Myths about UHMW Base Material and New Base Material Idea

[Tony Warren]

Any alt-formulation bases for us to try *expectant blink*

Sure, epoxy or polyurethane or hybrid resins and coatings loaded up with lots of Inhance UH1250 and TiC9000 or 9100 particles. The goal is to find a resin system that has high enough elongation for the ski to flex and that will stick well to the ski. Here are some good sources. Let me know what you think. If you market this I expect royalties as this is a new invention.

http://www.inhanceproducts.com/offerings/performance-additives/

These guys make a great coating that bonds really well.

https://www.quantumchemical.com/illustrium-tm

Add 40% UH1250 and 5% TiC9100 by volume to the coating and trowel it onto a piece of sailcloth and cure. Cut it out for a base and give it a rip. Wax will stick to it because the particles are polar, really really polar.

This should work well too.

https://theepoxyexperts.com/shop/ca...flexible-tough-high-elongation-clear-casting/

 

[Sergei M.]

I disagree with the idea that you wouldn't need to go all that far for a better mousetrap.

If you have that solution...

Hey Tony.
We have a solution. We begin to produce thermoplastic UHMWPE in the 2Q 2018.
Polymeric alloys based on UHMWPE, grafting, etc.

 

[Dakine]

Sorry I missed this thread.
neonorchid is exactly right about the porosity of sintered, porous UHMWPE, there can be as much porosity as one wants at the expense of mechanical strength.
UHMWPE can be sintered under pressure to very low porosity but this process is called compression molding not sintering.
Porosity in bases consists of two types.
Closed porosity that is not accessible to wax penetration and open porosity that is.
I suspect ski base material is sintered to give as high as possible open porosity since closed porosity does not accept wax and degrades strength.
Digging down to the next level of polymer science, one soon runs into the concept of "free volume".
Polymers are like knotted ropes and when the polymer chains get long enough they entangle making the plastic very strong.
But, just like a big knot, there is a lot of space between the polymer chains.
This space is called free volume and there can be a lot of it in high molecular weight polymers.
Smaller hydrocarbon molecules (ski wax) can hide out in the free volume and become dissolved in the polymer.
Some of this dissolved wax can end up trapped in the closed porosity.
So, ski wax in a base can be in the free volume, the closed porosity and the open porosity.
Multiple waxing cycles probably transfer wax from the open porosity to the closed porosity and free volume.
That is probably why hot boxing works.
The whole subject is very complicated and I expect only a few polymer physicists who work for wax companies sorta understand it well.
So, just keep waxing........

 

[Franzz]

Very well explain^^ thank you. Decades ago i had access to a fire hose dryer, with multiple moly wax cycle, polar wax and days wax my skis were faster than me, i didn't get that feeling again even if i still have fast skis now with regular iron waxing.

 

[CalG]

The interaction of a ski base and applied wax may be a matter of definition and symantics.

http://www.differencebetween.net/science/difference-between-adsorb-and-absorb/

The line blurs at the molecular level. What is a Surface? At some magnification, any ski base will look like the bad lands of the Dakotas.
Certainly much more surface area than could be calculated by a length and width multiplication.
The topic may bend to polar actions or affinity.

 

[Sergei M.]

The topic may bend to polar actions or affinity.

Grafting the polar groups on the UHMWPE is a solved problem.

 

[Dakine]

I was lucky enough to study polymer science while working with this guy.
https://books.google.com/books/about/Selected_papers_of_Turner_Alfrey.html?id=_OCFAAAAIAAJ
Cal G brings up and interesting subject.
Where it becomes really important is when you move from pure hydrocarbon waxes that are chemically (not structurally) identical to the base UHMWPE.
Hydrocarbon waxes dissolve into the free volume of the base very well.
This is not true for fluorinated waxes and solid lubricants like moly or graphite do not dissolve at all.
Skis should always be saturated with pure hydrocarbon wax before overlaying fluoro waxes.
For ultimate wet performance you are trying to build a graded structure with no fluoros deep in the base and very high fluoro at the surface.
You want the high fluoro surface when it is wet because fluorine has the highest surface energy of all possible waxes.
But that is another subject.....

 

[Tony Warren]

Sorry I missed this thread.
neonorchid is exactly right about the porosity of sintered, porous UHMWPE, there can be as much porosity as one wants at the expense of mechanical strength.
UHMWPE can be sintered under pressure to very low porosity but this process is called compression molding not sintering.
Porosity in bases consists of two types.
Closed porosity that is not accessible to wax penetration and open porosity that is.
I suspect ski base material is sintered to give as high as possible open porosity since closed porosity does not accept wax and degrades strength.
Digging down to the next level of polymer science, one soon runs into the concept of "free volume".
Polymers are like knotted ropes and when the polymer chains get long enough they entangle making the plastic very strong.
But, just like a big knot, there is a lot of space between the polymer chains.
This space is called free volume and there can be a lot of it in high molecular weight polymers.
Smaller hydrocarbon molecules (ski wax) can hide out in the free volume and become dissolved in the polymer.
Some of this dissolved wax can end up trapped in the closed porosity.
So, ski wax in a base can be in the free volume, the closed porosity and the open porosity.
Multiple waxing cycles probably transfer wax from the open porosity to the closed porosity and free volume.
That is probably why hot boxing works.
The whole subject is very complicated and I expect only a few polymer physicists who work for wax companies sorta understand it well.
So, just keep waxing........

Yet, I show you a photomicrograph of sintered UHMW from the premium supplier of such plate on earth and you can see there is zero porosity.

That said, of course there have been many developments in the creation of porous UHMWPE in biomedical fields. For the most part though these are not sintered but rather compression moulded and are at the low end of the molecular weight requirements for classification as ultra-high. But these are developments over the past perhaps 10 years and I suspect are incredibly expensive compared to the base materials used in ski bases.

I may be wrong but there are no hydrocarbon molecules that are as small as water. Water absorption in sintered UHMW is less than 0.01 tested using ASTM D570(2). I tried to increase this in my lab under vacuum and it was the same.

Thinking on the fly here, but I also observed that many hydrocarbons can cause varying amounts of swelling of UHMW, so perhaps it is that simple, hot wax causes surface swelling of the UHMW and this allows the wax to easily permeate a thin top layer of the ski base.

I like that solution because it sorts well with what we all see happening on our ski bases everything we wax.

 

[Tony Warren]

Grafting the polar groups on the UHMWPE is a solved problem.

I spent a lot of time doing this with fluoro-oxidation. I got the most astonishing adhesion to UHMW as a result. We tested skis with this product (we burned a few pairs of K2's in the process) and had perfect wax adhesion until the wax was gone. At the Noram Level this would be about 3/4 of the way down the Lake Louise Downhill. Then the thin layer of hydroxyls, carbonyls, and carboxylics, were gone by the end of the race.

That said, I would like to hear more about what you are doing. I have an interesting adhesion problem that I would like to know more about your process for.

 

[Sergei M.]

That said, I would like to hear more about what you are doing. I have an interesting adhesion problem that I would like to know more about your process for.

Let's move to PM. I registered, solely because of Google's search for your message ))

 

[Dakine]

@Tony Warren
Funny, I have used sintered UHMWPE filters many times.
They are available in many porosity grades.
Here is what Wikipedia says about it.
You have the wrong photomicrograph.

"Plastics sintering
Plastic materials are formed by sintering for applications that require materials of specific porosity. Sintered plastic porous components are used in filtration and to control fluid and gas flows. Sintered plastics are used in applications requiring caustic fluid separation processes such as the nibs in whiteboard markers, inhaler filters, and vents for caps and liners on packaging materials.[4] Sintered ultra high molecular weight polyethylene materials are used as ski and snowboard base materials. The porous texture allows wax to be retained within the structure of the base material, thus providing a more durable wax coating"