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Cutting-Edge Research Shows How Hair Dulls Razor Blades

Which is counterintuitive to other findings that the "sharpness" (however defined - I believe in studies presented the pressure - or lack of - needed to sever a piece of filament) actually increases after first use of a blade, to a point. Clearly some micro-physics at work here at the supramolecular level.
 
What is new about this info? What is the takeaway lesson from this? Does it suggest any shaving strategies to reduce and slow blade wear?

Hardness of water would also be a suspect for the rate of blade deterioration. The entire issue is very complicated.
 
I was tempted to purchase the whole article to see how complete their research was. They did say that the angle of the blade to the hair matters, do they know that most of us here pay attention to this with our WTG, XTG, and ATG, only going ATG after reducing the hair via the other strokes. The other factors that they talked about like microcracking and ductility are already being discussed among people who study cutting edges, though not specifically razors. At odds are that the alloys that resist corrosion also form large carbides which upsets the uniformity and reduces the ductility. Since hair to my knowledge does not contain abrasive material the value of the hard carbides in a razor edge is questionable.
 
The next-generation blades may be improved by metallurgy :

Another thing that contributed to cracking and chipping is differences within the blade — if there are zones within the metal that are slightly harder or slightly softer. That might be easier to try to control, Tasan says, by coming up with steel that is as hard as today's razors but has a more uniform internal structure. The group has already filed a provisional patent on a process that could do that.
 
The next-generation blades may be improved by metallurgy :

Another thing that contributed to cracking and chipping is differences within the blade — if there are zones within the metal that are slightly harder or slightly softer. That might be easier to try to control, Tasan says, by coming up with steel that is as hard as today's razors but has a more uniform internal structure. The group has already filed a provisional patent on a process that could do that.


I'd love to have him scan some of those blades from the "lets use blades an infinite amount of times club". I am almost tempted to email him and point him at this site. The reason I say this is the statistical variability in long term usage of blades themselves will tell you something about the long term resilience of various alloys and coatings currently used empirically.

To be honest - while that article is in Science - I would be dumbfounded if P&G /Gillette didn't do this way back in the day and have optimized the alloy to account for this. Its the first experiment that any one would come up with when thinking about blades. I think its possible the better quality blades / steels use a more uniform allow w/ the right degree of softness to prevent the brittle behavior.

For the DE folks I would not be surprised of the seemingly biphasic response to feathers is due to an extreme brittleness - (sharp but probably chips quickly enough to dull or otherwise be uncomfortable).

What I am super curious about though is how this would pan out for a well designed ceramic blade. I think this would say it would be worse - but it would be cool just to see and see if there was a path where you could optimize ceramics to give you long lasting best of both worlds.

I had some spare money hiding in P&G I'd throw money at this :).

Avi
 
To be honest - while that article is in Science - I would be dumbfounded if P&G /Gillette didn't do this way back in the day and have optimized the alloy to account for this. Its the first experiment that any one would come up with when thinking about blades. I think its possible the better quality blades / steels use a more uniform allow w/ the right degree of softness to prevent the brittle behavior.

Considering Gillette's profit model is based upon the selling of the blades, if anything they researched how to make a blade deteriorate quickly so they won't last as long.
 
Considering Gillette's profit model is based upon the selling of the blades, if anything they researched how to make a blade deteriorate quickly so they won't last as long.

+1! ‘Profit from selling the blades, not the razor!’
 
Considering Gillette's profit model is based upon the selling of the blades, if anything they researched how to make a blade deteriorate quickly so they won't last as long.

I recall Gillette's own recommendations for the cartridges are an absurdly long turnover time. I just looked this up - they are claiming a month here. That is 30 days on the same cartridge - which I think naively is equivalent to 6 days worth of pressure per blade (clearly that is not really true) .. I would think to get that, someone must have done this type of metallurgy. Regardless to your point - if your goal is to deteriorate the blade you'd have to do the same analysis backwards :)


Perhaps as an aside I would say these arguments about profit models (in cheap deteriorating blades) is not really the right way to think about this (and I am sure (hope?) they don't). The reason for that is if your profit model is based on selling something sub quality for the purpose of profit - you can be sure there will be hungry competitor / startup that will eat your lunch [the Harry's/ Dollar Shave Club's of the world would have been that wakeup call, if someone wasn't already cognizant of such things ]. This applies just as well to well designed non-deteriorating steel blades - which has great applications beyond disposables as well.
 
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Esox

I didnt know
Staff member
Cool .gif in there. I wonder what blade it is.

roscioli6_r.gif



Considering Gillette's profit model is based upon the selling of the blades, if anything they researched how to make a blade deteriorate quickly so they won't last as long.

Naamloos-1.jpg
 
I recall Gillette's own recommendations for the cartridges are an absurdly long turnover time. I just looked this up - they are claiming a month here. That is 30 days on the same cartridge - which I think naively is equivalent to 6 days worth of pressure per blade (clearly that is not really true) .. I would think to get that, someone must have done this type of metallurgy. Regardless to your point - if your goal is to deteriorate the blade you'd have to do the same analysis backwards :)


Perhaps as an aside I would say these arguments about profit models (in cheap deteriorating blades) is not really the right way to think about this (and I am sure (hope?) they don't). The reason for that is if your profit model is based on selling something sub quality for the purpose of profit - you can be sure there will be hungry competitor / startup that will eat your lunch [the Harry's/ Dollar Shave Club's of the world would have been that wakeup call, if someone wasn't already cognizant of such things ]. This applies just as well to well designed non-deteriorating steel blades - which has great applications beyond disposables as well.

I'm not so cynical to think that Gillette would actually try to make their blades deteriorate more quickly, but there is no profit in them researching how to make blades last longer. Once patents expire and competitors can start competing against their format, they change their format and patent it. 2 blades, 3 blades, 5 blades, 2 blades with a spacer in between.
 
Considering Gillette's profit model is based upon the selling of the blades, if anything they researched how to make a blade deteriorate quickly so they won't last as long.

I suspect they already have. I can only get three shaves from a Gillette Fusion. When the Fusion was new I could easily get over two weeks. That didn't last long.
 
Once patents expire and competitors can start competing against their format, they change their format and patent it.
Patents aren't the only thing in play, though. A huge part of metallurgy involves processes, and processes are amenable to protection by being held as trade secrets. Trade secrets are forever, they don't expire, you just have to be careful to keep them secret.

Heck, you can greatly improve hardenability in steel by adding as little as 0.001% boron, and if you never tell anyone a competitor might not notice it's there.
 
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Patents aren't the only thing in play, though. A huge part of metallurgy involves processes, and processes are amenable to protection by being held as trade secrets. Trade secrets are forever, they don't expire, you just have to be careful to keep them secret.

Heck, you can greatly improve hardenability in steel by adding as little as 0.001% boron, and if you never tell anyone a competitor might not notice it's there.

Oh, but they would. I once worked for an unnamed company in their materials lab, and our specific job was to - very thoroughly - analyze competitors' products, to a) determine if they had violated any of the company's patents, and b) to determine if there was anything of "interest" in their products. Just for the science, you know. Another level of management decided how "interested" they were.
 
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