A CO-ROTATING SELF-CLEANING TWO-SCREW EXTRUDER WITH A GRADUAL NUMBER OF THREADS AND THROUGH SELF-CLEANING FUNCTION， AND A PROCESSING METHOD USING THE SAME

摘要

A co-rotating self-cleaning two-screw extruder with a gradual number of threads and through self-cleaning function, and a processing method using the same, are disclosed. The screw assembly in the extruder includes a first screw (3) and a second screw (4) that co-rotate at the same speed in engagement; the first screw (3) includes a first single threaded element, a first transition element, a multiple threaded element, a second transition element and a second single threaded element that are connected in sequence; and the second screw (4) includes a first single threaded element, a third transition element, a multiple threaded element, a fourth transition element and a second single threaded element that are connected in sequence. The materials are transferred by rotation of the first (3) and second screws (4), and get their respective compositions mixed based on the structure of a gradual number of threads; with the flow passage expanded, contracted and re-expanded in shape in sequence, the materials undergo the single-to-multiple threaded, multiple-to-single threaded and again single-to-multiple threaded chaotic mixing in sequence; and the first and second screws achieve the self-cleaning effect by wiping each other.