Purging is a cleaning process of injection molding to clean thermoplastics molding machines and extruders. This process is very important as a virgin resin cannot effectively remove previous resin residuals from the previous run.[1]
 Before and after purging image of injection molding machine screw | |
| Process type | Cleaning process of Injection moulding |
|---|---|
Method
editBelow are the major steps for purging-[2]
- Turn off the material flow in the injection molding machine
- Turn off the colorant flow which is added or applied in order to change the colour of a material
- Maintain existing process settings and continue manufacturing plastics parts
- When last part is completed, set the nozzle retraction mode
- Clean hopper and colorant blender (whichever necessary)
- Load any commercial purging material or new material to be used into hopper feed zone
- Clean nozzle and sprue bushing by making few shots
- Continue purging until most of the commercial purging material is out of the hopper
- Feed at least one injection capacity of the next production resin to rinse out any residuals
- Start the next production with new resin
References
edit- ^ "Tips of the trade: Purging troubleshooting for injection molding". Plastics Today. August 23, 2010. Retrieved November 18, 2020.
- ^ "Follow These Tips to Power Up Your Purging Process". Plastics Technology. Retrieved November 18, 2020.