puncture resistance of polyester (pet) and polypropylene (pp) needle-punched nonwoven geotextiles

it is common practice to use needle-punched nonwoven geotextiles as puncture protection for geomembranes against sharp objects like gravel or stones in either the soil above or the underlying soil/rock below. there are several design and experimental methods available for geotextile selection in this regard. none, however, directly address the type of resin or fiber from which the geotextile is made. this paper does exactly that insofar as a direct comparison of similar mass per unit area polyester (pet) versus polypropylene (pp) geotextiles are concerned. furthermore, two types of pp geotextiles are evaluated; one made from continuous filaments and the other from staple fibers. three different size and shaped puncture probes are used in the testing program. all three are astm standards, i.e., d4833, d5495 and d6241. the test results clearly indicate that geotextiles made from pp fibers outperform those made from pet fibers at all masses evaluated. clearly, the present trend of using pp resin for heavy nonwoven protection geotextiles seems justified on the basis of these test results. in addition, the continuous filament pp and staple fiber pp geotextiles performed equivalently over all mass ranges for the three different types of puncture tests.