Assisting with screw pulls
Anyone that has pulled a screw can attest to the time consuming nature of the work.
Is the temperature just right? Is everyone acting in a safe manner? What are we going to find when we get that screw out of there?
Using a purge compound to clean and then pull a screw is the safest, most efficient way to get the job done. Using a glass-filled grade will speed up the job even further. The screw will be easier to pull, and there will significant labor savings in terms of actually cleaning the screw when it comes out – some purging agents actually just peel right off. A good technical sales rep will be able to assist in determining the best temperature range and techniques for a specific grade when pulling a screw. It is important to request specific procedures for this from the purge supplier.
Generally speaking, the operator should clean the screw using the purge instructions above. First, remove the screen pack and increase the head temperature, while keeping it within the safe operating range. Purge the screw and barrel until the purge pile is free of contamination. Then, drop the barrel and head temperatures to the supplier recommended levels and proceed with screw pull.