analyze rubber type

If you are going to all the trouble of getting stuff custom molded you might want to:

1) Consider alternative materials that are less likely to deteriorate with age, a silicone or polyurethane perhaps? 2) Investigate the market for selling these replacements to other growers who may be in the same predicament and cover your costs.

Pete C.

compression

Good suggestions. My first thought was, why go with a 30 year old material and not take advantage of more modern materials? The problem is identifying what you need. Considering where you are, I would contact the University of Minnesota Institute of Agriculture and see what they might suggest. I don't know how they are today, but, years back, helping farmers with such problems was part of their charter.

Jerry

========================= Given the large improvements in materials over the last 30-40 years it may well be that you should upgrade to a urethane or silicone rather than simply duplicating (buna? nitral?) what was on the machine.

What do the new machines spec? As you are only going to need 80 of these, saving a few cents [or even a few dollars] per cup will not be a consideration, if you can increase performance/durability.

As you are not the only one with old machines, be sure to get the word out that you have replacement cups.

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

As others have said, I'd probably switch to urethane. Done right, it's tough and long lasting for that kind of thing. You can also match just about any durometer rating without a battle to insure you get what you want. Heck...if others are having the same problem as you, making replacement parts might be a good sideline (see Allen Machinery below).

On a lark you might try calling:

Fabreeka International

696 W Amity Rd Boise, ID 83705-5401 Phone: (208)342-4681

They manufacture several styles of "orphan" belting (or at least used to). Even if they can't do what you want, they may at least be able to steer you a bit. The business aint what it used to be (old salts retired) but it may be worth a phone call.

Kind of surprised that FMC has orphanized the belt. Before they became a "buy up companies" business, they were pretty good at customer service. I would have steered you to Allen Machinery who used to do a lot of that kind of thing (Formerly a sideline of Allen Fruit Company) but FMC gobbeled them up also and they are a shell of what they used to be. Marq Packaging In Yakima used to (might still? can't remember the name) have a division that did Bin loaders and other fruit handling equipment..in desperation you might also try them to see if they can steer you anywhere (in case you don't want to reinvent the wheel)

Koz

There's dozens of different mixtures for rubber compounds for tires, some don't even use natural rubber as an ingredient. Tread compounds are different from sidewall compounds.

Urethane or silicone seem to be your choices here for do-it-yourself molding. You'll probably have to experiment with durometer hardness to get the right stuff for the job. There's a book that may or may not be available at your local library, How to Cast Small Metal and Rubber Parts, Amazon carries it. Most of what I know about home casting using RTV compounds comes from this. It's oriented more towards car parts, but the techniques should adapt to about anything.

Stan

If this item is exposed to natural daylight (outside), you will want to investigate the UV resistance of the materials you're looking at. I don't think that polyurethane is too good in that department. EPDM rubber, which would be compression molded, does well outside I think, but if it is exposed to oil or fuel it may not hold up. I don't think that "do it yourself" silicone is particularly durable. SBR, like they used to make tires out of, might be good. If there is an electric motor nearby you might want to look at the ozone resistance.

If your son works for a compression molder, I'll bet someone there could burn test a piece of your belt and tell you what it is (or isn't) or suggest a material for you.

Depending on your budget, there are some rapid prototyping processes that can be used to make a PU or silicone belt for you.

You may want to get an inexpensive durometer tester and test the hardness of the rubber. That way you can specify the proper compound and rubber hardness.

Tony

--Andy Asberry recommends NewsGuy--

Gee Karl, I guess to identify what you currently have, you could do a spark test..... Ken.

Thanks, this site is GREAT. I hadn't found it.

Karl