Posts: 2
From:India
Registered: Apr 2010

posted April 21, 2010 12:46 PM            

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m/c - 65/18 kolsite-Battenfeld
caco3 - 3 microns(stearate coated)
filler level - 4phr
production size - 1/2"(BS 3505)
production rate - 5 mts/min
temp. profile 180(BZ1),175,170,160(BZ4),152(CH),168(DZ1),175,180,185(DZ4).the problem is the pipe sometimes never pass the impact test in 3-5 days production but in some occasion it pass from the second day of production(there is no block in vent).can anybody help me to solve the problem

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Posts: 125
From:Silver City, NM, USA
Registered: Jun 2001

posted April 21, 2010 01:36 PM            

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First, even though you only use 4phr CaCO3,
I would suggest using smaller particle sizes--2, even better 1 micron.
Then,I would add about 1.0 phr of acrylic process aid like K-120N,to promote more complete fusion during extrusion.

Impacts should improve.

Skip

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Posts: 4
From:The Netherlands
Registered: May 2005

posted August 01, 2010 04:41 AM            

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Suggest to check following also:
- Gelation or fusion - Failing methylene-dichloride test, meaning bad gelation.
- Air inclusions - Insufficient vacuum. Glycerine test.
- Local thin wall - Check wallthickness around the circumference or centering.
- Pollution in material. Check dry blend visual or by sieving.
- Overgelation - too high melt temperature, almost near to burning.

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