Purging Compound Procedures for Injection Molding
- Always keep safety in mind by wearing safety glasses, gloves when purging ANY material.
- Refer to machine manufacture manual on safety procedures.
- Cover sprue bushing before purging.
- Make sure that all nozzle band wires are clear of purging direction of flow before starting.
- If machine is equipped with a vented barrel, clean the complete vented area and plug before purging with Purge Right.
- Retract the injection unit. Run the barrel empty using maximum back pressure until empty.
- Check to see that temperatures are correct for Purge Right grade being used. Most grades are effective from 360F to 600F.
- Thoroughly clean hopper and feed throat and all hoses if going to a new resin or color change.
- Load one to two times the barrel capacity of Purge Right into the hopper. This is the typical amount needed for most applications. The actual amount will depend on the condition of the equipment and resin being purged.
- With the screw in a forward position, increase the back pressure and start purging until the Purge Right begins coming out of the nozzle and becomes mostly white to clear.
- Drop the back pressure to zero and fill the barrel with Purge Right.
- A soak time of 5 minutes is recommended for optimum results.
- To insure that the Purge Right is at its maximum effectiveness, the purge should be rising, swelling or bubbling.
- Purge until all the remaining Purge Right is completely removed from of the barrel.
- Repeat steps 4-9 if contaminants are still visible.
- After all the Purge Right has been displaced in the machine, start with the screw in a forward position with maximum back pressure and introduce the next production material. Once the new resin appears adjust back press to your set up procedure.
Other Helpful Tips:
- Insure that the nozzle and nozzle tip are clean and seating correctly as this could cause hang ups and burning.
- For extreme contamination such as carbon, liquid color or highly loaded pigments in colorants, you may consider using a HDPE or PP to pre-purge prior to using Purge Right.
- One of our glass grades may be considered, consult with our technical personnel.
***Notice: The information herein is based on what we believe to be reliable data, but Plastic Solutions International Inc. MAKES NO WARRANTIES EXPRESS OR IMPLIED, including, but not limited to, the implied warranties or merchantability and fitness for a particular purpose. Because PSI Inc. has no control over the use to which others may put the product, it does not suggest or represent that the same results as these referred to herein will be obtained by another user. Each user of the product and the compositions mentioned herein should make his or her own tests prior to purchase to determine the product’s suitability for his or her own particular uses. Nothing contained herein is to be construed as a recommendation for the use in violation of any existing patent, foreign or domestic, or of applicable laws and regulations.