Yeah they don’t want a blade to last for too long. Lost profits. Like the short lived Personna 74s.
Cutting-Edge Research Shows How Hair Dulls Razor Blades
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Gillette certainly has the technology to make blades last much longer, but they’ll only implement it in their just released razors. Case in point is the Gillette Guard. When it was released, the blade edge stayed sharp. Some people were getting over a hundred shaves per cartridge. Now the same cartridge will get dull before 10 shaves. The Fusion and Mach3 before that used this same principle to get people to switch over.
rbscebu
Girls call me Makaluod
I remember many years ago talking with an engineer in GM. He was working on rear wheel axel designs. GM wanted an axel that had an average lifespan of 2 to 3 years. At that time, GM provide a 12-month/20,000 mile warranty.
It's all part of an engineer's job.
It's all part of an engineer's job.
On the other hand Personna had to discontinue the Personna 74 because they worked so well and lasted a very long time, thus, there was no profit it from a long lasting blade.
The article begins with a premise that is incorrect. "steel is hard and beard hair is soft". That is not quite the case. Yes, steel is harder than beard hair, but beard hair is far from soft. Hair is similar in strength to copper wire of the same diameter. Anyone who has tried to cut through copper wire with a pocket knife soon learns that it is not an easy task. The thicker the wire, the harder it is to cut. The same thing happens with beard hair; the thicker the strands, the more difficult it is to shave.
Well, I've been an engineer at GM for the last thirty years, and can assure you that I've never, ever heard anything like that.
rbscebu
Girls call me Makaluod
This was in Australia about 40 years ago when GM use to make vehicles there.
To be honest (as per @chilehed ) the idea of engineering for a warranty period is not really that plausible because for the really basic reason that it is really difficult to do. The reason for this is while a slew of "items" might have a most probable mean time to failure beyond some time limit (and one can guess at this), the distribution around that mean time is spread on log scale.
As such you in fact do have to over-engineer in ways you would not otherwise think to because if just a tiny fraction of a percent fail on the wrong side of your warranty period you are going to lose your company a lot of money. And since predicting a tail end of a failure distribution involving every part in a complex machine is really quite difficult, everyone just aims to over-engineer for really good basic economic and ethical reasons.
That comparison is often misquoted; in fact hair and copper wire of similar diameter have equivalent tensile strength. That does nor correlated to equally hard to cut and in fact hair is much easier to cut than copper wire.
Thicker hair certainly is harder to cut and hence the large variances in shaver's experience which I think was the thrust of your last two sentences.
Better living through Metallurgy!
Interesting...but just telling us what everybody already knows, that razors get dull from use.
Will this knowledge inspire me to change my shaving habits to better preserve the blades?
What do I care more about...my face or the razor-blade?
And who even uses these "everyday disposable razors" of which they speak?
Please put my shoes under your microscope, because I fear that the soles are slowly wearing down from some kind of friction or abrasion!
We need a microscopic analysis and scientific enquiry into this!
Interesting...but just telling us what everybody already knows, that razors get dull from use.
Will this knowledge inspire me to change my shaving habits to better preserve the blades?
What do I care more about...my face or the razor-blade?
And who even uses these "everyday disposable razors" of which they speak?
Please put my shoes under your microscope, because I fear that the soles are slowly wearing down from some kind of friction or abrasion!
We need a microscopic analysis and scientific enquiry into this!
There was another point in the study which is worth commenting.
According to the investigators the blade underwent more chipping when cutting the hair at angles deviating from a perpendicular orientation. Assuming the hair stands more or less perpendicular to the skin surface at the cutting point, I personally infer that shallow angles are favored for blade conservation. More chipping in the blade will also lead to more uncomfortable shaves. I think its the experience from the majority that steeper angles lead to harsher shaves, probably because of skin scrapping but may be also because of more blade chipping.
According to the investigators the blade underwent more chipping when cutting the hair at angles deviating from a perpendicular orientation. Assuming the hair stands more or less perpendicular to the skin surface at the cutting point, I personally infer that shallow angles are favored for blade conservation. More chipping in the blade will also lead to more uncomfortable shaves. I think its the experience from the majority that steeper angles lead to harsher shaves, probably because of skin scrapping but may be also because of more blade chipping.
There are very well documented ways to make blades last almost indefinitely. The key to making blades last is the same as almost everything else, quality materials and maintenance. Ask any straight razor shaver. You can get great daily shaves from a single blade for decades. Any micro damaged caused by shaving is easily and quickly repaired. The technology for maintaining disposable blades was invented and abandoned long ago. Google search auto strop. I very much doubt a maintenance free solution will ever be found think kitchen knives. All blades need to either be maintained or replaced. Which one is a balance of replacement cost and convenience.
Has there been a member that used there magnification tools to look at a DE blade edge? I would think that this would be something of interest for someone with the right equipment. If they looked at a new blade the next logical step would be look at an old one. Then maybe all of the shaves in between. If they could take pictures and post them, that would be great.
Unfirtunately, getting photos at a high enough magnification to allow a meaningful assessment of edge condition isn't as easy as it sounds - and that still wouldn't give much insight into wear mechanisms.
They are using a electron microscope (as was someone on this forum). The advantage of the MIT group is they are actually doing it dynamically so they can see the mechanism. That said I still think if someone emailed the primary author and mailed them some of those infinite use blades, he would be super interested in analyzing them.
