Posts: 6
From:Istanbul, Marmara, Turkey
Registered: Feb 2005

posted July 18, 2007 04:53 AM            

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Hi,

I work for a company that is producing rigid pvc window and door profiles. I generally see the impact tests of the colored profiles are significantly lower than the white ones. Anyone has any idea what should i do ?

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Posts: 874
From:Brodheadsville, PA USA
Registered: Jun 2001

posted July 18, 2007 08:22 AM            

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Typically the pigment load is much higher in colors as opposed to white and black. The higher loading casues an impact reduction.

Possible solutions are;

Higher impact starting formulations or additional impact modifiers
Dyes rather than pigments
Co-extruded cap layers of colored materials
Coated pigments?

Hopefully Skip will respond.

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Best Regards,

Tom Cunningham

www.ExtrusionTechnicalServices.com

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Posts: 6
From:Istanbul, Marmara, Turkey
Registered: Feb 2005

posted July 26, 2007 08:45 AM            

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In color formulations pigment load is max : % 1~1.2. In white is generally %5.

What can you tell me about migration of the dyestuff from the profile to the lamination film (eg: Renolit)

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Posts: 874
From:Brodheadsville, PA USA
Registered: Jun 2001

posted July 26, 2007 09:55 AM            

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In general filler and pigments which have irregular shapes, for adheasion to the polymer, and large particle size cause impact problems becasue they create stress concentration points in the compound. Stress concentration points are low radius voids in the compound. TIO2, which has a angular form, in known to cause problems with impact. Coatings help the TIO2 stick to the polymer which lessens the problem.

Dye migration is about chemical structure and compatibility with the matrix. Ask your colorant supplier.

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Best Regards,

Tom Cunningham

www.ExtrusionTechnicalServices.com

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