Hot Runner Cleaning

Open Mold Method

Introduction
Cleaning of Hot Runner systems using unfilled grades of ASACLEAN® (see grades below) may now be performed. ASACLEAN® that is run through hot runner channels will combine with residual materials and remove them safely while leaving a minimal amount of ASACLEAN® residue.

Precautions

• Unfilled grades of ASACLEAN® can pass through the same clearances as the resins being processed. Filled ASACLEAN® grades (EX grades) are not usually recommended for hot runner cleaning. Consult Sun Plastech Inc. for guidance on using filled grades for purging hot runners.
• External heating systems - Raise the manifold temperature 68°F – 86°F (20°C – 30°C) for improved flow. Use caution if running heat-sensitive resins; in which case, raise heats only if permissible, up to 50°F (10°C).
• Internal heating systems - Consult Sun Plastech for technical assistance before using ASACLEAN®.
• If available, apply mold release agent to reduce the potential for material sticking to the mold surface.
• Preparation: The entire Hot Runner System temperature must be within the temperature usage range of the ASACLEAN® grade to be used.
  
  

  UP	340°F - 570°F
  SX	570°F - 735 °F
  E	350°F - 530°F
  U	350°F - 680°F

Purging with Mold Plates Open

1. After the screw and barrel have been cleaned thoroughly using ASACLEAN®, seat the nozzle into the mold.
   
   
2. Open the mold plates.
   
   
3. Set up a Safety-approved surface for collecting the purging's.
   
   
4. Verify that the mold safety door is closed.
   
   
5. Add enough ASACLEAN® into the hopper to fill the barrel approximately 1/2 full.
   
   
6. Extrude ASACLEN through the hot runner system starting at a medium velocity. Increase screw speed to the maximum safe level for maximum cleaning. Once ASCLEAN is flowing adequately through all the gates, perform injection shots (air shots) with mold plates open.
   
   
7. Visually-inspect purging's for color and/or carbon contamination
8. If color and/or carbon still remain, repeat step 5 through 7 until the ASACLEAN® is visually free of color and/or carbon contamination and has returned to a clean appearance.
   
   
9. Purge out any remaining ASACLEAN® using the maximum safe screw speed. Adjust the temperatures in the barrel and hot runners to the processing conditions for the next resin to be processed.
   
   
10. Flush the system with the next resin to be processed using the maximum safe screw speed until the next resin is visually free of the ASACLEAN.
    
    
11. Resume production using normal production settings.

Although, to the best of our knowledge, the information contained herein is a fair and accurate representation, we assume no liability of any type in this regard. It remains the sole responsibility of the user to determine the suitability of the information and described product for the intended use and freedom from any patent infringement. We recommend that the user always adhere to relevant use and handling instructions from the manufacturer and supplier of any related equipment or material and that the user ascertain in all respects the suitability and safety for the intended purpose of any equipment, technique, or material described herein. Any part produced containing ASACLEAN® Purging Compound is not recommended for resale. ASACLEAN® is designed only for use as a purging compound.

Closed Mold Method

Introduction
Cleaning of Hot Runner systems using unfilled grades of ASACLEAN® (see grades below) may now be performed. ASACLEAN® that is run through hot runner channels will combine with residual materials and remove them safely while leaving a minimal amount of ASACLEAN® residue.

Precautions

• Unfilled grades of ASACLEAN® can pass through the same clearances as the resins being processed.
• Filled ASACLEAN® grades (EX grades) are not usually recommended for hot runner cleaning. Consult Sun Plastech Inc. for guidance on using filled grades for purging hot runners.
• External heating systems - Raise the manifold temperature 68°C – 86°F (20°C – 30°C) for improved flow. Use caution if running heat-sensitive resins; in which case, raise heats only if permissible, up to 50°F (10°C).
• Internal heating systems - Consult Sun Plastech for technical assistance before using ASACLEAN®.
• If available, apply mold release agent to the mold surface to assist in ASACLEAN® part removal. It is easier to remove parts from the mold while they are still warm.
• Preparation: The entire Hot Runner System temperature must be within temperature usage range of the ASACLEAN® type to be used.
  

UP	340°F - 570°F
SX	570°F - 735 °F
E	350°F - 530°F
U	350°F - 680°F

Purging with Mold Plates Closed

1. After the screw and barrel have been cleaned thoroughly using ASACLEAN, seat the nozzle into the mold.
   
   
2. Verify that the mold safety door is closed.
   
   
3. To reduce the small possibility of ASACLEAN parts getting stuck in the cavities, remove the pack and hold velocities and pressures from the mold (do not adjust pack and hold time).  Add enough ASACLEAN into the hopper to fill the barrel approximately ½ full.
   
   
4. Inject ASACLEAN using short-shot molding (approximately 50% shot size).
   
   
5. Eject parts immediately, while they are still warm.
   
   
6. Visually inspect parts for color and/or carbon contamination until parts are clean.
   
   
7. If color and/or carbon still remain, repeat step 4 through 6 until the ASACLEAN is visually free of color and/or carbon contamination and has returned to a clean appearance.  Purge out any remaining ASACLEAN using the same method as above.  Adjust the temperatures of the barrel and hot runners to the processing conditions for the next resin to be processed.
   
   
8. Flush the system with the next resin to be processed, molding parts until ASACLEAN can no longer be seen in the next resin.
   
   
9. Resume production using normal production settings.

Although, to the best of our knowledge, the information contained herein is a fair and accurate representation, we assume no liability of any type in this regard. It remains the sole responsibility of the user to determine the suitability of the information and described product for the intended use and freedom from any patent infringement. We recommend that the user always adhere to relevant use and handling instructions from the manufacturer and supplier of any related equipment or material and that the user ascertain in all respects the suitability and safety for the intended purpose of any equipment, technique, or material described herein. Any parts produced containing ASACLEAN® Purging Compound are not recommended for resale. ASACLEAN® is designed only for use as a purging compound.