A new test for pulp and paper forming fabric materials

Forming fabrics are an integral component in the production of paper. Wet paper is dewatered and partially dried on belts made from the forming fabrics. The process of moving across water removing devices at the high speeds causes the fabric to wear. In fact, wear is the primary degradation mechanisms which control the lifespan of the fabric. Several wear tests exist for measuring the wear of these forming fabrics, however, there is no agreed upon industry standard. Further these tests measure the resistance of a finished woven fabric to wear. In order to overcome this limitation, a new test was devised that measures the performance of single yarn filaments in a realistic simulated environment. This test also allows easy comparison of the wear caused by different counterfaces used during paper production. The test consists of a single loop of filament tensioned against a cylindrical form. This shaped loop is submersed in a test solution and run against a counterface. Two different filament materials were tested against alumina and zirconia counterfaces in several different test solutions. Tests were conducted for both a fixed distance and until filament failure. Scanning Electron Microscopy (SEM) was used to evaluate the wear mechanisms that occurred during testing. The fabrics tested displayed similar wear characteristics to fabrics used in actual paper production. Differences in wear rate were seen both for different filament materials and counterface materials. This indicates that this new test can be used to evaluate the wear behavior of forming fabrics.