Purging Procedures: Extrusion
Purging Compound Procedures for Extrusion
- Always follow safety procedures before performing start up or shut down on ANY material. It is the machine operator’s responsibility to wear the appropriate protective equipment such as gloves and safety shields.
- If the Extruder is equipped with a vented barrel; clean the area around the vent and the plug before sealing. You will need to monitor the upstream pressures.
- Refer to purging procedure on standard or vented barrel. Steps 1-8 need to be completed before attempting to purge the hot runner.
- Maintain resident temperatures when using PURGE RIGHT™.
- Run the Extruder empty by shutting off feed throat on existing resins, colorants and additives.
Clean the hopper, feed throat and loader hoses thoroughly.
- Remove the screen packs. Insure that the die opening is at least .030 inch.
- Begin purging 2 times the barrel capacity with PURGE RIGHT ™. Amount needed depends on condition of equipment.
- Purge should be rising, swelling or bubbling to insure you’re getting the maximum effectiveness.
- Purge through the die opening until PURGE RIGHT ™ is clean to white and free of contamination.
- Introduce your next production resin to flush out the PURGE RIGHT ™.
- Clean your die surface and install a new or clean screen pack.
- Readjust your die if necessary.
- You are now ready for production run.
Purging Procedures for Extruders with Acclimators:
- Follow safety procedures #1 and #2 above.
- Follow procedures #2 and #3 above on cleaning and removal of existing resin.
- Increase accumulator temperature by 50°F.
- Allow for at least 3 times accumulator capacity with PURGE RIGHT ™.
- Load the accumulator full with PURGE RIGHT ™. If the equipment is designed with more than one Accumulator, each Accumulator needs to load with PURGE RIGHT ™ and temperatures raised.
- Center your die and open the vale gap to ½ mm.
- Allow PURGE RIGHT ™ to soak 30-45 minutes.
- With the valve gap open to its maximum, empty PURGE RIGHT ™ from the Accumulator with one continuous purge.
- After the PURGE RIGHT ™ has been displaced with the next resin you are ready for production.
Other Helpful Tips:
- Consult with your PURGE RIGHT ™ technical team to determine which grade would be most effective.
- For extreme contamination such as carbon, liquid color or highly loaded pigments in colorants you may want to consider using a HDPE or PP to pre-purge prior to using PURGE RIGHT ™. Raising the temperatures 15° F on the soak time could also prove to be helpful.