From the Archives … Flexabrasion: A Method for Evaluating Hair Strength

Jun 1, 2014 | Contact Author | By: J. Alan Swift, University of Liverpool, Liverpool UK; Surinder P. Chahal and Debra L. Coulson, Croda Colloids Ltd., Ditton, Cheshire UK; Nicholas I. Challoner, Croda Oleochemicals Ltd., Goole, East Yorkshire UK
Your message has been sent.
(click to close)
Contact the Author
Save
This item has been saved to your library.
View My Library
(click to close)
Save to My Library
Title: From the Archives … Flexabrasion: A Method for Evaluating Hair Strength
testingx hair strengthx claim substantiationx hair breakagex flexabrasionx
  • Article
  • Media
  • Keywords/Abstract
  • Related Material

Keywords: testing | hair strength | claim substantiation | hair breakage | flexabrasion

Abstract: From the December 2001 issue of Cosmetics & Toiletries, this article describes how both bending and abrasion should be tested–along with extension–when evaluating hair strength, as the authors show here in tests of an active developed to increase the strength of bleached hair.

View citation for this article

JA Swift, SP Chahal, DL Coulson and NI Challoner, From the Archives … Flexabrasion: A Method for Evaluating Hair Strength, Cosm & Toil 129(5) 38-45 (Jun 2014)

Excerpt Only This is a shortened version or summary of the article you requested. To view the complete article, please log in or create an account. Registration is Free!

*Editor’s note: Sometimes, a second look is all it takes to reinvent an old favorite or uncover hidden answers. Cosmetics & Toiletries has therefore dusted off its bound volumes to give readers another look at this December 2001 article on flexabrasion for measuring hair strength.

Tensile test methods have been successfully used to demonstrate improvements in the mechanical properties of hair, however they assess only one aspect of the physical processes of hair fracture that the consumer normally uses to evaluate the strength of hairs on the head. A more realistic test would involve all the elements—fiber bending (flexure), abrasion and extension—encountered in normal hair fracture. This paper provides background about a test method that does measure an amalgamation of these three elements, and gives examples of its use to evaluate a new ingredient for hair products that increases the strength of bleached hair.

Tensile Strength

The need for claims substantiation: In addition to the paramount need to ensure product safety, the cosmetics and toiletries industry is under increasing pressure from various authorities to justify advertised claims, particularly new ones. This is to ensure the protection of manufacturers from competitors who might otherwise gain an unfair advantage in the marketplace by false or unsubstantiated claims of benefit. There are two main routes to meeting this need for product claim substantiation, presented individually or, on occasion, presented in mutual support. The more difficult and expensive route analyzes panelists’ reactions to the use of the product. Recognized and reliable methods of experimental design and of statistical analysis are employed to seek out the significance of the particular benefit.

The other main route for claim substantiation is by laboratory instrumental evaluation. This route is the focus of the present paper. The advantage of this route for the product developer, particularly where isolated strands of hair are tested, can be in the ability to rapidly screen experimental materials and finished products for their effectiveness.

Excerpt Only This is a shortened version or summary of the article you requested. To view the complete article, please log in or create an account. Registration is Free!

 

Close

Table 1. Flexabrasion Lifetimes of Virgin Brown Hair and Bleached Hair

Table 1. Flexabrasion Lifetimes of Virgin Brown Hair and Bleached Hair

Segments A and B were mounted in the flexabrasion apparatus in the absence of any tensile stress and were conditioned at 60% RH for 1 hr. The hair fiber segments were then lowered into their final position under the 12-g load and the flexabrasion test was carried out. Flexabrasion lifetimes for both segments are recorded here.

Table 2. Flexabrasion Lifetimes of Bleached Hair Treated with a Hair-strengthening Active

Table 2. Flexabrasion Lifetimes of Bleached Hair Treated with a Hair-strengthening Active

Both A and B segments were then conditioned, without load, at 60% RH for 1 hr before measuring their flexabrasion lifetimes. The results are shown here.

Table 3. Flexabrasion Lifetimes with Test Conditioner

Table 3. Flexabrasion Lifetimes with Test Conditioner

Flexabrasion Lifetimes of Bleached Hair Treated with a Hair-strengthening Active when Applied from a Conditioner Base

Figure 1. Movement of hair for test

Figure 1. Movement of hair for test

Movement of a hair segment over a drawn tungsten wire in the flexabrasion test

Figure 2. Sample preparation and mounting procedure

Figure 2. Sample preparation and mounting procedure

Two adjacent 14-mm segments were taken from the root end of the same hair fiber and mounted onto brass tabs using cyanoacrylate glue. One segment was used as a control and the second for the test treatment.

Figure 3. Effect of a new hair-strengthening active

Figure 3. Effect of a new hair-strengthening active

Effect of a new hair-strengthening active ingredient in three treatment forms, as evaluated by changes in the number of cycles to flexabrasion fracture

Footnotes [Swift 129(5)]

a Hair tresses, De Meo Bros.

Formula 1. Hair Conditioner

Formula 1. Hair Conditioner

An experiment was carried out to assess the effect of the hair-strengthening active from this conditioner formulation.

Next image >

 
 

Close

It's Free...

Register or Log in to get full access to this content

Registration includes:

  • Access to all premium content
  • One click ingredient sample requests
  • Save articles in the My Library tool

Create an Account or Log In