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Hair structure.The science the chemistry.

05 Mar

 Welcome to BACK2MYROOTS B2MR:

Regular postings of fresh new topic’s

                         Understanding hair structure:

To be a good hair colourist we have to know so much to understanding. How the hair structure works. What role it plays is key to  successful colouring. In order to understand the dynamics of hair colour we need to look at the hair’s inner structure and understand how it is affected and changed in the colour process.or any chemical process we apply.We also have to keep up with the changing chemistry of the products we use.We have to understand how they react on the hair. What is the chemistry in that tube of colour pigment or that relaxer.Is it safe can i trust it! Blind faith or trusting the sales rep is not enough!

The Cuticle:

The protective outer layer of the hair shaft the Cuticle is made up of Translucent overlapping layers of keratin protein.

Each layer completely encompasses the hair shaft.

Imagine a stack of paper cups that might give you a visual image of the Cuticle.

Just as you might be able to bend a stack of cups without pulling apart the structure of the hair has the same pliability.The cuticle affords the hair about 25% of its strength.When the Cuticle is healthy it will lie flat against the hair shaft light will reflect of the translucent layers allowing the hair to appear to shine.

When we perform a chemical service on the hair perming or colour the Cuticle has to be opened to allow any chemical process to penetrate into the cortex. To do this one has to change the natural Ph of the hair to do this we have to use an alkaline. in it’s natural state healthy hair has a ph of around 5.5. In the past ammonia has been the main driver of this part of the colouring process but it has always been though to cause damage and tends to smell.

More recently most of the major hair colour companies have been promoting healthy all natural products personally i find this marketing misleading now the catch words are herbal, organic, natural, unfortunately the products now driving the colour are MEA and Denatured Alcohol are they any less drying and damaging to the cuticle ? You decide! They all serve to open the cuticle they are all an alkaline. Personally i would rather know the strength of the ammonia in a colour rather than work with an unknown many professional hair colours did have quite high levels of ammonia i can live with ).4% up to2%.

Many Colour companies have replaced having bees wax as a buffer in hair colour with oil and silicon based chemistry.Naturally after any chemical service the the correct Ph level must be restored to close the cuticle and restore that natural looking sheen a chemical balancing product is good for this it will restore the hair back to a pH  of around 5.5.

The same applies when relaxing hair much talk and discussion about Keratin based products. Along with the relaxers comes the issues of chemistry disclosed and reactions caused. major discussions on Formaldehyde gas or vapours  being produced and now the new safer term Aldehydes watch out for both.

see past topic: http://back2myroots.co.uk/2012/02/29/what-is-an-aldehyde-you-need-to-know/

The Cortex:

The Cortex makes up the bulk of the hair shaft the Cortex is composed of Keratin protein and 19 Amino acids. Keratin is a natural fibrous protein cross linked by sulfur bonds in the cortex the inner structure of the hair is known as the helix. When the hair is wet it is quite fragile as we dry the hair the keratin starts to harden and becomes stronger. We also find covalent and ionic bonds these are also effected by chemical services. Keratin as i have said is another well marketed product. Found naturally in the hair. By definition when added to products it must be good healthy natural! Most hair products that have Keratin in them may well be source or derived from. Animal. Vegetable or mineral. All being natural organic. Keratin from these sources will only lie on the out side of the hair with over use they can make the hair slightly brittle Keratinisation. Given the cost restrictions and the hydrolisation process for human hair keratin extraction most companies opt for the cheaper sources Although these can and will give the sheen and make the hair look healthy they do not penetrate through the cuticle layer of hair. { molecular size is to Big 500}   The only keratin able to penetrate into the hair has to be hydrolyzed human hair Keratin.{molecular weight 150-300 able to penetrate the hair}

Fact {Hair is 89%protein and 10% moisture} so the only keratin that really can help the hair on an internal level is sourced from human hair.

picture above: healthy shining highlighted hair with Multi tones:

The medulla:

The medulla is the inner layer or center of the hair shaft, it is made up of softer Keratin protein than in the cortex it could be best described as being like raw sponge part of the  Medulla function is linked to the bodies excretory system. Understand the roles of the above layers is key to performing good chemical services on the hair.

http://www.back2myroots.co.uk/

The Above facts are well worth having in your tool kit of knowledge when performing Chemical services on the Hair!

Mike B2MR:


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