Q: What is the difference between normal nonwoven and calendared nonwoven (both needlepunched) geotextiles? Where can we use calendared nonwoven geotextiles?
A: Calendared nonwoven geotextiles are passed between a set of heated rollers that applies normal pressure as a tertiary process of the production. This process increases the modulus, strength, tear resistance, puncture resistance and impact strength of the geotextile. It simultaneously decreases the apparent opening size, percent open area, thickness, permittivity and frictional interaction of the nonwoven with a textured geomembrane. Manufacturers have a host of production variables in which they can tailor-make geotextiles directly to your specification.
Heat-bonded, calendared nonwoven geotextiles are primarily used for filtration, protection, reinforcement and separation.