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View Full Version : Speaking of stretchy-how stretchy is too stretchy



jivete
July 28th, 2008, 09:55 AM
So, after reading all about stretching hair, I've been playing with mine and oh man does it stretch. Like, I can double the length before it breaks. I'm deducing I need more protein. I've done some protein treatments and sometimes they make my hair feel gummy. I guess I wasn't moisturizing enough afterwards so this weekend I did another treatment and made sure to use my heavy conditioner afterwards. I didn't get the gummy feeling, but I'm still super duper stretchy.

So my question is, how stretchy is too stretchy? My hair will return to it's normal length if it's only stretched a little bit. If you assume hair is like many materials, including most metals, it should have an elastic (where it returns to it's previous shape) and a plastic range before it reaches failure as described here,

http://en.wikipedia.org/wiki/Deformation

what is considered the normal stretchable range?

So what do you guys think? My hair has been notoriously prone to breakage in the past, so I want to do what I can for it. If I do need more protein, is there a salon treatment that is especially good? I don't mind paying for salon treatments if they work better. At home I've used Henna/placenta, Aphogee and Ion treatments. I admit, I don't usually leave them on as long as I should and I don't use heat with them.

Thanks!

Riot Crrl
July 28th, 2008, 12:24 PM
I always heard it's like 20-30%.

I think the Sally's stuff you've been using should work fine, if you use it per the directions.

jivete
July 28th, 2008, 12:51 PM
Thanks. So 20-30% of original length? Meaning if you had an 8" piece of hair and it stretched to 10.4" before breaking that would be okay? Or should it be able to stretch 20-30% and still remain elastic? I guess usually we're stretching a 2-3" piece of hair in between fingers so it'd be more like if it stretches an 1" (or a little less) and returns to normal it's okay...?

Ohio Sky
July 28th, 2008, 01:20 PM
I have issues with this myself, because my hair seems to stretch quite a bit but I can't tell, even with the knowledge that it should stretch 20-30%, if it's TOO stretchy.

I've been using the Henna n' Placenta spray leave in, though, and it seems to be helping. I usually spray some in, then put a bit of Kimberlilly's defrizz spray before bed, and it leaves my hair softer and feeling stronger by morning.

Riot Crrl
July 28th, 2008, 01:27 PM
Thanks. So 20-30% of original length? Meaning if you had an 8" piece of hair and it stretched to 10.4" before breaking that would be okay? Or should it be able to stretch 20-30% and still remain elastic? I guess usually we're stretching a 2-3" piece of hair in between fingers so it'd be more like if it stretches an 1" (or a little less) and returns to normal it's okay...?

Yes. I think returning to (somewhat) normal is the key thing. If it stretches even farther than that but still returns to (somewhat) normal, it's probably OK too. If it is really lacking protein is when it just stretches out and doesn't return.

Iylivarae
July 28th, 2008, 01:34 PM
I think if you stretch it and it doesn't go back to its normal shape, you need more protein. Normal hair stretches and breaks, when then normal shape can't be maintained.

missy60
July 28th, 2008, 02:27 PM
I am a curly and I comb my hair in the shower with conditioner on it. I know I need protein when I comb and some hairs stretch past most of my other hair. If your hair is stretchy I would just keep doing protein treatments until it stops being stretchy. Your hair will let you know when its had enough. If you are loking for salon treatments Redkens Cat is a good one and so is Joico. I use both of those.

Nightshade
July 28th, 2008, 02:42 PM
So my question is, how stretchy is too stretchy? My hair will return to it's normal length if it's only stretched a little bit. If you assume hair is like many materials, including most metals, it should have an elastic (where it returns to it's previous shape) and a plastic range before it reaches failure as described here,

http://en.wikipedia.org/wiki/Deformation

what is considered the normal stretchable range?


Thanks!

:lol: Someone else that knows WTF the Tensile Stress-Strain Diagram is, that's fantastic! (I teach on metallurgy.)

I've thought about this too, and have experimented on a few of my shed hairs. After a shower they stretch to all hell, and I can always tell when I pass that yield point. Instead of it springing back to a normal-length hair, it's got all these kinks and bends in it, even though I was only pulling it straight.

The elastic range is a lot bigger when my hair is wet than when dry, which, sadly, also makes it easier to exceeded that yield point.

Finoriel
July 28th, 2008, 03:52 PM
I think itīs impossible to say exactly how stretchy is too stretchy for hair in general. Every head of hair is different in the thickness and sturcture of the hair and itīs history with treatments/products and such. Length and herewith age is another factor which changes the quality of one hair during its length. Weaker and therefore more stretchy at the tip makes it break easier there than near the root where it will eventually go back to itīs original shape, both at the same load on the same hair. So the yield point must be a very individual thing. Continuous stretching and reshaping of the hair, even if it stays under the yield point will damage the hair over time. Like an old hair elastic slowly wearing out before it becomes porous and rips. Constant dripping wears away the hardest stone... so avoiding stretching as far as possible is the safest way. Thatīs the point for many people to avoid combing or brushing wet hair, it easily overstretches when wet. To notice xy% of overstretching while combing and stopping then, could be hard anyway :wink:

Highjack for Nightshade: There are more out of us than you would expect. :D Shall I draw the complete iron-carbon diagram? Any discussions about melting points or crystal lattices? :eyebrows: Wanna see my samples of tensile tests or some notched bar impact testing? Mohs, Brinell, Vickers, Knoop or Rockwell? :wink: nice to see another "metal"-nerd.

shikara
January 13th, 2012, 03:59 PM
This whoke topic has been confusing for me too, when I would try to do tests to determine what I needed to do for my hair, and what shape it was in. Some say you should do the test wet, others say dry, others that it only gives a true answer if tugged from one end only rather than from both ends. Sometimes i couldnt tell if it was being pulled or if it was slipping in my hand. Also different hars did different things:rolleyes: So now I dont concern myself with that. I give it small doses of protein with shampoos and conditioners, and as long as it is manageable and seems hapoy, thats good enough for me!