transparent plastic tea filter - minimal discoloration & cracking 4

[maxvl]

I'm wondering what would be the best material, and whether there are coatings preventing discoloration.

PC would be my personal choice for this product as it seems the most widely used transparent plastic for kitchen appliances etc., I do see quite a few measuring bekers that crack. Is it correct that dicoloration occurs mainly because of microscopic surface damage, and particles getting stuck there?

I realise that my best option might be to go for a cheap material so that the filter can be replaced affordably, but obviously it would be better if waste and replacement could be prevented.

Kind regards,

Max

 

[Pud]

SAN for rigid, PP for semi-flexible.
PC does suffer from environmental stress cracking (ESC), also there is a big debate over whether PC should be used for food contact due to the bisphenol A component being a possible endocrine disruptor.

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[Pud]

Sorry, should have mentioned the PP should be a metallocene catalysed type for transparency.

H

www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.

 

[Demon3]

Agree with Pud 100%.

Chris DeArmitt - PhD FRSC CChem
Plastic & Additives Webinars
Instant Downloads & Inexpensive

http://www.plastictraining.com

 

[patprimmer]

So do I.

I would not recommend PVC for this.

As to staining, it can be very small particles trapped in very small cracks or scratches or other microscopic surface irregularities, but it can also be absorption into the matrix at a molecular level by diffusion, just like dyestuff is applied to textiles.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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for site rules

 

[Pud]

As Pat has described, tea contains tannins (brown) which stain/colour/deposit just about everything.
If you are a tea drinker, it goes with the territory - tea stains!
I never put my (Brown Bess) teapot in the dishwasher - it removes all the patina off the inside! Taste!

We are now digressing into forbidden realms I fear....

H


www.tynevalleyplastics.co.uk

It's ok to soar like an eagle, but weasels don't get sucked into jet engines.