Materials for making Molds

[nappy1]

Before I even ask this question I must qualify it by saying that I do CNC routing not forming.
I have a customer who makes chocolates. I've done other work for him and now he handed me a piece of Metapor and a disk and said can you make this on that. Well the actual process was easy. The results excited him. He is considering converting all his mold making to masters with inserts.
Well getting to my question. Are there any other products to use other than Metapor that are faster to machine with smooth finishes?
I'd include a photo but I signed a non disclosure. Chocolate guys, big secerets.
Go figure....

[judleroy]

Try testing with food grade plastics. Natural UHMW, and HDPE. If polypro is food grade it would need little or no release agent.

[nappy1]

You may have misunderstood my description. Why would I need release agent if I am vacuum forming ?

[judleroy]

Yea I did misunderstand sorry. For vaccumforming I would try polyurethane. Try rencast. How big are the molds.

[nappy1]

The current ones are about 2in x 8 in. x .38 thick.
Are these materials porous?

[judleroy]

No the material is not porous. Try hobbycast.com. I know your vaccumforming so your just looking at the polyurthane. If you need to make a bunch of the same peices for the form you can make a master and pour your molds but polurethane is easy to machine so either way. I believe renshape material is highlighted somewhere on the sight. It is precast polyurethane sheet for moldmaking. You would come out cheaper
making a small form the size you need for machining
and pouring your own sheets. Hope this helps.

[judleroy]

Click the freeman products tab for the sheet materials
available.

[One of Many]

We had a customer that does the same thing with chocolate.

Some of the methods we used for him were,

Magnesium etched plates with his customers logo's similar to what might be seen in the printing or hot stamping industries. I would cut these photo transfered and chem etched dies from a 3/16-1/4" plate of magnesium. Drill vac holes, then mount them to a plate of aluminum for vac forming .020 PETG. This would create a candy tray to fit his equipment that poured the chocholate into each mold cavity in the tray.

Other projects were where he did his own carvings from wax. He would create the master mold out of silicon from his wax carving, then create several epoxy copies which were again mounted to an aluminum plate after drilling for vac holes. Same process for making the trays from PETG, although sometimes we would use a thicker sheet for heavier candies. The draw back for thicker material was less detail. There were a few times I added some aluminum strips on the die to form in some ribs for tray stiffeners on the thin material to keep good detail.

Most of the materials we used back then were from freeman supply

DC

[nappy1]

You have all been helpful. He is now talking about buying a $60K Datron high speed mill to do the work. I don't know where I will fit in at that point. You know how it is. I did learn that I can use a .020 endmill at 80ipm without breaking the tool, which was a supprise.At least I got paid to learn something.