Another type of silicone material

[Wildstar87]

It just occured to me, that I have an incredibly durable, soft silicone gel that I have experience with for the last 4 years. You see, I am an amputee, and have I believe silicone gel liners (or something very much like that) that I use everyday in my interface between my prosthetic socket, and my residual limb. FYI, I am fairly active, I do a lot of cycling and skiing.

This material is extremely durable, and is soft at the same time. In fact I have to throw most of them away when I wear through the outer fabric material that covers the gel. Since I am a below knee amputee, there is a lot of repetitive bending, and stretching (like every time I take a step). There is a steel pin embedded at the bottom of the liner through a sort of metal "umbrella" to spread the pressure. This steel pin is what holds my leg on. The pin at the bottom locks into a receptacle at the bottom of the socket. So the liner serves two purposes, suspension of the leg, and comfort. There are some compression wrinkles at the back of the knee, but the important part, is that it never tears.

I have had other liners made out of a urethane gel that once a weak spot showed up, it would start splitting, and that usually happened right after the fabric cover was worn through. This liner I have been using for the past 4 years is completely different. I have never worn through the actual gel material, and it hasn't split once. I usually wear it down because it rubs against the socket edges on my prosthetic, so material gets slowly eaten away. Anyhow, I was thinking this would be a great material for a doll, and could solve the durabilty problems. Of course getting the actual formula, or identity of the materials could be difficult, but I am sure with all the minds here, we could find a way?

The liners I use are called Luxury Liners, and were made by USMC. Apparently they have been discontinued, but the following company has a similar liner. I have used both and they are essentially identical. The only reason I used the USMC one is because it had a straight seam in the fabric where I could put a reinforcement for the fabric. I have included the link below.
http://www.owwco.com/

[fourmaki]

You got it! Silicone is plenty tear strenth for what we do. It is compression that really screws up dolls and it seems to be the same in the prostehetic interface dilema.
Watch very closly as the compression crack develops. It exudes elastemer and fails.

Trick is to make soft and use no softner.
Ya we deal with this all day long and night.

As you can see it is as easy as dumping a bunch of stuff in a mold and out pops eather a prostehetic pad or a doll. Way more than meets the eye

3 things effect durablity
Mold / Product design
Material
Reinforcement

Thats about all you can do. Other than adjust use parameters, storage, and life cycle. Hate to be to nurdy but I like it.

Mark

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