As part of this process, various additives such as pigments or stabilizers are worked in and/or volatile components are degassed. Using a filtering process, contaminants are then separated out of the liquefied material before pellets with good transporting and processing characteristics are created in a pelletizer. During filtration, the liquefied plastic is pressed through a more or less tightly-meshed wire cloth, depending on the later use; the cloth rests on a support. State-of-the-art filter replacement is effected in such a way that continuous production is not interrupted. The non-stop screen pack changer developed by WP also works on this principle, but by comparison with conventional systems it demonstrates notable advantages.

Advantages

-

Large filter area in a compact construction and low weight, easy to handle

-

Multiple re-use of filter inserts once these have been cleaned

-

Long lifetime for filter inserts

-

Small volume filled with product

-

Short product holding time and heating time

-

Low changes in cross-section in molten material channel

-

Advantageous flow ratios

-

Lower pressure build-up, practically independent of screen pack changer

-

Even distribution of contaminants over the filter surface

-

Optimal use of filter surface

-

Minimal product contamination during filter change

-

Operationally safe, maintenance-free seal (no wearing parts such as: bronze sealing rings

Technical data: