Results tagged “hair damage”

Over the years, our research teams noticed a puzzling inconsistency in the rate of relaxing process: the same Sensitive Scalp Relaxers showed radically different activity, even though they were applied to the same single hair fibers. A close analysis of the procedures allowed us to find that such inconsistency occurs when the prepared Sensitive Scalp Relaxer (also known as No-Lye, Guanidine Hydroxide, etc) is not promptly applied.

In order to explain the unusual effect, we devised an experiment that tested several consecutive sections of the same hair fiber with the same relaxer. Only the first section was exposed to the fresh relaxer while the next fragment of hair was subjected to the same relaxer formula, which had been sitting on the bench for a selected amount of time. This procedure allowed for us to control a delay time between mixing and the moment of application.

The folks at Nalco Company (Yin Hessefort, Brian Holland, and Richard Cloud) published an interesting study that appeared in the July/August issue of the Journal of Cosmetic Science, where they studied the porosity characteristics of damaged hair.

The study used the gas sorption method to determine the total pore volume, adsorption pore-size distribution, and the surface volume of the damaged hair. The two types of damaged hair they looked at were bleached hair and hair that had been exposed to UV rays.

What they found was that bleached hair nearly tripled in surface area during the first minute of bleaching due to an increase in the number of pores, followed by a sudden drop after 10 minutes of bleaching, suggesting that smaller micropores (< 2 nm) break down into larger macropores (> 50 nm). In contrast, they found that UV damaged hair showed an immediate loss in surface area during the first 200 hours of exposure and a gradual increase as exposure time continued, which they theorized was caused by a fusion of cuticle cells followed by an increase in pores or cracks.

How Conditioners Can Help Repair Chemical-Related Damage

In "Conditioning the Hair, Part II", we discussed how combing and the weather can damage the hair and how conditioners can help. Here, we take a look at chemicals, in part three of this four-part series.

Relaxers contain sodium hydroxide, potassium hydroxide, lithium hydroxide or guanidine hydroxide as active ingredients. (To date, sodium hydroxide and guanidine hydroxide are the most effective straightening agents.) Relaxers work by changing a third of the cystine bonds into lanthionine bonds, and in the process, the hair experiences a twelve-to-fourteen percent loss in tensile strength.

Permanent waves contain ammonium thioglycolate as an active ingredient and have a pH of 9.0 - 9.5 (The pH level is attained when ammonium or monethanolamine - MEA - is added to the ammonium thioglycolate creme rearrangers or boosters during manufacturing.) Ammonium thioglycolate cremes reduce (or break) 20-40 percent of cysteine (1/2 of cystine) bonds before the hair is rodded. During neutralization process, the reduced bonds are oxidized with the help of sodium bromate, reforming 80 - 85 percent of the broken bonds. Therefore, 15-20 percent of reduced (broken) cystine bonds never reform, thus causing dryness to permanently waved hair.

Permanent hair colors contain hydrogen peroxide as one the active ingredients at 20 to 40 volume concentration. As the color of the hair is permanently altered, cystine bonds are changed to cysteic acid. This process is also extremely drying to the hair.

In each of the chemical processes described above, it is important that hair be well conditioned before, during, and after the procedure and that any existing damage be repaired. Attending to the hair in this way, while it's being chemically treated, will also help eliminate combing damage. Be sure to select chemical systems that incorporate such complete conditioning features.

cond3.pdf

In Part One of "Conditioning the Hair," four basic causes of hair damage were mentioned. In Part Two of this series, we will discuss two of those causes - combing and the weather - and what you can do as a stylist to prevent/eliminate these types of damage from occurring.

COMBING DAMAGE

Human hair is elastic but not perfectly so. Its elasticity allows it to sustain a certain degree of pulling force exerted by combing (or brushing). Many times, the pulling or combing force applied during regular and normal styling, stretches the hair beyond its limits causing breakage.

Combing force can be minimized by: using deep penetrating conditioners to detangle the hair and mend the broken areas along the hairshaft, which can snag on one another during combing; applying auxiliary products, such as leave-in conditioners if further detangling is needed to comb wet hair prior to blow drying or setting; always using a wide-tooth comb, particularly while hair is wet and most vulnerable; gently combing through the hair section by section starting at the nape and proceeding upwards towards the crown; and applying a dab of oil moisturizer or hairdress on dry hair, prior to styling.

You'll be able to gauge breakage by examining the hair left in the comb.

WEATHER-RELATED DAMAGE

The heat and ultraviolet rays from the sun have devastating effects on the hair. The heat generated by the sun dries out hair fibers and ultraviolet (UV) rays alter some of the cysteic acid bonds. This results in a weakening of the hair fiber and a small degree of color bleaching.

To combat sun-related damages, advise your clients to stay out of the sun as much as possible or cover the hair with a silk scarf when outside.

Other remedies include using an oil moisturizer or creme hairdress to help alleviate and replenish the loss of moisture from the hair or UV-absorbing or sun-screening products formulated especially for hair, containing such ingredients as para-amino benzoic acid. Some oil moisturizers or creme hairdressings contain UV absorbers. Ask your manufacturer if the brand you use contains sunscreening agents.

cond2.pdf

When formulating products, the termination of hair damage (minimization at the very least) is my primary concern. Take a look at an article I wrote regarding the causes of hair damage, how one can prevent it, and various cures/remedies for it:

HAIR DAMAGE: DEFINITION

Hair damage is essentially any condition whereby one or more of the hair structures, (cuticles, cortex, medulla, etc), are physically or chemically altered to the extent that they are unable to return to their original state. Examples of damage are:

Cuticle Loss and/or Erosion
Cuticles were designed by nature to protect the delicate inner structures of the hair, retain moisture and reflect light. They are configured like partially overlapping roof shingles, and on healthy hair, they are very tightly aligned.

When damaged, cuticles can become cracked and frayed. Some of the keratin material, (of which cuticles are composed), can dissolve and disintegrate, making the hairshaft thinner. In severe cases, entire portions of the cuticle layer can be removed altogether.

Longitudinal Rupturing
With extreme damage, the hair shaft can experience a massive crack along its length, damaging the cortex and medulla. The rupture leaves the hair fiber open and unprotected.

Fibril Disintegration
With excessive damage, the strong proteinaceous fibers of the cortex are weakened and often disintegrate. The fibers fray and give the hair shaft a ragged, unstable alignment.

EVIDENCES OF HAIR DAMAGE
The byproducts of hair damage include the following:

Loss of Elasticity & Tensile Strength
Elasticity is a measure of a hairs' ability to stretch and recover, without breaking. On average, untreated excessively curly hair should be able to stretch about 50% of its length before reaching its breaking point. When hair cannot be extended to this degree without snapping, it has lost some elasticity and tensile strength.

Breakage
Breakage is closely related to loss of elasticity. It occurs as weakened hair experiences mechanical manipulations. Even simple combing and brushing can cause significant breakage on a damaged head of hair.

Porosity/Moisture Loss
Porosity and moisture loss are close relatives. Porosity is a measurement of the ease to which the hair accepts and releases moisture and other substances. For instance, the more porous the hair, the easier it is to " take up" coloring solutions and the easier it is to air - dry. The healthier the hair, the more difficult it is for chemical solutions to penetrate and the longer it takes to air - dry the hair. Moisture loss occurs because the hair is more ready and willing to let the natural moisture escape from the inner fiber into the atmosphere. Healthy hair is well able to maintain its moisture levels. Both porosity and moisture loss are a result of cuticle damage. Simply put, the cuticle layer is no longer tightly aligned and is no longer providing adequate coverage to the inner hair shaft.

Dullness
On healthy hair, shine reflects upon a tightly aligned cuticle layer. Hair damage results in a dismantled cuticle surface, making it difficult, if not impossible, for hair to shine.

Brittleness
Hair becomes brittle when it has lost a significant degree of moisture. Cuticle and cortex damage and the porosity that results from such damage are the fundamental reasons that hair loses pliability and becomes straw-like in feel and appearance.

Splitting of Ends
Split ends are essentially longitudinal ruptures at the end of the hair shaft. Once split, these ruptures tend to travel up the hair shaft. And, because they expose the inner structures, split ends are typically dry and quite brittle.

Excessive Tangling
Hair that has suffered cuticle injury and damage to inner structures may be very difficult to comb. The frayed fibers interactions nagging, tugging and pulling one another. Both wet and dry combing is impeded.

Fly-Away Fibers
Damaged hair carries a more negative electrostatic charge than does healthy hair. Negatively - charged hair strands repel one another, producing fly - away strands, and makes hair difficult to manage over all.

Limpness/Lack of Body
Hair that has been damaged of ten won't hold curls well and does not have the
fullness and volume known as "body."

CAUSES OF DAMAGE
The sources of hair damage are many, and range from very ordinary practices and
procedures to very extreme ones.

Ultraviolet Exposures
Every day exposure to the sun affects the hair, even though it is seldom attributed to the damage of excessively curly hair textures. Ultraviolet rays from the sun can fuse the cuticle layers together, and this fusion causes the hair to be less elastic and more prone to mechanical breakage.

Mechanical Manipulations
Mechanical damage can occur when hair is combed, brushed, blown dry or styled. Infact, virtually any physical manipulation of the hair that entails even minimal tugging and pulling can damage hair. The damage caused, however, can range from slight to extreme depending on how carefully the hair is handled.

Chemical Processing
Chemical straightening, permanent waving and permanently coloring all irretrievably
alter the bond structure of hair. Whenever the bonds are affected in this way , the hair loses a degree of its tensile strength. Also, hair becomes prone to moisture loss since chemical processes lift and penetrate the cuticle. Once the cuticle layer is penetrated in this manner, some degree of moisture loss is typical.

Thermal Styling
The high temperatures of modern-day blow dryers, curling irons, flat irons, crimpers, straightening combs, can easily deplete hair of moisture. When coupled with chemical relaxing, heat styling may result in extreme hair dryness.

Shampoo
For many, the fact that simple shampooing can damage the hair is still a difficult one to accept. Nevertheless, it's true. A shampoo with a pH level higher than 5.5 will cause a pH imbalance and "rough- up" the cuticle layer. It will also strip much, if not all, of the natural oils from the hair. This sets the stage for mechanical damage because a stripped, rough cuticle layer sets the stage for considerable combing and styling damage.

Additionally, the natural intercellular cement, (which tightly binds the fibers of the cortex layer and accounts for much of hair's strength) can be dissolved by shampoo detergents to some extent . With repeated shampoos with a high pH, strong detergent formula, the break down the intercellular cement progresses. Under these circumstances, the cortex may be damaged cortex and the hair is weakened.

HAIR DAMAGE: PREVENTION

Ultraviolet Exposures
To prevent the sun's ultraviolet rays from fusing cuticle layers together, avoid exposing hair to intense sunlight. Hats or scarves should be worn when out in sunlight for extended periods of time. Also, when selecting conditioning and finishing products formulated for excessively curly hair, look for those that contain sunscreen ingredients. Such an ingredient is Para-Amino-Benzoic-Acid, (PABA).

Mechanical Manipulations
Excessively curly hair is relatively fragile, so great care should always be taken when handling it. Some suggestions are:
• Use only detangling/conditioning-formula shampoos for cleansing excessively curly hair.
• Comb hair gently, especially when it is wet. To detangle, a wide-tooth plastic or rubberized comb is the only choice.
• Deep condition the hair after shampooing, without fail. When time is of the essence, you may use a leave-in conditioner, but only one formulated specifically for African-American hair textures.
• Avoid using hair-tightening barrettes and rubberized elastic bands. Minimize the use of curling irons / heated rollers, especially when hair is not really clean. Also, ask clients to sleep in a silky cap, scarf or on a satiny pillowcase to avoid damage caused by abrasion. A silky scarf is also a good idea to prevent abrasion when wearing woolcoats and jackets. Ask your stylist to prescribe the hair care products you should use between salon visits.

Chemical Processing
• See your stylist for chemical straightening, permanent waving and permanent coloring treatments.
• The next time you see your stylist for a relaxer treatment, ask for Affirm® FiberGuard Conditioning relaxer system. It has been proven to help maintain the tensile strength and elasticity of hair during chemical processing:

Thermal Styling
To prevent extensive damage to the hair and significant moisture loss:
• Air dry chemically - treated hair if it is possible to do so and still achieve the desired style. It is best for the hair.
• If you must blow-dry, do so only after excess moisture has air-dried or been blotted from the hair. Blow drying from a soaking- wet stage stretches the hair severely and can result in extensive fibril damage, including breakage.
• Thermal style only after hair has been treated with an intensive conditioner, preferably one rich in moisturizers.
• Apply a light coating of a good thermal styling product before heat styling. A very small amount of a silicone laminate is excellent for thermal styling; it helps the styling comb/ brush glide through the hair easily, seals cuticles to reduce inter fiber snagging, and produces a great shine.
• Use only the degree of heat necessary. Implements with thermostatic controls should always be used. And, remember, properly relaxed hair requires minimal heat to achieve smooth, sleek styles.

Shampoo
• Cleanse only with high-quality conditioning/ detangling shampoos, formulated especially for excessively curly hair. Make sure that the pH of the shampoo is properly balanced, within the range of 5.5 and 6.5.
Avoid detergent formulas that strip the hair of its natural oils. Ingredients like those in the alkyl sulfates group, such as sodium lauryl sulfate, are harsh detergents. Shun shampoos containing such harsh detergents.
• While shampooing, try not to tangle the hair. Massage the shampoo into a rich lather throughout the hair and scalp, using the pads of your finger tips, not your fingernails. Be sure to rinse the hair thoroughly to remove all traces of shampoo.

HAIR DAMAGE: TREATMENTS
As indicated earlier, once hair is damaged there is no real way to completely restore it. Cutting is the only means of ridding hair of damaged areas. There are ways,
however, to make hair look, feel and handle more like healthy hair. Conditioners
play a key role in this pursuit.

The most widely - used categories of conditioners are as follows :

1. Leave-In Conditioners
These conditioners are applied sparingly after shampooing and left on the hair.
Some provide effective UV protection. Modern-day versions are lotion-like in
consistency and are quite excellent. They can moisturize dry hair, detangle, help
protect against thermal and mechanical damage, impart sheen and give hair a
soft texture.

2. Deep Penetrating Conditioners
Commonly known as substantive or intensive conditioners, this category of products penetrates the hair shaft to deposit moisturizing and/ or proteinaceous substances. They typically are left on the hair 20-30 minutes for the deepest penetration, and work to repair damaged areas, moisturize, detangle and eliminate static charge.

3. Reconstructors
Reconstructors are heavy-duty conditioners designed specifically for severely damaged hair. They typically contain micro- and macro- proteins to fill in cracks and ruptured areas on and within the hair shaft. Reconstructors may also contain polymeric agents to tightly bind the structures of the hairshaft together for the purposes of fortification and combability.

4. Moisturizers
Moisturizing Conditioners hydrate dry brittle hair and correct moisture imbalances.

5. Laminates
This category of conditioners is designed to: a) seal the cuticle layer for a glossy sheen, b) ease combing and c) ward off the style-wrecking affects of high humidity.

6. Thermal Styling/ Blow Drying Lotions
Used prior to heat styling, these conditioners help protect the hair from heat damage, reduce the force required to comb or brush the hair during blow-drying, provide sheen and eliminate static charge.

7. Finishing Conditioners
This category includes natural oils, cremes, mineral oil -based hair dressings, oil sheen sprays and laminate sprays. Such products are used to enhance sheen, manageability, and the oil-based products are sometimes used to lubricate the scalp.

8 . Pre-Chemical Conditioners
Pre-chemical Conditioners are sold as integral parts of some relaxer systems. These conditioners are especially formulated to deep condition and repair the hair during chemical processing. Depending upon the brand, a Pre-Chemical Conditioner will also leave hair with an extraordinarily silky texture and luster.

9. Post-Chemical Conditioners
Post-chemical Conditioners are also sold as integral parts of some relaxer systems. They work to sustain and augment the deep conditioning treatment that the Pre-Conditioner effected. Post-chemical Conditioners also help normalize and re-balance the pH of the hair.

On the chart that follows, the various types and evidences of damage are listed.
Specific treatments are recommended. While these listings are not exhaustive, they
provide a good starting point for addressing the special needs of damaged hair.

hairdamage.pdf

Here's a study that I helped author in 1995 regarding the physical properties of African American hair and how it differs from Caucasian hair. Enjoy.

Scientific innovations in chemical treatments that alter the texture of African-American hair, as well as a plethora of style trends, have spurred phenomenal growth in this
segment of the hair-care market throughout the past three decades. The level of research & development by manufacturers in the area of product formulation has steadily elevated; yet, a great deal remains to be learned about the unique physical properties of African American hair. Compared to the vast body of research regarding Caucasian hair, the study of African-American hair is at best limited.

A Review of Research

In published studies, J. Menkart et al, Epps et al and Kamath et al reveal that some important research has indeed been conducted on the physical properties of highly curly hair. The efforts of these researchers and the results of their studies serve as a starting point for the further study of African-American hair. Other general observations about hair, such as those pertaining to static charge (Jachowicz and C.R. Robbins) and theories about moisture content, serve as a springboard for advancing the study of African American hair.

Shape: Menkart and Wolfram report that African-American hair has a physical shape resembling a twisted oval rod, whereas Caucasian hair is more cylindrical. They found evidence of this when they made elliptic comparisons or hair cross-sections. Using a formula in which the minor axis is divided by the major axis, Menkart and Wolfram
determined that African-American hair has a ellipticity index of 0.56 and Caucasian hair has an index or 0.7.1. The tensile-strength data gathered during this research shows that the breaking stress of African·American hair (1.24 g/denier, a unit of fineness equal to the fineness of a yarn weighing 0.05g for each 450m of length or 19 for each 9000m.) is less than that of Caucasian hair (1.41 g/denier). The yield stress for African-American hair, however, is slightly higher (0.46 g/denier VS 0.42 g/denier).

Kamath and Hornby studied the fractographic behavior of African-American hair to view both major and minor rods at low levels of extension. They examined the ellipticity of
hair fibers and reported ellipticity indices of 1.89±0.083 and 1.0 to 1.4 for African-American and Caucasian hair, respectively. In this study, the ellipticity index was calculated by dividing the major axis by the minor axis, which is the reverse of the formula used by Menkart and Wolfram.

Combability: Epps and Wolfram conducted combing comparisons between African-American and Caucasian hair using combability techniques used by Garcia and Diaz. Garcia and Diaz report that African-American hair, due to its curliness, is much more difficult to comb than Caucasian hair. It was also determined that African-American hair is easier to comb wet than dry.

Using a scanning electron microscope at a magnification of about 300X, Kamath and Hornby also observed that African American hair display frequent twists with random reversals in direction and pronounced flattening. During fractographic study, the break stress of African-American hair was reported to be (0.123 ± 0.016) 10^9 N/m^2 when dry (65% relative humidity [RH]) and (0.119 ± 0.010) 10^9 N/m^2 when wet. The breaking elongation for wet and dry (65% RH) fibers was found to be 44% ±3% and 27% ± 5%, respectively.