The PPD series utilizes gradient pore fiber depth filtration technology, combined with filter membranes of varying thicknesses, greatly enhancing the dirt-holding capacity of the filter. This design prevents clogging of the filter's surface, with the upstream pore size being coarser and the downstream finer, allowing for graded retention of impurity particles. The service life is more than twice that of ordinary filters, reducing replacement frequency and lowering usage costs. The high dirt-holding capacity and deep pleated design make it widely used in high-load applications such as semiconductor CMP processes, cleaning points in panel new energy, and MLCC slurry filtration.