Friction Levels Of Raw Vs Coloured PTFE

[JACKE1]

Hi,

This may seem like a "just google it" type of question (I thought it was myself), but it wasn't as easy as I thought to get a simple answer. I would greatly appreciate any input.

I'm developing a product that utilises PTFE/Teflon to limit the amount of friction when in contact with skin/nail.

At this point, please keep in mind that I have zero engineering experience, so I apologise in advance if the answer is very obvious.

The original plan was to use raw PTFE for the product, however, having the option to switch to coloured PTFE (such as what you will commonly see used for PTFE seal tape) would be fantastic.

I assume switching to coloured PTFE will negatively impact its low friction properties and thus make it less effective for my application.

Assuming the above is correct, where might I be able to find exactly the difference in friction levels between raw PTFE and coloured?

If the difference is relatively minor, it will most likely be worthwhile switching to coloured for aesthetics.

Thank you for reading.

 

[Compositepro]

You would only get that information from the supplier of the specific material you are considering. There is no generalization that can be made here. PTFE is not a magical material and actually getting low friction requires attention and control of details like surface smoothness and contact pressure. When you mention skin/nail, I suspect that you will be disappointed with your results. Sealing tape has very little in common with solid PTFE properties and uses.

 

[3DDave]

Pure/virgin PTFE is a poor material for low friction use. While the nominal coefficient of friction is low, the material is very soft/weak and gouges easily and tends to flow under low continuous loads. UHMWPE is often better as it is nearly as low but is much more abrasion resistant.

You'll need to create samples and test them if the friction level is critical.

 

[JACKE1]

Thank you for your input, Compositepro. The PTFE part will be shaped using a CNC lathe accurate to 0.0002" to 0.0003". Assuming all PTFE/Teflon is the same in terms of make-up, I wouldn't need to worry too much about the surface straight from the supplier since it will be carved away when it comes to machining. Contact pressure will only be between 60-90g. With that in mind, do you still expect disappointing results when using raw (or that matter, coloured) PTFE?

I only mentioned sealing tape as an example of the colouration that I had in mind, apologises for any confusion. If coloured PTFE has similar enough properties to raw PTFE in terms of levels of friction under the conditions above, I would simply have the PTFE part carved out of a coloured PTFE block rather than raw.

Thank you for your input, Dave. Continuous load and abrasion shouldn't be an issue, the PTFE part will only have 60-90g of pressure applied for a few minutes at a time. I hadn't considered UHMWPE, I will do some research on the material.