Rexolite 1422 1

[sdavfc]

Rexolite 1422 as I understand is a rigid and translucent thermoset. It has excellent dielectric, rigidty and dimensional properties, radiation resistance and is able to withstand high voltage.
I1m looking for a injection mouldable thermoplastic grade as an equivalent, if it exists.
Any suggestions ?

 

[DROSSI]

you might want to look into a modified talc filled gtx. you can get all the info on this form the GE web site. the only thing i don't know about the gtx is the voltage/amps restrictios.

hope this helps!!

 

[Pud]

Hi sdvac,

What is the ranking of your criteria? Dielectric, rigidity, dimensional stability, radiation resistance. In what order would you put them if you ranked them in importance?

A very similar material (but mouldable) is syndiotactic polystyrene (semi crystalline polystyrene) Is also high temperature. Problem is DOW have stopped making it but I believe a Japanese company is continuing. (Perhaps someone else knows?)


Rgds

Harry

 

[sdavfc]

My understanding is that the dielectrice properties are the most important. The component is is part of an antenna for a satelite dish.

Thanks

 

[Pud]

Hi sdavfc,

We once looked at the feasibility of making a microwave antenna lens (fitted on end of waveguide, looked like stepped cone, made of rexolite or similar) in a glass filled polystyrene, injection moulded. Polystyrene has similar characterstics to Rexolite (cross-linked styrene), but much cheaper! Problem we had was the tooling cost did not justify the tooling expenditure, so the customer carried on machining from solid. LNP and others make glass filled polystyrene.

 

[sdavfc]

Hi Pud

This too is a stepped cone of varying sizes and customer also machines them at present. Some have quite thick sections and will be too big to mould as voids cannot be tolerated. I will give the LNP option a try as it sounds like both are similar applications.

Regards

Steve

 

[Pud]

Hi sdavfc,

Sounds like the same parts!

Thw rf engineers i dealt with seemed to think that a cored out version with a reasonable wall thickness would work as well, but we never got round to actually prototyping one by machining. Worth a try imho.

Rgds

Harry

 

[sdavfc]

Hi
I too thought a cored out option would have been worth a try but they rejected this idea on the basis that they cant tolerate any voids.

Thanks

Steve

 

[taz1]

I know this application and the material involved. There could be an alternative being developed for this application that is cheaper and more readily avilable. If you are interested then I could put you in touch with the relevant people depending on your location and interest.

 

[Demon3]

Hello,

Good replies to this one already. I think that the syndiotactic polystyrene Questra from Dow would have been excellent had it not been discontinued.

The high costs of injection molds was mentioned. Why not rapid prototype using the 3D printing method. It is not the old laser method. The new 3D printing lets you print the part direct from a CAD file with no mold needed. You get a part in thermoplastic like polystyrene, ABS, polycarbonate with good mechanical properties. Stratasys are world leaders in that so contact them (

http://www.stratasys.com).

You don't need to buy a machine you can have the work done on a contract.

Another alternative is if you can thermoform the part. I.e. for sheet-like parts (dishes etc) you can get a thermoform mold made really cheaply from wood and use that. It's much better than injection molding for small production runs.

If you specified what properties you need more closely then perhaps I could recommend a material for you. Take a look at

http://www.matweb.com

to get some ideas.