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Thank you, Bart,
A quick skim through was definatley interesting.
Seems as if Mr. C has a pretty tough beard.
The whole article seems as if it's a bit of comfirmation for what seems like very intuitive results (at least in my limited understanding). I wasn't really surprised by any of the findings as they seem to align pretty closely with what I'd imagined was going on.
How on earth do you find this stuff? Got anymore?:thumbup:
The shaving angle myth debunked. Or maybe not. There's a lot to frown upon with this study.
Yes, the force the shave the hair showed no significant relation to the angle variations (within the tested limits). But they didn't shave on human skin... And they had a number of random failures, when the edge cut into the elastomeric base, before shaving the hair. That sounds line a "nick" to me...
But I like the research, because they discovered something similar as we notice during the HHT. They even defined 4 different stages, their 4th one almost identical to what we call HHT-1: catch and split lenthtwise. (Interesting that they found it happens much easier with a dry hair than with a moistened one). The fact they got that when they tried shaving at about 6 diameters above the holding point, tells me that the razor blade used wasn't very keen to start with. The average beard hair diameter of the test was stated to be 140 micron. 6X 140 micron = 840 micron. That is less than one mm. If I get a HHT-1 at 1mm of the holding point, I'm not even going to think about test shaving.
But these pictures are mind-boggling , aren't they? Amazing what they can do nowadays with high speed video and magnification.
Too bad a human can't be fitted into the vacuum chamber of a SEM to shave a patch of his mustache... :sleep: It would surely deliver great insight.
Oh yes, that was a fascinating read, and the pictures were incredibly cool. My problem is that I sell medical devices to neurosurgeons. When I first started, I would read studies, and think that I had great ammunition for my next sales call only to have them completely rip the study apart. Over time, I've started reading studies just as critically.
But, yeah, it's definitely well worth the read :thumbup:
My critical reading skills ain't all that, but it seems to me to be quite a humble little study. Fundamentally, the only real objective seems to be evaluating the reduction in cutting stresses due to the presence of moisture. The failure mechanisms and blade angle seems to be secondary to the whole objective. In a shave, we automatically compensate for those failures, either by a subsequent pass in a differing direction, by maintaining a sharper blade, and by maintaining/controlling the distance from the base. I'm not sure where all the differing cut angles come in either, other than as a function of blade distance from base.
It seems to beg the question: if water saturation reduces the cutting forces necessary, how much further reduction does shaving lather offer? I wonder if there is any inherent effect from lather, or if it just speeds up the rate at which water is absorbed by the hair shaft, or is it's function simply to reduce friction between the skin and blade?
^ Yes, it does seem like lather effects were noticably absent. In fact, I'm surprised that this is such basic research (e.g., investigate cutting behavior of beard hair as affected by moisture, subject age, blade approach angle, proximity of the initial contact point from the base of the hair, etc.) given the fact that this was funded by Gillette, the high-tech shaving 'gurus'. I would have thought they would have had this type of stuff done decades ago in their quest for even more machturbofusions.