UV stabilized plastic reccomendation 5

[fade2blue]

I have a thermoformed HDPE cover that is used outdoors as a machine guard. After a few months in service the part becomes brittle and fails. Can anyone reccomend a material that has similar mechanical poperties with enhanced UV stability? The color must be white or a carbon black would be substituted. Also the production volume is fairly low so a higher priced stocked material would be preffered to an X ton minimum order. Would a TiO2 additive help?

 

[patprimmer]

TiO2 is a white pigment. It has at least 2 crystal forms. The rutile form blocks UV light but a lot depends on particle size and distribution. Carbon black also blocks UV light. Same deal re size and distribution.

It can only protect what is behind it, not what is in front of it.

Stabilisers that dissolve at a molecular level are required to protect the surface. There are numerous types and different modes of action. Different formulations are used for each polymer. To explain it in full detail would be a few hundred pages.

Grey "outdoor PVC normally contains TiO2 and carbon black to get the grey colour. It also contains some antioxidants (previously lead compounds, but now more likely tin compounds) and cheap mineral fillers.



Regards
Pat
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[automatic2]

TiO2 was the primary UV blocker in our siding. Tin was a heat stabilizer and various waxes where lubricants. Yesteryear lubricants did have lead content.

 

[Jboezi]

2 questions
1. Anyone have recommendations on a UV blocking PP that is FDA compliant (injection moldable)?
2. If I wanted to spec a resin that blocks 90% of UV light from passing through how would I do so? Is there an ASTM spec? As I understand ASTM D1003 Haze isn't the right thing.

 

[Pud]

qtg836b: suggest you start a new thread rather than hijacking this one - you will get a better response.

You will also need to define your requirements much more than you have done...

H

http://www.tynevalleyplastics.co.uk

 

[patprimmer]

^^^^ Like Pud says

Regards
Pat
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