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green thermoplastic material

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angelino310

Mechanical
Jan 23, 2006
3
US
I’m working on a new design of a custom black color end cap piece that’ll function as a non-adjustable furniture glide for storage units. I’m looking for a least, preferably not carcinogenic material (definitely non-PVC) for injection molded process. Would nylon, LDPE or PP be appropriate for this application and environmental considerations? Thank you.
 
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All three are suitable for glides or bearings and all three are used extensively in such applications. Which one is most effective depends on a lot of factors not yet mentioned.

Different colour formulations can significantly alter the performance. Even 2 different blacks can have significantly different performance if one uses carbon and the other uses a dyestuff like Nigroseine.

Regards
Pat
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patprimmer - Can you describe or elaborate more on the performance difference between using carbon and nigroseine for color dye. I think LDPE might be too soft for this application. HDPE & the other two mentioned would be more suitable.
 
Carbon black is a nucleating agent and Nigroseine is a nucleation inhibitor.

That influences the rate of crystal growth, the number of crystals and the nature of the crystals as the material changes from liquid to solid phase.

The different crystal structure has a significant effect on physical properties.

Regards
Pat
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Carbon black is by far the most common colourant used in colouring thermoplastics. As it is encapsulated in the polymer, the risk factor is so close to zero so as not to be of interest except for food contact applications.

Regards
Pat
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'Most common' doesn't have any relevance to whether or not it's 'green'.

As to your point about the polymer encapsulating the carbon black, it's a good point. A little research shows that the FDA actually approves carbon black for some food applications as it deems it a carcinogen only in the respiratory sense.

Still, knowing it's a carcinogen in any form would make me uneasy about calling it green considering it's dirty beginnings. (also, consider the workers at the plant who may breathe it in, I hope they've come a long way from this, but maybe not...
I guess it all depends on how 'green' you want to make it

Chris Loughnane - Product Design

 
There are many different grades of carbon black. It's not the carbon that is carcinogenic but the impurities. There are grades you can safely eat. Breathing fine dust of any kind is bad for you.
 
If you really want to be "green" go with recycled re-grind HDPE. There are plenty of suppliers who manufacture HDPE using a high percentage of recycled HDPE material with a minimum virgin material added.
 
Chris Loughnane wrote - "Still, knowing it's a carcinogen in any form would make me uneasy about calling it green considering it's dirty beginnings. (also, consider the workers at the plant who may breathe it in, I hope they've come a long way from this, but maybe not...
I wonder if the jury will decide the mine worker was at greater risk from the vast quantities of carbon he inhaled or the cigarette he's smoking.
 
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