Looking for a chart that catagorizes natural rubbers and synethics.

[texaspete]

Hi I am looking for a chart to help me understand both types of Rubbers - Natural Rubber and Syn. Rubber. I would like to understand via mechanical properties lowest grade rubber to highest grade rubber. I am designing a pump where a mechanical roller rolls over a hose collapsing the hose completely plus compressing the hose an additional 8%. This pinch point creates a pressure side on one side and vaccum on the opposite side. The problem are I have to last 300 hours. Currently I have tested latex with 1/8 walls and it lasted 170 hours. The hose failed by splitting the outer surface of the hose at the pinch point. Could someone guide me in the selection of rubber or have I choosen the best material for the application. Thanks Texaspete.

 

[tomaspin]

Pete,

What you are designing is in effect a peristaltic pump.
I did a quick web search for 'peristaltic pump tube', which brought up a lot of good hits for long life tube. For example:

http://www.gore.com/sealants/uk/uk_pump_tubes.html

looks quite useful.

I hope this helps

Tom


"Doing a good job is like wetting yourself in a dark suit:
you get a nice warm feeling, but nobody notices"

 

[texaspete]

Thanks Tomaspin, I looked up the website and noted that it was in the United Kingdom. The company that I work for would like to find something in the United States. The annual volumes for this pump are 1000. The pump will be used like a water gun. - It's actually going to be used as a toy. The current goals of the project are marketing testing and evaluation. We are a small 3 man design team.
PS. Could you tell "did you use google for a search engine and what was the search criteria.
Thanks again for your help. Texaspete

 

[tomaspin]

Pete,

I use Google, and used the search term 'peristaltic pump tube'

This is a US site that I picked up with this search:

http://www.clarksol.com/html/tubing.htm

It is worth tring to get some guidance on roller speed and compression from the tube manufacturers - this will ensure that you get the maximum life out of the tube.

I design anti-vibration mountings, and for this carbon black filled natural rubber compounds have unmatched fatigue resistance, and may be worth trying. A search for 'natural rubber tubing' will give you lots of suppliers.

Best regards,

Tom.

" I'd rather have a bottle in front of me than a frontal lobotomy"

 

[texaspete]

Tomaspin
Not to be nosey, You mentioned vibration mounts, Are you designing / engineering automotive components. I just came from designing Automotive head lamps, tail lamps, door lights and overhead consoles. I use CATIA V4 V5 and Pro/E. Do you ever need contract help, I'm located in Holland Michigan.
again if I have cross a boundary, please forgive me.
Thanks texaspete

 

[garrity]

You might consider using urethane as a replacement for natural rubber. It is the only flexible material with higher overall strength than natural rubber and recall a pencil eraser, natural rubber tends to harden over its lifetime whereas urethane won't. One of the problems with any rubber compound is that if it has a high filler loading, strength may be compromised so you would probably do well to ask the supplier for the mechanical properties of the compound you are testing. The first info will give you a benchmark for comparing other compounds as you continue testing. Finally, natural rubber is almost its own material category with many grades within that broad classification so you'll want to "lock in" your supplier to a specific formulation once you find something that works.