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African~American                                                           Hair
                               Its physical properties and differences relative to Caucasian hair


                                       BycAlicN.Syed, Anna Kuhajda, Hassan Ayoub, Kaleem Ahmad
                                        quot;         ,      Avlon Industries Inc., Chicago, It; USA


                                                                  Eugene M. Frank, Ph.D.
                                                              Raani corp., Chicago, IL, USA




    'l dentine innovations in chemical treatments that alter                        that tbquot; breaking stress of African·American hair (L24 gI
  S . the textllreof African-American hair, as well as a pletllora
  of style trends, have spurred phenomenal growth in this
                                                                                    denier, a unit of fineness equal to the fineness of a yarn
                                                                                    weigbing 0,05g for each 450m of length or 19 for each
  segment of the hair-care market throughollt the past three                        9000n.) is less than that of Caucasian hair (L41 gldenier).
  clcc(<lcs.:JTlw, level or research & development by manufac-                     The yield stress for African-AnJerican hair, however, is
  lur<~rs ill t:Iw area of product fi:mnulaUon hus steadily el-                     slightly higher (0.46 gldenier VS c0.42 gldenicr).
  evated; yet, a great deal remains to be learned about the                             Kamath and Hornby studied the fractographic behavior
  unique physical properhes of African-American hair. Com-                          of Ali'ican-American hair to view both mHJor and minor rods
  pared to the vast body ol'research regarding Caucasian hair,                      at low levels of extension,quot; They examined the ellipticity of
  the study ofquot; African-American hair is at best limited.                           hair fIbers and reported ellipticity indices of LS9± OcOS3 and
                                                                                    1.0 to 1.4 for African-American and Caucasi~n hair, respec-
  A Reveiw of Research                                                              tively. In this study. thetheellipticityinclcxwas calculated hy
                                  r
        In published studies, Menkart et al.' Epps et ai' and                       dividing the mcior axis by the minor axis, whidl is the reverse
    Kamath d al li reveal that some important research has                          of the formula used by Menkmt ancl Wolfram.
    indeed been conducted on the physical properties of highly                          Combability:Epps and Wolfram' conducted combing
    curly hair. The efforts of these researchers and the resulls of                 comparisons between African-American a11u Caucasian hair
    th{'~ir studi(;s ~ervc as a startingpoint for the further study of              using eombability techniques used by Garcia and Diaz.'
.,.,Ali-icap,-AxneIican haiL OthCl::gf3Ileral.~?qse1VaU(mS ahmrt                    Garcia and Diaz repOlt that African-American hair, due to
    hair, such as those pertaining to static charge (Jachowicz5                     its curliness, is much more difHcult to comb than Caucasian
    and C.n. HobbinsO) and theories about moisture content,                         hair. It was also determined that African-American hair is
    serve as a springboard for advancing the study of African-                      easier to comb wet than dry.
    American hair.                                                                      Using a scanning electron microscope at a ma6'uIDcation of
        Shape: MenkartanclWolfram7 repOltthat African-AmeJi-                        about 300X, Kamath and Hornby also obselved tllat African-
   can hair has a physical shape resembling a twisted oval rod,                     Americ,mhairdisplayfrequent lVvists with random reversals in
    vllcreas Cauca.sian hair is more cylindrical. They                             ,lirection and pronounced Ilattcningc DUling fraetographic
    foundcvic1ellce of this when they made elliptiC cornparisons                    study, the break stress of Aflican-American hair was reported
  or    hair cross-sections. Using a formula in which the rninor                    to be (0.12.1 ± 0,(16) 10' N/m' when dry (65% relative
   axis is divided by the major axis, Menkart and Volfram                          humidity [m'l]) and (0,119 ± Oe01m 10' N/m'when wet The
   determined that Africall-Amelican hair has a ellipticity                         breaking elongation for wet and dry (65% HU) fIbers IVas
    index of 0.56 and Caucasian hair has nn index 0.7.1. The or                     founcl to be 44% ± 3% and 27% ± 5%, respective1yc
    tensile-strength data gathered during this research sllows                          Jachowicz et al and CeI. Hobbins discuss static-charge


                                Heproduction in EngHsl-1 or any otller language of all or part of this article is strictly prohibited.

  Vot. 110. Oclober   199~.i                 0361t1:n7 N~!OD1nf().19)rr~(O;nF;, 19% !-'.!Iured Publishing Corp.      Cosrnelics & 1o!l(~tr!0<;quot;quot; rnClgozlne/39
Table 1. Diameter of African-American hair

                                                                                   FiberNo.    Maximum (pm) Minimum 1m)       o       Effipticilyquot;
                                                                                        C          88.62             47.12             1.8807
                                                                                        D         101.76             59_95             1.6974
                                                                                        E          98.73             53.76             1.8365
                                                                                        F          91.36             47.42             1.9266
                                                                                        G          96.10             57.44             1.6'731
                                                                                        H         111.04             5[l.OB            2.0 fiO
                                                                                        I          84.76             48.99             1.7302
                                                                                        J          87.34             51.72             1.6887
                                                                                        K         120.55             57.71             2.0889
                                                                                        L         108.63             61.76             1.7589
                                                                                 Average = 1.8297 ± 0.1456

                                                                                 • Ellipticity =Maximum Diameter + Minimum Diameter


                                                                              determination of hair fibers and the fibers positive or nega-
                                                                              tive sign in detail. All examination of'African.. Allwrican hair,
                                                                              however, was not involved in the study.
                                                                                 Chemists and obselvers ill the ethnic hair-care industry
                                                                              generally theorize that African-American hair llils less mois-
                                                                              ture (water) content than does Caucasian hair. ·uy little
                                                                              scientinc data, however, is available to suhstal1liatl' (Ilis cIaiin.
  prcdispersed micronizod titanium dioxide products
                                                                                 To expand our knowledge or Ihe dj{T(~rcllces between
  Request Samples Today via Phone, Fax or E-Maill                             African-Amelican and Caucasian hair, we will review the
       (OLLAnOflATIVE                 telephone 516.689.0200                  Hndings of scientific studies we conducted. SOl no of our
       LABORATOllIES                   facsimile 516.689.0205                 investigations pertained to properlil:s that have already
                                 [>-Mail, colloblb@mail.lihlLorg              received attention hom researchers, narnelv fiber diameter,
                 3 TE,chnology Drive· East Setauket, NY 11733
                                                                              tensile strength, and ease ofwot and dry cO';lhi ng. To extend
                                                                              the body of research specific to Al'ricHll·i ll1(~ric<l11 hail', we
                                                                              abo analy;;ed static charge and moisture content. Compara-
                                                                            . tive studies like these may help hair-care manufacturers
                                                                              more sllccinctly idclltif)· dhnic COllsumer needs, paving the
                                                                              way for refinement o[existing product {ormlilatiolls and the
                                                                              conceptualization of more effective ones.

                                                                             Hair Diameter
                                                                                 All of the African-American and Caucasian hair fibers
                                                                             studied in our current project were purchased from DeMeo
                                                                             Brothers of New York. Except where noted, all of the hair
                                                                             tested is untreated, virgin hair. Bulk samples of eaeh hair
                                                                             type purchased may represent a blend of fibers from more
                                                                             than one individuaL
                                                                                 llair diameter via itlwge analysis: To determine Afri-
                                                                             can-American hair-fiber diameter, weselectcd 10 Imir fibers
                                                                             at random from the blend. Each hair fiber was Singly mounted
                                                                             between 2 glass slides and placed under a compound micro-
                                                                             scope. The microscope was connected to a video camera and
                                                                             used image analysis software. vVe took diameter measure-
                                                                             ments of each fiber at 1 rom intelvals from its root to end. We
                                                                             noted the maximum and minimum diameters and divided
                                                                             the maximum diameter by the minimum diameter to deter-
                                                                             mine an ellipticity measurement (Table 1). The ellipticity
                                                                             measurements for the 10 fibers wore averaged [or purposes
                                                                             of comparison against Caucasian fibers. 'rhe salllo proce-
                                                                             dure was used for Caueasiou hair Crable 2).
                                                                                 Results: Fibers of African-American hair exhibit consid-
                                                                             erable vadations in diameter. The ellipticity index averages
     Crodn Inc     7 Century Or Pilrsippnlly NJ 07054   1.01-644-4900        1.8297 ± O.H56 I(Jr the 10 hairs studied, indicating a hi·gh
--                                                                      1
                                                                                      or
                                                                             <lcgrce irregularity in the diameter or Arrican-American

o12jCosmot!cs & Toilo1riesquot; mO(j07iIVJ                                                                                        Vol. 110. October 1995
Table 2. Diameter of Caucasian hair                                  ~O       ~.




      Fiber No. Maximum Oun) Minimum (pm)                    Ellipticity
          A            85.36                61.97             1.3774
          13           77.10                65.47             1.1776
          D            73.82                61.04             1.2094
          E            89,75                6~i.47            1.3709
          F            73.06                62.51             1.1688
          G            73.48                65.25             1.1261
          II           90.34                62.84             1.4376
          1            81.50                65.88             1.2371
          J            89.75                69.52             1.2910
          1<           97.28                65.25             1.4909                  ,
   Avera9C ;-;: 1.2887 ± 0.1182                                                           quot;              DISTANCE (mm)

   • Ellipticityquot;quot; Maximum Diameter .,. Minimulll Diameter
                                                                              Figure 1.


llair along a single strand. Tllis measurement is vel}' close to           Comparison of Tensile Strength Properties
Kamatl/s ami J lornhv's findings of' 1.89 ± 0.083. 'flw slight                To find the tensile strength ofwet African-Arncricall hair,
difTerence in fIle imli(;cs could lw due to the l~K~t that Kalllalh        fihers were Ilrst cleansed with a J.2.5% solution o/quot; sodiutn
Hnd Homhy studied fJbers [rolll one individual head, whereas               lanr)'1 sulfate, rinsed for 30 minutes, allmvecllo dry and thell
we usee! hair from Hlore thall one individual.                             eqUilibrated overnight at 659::, HH and 2.rC. Fibers of
    Caucasian hair is more reglllar compared vith i/quot;rican-              visually similar diameters were selected and crirnpc'd at a
American hair. The ellipticity index of Caucasian hair is                  30.00 mrn length for mounting on a Dia-Slron MT'1''' tcnsile-
1.2887 ± 0..1182, demonstrating little variation between tll('             strength determination device. Each crimped fiber was
ma:dmum and minimum hair··shalt diameters. These flnd-                     incHvi<-lual1yscanned at 1.0 mm intervals along the hairshaft.
ingssuhst<ultiate thoseofKamatll ilild J-lornby, vhich rcllect            The lnaximum and minimum diameters were dclennined in
all ellipticity illdex of 1.0-1.4. Figore 1 graphically iilostratcs        the manner described above.
the lJigldy irregular diarneter        or
                                      Afj'ican-American hair vs.
th(~ lnon' COllsislent diameter of Callcasian hair.                        quot;Din-Stron M'IT lllanuhlctnred by Din-Stron, Andover, Hampshire, UK




Vol. 110, Oclob8r 1995                                                                                    Cosmetics & Toiletriesquot;) rnogazlnej43
Since African-American hair is highly elliptical (Table 1),
                                                                         dlc arca of a cross-section cannot be determined from the
                                                                         nhcr diameter as it could if the hail' nber was cylindrical.
                                                                         Therefore, we used the following fonnula: J
                                                                                                A = D x d x nl4
                                                                              Where A= Area of cross-section; D := Major axis;
                                                                                               and d = Minor axis.
                                                                            VVa studied the breaking stress and breaking elongation
                                                                         of the nbers using the Diu-Stron MTT. Fibers similar ill
                                                                         cross-sectional area were selected for stress-strain deter-
                                                                         minations under wet conditions. Vhile keeping them im-
                                                                         mersed in water, the Ilbers were mounted singly between the
                                                                         quot;jawsquot; of the device. The stress and elongation at break point
                                                                         were determined nsing the following (onmth, (Table 3):
                                                                                  Stress    Load!A
                                                                            Stress at
                                                                         break point        [(Breaking load in Kg) x (g)JI A
         The New Standard for                                                               [(Breaking load in Kg) x (9.81mN)]IA in 11l'
                                                                                            Breaking stress in N!Jl19.
            Transparency &                                                                  Breaking stress in Pascals
             UV I'rotection                                                The parameters of the device are shown ill Tahle 4
         I'd 1115 conla ining 45'1., pigment are                           Dry African-American hair: The same procedure was
                   transparent on glass.                                 used to find the tensile strength of dry Aftican-American
         For information on our Dispersions, please contact:
                                                                         hair, except that the stress-strain determination was made
                                                                         under dry eonditions at 65% lUI and 21°C Crable 3).
                            KOBO                                           Again, we used thesarne procedure to testvd Caucasian
                         PRODUCTS INC.                                   hair except the fiber was twisted once at H'H)quot; while heing
           690 Montrose Ave., South Plainfield, NJ 07080 USA             mounted between the jaws of the Dia-Stroll jylTT to vicw
             Tel. (908) 757-0033     FAX (908) 757-0905
                                                                         hoth major and minor axes. The average stress and elollga..
                                                                         lion at break point is shown in Tahle 5.
                                                                            The same procedure was used Cor ,vet Caucasian hair as
                                                                         for dry Caucasian hair except the stress-strain determination
                                                                         was made under dry conditions (Table 5).
                                                                            Results: The break stress of wet, untreated African-
          Second generation distillers of fille c!,scntiaf oils          American hail' is 0.089 109 N/m'± 0.025 lOquot;N/m', consider-
                                                                         ably lower tban that of the Kanwth and Homby Study.'
  Producers of IXlre, natlll,li CEDARWOOD oil, in Ule hemt of            Break elongation is 42.04% ± 4.9%.
      Ihe Texas Hill COllnhy. Atolally quot;greenquot; 0llelalion.                  The break stress ofwet Caucasian hair is 0.165:1: 0.025NI
                                                                         Ill~',
                                                                              higher than that of wet African-American hair.
                                                                             The break elongation of wet African-American hair is
      OUf steam distilla1ion plant and on-site vacuum                    42.04% ± 4.HO%, and break elOllgation ofweI: Caucasian hair
   refining capabilities enable us to supply perfumers and               is 61.61 ± 4.1 %. When compareel, these values suggest that
   compounders with consistent qualities. We offer all                   wet African-American hair does not extend as lTlllch before
   grades and compositions of Texas cedarwood oils at                    breaking as does vet CaucHsiall Jlair (Tables:3 al1d 5).
   competitive prices.                                                       The break stress of dry African-American hair is (0.153 ±
      Order 1 kg or 100 drum quantities, and expect                      0.015) 10quot;N/m' as comparcd to the break stress of 0.189
   prompt shipment by UPS, air freight or ocean freight                  lOquot;N/m' ± 0.019 lOquot;N/mquot; for dry Caucasian bair (Tables .3
   to any coulltry in the world, FOB Houstoll, Texas.                    and 5). Upon comparison oftheso values, it is clear that dry
                                                                         African-American hair breaks more readily tlran does dry
      Our Tcxaromc qualily is also available from stock                  Caucasian hair.
   at your favorite loctll broker & dealer.                                 The break elongation ofdty African-American hair fibers
                                                                         is 3[1.35% ± 4.9% as compared to the break elongation of
                        Ask fol' it by /lame.                            49.57% ± 4.4% for dry Caucasian hair (Tables 3 and 5).
                                                                         Comparing these values, it is clear that dty African-Ameli-
                                                                         can hair does not extend as much before breaking as dly
   Cafl or fax youfofders directly fa tiS in English French, German or
   Spanish andexperience (rielldfy, personalizedservice, Texas style.    Caucasian hair. Therefore, Aftican-American hair is more
                 PO Box 157, Leakey, TX 78873 USA                        fragile in wet and <lry conditions tlran Caucasian Irair.
         Telephone 21 0-212-()079 • Toll-free 800-514-1363
                           r,lX   210-232-5716                           Comparison of Wet and Dry Combing I'roperties
                                                                            lVet combing:African-American lurirwas assembled into
                                                                         a 1.5 g tress and cut to 12 em in length to test wet combing.
44/Cosrnolics & 1oiletrlct,) JT10o(uine                                                                             Vol. 110, Oclober 1995
Table 3. Tensile strength properties                                                                                                                       Table 4. Dia-Stron MTT testing parameters
                                        of untreated African-American hair                                                                                                                            for breaking stress and elongation
    -·---···----·---··-----------·---·---1
 Test Condition   No. of  Cross-SecUonaJ                                                                                 Break Stress                                Elongation at                           Range:                      150.00 gram force
    RH (%)      Specimens     Area                                                          nr                             UP N/nf!                                    break(%)                              Gauge:                        2.00 gram force
                                                                                                                                                                                                             Sample Size:                 30.00 mm
   Wei (100)                                   20                          6.27 x 10'                                   0.089 ± 0.025                                 42.04 ±4.9                             Phase 1:                    100.00 %
   Dry (65)                                    20                          6.74 x 10'                                   O.153:tO.015                                  39.35 ±4.9                             Pllase2:                      0.00 sec
                _                                                           _-----
                                                                                                                                                                                             Lj
             .. .•.._ - - - - - _ ...                                                                                                                                                                        Phase 3:                      0.00%
                                                                                                                                                                                                             Phase 4:                      0.00%
                                                                                                                                                                                                       ,     Speed:                       15.00 mm/min
                                        Table 5. Tensile strength properties                                                                                                                                 No. of Cycles:                1
                                                    of untreated Caucasian hair

 Test Condition   No. of                                            Cross~Sectlonal                                      Break Stress                                Elongation at                 Table 6. Dla-Stron MTT testing parameters
    Rft (%)     Speclmons                                                     Areanr                                       UPNlm'l                                     break(%)                             for dry and wet combing
   Wet (100)                                   20                          6.25 x 10'9                                 0.165 ± 0.025                                   61.61 t 4.1
    Dry (6.'quot;5)                                20                          6.72 X 10.9                                 0.189±0.019                                     49.57 ± 4.4                           Range:                   2,000.00   gram force
----_...                   ..     __.._ - - - - - - - - -                                                                                                                                                    Gauge:
                                                                                                                                                                                                             Sample Size:
                                                                                                                                                                                                                                          0.00
                                                                                                                                                                                                                                         20.00
                                                                                                                                                                                                                                                 gram force
                                                                                                                                                                                                                                                 mm
The tres!'i was then soaked in lap water at room temperatnre for 15                                                                                                                                          Phase 1:                   600.00   %.,
minutes and mounted on a Dia-Stroll MTT combing device using the                                                                                                                                             Phase 2:                       0.00 sec
                                                                                                                                                                                                             Phase 3:                       0.00%
paramelers in Table 6.                                                                                                                                                                                       Phase 4:                      0.00%
   The teeth of the hard-rubber comb were spaced 2.0 mm apart. The                                                                                                                                           Speed:                       60.00 mrn/min
                                                                                                                                                                                                             No. of Cycles:                 1
work dOllC (ill joules) to pass the COlllb through the hair tress reflects an
average or three combings.
   The Sil!nc procedure and parameters used ahove were used fl.H' vet                                                                                                                                Table 7. Combing work for untreated
combing of Caucasiall hair (Figure 2 and Table 7).                                                                                                                                                  African-American hair and Caucasian hair
   Dry combing: Tile same proccchlre vas used for (hycombing both
African-Amcrican and Caucasian hair, except that the hair tress was                                                                                                                                                         _~~1!!:!?!'!JL~?~~.!~!._~'!!-'~~_
equilibrated and combed at G5% HI-l (Figure 3 and Table 7).                                                                                                                                            Hair Type             Wet Hair            Dry Hair
   lkRrtltH: The -vork of combing wet black hair is almost 5 times that                                                                                                                               African-American 0.0392                   0.3017
of combing wet Caucasian hair Crable b). lilorcovcr, the work                                                                                                                         or              Caucasian        0.0082                   0.0057




                                         JJ~



                                                                      For marketing & technical information on
                                                               Evening Primrose Oil and Storflower Oil (Boroge Oil),
                                                                           the high purity sources of GLA
                                                                 contact The Cosmetic & Specialty Chemicals Group
                                                                      f10che Vitamins & Fine Chemicals Division
                                                                                  Nutley, NJ 07110
                                                                  Phone it 201/909-8332       Fax II 201/909-5592
    quot;%quot;quot;quot;;;m=_quot;,,,,.3lquot;.,;'T'!.,:,;]quot;quot;i.t))J:'i::&i§iquot;quot;4E;.<jW§rnJ;k;':i:;;quot;';'~~§9«':;;«tquot;»i';;d:;quot;quot;quot;,mquot;iii<ki'i'£m'h<4)A?lquot;;./:ci:;;s>!;;>Ji~J,,,x,>'.iM¥,'quot;m,mquot;,.:,quot;·
                       ·                                                                                                                                                     quot;quot;.~m'i;,,,,,,m;s,mm~1ii%!quot;quot;'!l!!!l~,,,,,,,miilll!iWJl;;;rrnmgmmm_!1!Ilil1JIDj!1ffP~

Vol. 110, October 1995                                                                                                                                                                                                     CosmetIcs &      Tolletrles~   mogozine/45
hetween the teeth. The tress was then placed at a pre-
                                                                    determined distance in Trek ESD 425 Modelh and static
                                                                    charge was llleasured. An average static charge of three
                                                                    tresses is shown in Table 8 and Figure 4.
                                                                       quot;Va used the same procedure to dderlllilH~ the static
                                                                    charge on Caucasian hair. An average slat ic charge or three
                                                                    tresses is shown in Table 8 and Figure 4.
                                                                        Hesults: Aftican-American hair develops a highly nega-
                                                                    tive electrostatic charge (~2,5.4 KV/m) (Table H).In contrast,
                                                                    Caucasian hair develops a velY low positive c1ectrostalic
                                                                    charge (+6.6 KV/m). The relatively high negative charge
                                                                    acquired by dry AfricaIl~American hair during combing
                              COMBING DISlANCli (mm)
                                                                    may be <lIte to the extraordinarily lligh degree oi'pulling
      figure 2.                                                     force required to pass the comb through the entangled
                                                                    hair fibersY
                                                                       The combing of chemically straightened blaek hair re-
I                                                                   sults in a positive electrostatic charge (+25.9 KVlln). This
                                                                    revrrsaJ is thought to be attributable to a f.;rcater case of
                                                                    combing and rninimal hair-fiber entanglemcnt.
I                                                                      quot;Vhether untreated or chemically straightencd, A [l'ican-
                                                                    Arnerican hair develops a signiHcantly higllCr electrostatic
I                                                                   charge than does Caucasian hair. The relatively high electro-
                                                                    static charges could produce a quot;balloon effectquot; and contrib-
                                                                    ute to the higher degree of umnanagcability.f1

                                                                    COm(larison of Moisture Contents
I                                                                       To determine moisture content              or
                                                                                                                 African-American
I
                                                                    11,lir, African-American hair fibers were clealIS{,d alld equili-
                              COMBIIlG IlISTIINCE (mm)              brated to GS91 un at room tempnratllm as in the above
                                                                                    0
       Figure 3.
                                                                    procedure for determining tensile strength. The root end of
                                                                    caell llair nbcrwas eut into small pieces and placed ill a prc-
                                                                    weidlCc1 alumInum pan using a Cahn MicrobalaIlccquot;. Tile
                 :---------'~------1                                allll;linum pan containing the {utiI' salnplewas then placed in
                                                                    an analyzer (DSCd) and a moisture isothenn was obtained
            :g                                                      using the following parameters in Table 9.
            g
            IU 10                                                       After tlle run is complete, the aluminum pan cOlltaining
            quot;
            quot;
            <
            r                                                       the hair sample was transferred to a desiccator for 2 hours
            quot; '
            quot;                                                       and then weighed again using a balance. The moisture
            ~                                                       content was determined as follows:
            quot;.10
            ~
                                                                             % Moisture content = [(weight ofhair sample
            ~    ro
                                                                      before healing) - (weight of hair sample after heating)]/
                                                                                 [(weight orhair before heating) x 100]
                                                                       Again, the same procedure was used to determine the
                                                                    moisture content of Caucasian hair.
       figure 4.
                                                                       Hesults: The moisture content of African-American hair
                                                                    tends to be less than that of Caucasian hair. African-Ameri-
C'olll)ing is almost 50 times greater [or African-Ameli.can hair   can hair contains 17.69% moisture by weight vs. 18.66% for
thall Caucasian bairwllcn dry. Arrican~AJllerican hair is allnost   Caucasian hair. The Aflican-American hair has 5.20% loss
8 times more difficult tocombwct than cIty, The relatively high     moisture content than Caucasian hair (Table 10).
degree ofwork required to comb the assemhlyof dlY African-
An;etican hair is due to its extwmelycurly conBguration and         Conclusions
consequential entanglement. Figures 2 and 3 depict the                 African-American hair fibers, when compared with Cau-
combing curves ofwet and dry hair ofbotb Iypes.                     casian hair fibers, exhibit the follOWing properties:
    Comparison of Static·Charge Properties                            • Irregular diameter along the hair shaft. This phenom.
                                                                         enon may well be a major contributor to the compara-
       African-American hair fibers were assemblec1into a 1.0 g.         tive weakness of African-American hair.
    tress cut to 20.0 em in length. The background static charge
    of the tress was measured before combing. 11I measure-         Ic['rck Industries, Medina, NY
    ments were cOlHl11cted at 21quot;C ancl38% BH. The tress was        cCalm Microbalance, ATI Orion, Boston, lvlA
    combed 10 times with a harc1-ruhher comh vith 2.0 mm           <I])igilnl Scanning Calorimeter (1)5C), Jl('rkln-EllllGr Corp, Norwalk, CT

    t16/Cosrnetics & Toilclries0 mog01ine                                                                            Vol. 110, October 1995
o A relative low break stress and break elongation hI bOtll
                                                                                                Table 8. Static charge on African-American hair
     wet a)l(I dry stales. Thus, African-Americ~lnhairgener-
                                                                                                 and Caucasian hair using hard rubber comb
     ally has le;.;s tcnsile strength amI breaks more easily
     thall Caucasian hair does. Thus, AfticClu-Amcrican hair                                           Hair Type       Static Charge in KiloVolts/meter
     tends to be the Inure delicate of the two hair types.                                             Black                         - 25.4
  (I A relatively high resistance to combing in the wet: state                                         Relaxed black                  25_9
     all(1 even mom so when dry. The likelilJood ofeffecling                                           Caucasian                       6.6
     mcchanica[ damage by simple grooming is, therefore,
     lllllCh great {'Iquot; Cor African-Illlcricatl llair Iwc<luse of its
     lligltly cnrly cOllfiguralion.                                                                   Table 9. Digital Scanning Calorimeter
  (I A bigh stalic charge when combed in a dry state. This
                                                                                                               testing parameters
     finding indicates that normal styling and grooilli lit-; can
                                                                                                       Heating rate                   lOge/minute
     make AfricalHmcrican hair conSiderably less man-
                                                                                                       Starting Temperature             40QC
     ageable since static causes fly-away Gbers.                                                       Ending Temperature               260'C
  It A lower kn·l or Illoisture. The 10v8r rnoisture content                              '-----------------------'
     orAfricall-Alllcrican hair may be asignil1cantcontril)ll-
     [or to its relative fragility.                                                                 Table 10. Moisture content of untreated
    The results of' this research have parUudar relevance 1'01'                                    African-American hair and Caucasian hair
chemists and new-product development specialists who
work ill the ethnic hair··care market. It is clear that- ArrIean-                                                       _Com!!.~~~ryy9.!'~J~'~C!.ules
                                                                                                       Hair Type       mglg of Iwir             %
American bail' difJers fmm Caucasian hair in a number of
                                                                                                       African-American 176.9                 17.69%
i mporl<tnt ways, suggesting that the products formulated f(.H·
                                                                                                       Caucasian         186.7                 18.66
Caucasian hair and sold ill the general market may not
adequately address the special hair-care needs of the Afri-
                                                                                           AfIican-Amedcan hair, makeitpainfullyapparcnt thatt-here
can-American COllSttmer. It may well be that smIle               the                  or   are many more questions to be ansvered before we have an
products and practices now used in the ethnic market arc
                                                                                           adequate knowledge of this hair lype, Those of us who are
inappropriate alld ineffective, given that African-American
                                                                                           professionally mId/or academically involved with ethnic hair
llair lends to h{~ relatively fragile and diHlcult to comb and as
                                                                                           are beckoned to delve even further into its nnique
a lligh sialic ('[large and lower moisture content.
                                                                                           characteristicsand how it reacts with various products,
    Th i:_,; n~.'il·'lrcil, aiulig with other studies cOlldllctcd on
                                                                                           treatments, temperatures. environmental conditions and
                                                                                           styling/grooming practices. As the body of scientific
                                                                                           knowledge broadens, the consumer is suquot;re t.o be better
                                                                                           served and the entire ethnic hair-care industIy will be
                                                            OUR CREDO TO                   enormously enriched.
                                                             FLAVOR AND                    References
                                                             FRAGRANCE                     Address correspondence to Ali N. Syed, c/o Editor, Cosmetics &
                                                               BUYERS                      Toiletrle#magazine, 362 South Schmale Road,' Carol Stream, IL
                                                                                           60188-2787 USA

                                                                                            1, J Epps and LJ Wolfram, Letter to the Editor, Journal of Society of
                                                                                               Cosmetic Chemists 34 213-214 (JUly 1983)
                                              NO ORDER TOO LARGE                            2. ML Garcia and J Diaz, Combability Measurements on Human
                                              NO ORDER TOO SMALL                               Hair, Journal of Sociely of Cosmetic Chemists 27 379 398 (1976)
                                                                                                                                                       8




                                                                                            3. K Gieck and R Geick, Engineering Fonnu{as, 6th ed, New York:
                                               We don't set minimum require-                   McGraw-Hili p 83 (1990)
                                              ments because we have found that              4. Ibid, P 267
                                               quot;tc,t ordersquot; often lead to long             5. J Jachowicz, G Wls-Surel and ML Garcia, Relationship between
                                                 term relationships. This is a                 Triboelectric Charging and Surface Modifications of Human Hair,
                                                policy we have adhered to for                  Journal of Society of Cosmetic Chemists 36 189-212 (May/June
                                              over 110 years. So let us have the               1985)
       Alan P.llirnbaum, Presidelll                                                         6. YK Kamath and S. Hornby, Mechanical and Fractographic Behavior
                                               opportunity of bidding on your
                                                next order, no matter it's size.               of Negroid Hair, Journal of Society of Cosmetic Chemists 35 21-
                                                                                               43 (January/February 1984)
                                                                                            7. J Menkart, LJ Wolfram and I Mao, Caucasian Hair, Negro Hair,
                                                                                               and Wool: Similarities and Differences, Journal of Society of
        Just say: quot;CHAUVETquot;                                                                    Cosmetic Cllemists 17 769-787 (1966)
                                                                                            8. WE Morton and JWS Hearle, Static Electricity, Physical Properties
                                    Since 1881                                                 of Textile Fibers, Manchester, UK: The Textile Institute 529(1986)
                                                                                            9, CR Robbins, Physical Properties and Cosmetic Behavior of Hair,
                           PIERRE C1IAUVET_oc
         (!I$lIbSidiilryol ri~rrc ChalJvcl, SA Fr,ll1t~ Tel: 9-175%,03 Fax9-U6.%1G)
 3IlEUTElI [JRquot; CLOSTEfl, fU 07624 TEL: 201.784.9300 FAX: 201.784.0604
                                                                                               Cllemical and Physical Behavior of /-Iuman Hair, New York:
                                                                                               Springer-Veriag (1988), p 268
                                                                                           10. AN Syed, EthnicHairCare: History, Trends and Formulation,
                                                                                                                                                           I   .
                                                                                               Cosmetics & Toiletries 108 99·107 (September '1993)

48/Cosrnellcs & ToilntrlesSl              m(l{~Jmjne                                                                                     Vol. 110, October 1995

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African American Hair

  • 1. African~American Hair Its physical properties and differences relative to Caucasian hair BycAlicN.Syed, Anna Kuhajda, Hassan Ayoub, Kaleem Ahmad quot; , Avlon Industries Inc., Chicago, It; USA Eugene M. Frank, Ph.D. Raani corp., Chicago, IL, USA 'l dentine innovations in chemical treatments that alter that tbquot; breaking stress of African·American hair (L24 gI S . the textllreof African-American hair, as well as a pletllora of style trends, have spurred phenomenal growth in this denier, a unit of fineness equal to the fineness of a yarn weigbing 0,05g for each 450m of length or 19 for each segment of the hair-care market throughollt the past three 9000n.) is less than that of Caucasian hair (L41 gldenier). clcc(<lcs.:JTlw, level or research & development by manufac- The yield stress for African-AnJerican hair, however, is lur<~rs ill t:Iw area of product fi:mnulaUon hus steadily el- slightly higher (0.46 gldenier VS c0.42 gldenicr). evated; yet, a great deal remains to be learned about the Kamath and Hornby studied the fractographic behavior unique physical properhes of African-American hair. Com- of Ali'ican-American hair to view both mHJor and minor rods pared to the vast body ol'research regarding Caucasian hair, at low levels of extension,quot; They examined the ellipticity of the study ofquot; African-American hair is at best limited. hair fIbers and reported ellipticity indices of LS9± OcOS3 and 1.0 to 1.4 for African-American and Caucasi~n hair, respec- A Reveiw of Research tively. In this study. thetheellipticityinclcxwas calculated hy r In published studies, Menkart et al.' Epps et ai' and dividing the mcior axis by the minor axis, whidl is the reverse Kamath d al li reveal that some important research has of the formula used by Menkmt ancl Wolfram. indeed been conducted on the physical properties of highly Combability:Epps and Wolfram' conducted combing curly hair. The efforts of these researchers and the resulls of comparisons between African-American a11u Caucasian hair th{'~ir studi(;s ~ervc as a startingpoint for the further study of using eombability techniques used by Garcia and Diaz.' .,.,Ali-icap,-AxneIican haiL OthCl::gf3Ileral.~?qse1VaU(mS ahmrt Garcia and Diaz repOlt that African-American hair, due to hair, such as those pertaining to static charge (Jachowicz5 its curliness, is much more difHcult to comb than Caucasian and C.n. HobbinsO) and theories about moisture content, hair. It was also determined that African-American hair is serve as a springboard for advancing the study of African- easier to comb wet than dry. American hair. Using a scanning electron microscope at a ma6'uIDcation of Shape: MenkartanclWolfram7 repOltthat African-AmeJi- about 300X, Kamath and Hornby also obselved tllat African- can hair has a physical shape resembling a twisted oval rod, Americ,mhairdisplayfrequent lVvists with random reversals in vllcreas Cauca.sian hair is more cylindrical. They ,lirection and pronounced Ilattcningc DUling fraetographic foundcvic1ellce of this when they made elliptiC cornparisons study, the break stress of Aflican-American hair was reported or hair cross-sections. Using a formula in which the rninor to be (0.12.1 ± 0,(16) 10' N/m' when dry (65% relative axis is divided by the major axis, Menkart and Volfram humidity [m'l]) and (0,119 ± Oe01m 10' N/m'when wet The determined that Africall-Amelican hair has a ellipticity breaking elongation for wet and dry (65% HU) fIbers IVas index of 0.56 and Caucasian hair has nn index 0.7.1. The or founcl to be 44% ± 3% and 27% ± 5%, respective1yc tensile-strength data gathered during this research sllows Jachowicz et al and CeI. Hobbins discuss static-charge Heproduction in EngHsl-1 or any otller language of all or part of this article is strictly prohibited. Vot. 110. Oclober 199~.i 0361t1:n7 N~!OD1nf().19)rr~(O;nF;, 19% !-'.!Iured Publishing Corp. Cosrnelics & 1o!l(~tr!0<;quot;quot; rnClgozlne/39
  • 2. Table 1. Diameter of African-American hair FiberNo. Maximum (pm) Minimum 1m) o Effipticilyquot; C 88.62 47.12 1.8807 D 101.76 59_95 1.6974 E 98.73 53.76 1.8365 F 91.36 47.42 1.9266 G 96.10 57.44 1.6'731 H 111.04 5[l.OB 2.0 fiO I 84.76 48.99 1.7302 J 87.34 51.72 1.6887 K 120.55 57.71 2.0889 L 108.63 61.76 1.7589 Average = 1.8297 ± 0.1456 • Ellipticity =Maximum Diameter + Minimum Diameter determination of hair fibers and the fibers positive or nega- tive sign in detail. All examination of'African.. Allwrican hair, however, was not involved in the study. Chemists and obselvers ill the ethnic hair-care industry generally theorize that African-American hair llils less mois- ture (water) content than does Caucasian hair. ·uy little scientinc data, however, is available to suhstal1liatl' (Ilis cIaiin. prcdispersed micronizod titanium dioxide products To expand our knowledge or Ihe dj{T(~rcllces between Request Samples Today via Phone, Fax or E-Maill African-Amelican and Caucasian hair, we will review the (OLLAnOflATIVE telephone 516.689.0200 Hndings of scientific studies we conducted. SOl no of our LABORATOllIES facsimile 516.689.0205 investigations pertained to properlil:s that have already [>-Mail, colloblb@mail.lihlLorg received attention hom researchers, narnelv fiber diameter, 3 TE,chnology Drive· East Setauket, NY 11733 tensile strength, and ease ofwot and dry cO';lhi ng. To extend the body of research specific to Al'ricHll·i ll1(~ric<l11 hail', we abo analy;;ed static charge and moisture content. Compara- . tive studies like these may help hair-care manufacturers more sllccinctly idclltif)· dhnic COllsumer needs, paving the way for refinement o[existing product {ormlilatiolls and the conceptualization of more effective ones. Hair Diameter All of the African-American and Caucasian hair fibers studied in our current project were purchased from DeMeo Brothers of New York. Except where noted, all of the hair tested is untreated, virgin hair. Bulk samples of eaeh hair type purchased may represent a blend of fibers from more than one individuaL llair diameter via itlwge analysis: To determine Afri- can-American hair-fiber diameter, weselectcd 10 Imir fibers at random from the blend. Each hair fiber was Singly mounted between 2 glass slides and placed under a compound micro- scope. The microscope was connected to a video camera and used image analysis software. vVe took diameter measure- ments of each fiber at 1 rom intelvals from its root to end. We noted the maximum and minimum diameters and divided the maximum diameter by the minimum diameter to deter- mine an ellipticity measurement (Table 1). The ellipticity measurements for the 10 fibers wore averaged [or purposes of comparison against Caucasian fibers. 'rhe salllo proce- dure was used for Caueasiou hair Crable 2). Results: Fibers of African-American hair exhibit consid- erable vadations in diameter. The ellipticity index averages Crodn Inc 7 Century Or Pilrsippnlly NJ 07054 1.01-644-4900 1.8297 ± O.H56 I(Jr the 10 hairs studied, indicating a hi·gh -- 1 or <lcgrce irregularity in the diameter or Arrican-American o12jCosmot!cs & Toilo1riesquot; mO(j07iIVJ Vol. 110. October 1995
  • 3. Table 2. Diameter of Caucasian hair ~O ~. Fiber No. Maximum Oun) Minimum (pm) Ellipticity A 85.36 61.97 1.3774 13 77.10 65.47 1.1776 D 73.82 61.04 1.2094 E 89,75 6~i.47 1.3709 F 73.06 62.51 1.1688 G 73.48 65.25 1.1261 II 90.34 62.84 1.4376 1 81.50 65.88 1.2371 J 89.75 69.52 1.2910 1< 97.28 65.25 1.4909 , Avera9C ;-;: 1.2887 ± 0.1182 quot; DISTANCE (mm) • Ellipticityquot;quot; Maximum Diameter .,. Minimulll Diameter Figure 1. llair along a single strand. Tllis measurement is vel}' close to Comparison of Tensile Strength Properties Kamatl/s ami J lornhv's findings of' 1.89 ± 0.083. 'flw slight To find the tensile strength ofwet African-Arncricall hair, difTerence in fIle imli(;cs could lw due to the l~K~t that Kalllalh fihers were Ilrst cleansed with a J.2.5% solution o/quot; sodiutn Hnd Homhy studied fJbers [rolll one individual head, whereas lanr)'1 sulfate, rinsed for 30 minutes, allmvecllo dry and thell we usee! hair from Hlore thall one individual. eqUilibrated overnight at 659::, HH and 2.rC. Fibers of Caucasian hair is more reglllar compared vith i/quot;rican- visually similar diameters were selected and crirnpc'd at a American hair. The ellipticity index of Caucasian hair is 30.00 mrn length for mounting on a Dia-Slron MT'1''' tcnsile- 1.2887 ± 0..1182, demonstrating little variation between tll(' strength determination device. Each crimped fiber was ma:dmum and minimum hair··shalt diameters. These flnd- incHvi<-lual1yscanned at 1.0 mm intervals along the hairshaft. ingssuhst<ultiate thoseofKamatll ilild J-lornby, vhich rcllect The lnaximum and minimum diameters were dclennined in all ellipticity illdex of 1.0-1.4. Figore 1 graphically iilostratcs the manner described above. the lJigldy irregular diarneter or Afj'ican-American hair vs. th(~ lnon' COllsislent diameter of Callcasian hair. quot;Din-Stron M'IT lllanuhlctnred by Din-Stron, Andover, Hampshire, UK Vol. 110, Oclob8r 1995 Cosmetics & Toiletriesquot;) rnogazlnej43
  • 4. Since African-American hair is highly elliptical (Table 1), dlc arca of a cross-section cannot be determined from the nhcr diameter as it could if the hail' nber was cylindrical. Therefore, we used the following fonnula: J A = D x d x nl4 Where A= Area of cross-section; D := Major axis; and d = Minor axis. VVa studied the breaking stress and breaking elongation of the nbers using the Diu-Stron MTT. Fibers similar ill cross-sectional area were selected for stress-strain deter- minations under wet conditions. Vhile keeping them im- mersed in water, the Ilbers were mounted singly between the quot;jawsquot; of the device. The stress and elongation at break point were determined nsing the following (onmth, (Table 3): Stress Load!A Stress at break point [(Breaking load in Kg) x (g)JI A The New Standard for [(Breaking load in Kg) x (9.81mN)]IA in 11l' Breaking stress in N!Jl19. Transparency & Breaking stress in Pascals UV I'rotection The parameters of the device are shown ill Tahle 4 I'd 1115 conla ining 45'1., pigment are Dry African-American hair: The same procedure was transparent on glass. used to find the tensile strength of dry Aftican-American For information on our Dispersions, please contact: hair, except that the stress-strain determination was made under dry eonditions at 65% lUI and 21°C Crable 3). KOBO Again, we used thesarne procedure to testvd Caucasian PRODUCTS INC. hair except the fiber was twisted once at H'H)quot; while heing 690 Montrose Ave., South Plainfield, NJ 07080 USA mounted between the jaws of the Dia-Stroll jylTT to vicw Tel. (908) 757-0033 FAX (908) 757-0905 hoth major and minor axes. The average stress and elollga.. lion at break point is shown in Tahle 5. The same procedure was used Cor ,vet Caucasian hair as for dry Caucasian hair except the stress-strain determination was made under dry conditions (Table 5). Results: The break stress of wet, untreated African- Second generation distillers of fille c!,scntiaf oils American hail' is 0.089 109 N/m'± 0.025 lOquot;N/m', consider- ably lower tban that of the Kanwth and Homby Study.' Producers of IXlre, natlll,li CEDARWOOD oil, in Ule hemt of Break elongation is 42.04% ± 4.9%. Ihe Texas Hill COllnhy. Atolally quot;greenquot; 0llelalion. The break stress ofwet Caucasian hair is 0.165:1: 0.025NI Ill~', higher than that of wet African-American hair. The break elongation of wet African-American hair is OUf steam distilla1ion plant and on-site vacuum 42.04% ± 4.HO%, and break elOllgation ofweI: Caucasian hair refining capabilities enable us to supply perfumers and is 61.61 ± 4.1 %. When compareel, these values suggest that compounders with consistent qualities. We offer all wet African-American hair does not extend as lTlllch before grades and compositions of Texas cedarwood oils at breaking as does vet CaucHsiall Jlair (Tables:3 al1d 5). competitive prices. The break stress of dry African-American hair is (0.153 ± Order 1 kg or 100 drum quantities, and expect 0.015) 10quot;N/m' as comparcd to the break stress of 0.189 prompt shipment by UPS, air freight or ocean freight lOquot;N/m' ± 0.019 lOquot;N/mquot; for dry Caucasian bair (Tables .3 to any coulltry in the world, FOB Houstoll, Texas. and 5). Upon comparison oftheso values, it is clear that dry African-American hair breaks more readily tlran does dry Our Tcxaromc qualily is also available from stock Caucasian hair. at your favorite loctll broker & dealer. The break elongation ofdty African-American hair fibers is 3[1.35% ± 4.9% as compared to the break elongation of Ask fol' it by /lame. 49.57% ± 4.4% for dry Caucasian hair (Tables 3 and 5). Comparing these values, it is clear that dty African-Ameli- can hair does not extend as much before breaking as dly Cafl or fax youfofders directly fa tiS in English French, German or Spanish andexperience (rielldfy, personalizedservice, Texas style. Caucasian hair. Therefore, Aftican-American hair is more PO Box 157, Leakey, TX 78873 USA fragile in wet and <lry conditions tlran Caucasian Irair. Telephone 21 0-212-()079 • Toll-free 800-514-1363 r,lX 210-232-5716 Comparison of Wet and Dry Combing I'roperties lVet combing:African-American lurirwas assembled into a 1.5 g tress and cut to 12 em in length to test wet combing. 44/Cosrnolics & 1oiletrlct,) JT10o(uine Vol. 110, Oclober 1995
  • 5. Table 3. Tensile strength properties Table 4. Dia-Stron MTT testing parameters of untreated African-American hair for breaking stress and elongation -·---···----·---··-----------·---·---1 Test Condition No. of Cross-SecUonaJ Break Stress Elongation at Range: 150.00 gram force RH (%) Specimens Area nr UP N/nf! break(%) Gauge: 2.00 gram force Sample Size: 30.00 mm Wei (100) 20 6.27 x 10' 0.089 ± 0.025 42.04 ±4.9 Phase 1: 100.00 % Dry (65) 20 6.74 x 10' O.153:tO.015 39.35 ±4.9 Pllase2: 0.00 sec _ _----- Lj .. .•.._ - - - - - _ ... Phase 3: 0.00% Phase 4: 0.00% , Speed: 15.00 mm/min Table 5. Tensile strength properties No. of Cycles: 1 of untreated Caucasian hair Test Condition No. of Cross~Sectlonal Break Stress Elongation at Table 6. Dla-Stron MTT testing parameters Rft (%) Speclmons Areanr UPNlm'l break(%) for dry and wet combing Wet (100) 20 6.25 x 10'9 0.165 ± 0.025 61.61 t 4.1 Dry (6.'quot;5) 20 6.72 X 10.9 0.189±0.019 49.57 ± 4.4 Range: 2,000.00 gram force ----_... .. __.._ - - - - - - - - - Gauge: Sample Size: 0.00 20.00 gram force mm The tres!'i was then soaked in lap water at room temperatnre for 15 Phase 1: 600.00 %., minutes and mounted on a Dia-Stroll MTT combing device using the Phase 2: 0.00 sec Phase 3: 0.00% paramelers in Table 6. Phase 4: 0.00% The teeth of the hard-rubber comb were spaced 2.0 mm apart. The Speed: 60.00 mrn/min No. of Cycles: 1 work dOllC (ill joules) to pass the COlllb through the hair tress reflects an average or three combings. The Sil!nc procedure and parameters used ahove were used fl.H' vet Table 7. Combing work for untreated combing of Caucasiall hair (Figure 2 and Table 7). African-American hair and Caucasian hair Dry combing: Tile same proccchlre vas used for (hycombing both African-Amcrican and Caucasian hair, except that the hair tress was _~~1!!:!?!'!JL~?~~.!~!._~'!!-'~~_ equilibrated and combed at G5% HI-l (Figure 3 and Table 7). Hair Type Wet Hair Dry Hair lkRrtltH: The -vork of combing wet black hair is almost 5 times that African-American 0.0392 0.3017 of combing wet Caucasian hair Crable b). lilorcovcr, the work or Caucasian 0.0082 0.0057 JJ~ For marketing & technical information on Evening Primrose Oil and Storflower Oil (Boroge Oil), the high purity sources of GLA contact The Cosmetic & Specialty Chemicals Group f10che Vitamins & Fine Chemicals Division Nutley, NJ 07110 Phone it 201/909-8332 Fax II 201/909-5592 quot;%quot;quot;quot;;;m=_quot;,,,,.3lquot;.,;'T'!.,:,;]quot;quot;i.t))J:'i::&i§iquot;quot;4E;.<jW§rnJ;k;':i:;;quot;';'~~§9«':;;«tquot;»i';;d:;quot;quot;quot;,mquot;iii<ki'i'£m'h<4)A?lquot;;./:ci:;;s>!;;>Ji~J,,,x,>'.iM¥,'quot;m,mquot;,.:,quot;· · quot;quot;.~m'i;,,,,,,m;s,mm~1ii%!quot;quot;'!l!!!l~,,,,,,,miilll!iWJl;;;rrnmgmmm_!1!Ilil1JIDj!1ffP~ Vol. 110, October 1995 CosmetIcs & Tolletrles~ mogozine/45
  • 6. hetween the teeth. The tress was then placed at a pre- determined distance in Trek ESD 425 Modelh and static charge was llleasured. An average static charge of three tresses is shown in Table 8 and Figure 4. quot;Va used the same procedure to dderlllilH~ the static charge on Caucasian hair. An average slat ic charge or three tresses is shown in Table 8 and Figure 4. Hesults: Aftican-American hair develops a highly nega- tive electrostatic charge (~2,5.4 KV/m) (Table H).In contrast, Caucasian hair develops a velY low positive c1ectrostalic charge (+6.6 KV/m). The relatively high negative charge acquired by dry AfricaIl~American hair during combing COMBING DISlANCli (mm) may be <lIte to the extraordinarily lligh degree oi'pulling figure 2. force required to pass the comb through the entangled hair fibersY The combing of chemically straightened blaek hair re- I sults in a positive electrostatic charge (+25.9 KVlln). This revrrsaJ is thought to be attributable to a f.;rcater case of combing and rninimal hair-fiber entanglemcnt. I quot;Vhether untreated or chemically straightencd, A [l'ican- Arnerican hair develops a signiHcantly higllCr electrostatic I charge than does Caucasian hair. The relatively high electro- static charges could produce a quot;balloon effectquot; and contrib- ute to the higher degree of umnanagcability.f1 COm(larison of Moisture Contents I To determine moisture content or African-American I 11,lir, African-American hair fibers were clealIS{,d alld equili- COMBIIlG IlISTIINCE (mm) brated to GS91 un at room tempnratllm as in the above 0 Figure 3. procedure for determining tensile strength. The root end of caell llair nbcrwas eut into small pieces and placed ill a prc- weidlCc1 alumInum pan using a Cahn MicrobalaIlccquot;. Tile :---------'~------1 allll;linum pan containing the {utiI' salnplewas then placed in an analyzer (DSCd) and a moisture isothenn was obtained :g using the following parameters in Table 9. g IU 10 After tlle run is complete, the aluminum pan cOlltaining quot; quot; < r the hair sample was transferred to a desiccator for 2 hours quot; ' quot; and then weighed again using a balance. The moisture ~ content was determined as follows: quot;.10 ~ % Moisture content = [(weight ofhair sample ~ ro before healing) - (weight of hair sample after heating)]/ [(weight orhair before heating) x 100] Again, the same procedure was used to determine the moisture content of Caucasian hair. figure 4. Hesults: The moisture content of African-American hair tends to be less than that of Caucasian hair. African-Ameri- C'olll)ing is almost 50 times greater [or African-Ameli.can hair can hair contains 17.69% moisture by weight vs. 18.66% for thall Caucasian bairwllcn dry. Arrican~AJllerican hair is allnost Caucasian hair. The Aflican-American hair has 5.20% loss 8 times more difficult tocombwct than cIty, The relatively high moisture content than Caucasian hair (Table 10). degree ofwork required to comb the assemhlyof dlY African- An;etican hair is due to its extwmelycurly conBguration and Conclusions consequential entanglement. Figures 2 and 3 depict the African-American hair fibers, when compared with Cau- combing curves ofwet and dry hair ofbotb Iypes. casian hair fibers, exhibit the follOWing properties: Comparison of Static·Charge Properties • Irregular diameter along the hair shaft. This phenom. enon may well be a major contributor to the compara- African-American hair fibers were assemblec1into a 1.0 g. tive weakness of African-American hair. tress cut to 20.0 em in length. The background static charge of the tress was measured before combing. 11I measure- Ic['rck Industries, Medina, NY ments were cOlHl11cted at 21quot;C ancl38% BH. The tress was cCalm Microbalance, ATI Orion, Boston, lvlA combed 10 times with a harc1-ruhher comh vith 2.0 mm <I])igilnl Scanning Calorimeter (1)5C), Jl('rkln-EllllGr Corp, Norwalk, CT t16/Cosrnetics & Toilclries0 mog01ine Vol. 110, October 1995
  • 7. o A relative low break stress and break elongation hI bOtll Table 8. Static charge on African-American hair wet a)l(I dry stales. Thus, African-Americ~lnhairgener- and Caucasian hair using hard rubber comb ally has le;.;s tcnsile strength amI breaks more easily thall Caucasian hair does. Thus, AfticClu-Amcrican hair Hair Type Static Charge in KiloVolts/meter tends to be the Inure delicate of the two hair types. Black - 25.4 (I A relatively high resistance to combing in the wet: state Relaxed black 25_9 all(1 even mom so when dry. The likelilJood ofeffecling Caucasian 6.6 mcchanica[ damage by simple grooming is, therefore, lllllCh great {'Iquot; Cor African-Illlcricatl llair Iwc<luse of its lligltly cnrly cOllfiguralion. Table 9. Digital Scanning Calorimeter (I A bigh stalic charge when combed in a dry state. This testing parameters finding indicates that normal styling and grooilli lit-; can Heating rate lOge/minute make AfricalHmcrican hair conSiderably less man- Starting Temperature 40QC ageable since static causes fly-away Gbers. Ending Temperature 260'C It A lower kn·l or Illoisture. The 10v8r rnoisture content '-----------------------' orAfricall-Alllcrican hair may be asignil1cantcontril)ll- [or to its relative fragility. Table 10. Moisture content of untreated The results of' this research have parUudar relevance 1'01' African-American hair and Caucasian hair chemists and new-product development specialists who work ill the ethnic hair··care market. It is clear that- ArrIean- _Com!!.~~~ryy9.!'~J~'~C!.ules Hair Type mglg of Iwir % American bail' difJers fmm Caucasian hair in a number of African-American 176.9 17.69% i mporl<tnt ways, suggesting that the products formulated f(.H· Caucasian 186.7 18.66 Caucasian hair and sold ill the general market may not adequately address the special hair-care needs of the Afri- AfIican-Amedcan hair, makeitpainfullyapparcnt thatt-here can-American COllSttmer. It may well be that smIle the or are many more questions to be ansvered before we have an products and practices now used in the ethnic market arc adequate knowledge of this hair lype, Those of us who are inappropriate alld ineffective, given that African-American professionally mId/or academically involved with ethnic hair llair lends to h{~ relatively fragile and diHlcult to comb and as are beckoned to delve even further into its nnique a lligh sialic ('[large and lower moisture content. characteristicsand how it reacts with various products, Th i:_,; n~.'il·'lrcil, aiulig with other studies cOlldllctcd on treatments, temperatures. environmental conditions and styling/grooming practices. As the body of scientific knowledge broadens, the consumer is suquot;re t.o be better served and the entire ethnic hair-care industIy will be OUR CREDO TO enormously enriched. FLAVOR AND References FRAGRANCE Address correspondence to Ali N. Syed, c/o Editor, Cosmetics & BUYERS Toiletrle#magazine, 362 South Schmale Road,' Carol Stream, IL 60188-2787 USA 1, J Epps and LJ Wolfram, Letter to the Editor, Journal of Society of Cosmetic Chemists 34 213-214 (JUly 1983) NO ORDER TOO LARGE 2. ML Garcia and J Diaz, Combability Measurements on Human NO ORDER TOO SMALL Hair, Journal of Sociely of Cosmetic Chemists 27 379 398 (1976) 8 3. K Gieck and R Geick, Engineering Fonnu{as, 6th ed, New York: We don't set minimum require- McGraw-Hili p 83 (1990) ments because we have found that 4. Ibid, P 267 quot;tc,t ordersquot; often lead to long 5. J Jachowicz, G Wls-Surel and ML Garcia, Relationship between term relationships. This is a Triboelectric Charging and Surface Modifications of Human Hair, policy we have adhered to for Journal of Society of Cosmetic Chemists 36 189-212 (May/June over 110 years. So let us have the 1985) Alan P.llirnbaum, Presidelll 6. YK Kamath and S. Hornby, Mechanical and Fractographic Behavior opportunity of bidding on your next order, no matter it's size. of Negroid Hair, Journal of Society of Cosmetic Chemists 35 21- 43 (January/February 1984) 7. J Menkart, LJ Wolfram and I Mao, Caucasian Hair, Negro Hair, and Wool: Similarities and Differences, Journal of Society of Just say: quot;CHAUVETquot; Cosmetic Cllemists 17 769-787 (1966) 8. WE Morton and JWS Hearle, Static Electricity, Physical Properties Since 1881 of Textile Fibers, Manchester, UK: The Textile Institute 529(1986) 9, CR Robbins, Physical Properties and Cosmetic Behavior of Hair, PIERRE C1IAUVET_oc (!I$lIbSidiilryol ri~rrc ChalJvcl, SA Fr,ll1t~ Tel: 9-175%,03 Fax9-U6.%1G) 3IlEUTElI [JRquot; CLOSTEfl, fU 07624 TEL: 201.784.9300 FAX: 201.784.0604 Cllemical and Physical Behavior of /-Iuman Hair, New York: Springer-Veriag (1988), p 268 10. AN Syed, EthnicHairCare: History, Trends and Formulation, I . Cosmetics & Toiletries 108 99·107 (September '1993) 48/Cosrnellcs & ToilntrlesSl m(l{~Jmjne Vol. 110, October 1995