Mold material for tinted PC (Makrolon)

[GalaticDan]

Hi,

I'm thinking of buying a small benchtop plastic molder from Travin Products (manual plunger type). I have a few Kilos of tinted Makrolon, high melt PC which was used by a safty lamp supply for lenses.
Is it possible to use this material in a benchtop type molder and if so, what are the things I should know about molding and creating a mould for this material?
I've read a simple book recently on plastic injection molding and have a 30min. video from the library ment for School education.
I was thinking of a platten size of about 6inch square and want to create simple sign letters I mount in MDF with a tube light behind them. I was also hoping to do a simple pencel pack fresnel or v-groove type refractor.
I'm undersure of the mold material. If I went for aluminum; what grade should I use and whats the average life for such a mold?
Do I need to polish the mold? and what with?
Do I need to sand the mold? and what grit?

Dan

[dpryor]

Dan-

What is your mold steel type? or is that the question?
Do you want your letters crystal clear?

[GalaticDan]

I guess I'm would like to know the best material for a mold? and things like mold life for that material?

Also what's this about the tinted PC and crystal clear? I did assume it would be clear tinted because the material granulate is? (i.e. it looks like colored glass)

Thanks,

Dan

[dpryor]

Dan-

A P-20 steel tool would be fine for your application.
You may want to consider chrome plating.

As far as the clarity question, that was in reference to your poslihing question.
The better you polish your mold cavity, the more transparant your part will be. The plastic may be crystal clear but if your cavity finish is not polished enough, your part could look "hazy".

[One of Many]

I have seen claims of software that can tell you if this is possible based on your surface area and flow requirements. You must know what PSI and shot size the part may take to get a decent result. You can risk the shot being short or not enough pressure in the injection stage, along with the platten holding power to keep the dies close to prevent flashing. I'd imagine this to take some years of experience to have it as second nature insight.

PC will require a polished mold on all surfaces you expect to be crystal clear.

DC