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| Author | Topic: carbon contamination in product |
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imn Member Posts: 2 |
posted October 19, 2003 02:47 AM
  
hello all, we are consistently facing carbon contamination in our polycarbonate product. We have checked for any air leakages and overheating but so far found none. Would really appreciate any advice on the source of the contamination. Thanx! IP: Logged |
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Tom C Moderator Posts: 243 |
posted October 19, 2003 10:24 AM
Simple. Tear apart the extruder and look for burnt areas. Clean out the buildup. Put it back together. Run. Better to redesign the areas to prevent stagnation. Tom C IP: Logged |
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DK Member Posts: 4 |
posted October 26, 2003 08:24 PM
SOMETIMES CARBON IS DUE TO DEGREDATION OF OF YOUR RAW MATERIALS. WHEN YOU PURGE YOUR EXTRUDER AND IT SITS FOR AWHILE THE MATERIAL THAT IS LEFT INSIDE WILL START TO DEGRADE AND CAUSE CARBON BUILD UP. HAVE YOU TRIED USING A SCREEN PACK BEHIND YOUR DIEHEAD? IT WILL TAKE CARE OF 99% OF YOU ISSUES. IP: Logged |
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imn Member Posts: 2 |
posted October 27, 2003 08:25 AM
yeps we have filter, but the black specks are smaller than the filter media, so it cannot be trapped. We did find some corrosion on the screw surface, so is this a possibility of the contaminants? What could the other factors be? IP: Logged |
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Tom C Moderator Posts: 243 |
posted October 27, 2003 04:55 PM
1) First make sure your material supplier is not delivering black specs to you. One large black spec can make thousands going through the extruder. 2) Make sure your not contaminating the material yourself before it gets to the extruder. Tom Cunningham IP: Logged |
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DK Member Posts: 4 |
posted October 28, 2003 01:36 AM
IF YOU ARE USING A SCREEN PACK, WHAT SIZE MESH ARE YOU USING? IF SO, IS IT A SINGLE LAYER OR A MULTI LAYER SCREEN PACK? IP: Logged |
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