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Author
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Topic: effective purging compound for pvc
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Brie Williams
Member Posts: 3
From:Coeur d' Alene ID, 83814
Registered: Oct 2003
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posted October 29, 2003 03:21 AM
  
I work for a custom injection molder where we often run pvc, both rigid and flexible in black. These materials are causing major carbonization in our barrels. We often have to run white or yellow Bayblend after these PVC jobs and we just fight the contamination like crazy. We purge tons of Grak and a product called Instapurge, but we almost always end up pulling the nozzle body and manually cleaning it with a steel brush attached to a drill, and that still doesn't solve the whole problem. If anyone knows of a good purging compound for PVC please let me know.IP: Logged |
2beeps
Moderator Posts: 56
From:Silver City, NM, USA
Registered: Jun 2001
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posted October 29, 2003 10:48 AM
Brie,
Here is a purge formulation that I used in rigid PVC extrusion(using K67 pvc) that I feel can be used in injection molding by
using the molding grade PVC resin (K55-60).PVC (K 55-60) 100parts
CaCO3 (1-2micron) 100parts
Calcium Stearate 4.0 parts
165 Paraffin Wax 3.5 parts
Methyl or Butyl Tin
Mercaptoester Stabilizer 10.0 parts
Indicator pigment as desired This is blended in a high intensity mixer and
used as a powder blend to furnish a mild
scrubbing action ----at least in twin screw and single screw extruders it worked well.
Should work in IM machines as well--to clean both rigid and flexible compounds out. You could try to get someone to pelletize this purge--although the pellets would break up easily due to the high filler content. Skip IP: Logged |
Brie Williams
Member Posts: 3
From:Coeur d' Alene ID, 83814
Registered: Oct 2003
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posted October 30, 2003 04:36 AM
Thank you kindly  I will talk to our engineers and see if we can give it a try.IP: Logged |
JInman
Senior Member Posts: 9
From:Appleton,WI, USA
Registered: Oct 2003
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posted October 30, 2003 09:51 PM
Try Dynapuge V or Asaclean. I've tried both on rigid PVC going from black to white or natural and have had pretty good results. Addedbous you can get free samples of both. I looked at Instapurge and it was not really ideal for lower melt temps and cost a hell of a lot more than the other two.IP: Logged |
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