Device for mixing additives and introducing the same into a polymer melt stream

摘要

The invention pertains to an apparatus for premixing additives and feeding them into a polymer melt stream. The apparatus has a conducting element 2, first and a second intermediate element 4a and 4b, and a pump assembly 6, wherein the polymer melt stream is guided through channels 8 and 10 of the conducting element. The second intermediate element 4a has a feed element 12 that extends into the first channel 8 to form a ring channel. The feed element 12 is surrounded by openings 14, through which a portion of the polymer melt is drawn off, so that it can be mixed with an additive inside the pump assembly 6. This mixture is then returned via the feed element 12 to the polymer melt stream. The apparatus according to the invention makes it possible to decrease the residence times of the polymer and requires very little in the way of apparatus.