Selecting the correct machine depends heavily on the input material type (e.g., denim, cotton yarn, non-woven fabrics, or synthetic fibers). For hard waste like denim or yarn, you must prioritize machines with high-speed spiked cylinders and multiple opening stages (usually 2 to 6 stages) to ensure fiber length is preserved. For soft waste like garment offcuts, a standard tearing machine with a focus on output volume is sufficient. Always verify the cylinder diameter and wire clothing specifications, as these directly impact the quality of the recycled fiber.