Making rubber parts.

[jaru-eri]

I need to make some rubber parts for my machine and need to know if there are any good forums on the web where molding, vulcanizing techniques of both natural and artificial rubber and other topics regarding this are discussed.

[svanommen]

This may not be quite what you are looking for but once upon a time I ran across this site that had several (good) how-to videos on rubber casting, mold construction, etc.

FreemanSupply.com - Mold Making, Casting Resin, & Foundry Materials

Hope that helps

[Festus440]

I don't have a source either, but I use to work at a plant that had a small department that made rubber parts. They use to mill the raw material and the formulas were often complex with additional ingredients such as carbon black, clay, and soap flakes (They needed the rubber to have some very specific damping properties.)

Once the material was milled, they normally used molds called "transfer" molds. The raw rubber comes off the mill in a thick sheet or slab. This was cut up and weighed out and placed in a reservoir in the top of the mold. The top plate on the mold had a male plunger that matched reservoir.

The mold was then pushed into a heated press. Under heat and pressure the rubber would be squeezed through openings from the upper reservoir to the part cavities below it. The cure time was around 7 minutes but I don't remember the temperature. After curing, the molds were pried open and the parts removed with an air gun. The parts always had some flash on them and it was often removed by freezing the parts with liquid nitrogen, putting them in a wooden box, and shaking them in a paint shaker

Anyway... much much easier to use some type of cast urethane or silicone rubber unless you really need to have the properties of real rubber.

Bob

[draughted]

you are going to have to do some research but you should find a local source for composites and make your challenge a little easier with a flexible silicone or urythane