Myths about UHMW Base Material and New Base Material Idea

[mishka]

How about lovingly handcrafted by expert specialists in all aspects of the skiing arts?

I like where you going with that

.

My opinion is, when we see wax absorbed we are really seeing the VOC's in the wax vaporize and disappear into the air in the wax room and our lungs. He says coughing because he spent a lot of time in a wax room without an organic filter mask on!

so basically you're saying this is a conspiracy aaammmm mirage

btw if your product have better adhesion without worry of delamination and need no flame treatment

 

[Tony Warren]

I like where you going with that


so basically you're saying this is a conspiracy aaammmm mirage

btw if your product have better adhesion without worry of delamination and need no flame treatment

Most plastic suppliers will be happy to give you a piece of UHMW for a few bucks. Get the white 'virgin' UHMW. Weigh it carefully and then dip it in ski wax. Scrape all the wax off. Then weigh it again I have a 0.001 gram scale so I can do it, you will find that perhaps some of the pigment has hung around and could be weighed.

Now take the same sample or a new piece and put some texture on it. You should find that a bit of wax adheres but is pretty easy to scrape off. The roughened surface increase the surface energy of the UHMW. It gives it a tiny bit of adhesion that disappears in short order if you run a bit of a sand slurry over it. You should get a few micrograms per C2 of wax to stick to it.

Then take a third piece and flame treat it with a propane torch. You should see the surface oxidize a bit. This increases the surface tension enough to get some decent adhesion to the UHMW. Repeat the same experiments with this material. Again you should get a few micrograms more to stick to the base.

The wax is too soft to have the ability to resist a lot of abrasion. It just comes off because it is not highly crosslinked or of high strength.

My product will adhere structurally to the bottom of the ski perfectly provided the bottom is lightly sanded and cleaned with a solvent that leaves no residue, such as acetone. Any epoxy used to make skis should get incredible levels of crosslinking to the base. It will simply not delaminate if applied properly. Of course it will be applied to a ski during layup so there is little doubt great adhesion will result.

 

[mishka]

how far out from production you are?

your product how it's compared to crown plastics 2001 or 4001?

you probably know it. Thickness have to be 1.4 mm or 1.8 mm edges comparable

 

[Tony Warren]

how far out from production you are?

your product how it's compared to crown plastics 2001 or 4001?

you probably know it. Thickness have to be 1.4 mm or 1.8 mm edges comparable

It is a completely different idea than a polyolefin base. The thickness is the least of my worries.

The base will be difficult to produce in big quantities and will take some skill to get it so that it has no voids and cures quickly.

I anticipate it will take a year from now before I am ready to release it in even small quantities. This is a year for lab tests, on snow testing, and killing the really stupid ideas in hope that somehow one or two good ideas survive.

 

[cantunamunch]

For completeness' sake, I should mention it is possible to make pores in UHMWPE by using inorganic fillers and leaching them out afterwards. What Crown Plastics or other ski base makers actually do, I have no idea.


Example (uses NaCl - calcium salts are also commonplace) including SEM pron:

https://www.researchgate.net/public...ene-Based_Porous_Structures_for_Bone_Implants

 

[Tony Warren]

For completeness' sake, I should mention it is possible to make pores in UHMWPE by using inorganic fillers. What Crown Plastics or other ski base makers actually do, I have no idea.


Example (uses NaCl - calcium salts are also commonplace) including SEM pron:

https://www.researchgate.net/public...ene-Based_Porous_Structures_for_Bone_Implants

I have spoken with the tech guy at Crown on this topic. They use neat resin and in some instances add pigments. Nothing else.

Adding salts to UHMW and dissolving them is an interesting way to make a framework for tissue to grow into. With 90% salt though, little of the mechanical properties of the UHMW would remain.

 

[cantunamunch]

I have spoken with the tech guy at Crown on this topic. They use neat resin and in some instances add pigments. Nothing else.

Yep, you mentioned this further up the thread, I was taking it for granted. I'm just putting this in context for people who may get confused over all the talk of extrusion vs. sintering and then also noticing microporous PE membranes in batteries or gas filters or breathable textile coatings.

With 90% salt though, little of the mechanical properties of the UHMW would remain.

Sure. I would expect them (meaning any company doing micropores, say Daramic for their battery separators) to vary the mass ratio of fillers according to the mechanical properties they're trying to achieve; and to add various process oils also.

 

[Tony Warren]

Yep, you mentioned this further up the thread, I was taking it for granted. I'm just putting this in context for people who may get confused over all the talk of extrusion vs. sintering and then also noticing microporous PE membranes in batteries or gas filters or breathable textile coatings.



Sure. I would expect them (meaning any company doing micropores, say Daramic for their battery separators) to vary the mass ratio of fillers according to the mechanical properties they're trying to achieve; and to add various process oils also.

Got it. Controlling vapour transmission in polyolefins is interesting stuff. One of my colleagues from the past worked for many years in the battery barrier field.

 

[Swiss Toni]

Ski bases made in Europe are usually made from Ticona GUR or DSM Stamylan resins. Two of the base material manufactures,
CPS GmbH (P-tex) and Isosport (Isospeed) heat and then quench the sintered skived UHMWPE film. This process reduces the degree of crystallinity of the base material, which increases wax absorption http://www.google.ch/patents/US5468543 http://www.google.ch/patents/US5189130 In view of this I think it’s safe to say that the wax gets into the amorphous regions.

If you look at the Isospeed brochure http://goo.gl/O6QhP0 you can get some idea of what they add to their base material.

Crown Plastics is principally a industrial UHMWPE manufacturer, their material is mainly used by snowboard manufacturers as their process allows them to make wider strips than the other manufacturers can. Another industrial supplier is OKULEN http://www.okulen.de/home-en.html both have a reputation for producing durable bases but they aren’t what you use if you want a fast base.

 

[Tony Warren]

Ski bases made in Europe are usually made from Ticona GUR or DSM Stamylan resins. Two of the base material manufactures,
CPS GmbH (P-tex) and Isosport (Isospeed) heat and then quench the sintered skived UHMWPE film. This process reduces the degree of crystallinity of the base material, which increases wax absorption http://www.google.ch/patents/US5468543 http://www.google.ch/patents/US5189130 In view of this I think it’s safe to say that the wax gets into the amorphous regions.

If you look at the Isospeed brochure http://goo.gl/O6QhP0 you can get some idea of what they add to their base material.

Crown Plastics is principally a industrial UHMWPE manufacturer, their material is mainly used by snowboard manufacturers as their process allows them to make wider strips than the other manufacturers can. Another industrial supplier is OKULEN http://www.okulen.de/home-en.html both have a reputation for producing durable bases but they aren’t what you use if you want a fast base.

It's an interesting patent and claims. The patent no longer applies because of its age. I found the method of determining wax absorption interesting. I will try the method with a piece of virgin white UHMW from PolyHi when I am settled into Penticton after October 1. Ticona and DSM supply quality resins as do many others including Celanese. I tend to think of these resins as generic, it is what manufacturers add to those resins that is interesting.

All that said, and indeed I thank you for the additional research you have provided, doesn't change my goal of creating something very much different than any polyolefin product.

 

[cantunamunch]

Bump. Anyone heard from @Tony Warren ?

 

[Swede]

Haven't seen this thread. Interesting. The Swedish report Tony reffered to further up has been debated quite a lot over here and critisised for how tests were performed. The guy who wrote it is/was the husband (I believe) and then service man of Russian XC skier Ordina, who moved to Sweden and became a Swedish citizen. He later developed a structure tool, which I'm not familiar with, that was supposed to be used instead of waxing.

 

[cantunamunch]

Yeh I have one of the Kuzmin scrapers. I had several dozen objections to the paper when it came out especially to the logic in appendix A, but his point about drop contact angle gets cited a lot in more modern research. Which just tells me Terry Hertel should have published more because his numbers directly contradict Kuzmin 's.

 

[CalG]

Well, I'm no wax guy (surface energy and contact angle is in my scope) but....

If the racers wax in layers to make a single run, It seems logical that wax does not really last that long on a ski base. Pores or no.

Heck. I waxed my work skies exactly ZERO times during the season this year. They worked fine for me, no issues at all.
I did start the season well waxed, and now that conditions are thin again, I waxed those DD's for storage, ready to go when called on next year. ( after a good brushing)

 

[oldschoolskier]

Wax is is surface tension breaker in various forms. Recently through and Aerosoacr specialist I was informed that all of the top waxes (ingredients ) are used in some form or other in the aerospace industry though not as waxes, but as prep chemicals for materials.
The properties that make them good to do this are the same as those required for waxes.


Surface roughness effects laminar flow, this is structure. Simple fluid dynamics.

The trick is to combine both to provide the lowest stiction and best laminar flow which from a skier stand point is a fast ski.

Materials used sort of play into both.

My 2 cents.

 

[cantunamunch]

Heck. I waxed my work skies exactly ZERO times during the season this year. They worked fine for me, no issues at all.

I have three pairs of extruded ski bases that get Skivisions scraping (and no wax, ever - it's a complete waste of wax) and two pair of XCD/nordic that get the Kuzmin. Unfortunately all of the nordic were substantially unusable during our last two non-winters. By substantially unusable I mean "Had no glide whatsoever on the slushy mix and then picked up too much moisture and became clumping monsters". My inner thought is "Good performance with no wax or gulf wax just means you have good snow"

Nevertheless, it seems like in the last pages of the thread we're mostly in consensus - let's see what @Tony Warren can come up with.

 

[Jacques]

I have spent a great portion of my career working with Ultra High Molecular Weight Polyethylene. It is a great wear material for sliding abrasion and has many other wonderful properties.

UHMW does not have a melt-flow point. It requires a lot of pressure to either extrude it or sinter it. Materially there is no difference between the two processes. If one uses the same resin for either process one gets identical properties.

Over the years I have been told that bases need to be heated so that the wax can penetrate its pores. I have seen UHMW under electron microscope magnification. It does not have any pores at all. None, zero, nadda, zilch.

UHMW is not easy to adhere to. There are several processes that are used to increase the surface energy of UHMW. Crown Plastics uses flame treating, others use corona treatment. The object is the same, to oxidize the surface to increase its surface energy and perhaps to create some polar bonding sites.

The best treatment is fluoro-oxidation. It is a specialized process that must be done correctly. It uses Fluorine gas and heat to work. Fluorine gas is the most reactive element in the periodic table. Under the correct conditions it can start steel on fire! To get Fluorine gas one must crack it out of hydrofluoric acid. An HF spill of any size is very nasty because it dissolves the calcium in your body. 250 ml spilled on your body will kill you within a few hours. All that said, done correctly fluoro-oxidation increases the surface energy of UHMW more and more permanently than any other method. Great adhesion to the ski is the result.

Melted wax has very low surface energy. It adheres well to the UHMW of the base. However it simply does not last all that long. Most of the time we are just skiing on the uncoated base.

I am working on an alternative to UHMW ski and board bases. One issue that I find difficult to believe is the idea that 'texturing' the ski base actually makes it faster. Wax may adhere better to these bases but again that wax is so comparatively soft with relation to the abrasive ice crystals in the snow that I doubt it stays on for more than a few runs. I would like to get some comments from more learned community members to demonstrate to me why I should texture my new base instead of polishing it.

I saw this before I joined here, so I could not reply then, Now I can.
Sintered UHMWPE can even be used as filtration devices. Sure it needs to be made in a very careful fashion.
Although there are not "pores" per say, there will be voids where other things can seep through.
Here is one article that speaks somewhat to that. http://onlinelibrary.wiley.com/doi/10.1002/app.36750/abstract
I'll see if I can find another......http://www.hipolymers.com.ar/pdfs/gur/aplicaciones/GUR_Sintered_Filter_01_338res72dpi.pdf
There are many more papers that speak of these things.

Sorry, Tony but you are wrong. A good sintered base will take some wax. May not go too deep, but when waxed well for multiple cycles of heating and cooling (I use a hot box as well) the skis become faster and glide better. The more work, the longer it last. I have prepared bases and skied at 50 mph for many many miles and still had no burn and a glossy shiny base. The trick is to re-wax before it goes dry.

If you can make a better base, I'm all for it. As stated earlier in this thread there is another base that was tried. The companies that used it to my knowledge have discontinued using for the time being. I know this because I asked one of them. The guy could only tell me they might try again later. There is one brand of skis that uses it and they are the ones that came up with the idea to my knowledge.

 

[cantunamunch]

I saw this before I joined here, so I could not reply then, Now I can.
Sintered UHMWPE can even be used as filtration devices. Sure it needs to be made in a very careful fashion.
Although there are not "pores" per say, there will be voids where other things can seep through.

Yeh, the battery separators I quote above do that all the time - and Proctor and Gamble make millions of diapers; @Tony Warren's point that it isn't sintering that provides that level of porosity is well taken though.

If you can make a better base, I'm all for it. As stated earlier in this thread there is another base that was tried. The companies that used it to my knowledge have discontinued using for the time being. I know this because I asked one of them. The guy could only tell me they might try again later. There is one brand of skis that uses it and they are the ones that came up with the idea to my knowledge.

IIRC those were polypropylene instead of polyethylene - still a polyolefin tho.

 

[Jacques]

Yeh, the battery separators I quote above do that all the time - and Proctor and Gamble make millions of diapers; @Tony Warren's point that it isn't sintering that provides that level of porosity is well taken though.



IIRC those were polypropylene instead of polyethylene - still a polyolefin tho.

Did you read the articles? I just get so tired of folks that say wax molecules can't penetrate into a sintered ski base.
IsoSport and Ptex even claim wax absorption in their extruded base materials. After lots of work on some Dynastars I have I now believe it. Takes a lot of work though. Just a "regular" waxing on those last about 4 hours tops at average skiing speeds.

I do believe that the faster a ski travels the faster the wax bleeds out. So skiing 65 to 80 mph takes the wax out very quickly.

 

[cantunamunch]

Did you read the articles? I just get so tired of folks that say wax molecules can't penetrate into a sintered ski base..

Read the appendices to Kuzmin's paper - they will make you even more steamed at unsupported assertions .