Posts: 2
From:Lodi, Nj USA
Registered: Apr 2005

posted April 13, 2005 10:40 PM               

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We Have recently been running Polypro Type Profax 7823 and always have problems getting started. We produce plastic tubes of 1 3/16" diameter with a wall thickness of .014". Our extrudate looked very scaly and the finished tube has a rough surface. we use a dual tank vacuum sizer with our water temperatures between 25°c-30°c. extruder temperatures are as follows:

Feed Bushing 35°c
Feed Section 200°c
Compression 200°c
Metering 1 200°c
Metering 2 190°c
Output 185°c
Connection Pc. 230°c
Hinged Flange 230°c
Die Head 1 230°c
Die Head 2 300°c
Die 300°c
Melt Temp. 300°c

these temperature settings have been provided from a reference from Breyer extruder company. Can anyone tell me how can I help this issue. is there something going on in the process? we do not run this material very often but when we do i want to make it simple for our employees to start.

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Posts: 2
From:Lodi, Nj USA
Registered: Apr 2005

posted April 13, 2005 10:41 PM               

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I forgot to add that we are mixing this material with color concentrate Blue white X26272 at a 49:1 ratio

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Posts: 500
From:Brodheadsville, PA USA
Registered: Jun 2001

posted April 14, 2005 07:12 AM               

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CoronaDrinker,

Personally Yuengling Lager keeps me going.

The PP you use has a melt flow of 0.4 . This is a nice viscous grade for extrusion. However it is not going to be too happy with the 185-190C temperatures you have set on the screw. Try progressing to about 240C at the end of the screw.

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Best Regards,

Tom Cunningham

Extrusion Technical Services

www.ExtrusionTechnicalServices.com

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Posts: 361
From:McHenry, IL USA
Registered: Nov 2002

posted April 20, 2005 08:17 AM               

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Could also be that your color concentrate is not compatible. What is the base resin used, and what is the MFR of it?

In general, most CC's are not of the same generic class of resins.

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