture is determined. Moreover, the weighted resistance values of the individual components of the mixture are calculated in order to determine the toughness of the mixture itself. Starting from the toughness of the mixture, as estimated above, the resistance of the resulting nonwoven geotextiles is linearly obtained. In order to evaluate this model, the values of an historical series of production control tests have been processed.