Personna Meds vs Labs (SEM Comparision)

[GBerry]

Steve,

Thanks for this very well done construction / failure analysis. This is a real treat.

If I understand the shots well enough, it looks as if there is a variability in the bevel on the Lab that does not exist on the Med. Is that right?

Did you happen to look at the "Comfort Coating"?

Thanks again.

 

[ackvil]

First, this is an excellent well done thread.

Jim,

As a component engineer, I often get involved in manufacturing process details whether I want to or not.

I have since recognized there is a definite process window that virtually all manufacturers will strive to maintain.

The blades we receive can be anywhere within this process window. A defective lot would be outside of the process window.

I would expect there would be differences between machines also.

For sure there will be variances from one manufacturing lot to the next and variances from blade to blade within the lot.

I do not have any good knowledge of the blade manufacturing steps but I do believe the grinding / polishing steps are separate from the stamping steps.

Machines may have been changed over the course of time.

The SEM shots clearly show these two blades are different.

I have read posts at B&B ASR stated the two blades are made to the same specification. There is enough difference here to say these two blades are not made to the same specification.

Hope this helps,
Gene

Thanks, Gene. I appreciate your analysis. As with all things Personna, everything the parent company says must be taken with a grain of salt.

 

[Evil4blue]

Steve,

Thanks for this very well done construction / failure analysis. This is a real treat.

If I understand the shots well enough, it looks as if there is a variability in the bevel on the Lab that does not exist on the Med. Is that right?

Did you happen to look at the "Comfort Coating"?

Thanks again.

I think there's variability in both blades as per most machining processes. Even if the Med Preps and Labs are built to the same spec, the tolerances in the machines maybe different or the Meds maybe held to a tighter tolerance. Of course, this is all speculation.

For me, my face, I can't really tell a huge difference between the 2 blades. I think the Meds are smoother, longer. I mean the the 4th shave with the Meds is smoother than the 4th shave with a Lab. Of course it's all YMMV.

The comfort coating is a poly coating which really doesn't scan well using EDS analysis, partly because its made of long chain carbon atoms (which gets lost in the carbon found in the steel) and hydrogen atoms which don't scan at all. The personna blades lay that coating really thin (as compared to other manufactures) but doesn't really look all the different between the 2 blades.

 

[GBerry]

Thanks, Gene. I appreciate your analysis. As with all things Personna, everything the parent company says must be taken with a grain of salt.

There are likely to be a variety of reasons why ASR/Personna does not release information. They do not want their competitors to know. They would not want to admit some machines produce good product and some bad product. Some other little secret.

I do like their blades and without question will order some Med Preps to check them out with a number of other test candidates.

Steve's analysis reveals there are significant differences between the two.

 

[GBerry]

I think there's variability in both blades as per most machining processes. Even if the Med Preps and Labs are built to the same spec, the tolerances in the machines maybe different or the Meds maybe held to a tighter tolerance. Of course, this is all speculation.

For me, my face, I can't really tell a huge difference between the 2 blades. I think the Meds are smoother, longer. I mean the the 4th shave with the Meds is smoother than the 4th shave with a Lab. Of course it's all YMMV.

The comfort coating is a poly coating which really doesn't scan well using EDS analysis, partly because its made of long chain carbon atoms (which gets lost in the carbon found in the steel) and hydrogen atoms which don't scan at all. The personna blades lay that coating really thin (as compared to other manufactures) but doesn't really look all the different between the 2 blades.

Thanks for the correction. To understand it is good to know alot about the measurement technique and how the product is made (materials).

I was just thinking the coating could be a factor. We just can not measure it with this tool very well.

I guess that is where some of these well calibrated faces come in. I know that I will buy some and test them along with a few others and let my face decide.

Thanks again for this very informative thread.

 

[snowman]

Great thread and info. I am endlessly astounded by the generous folks at B&B. Thank you for the pics. Outstanding.