FDA approved plastic for use in -40C, -40F, with impact toughness
FDA approved plastic for use in -40C, -40F, with impact toughness
(OP)
Hello.
I am investigating what material to use in a part used in a freezer at -40C.
The material now used is an unfilled copolymer POM.
What has happened is that it does not have enough impact toughness and chips falls of if the part is "mistreated".
So I wish to improve the impact toughness.
I don't know the necessary yield strength but the same as unfilled POM is enough.
The part is injection molded and it would be good to be able to use the current mould.
I'm thinking of finding a POM with some kind of additive mainly because I don't have enough knowledge to know what else to look at.
Do you guys have any tips for material for me to look into?
Thanks.
I am investigating what material to use in a part used in a freezer at -40C.
The material now used is an unfilled copolymer POM.
What has happened is that it does not have enough impact toughness and chips falls of if the part is "mistreated".
So I wish to improve the impact toughness.
I don't know the necessary yield strength but the same as unfilled POM is enough.
The part is injection molded and it would be good to be able to use the current mould.
I'm thinking of finding a POM with some kind of additive mainly because I don't have enough knowledge to know what else to look at.
Do you guys have any tips for material for me to look into?
Thanks.





RE: FDA approved plastic for use in -40C, -40F, with impact toughness
DSM or DuPont should be able to help.
Polycarbonate may also be suitable depending on actual properties required.
Regards
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RE: FDA approved plastic for use in -40C, -40F, with impact toughness
I think the polycarbonate seams very interesting.
I read that it does have poor resistance to chemicals but do it withstand washing detergents? Is there something else strange with this material? And thanks for the tips to contact DuPont I will do that but first try to get a little background to have things to talk about.
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
Polycarbonate like all materials has a full range of unique properties.
We always need to consider compromises for acceptable balance when matching materials to applications, and that is impossible to consider with piecemeal and incomplete information.
Regards
eng-tips, by professional engineers for professional engineers
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RE: FDA approved plastic for use in -40C, -40F, with impact toughness
LLDPE is good for -70 Deg C whilst retaining impact strength.
The lower the MW the better...
Although as Pat mentioned, an impact modified POM would be much easier change and be much better.
Cheers,
Harry
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
Once you write it, it's carved in stone
That is unless you are rude or well outside the forum rules, then they seem to get deleted entirely.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
some PC grades have good impact property at -40C, but as you said, it's chemical resistance is poor, And for detergant and cleaners, Mild soap solutions are generally compatible, Stronge akaline materials should be aviod.
Regards
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
Homopolymer breaking down in alkali won't be an issue if you can control the temperature.
That said, we saw degradation of acetal polymers at temperatures above about 140-160 F in an alkaline (NaOH and NaOCl) clean-in-place application, and had to move to fluoropolymers because we couldn't guarantee that users would not mix the powdered cleaning solution with hot (190-210 F) water.
So that if is a very big IF.
RE: FDA approved plastic for use in -40C, -40F, with impact toughness
It is really susceptible to acids at any temp and quite susceptible to hydrolysis at elevated temps.
Co-polymer is down a bit on physical properties, but is a bit better to chemicals.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: FDA approved plastic for use in -40C, -40F, with impact toughness