A manual screen changer is a core auxiliary filtration device specially designed for plastic pipe extrusion production lines. Installed between the extruder and die head, it plays a vital role in purifying molten plastic, stabilizing extrusion processes, and improving finished pipe quality, making it a staple device in small and medium-sized plastic pipe factories worldwide. In plastic pipe production, raw materials often contain impurities such as unmelted polymer particles, carbonized gels, an