Can molded/formed thermoplastic parts be cost-effective in low qtys? 2

[tluxon]

I'm designing the mechanical portion of a new product that utilizes a fan-aspirated solar shield accommodating a temp/relative humidity sensor. Some of these units will be used in harsh marine environments. I'd like the shield to have as low a thermal mass as practical so a thermoplastic material seems to hold a lot of merit.

The caveat is that our expected quantities for this shield are only in the neighborhood of 50 per year, so I'm wondering if it's feasible to make parts that likely require molding/forming tooling.

I appreciate all advice and suggestions.

Thank you!

Tim

 

[berkshire]

Depending on the requirements of the finished part, you might look at thermoset plastics using RIM or VARIM. The tooling for reaction injection molding can be made for far less cost than for hot molding with thermoplastics.
In some cases the tooling can be considered disposable.
B.E.

 

[Compositepro]

The key to economical low volume manufacture is to keep tooling cost low and labor cost reasonable. Vacuum forming thermoplastic sheets can be done at as low a cost as any process. Single sided molds are used which can be made from wood or plaster. At 50 parts per year it will never be cheap if you include set-up costs.
Be aware that plastics have a high heat capacity per unit weight but low density and low thermal conductivity. They will take longer to reach thermal equilibrium than metals and therefore may have less effect on a nearby sensor, which is what you maybe desiring.