Suitable plastic for -40º, low CTE and isopropanol resistant
Suitable plastic for -40º, low CTE and isopropanol resistant
(OP)
Hi there,
We need a plate where we have some cooling system inside at -40ºF/-40ºC. Covering it we have a glass bell. There will be an o-ring (maybe silicone) on a slot of the perimeter where the bell lays to seal it. We have inside an atmosphere of isopropanol.
The idea was making this plate in plastic (low conductivity), so we need a material that:
- Can resist the lower temperature
- Can be purchased in a thickness of 1 inch/25mm and area of 47 square inches (1200 mm2)
- Is resistant to an atmosphere of isopropanol
My first thought was cheap PVC but it won't withstand the low temperature. Checking in the forum I saw PTFE or PVDF. The second is very expensive and here is the problem with PTFE: The CTE is pretty big (70in/in/R 120mm/mm/K). So because of the big plate dimensions, I'm afraid it will shrink too much (moving the o-ring position).
CTE for plastics is bigger than metals.
Another option would be using a thin stainless steel plate, but with the thermal stress I am afraid it won't stay flat for long
Do you have any recommendation for a suitable material?
thank you
We need a plate where we have some cooling system inside at -40ºF/-40ºC. Covering it we have a glass bell. There will be an o-ring (maybe silicone) on a slot of the perimeter where the bell lays to seal it. We have inside an atmosphere of isopropanol.
The idea was making this plate in plastic (low conductivity), so we need a material that:
- Can resist the lower temperature
- Can be purchased in a thickness of 1 inch/25mm and area of 47 square inches (1200 mm2)
- Is resistant to an atmosphere of isopropanol
My first thought was cheap PVC but it won't withstand the low temperature. Checking in the forum I saw PTFE or PVDF. The second is very expensive and here is the problem with PTFE: The CTE is pretty big (70in/in/R 120mm/mm/K). So because of the big plate dimensions, I'm afraid it will shrink too much (moving the o-ring position).
CTE for plastics is bigger than metals.
Another option would be using a thin stainless steel plate, but with the thermal stress I am afraid it won't stay flat for long
Do you have any recommendation for a suitable material?
thank you






RE: Suitable plastic for -40º, low CTE and isopropanol resistant
RE: Suitable plastic for -40º, low CTE and isopropanol resistant
I made a mistake and it was 47inches by 47 inches (1.2m x 1.2m), this is a bit difficult also to find. Also I forgot a 10e-6 in the CTE units
With the thermal stress I meant the possibility of twisting the plate by this change of temperature. Then the bell won't seal anymore. No detonations
thank you
RE: Suitable plastic for -40º, low CTE and isopropanol resistant