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injection molded plastic resistant to alkaline battery acid

injection molded plastic resistant to alkaline battery acid

(OP)
I am looking for an alternate material for injection molding that would be resistant (long term) to battery acid leaked from alkaline cells.

The current material has the following processing properties that we'd like to stay close to:
Mold Shrinkage, flow, 3.2 mm (5) 1 - 1.2%
Melt Flow Rate, 250°C/5.0 kgf 11.4 g/10 min
tensile (yield) ~ 7kpsi

Typical usage is periodic submersion in water (salt, fresh, brackish, drinking, and polluted)
temp range in service of -20 to 80C

Any suggestions or families in which to start exploring?

We're looking into Acetals but have not had the best of luck finding much information about resistances to this type of chemical attack

RE: injection molded plastic resistant to alkaline battery acid

Polypropylene is the place to start. You can find extensive chemical resistance charts for polymers online.

Here is one example: http://www.rtpcompany.com/info/guide/rtp-chemical-...

There are different types of battery. Alkaline batteries I have to assume are alkaline, the opposite of acidic.

Lead acid batteries contain acid.

PP resists alkali and even really strong acid for a long time. PE is likely to be even more resistant and really cheap too. As you will see in that char, Acetals are attacked easily by acids and bases. PP and PE are more resistant by far and cheaper too.

Chris DeArmitt - PhD FRSC

Plastics & Materials Consulting
www.phantomplastics.com

Plastic Training Seminars
www.plastictraining.com

RE: injection molded plastic resistant to alkaline battery acid

Is the part stressed at -20ºC? If so, PP is somewhat brittle below around zero.
LLDPE* is tough down to -70ºC, but 80ºC maybe on the high side (dependant on use, stresses, time, etc.)

* Linear Low Density PE

H

www.tynevalleyplastics.co.uk

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

RE: injection molded plastic resistant to alkaline battery acid

There are "tons" of charts on plastic properties, do research on your computer. Over the years I have perused thru a lot of charts on plastic properties in various periodicals and handbooks, so you should not have a problem with this research.

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