Backward Pumping Kneading Block

The backward pumping kneading block plays a role of adjusting the fullness of the material and extending the residence time of the material in the barrel during the material mixing. Its blocking force is weaker than the reverse feed screw sleeve, but slightly stronger than the 90 ° kneading block. Which area should choose the backward pumping kneading block? How to use it with the reverse screw sleeve in the full length? How many reverse elements should be selected for the full length of the screw? All of these questions are testing the experience and skill of the modification engineer, which has a considerable impact on the quality of the modified special material or masterbatch. For example, in the case of nylon (PA66) flame retardant enhanced modification, the first kneading zone must be stringed by four kneading blocks (such as 30 ° + 45 ° + 45 ° ++ 45 ° L), and must be finished by 45 ° L blocks Stuffing, the whole machine can stably plasticize and stably extrude the PA66, a strong crystalline plastic.