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spring materials
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Posted by: huppmald

09/01/2004, 08:21:23

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I'm looking for suggestions on a spring material, not steel or s/stl, to use in the medical field. My application consists of a needle piercing a rubber bladder to fill a bottle below. The needle stays within the rubber bladder during its application. But after removal of the needle, the bladder "dribbles" for 5 seconds or so. I'm looking at an insert of possibly two pieces into the .50 bore beyond the bladder that will spring load a secondary seal against the bladder that will be pushed away when the needle in inserted through the bladder. I need a backup spring or spring material that will be forgiving as the needle enters and will push back when the needle is removed.

Any suggestions are welcomed. Nothing is a bad idea.


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spring materials
Re: spring materials -- huppmald Post Reply Top of thread Forum
Posted by: randykimball
09/01/2004, 20:13:47

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I can't see the whole thing in my head, but I'd sure consider a polyurethane spring. We use them for several applications and they do well. A polyurethane spring is basicly a round cylinder of the material picked by size and durometer (softness/hardness) your design requires.
Contact your plastics supplier and see if you can get a few different hardness samples and sizes..... and play with it...
excuse me ... do some R&D.


The worst suggestion of you lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

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