Technical Notes

Thrace-LINQ TECH NOTE #18
THERMAL WELDING OF NON-WOVEN GEOTEXTILES

Thermal welding can be performed on nonwoven needlepunched geotextiles. A wedge welder can thermally seam geotextiles 3.5 ounces per square yard and heavier. A hand held hot-air welder should only be used on geotextiles having a nominal mass per unit area of 7 ounces per square yard or greater. Thermal seaming with a hand held hot-air welder can be accomplished by applying hot air approximately 1 - 6 inches away from the geotextile surface. Seams shall be a minimum of 4 inches unless a wedge welder is used, in which case the width of the wedge welder will serve as the minimum requirement. Mechanical pressure through use of a roller is required to complete the seam. An overlap seam geometry is recommended for both methods as it has proven to result in a higher efficiency.