Geosynthetic clay liner

Geosynthetic clay liners (GCLs) are factory manufactured hydraulic barriers consisting of a layer of bentonite or other very low-permeability material supported by geotextiles and/or geomembranes, mechanically held together by needling, stitching, or chemical adhesives.

[1][self-published source] The origin of GCLs can be traced back to 1962 when Arthur G. Clem filed a patent for preformed moisture impervious panels which combined bentonite clay with corrugated paperboard.

[2] In 1982, Arthur J. Clem filed a patent for a what would today be recognized as a GCL which combined bentonite clay, adhesive, and a geotextile.

About the same time a different product in Germany, Bentofix, was manufactured by placing bentonite powder between two geotextiles and then needle punching the three-components system together.

The needle punching method of manufacture (US patent filed in 1989) gave the resulting composite material shear strength, a critical feature for installation on slopes.