CA1057465A - Postemulsifiable dye penetrant system and method for using same - Google Patents
Postemulsifiable dye penetrant system and method for using sameInfo
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- CA1057465A CA1057465A CA257,887A CA257887A CA1057465A CA 1057465 A CA1057465 A CA 1057465A CA 257887 A CA257887 A CA 257887A CA 1057465 A CA1057465 A CA 1057465A
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- dye
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Abstract
POSTEMULSIFIABLE DYE PENETRANT SYSTEM
AND METHOD FOR USING SAME
ABSTRACT OF THE DISCLOSURE
Postemulsifiable dye penetrant inspection system and method employing substantially biodegradable dye penetrant compositions and emulsifiers, for use in non-destructive testing of objects to locate voids and defects therein.
AND METHOD FOR USING SAME
ABSTRACT OF THE DISCLOSURE
Postemulsifiable dye penetrant inspection system and method employing substantially biodegradable dye penetrant compositions and emulsifiers, for use in non-destructive testing of objects to locate voids and defects therein.
Description
1057465`~
This invention relates to an improved postemul~ifiable dye penetrant sy~tem and method for non-destructively testing material specimens to locate and identlfy Rurface voids, cracks or defects~ :.
and more particularly to an improved sy~tem and method a~ de~cribed above employing therein certain combinations of biodegradable non-ionic dye penetrants and biodegradable nonionic emulsifiersO The invention i9 especially concerned with a postemulsifiable dye penetrant inspection system and method employing stable and sensi-tive dye penetrant compo~itions of the above type having the charactexigtic~ o being able to disclose a wid~ range of defective conditions in part~, employing as solvent or vehicle a biodegrad-able nonionic surfactant in the form of certain combinations or ~
~xtuxes of certain oxyalkylated alcohols, and al30 employing - - ;
emul~ifier~ for such dye penetrant compositions, containing a biodegradable nonionic surfactant of the general type employed in the dye penetrant, but having a higher degree of water washability, to permit rapid removal of the amulsified dye penetrant by appli~
f cation of waterO
In known penetrant inspection methods for rapid location and evaluation of ~urface flaws or cracks in test bodies or parts, a dye penetrant composition, preferably containing a ~luorescent - i . dye, and which will penetrate the openings of the ~urface cracks ~
or flaws in the part, i9 applied to the surface of the test body, ~ :
and the exce~s penetrant composition i9 removed from the surface .- of the bodyO A developer composition may then be applied to the . part surface, which acts as a wic~ and causes the liquid penetrant .~ containing the ~luorescent dye, which wa~ retained in the cracks or surface flaws, to be drawn up out of the surface defect~ by :
3 capillary action~ The part is then expo~ed to appropriate
This invention relates to an improved postemul~ifiable dye penetrant sy~tem and method for non-destructively testing material specimens to locate and identlfy Rurface voids, cracks or defects~ :.
and more particularly to an improved sy~tem and method a~ de~cribed above employing therein certain combinations of biodegradable non-ionic dye penetrants and biodegradable nonionic emulsifiersO The invention i9 especially concerned with a postemulsifiable dye penetrant inspection system and method employing stable and sensi-tive dye penetrant compo~itions of the above type having the charactexigtic~ o being able to disclose a wid~ range of defective conditions in part~, employing as solvent or vehicle a biodegrad-able nonionic surfactant in the form of certain combinations or ~
~xtuxes of certain oxyalkylated alcohols, and al30 employing - - ;
emul~ifier~ for such dye penetrant compositions, containing a biodegradable nonionic surfactant of the general type employed in the dye penetrant, but having a higher degree of water washability, to permit rapid removal of the amulsified dye penetrant by appli~
f cation of waterO
In known penetrant inspection methods for rapid location and evaluation of ~urface flaws or cracks in test bodies or parts, a dye penetrant composition, preferably containing a ~luorescent - i . dye, and which will penetrate the openings of the ~urface cracks ~
or flaws in the part, i9 applied to the surface of the test body, ~ :
and the exce~s penetrant composition i9 removed from the surface .- of the bodyO A developer composition may then be applied to the . part surface, which acts as a wic~ and causes the liquid penetrant .~ containing the ~luorescent dye, which wa~ retained in the cracks or surface flaws, to be drawn up out of the surface defect~ by :
3 capillary action~ The part is then expo~ed to appropriate
- 2 - ~
,.. , , ; , , ., ~, : .: . . . .
, . . . . . .
~ 0579~65 lighting conditions such as invisible fluorescigenous lightj and the location of the surace flaw~ i5 revealed by the emission of -visible fluore~cent light by the penetrant dye which wa~ retained in the cracks or flaws after the penetrant composition was re-moved from the suxface of the partO
For best efficiency, particularly for the detectisn and lo-cation of minute ~urface cracks and flaws, as well a3 inter~
mediate size and gros~ cracks) it is neces~ary that the dye pene- ~ ~
trant composition have high sensitivityO ~ ~ :
Volatile type solvents are commonly employed for extending or thinning dyes penetrant inspection solutions or compo~ition~. This i9 done chiefly for the purpose of lowsring the viscosity of the ~; penetrant in order to adapt it ~or application in spraying systems ~hus for example solvents such as kero~ene, light fuel oils, and f . methyl e~hyl ketone, all highly volatile solvents, have heretofore been employed in prior art dye penetrant~O See for example UOSo Patent NoO 2,806,9590 ~urther, most dye penetrant ~olutions in ~ practice generally require the use of a combination of solvents, : including primary and secondary solvents, extender solvents and '~ 20 wetting agentsO
~ owever, $he use of volatile solvents in dye penetrant com-positions has certain disadvantage O Thus9 the use of volatile ~ .
solvent~ in dye penetrants results in the evolution of fumes and solvent vapors which are rapidly formed by the evaporating solvent.
Since the use of organic solvents as noted above in the dyepenetrant composition doe~ not render the excess dye penetrant com-position readily removable from the ~urface of the part by waS~er~
an emulsifier i~ often applied ov~.r the dye penetrant applied to the ~urface of the part, to render the emulsified excess dye : :
.. , . ., , ., . .. ~.. ,, . ~ ,, ~ ;, . :
~57~65 .
penetrant water washable7 followed by removal of the emulsified penetrant with a water washO
In these dye penetrant ~ystems an additional criterion has recently been developed with respect to both the dye penetrant ~olutions and emulsi~iersO Generally dye penetrant solutions and emulsifiers presently employed and containing solvents and wetting agents present a disposal problem in that they generally contain petroleum 301ven~s and oil3 which are substantially non-biodegrad-able, that i5J they are very difficult to decompo~e by bacteria and sewage disposal plants, and constitute seriou~ pollutersO
~ence the necessity ~or the development of dye penetrant ~olution~
and emulsifiers for use in a postemul~iiabla dye penetrant in-spection system, which penetrant solutions and emulsifiers employ dye solvents and carrierC which are biodegradableJ and are readily ~ ;
available despite the petrochamical shortage, and which render the emulsified penetrant readily water wa~hable, has attained con- ; :
siderable importanceO
UOSo Patent ~oO 3,716,492 disclo es a liquid penetrant com-position con~isting essentially of a major amount of methyl sster il of a fatty acid, such as Methyl Sperm, and which is essentially water insoluble, and a minor amount of a nonionic surfactant ~uch :~' as polyethoxylates o~ ~acondary linear alcohols, the methyl esker being the principal liquid vehicle and the nonionic surfactant ~: functioning to emuls if y the methyl e~ter to form a water base emulsion, the methyl ester and nonionic surfactant being biodegradableO . ::
` ln UOSo Patents 33915,885 and 3,9159886, here are dis-closed novel dye penetrant compositions having improved senYitivity characteristic~, and which are biodegradable, containing as the .
~`
, . .. .. .
, , . : .
vehicle for the dye, certain biodegradable nonionic oxyalkylated alcohols Although dye penetrants of this type have been tested ; extensively and have proved highly sati~factory and effective formost applications, certain of theqe formulations having high sensitivity, and containing certain of the above noted oxyalkylat- :
ed alcohols as -~urfactant9 require employment of relatively hi~h volumes of water and increased pressure to wa~h excess penetrant from the surface of the test specinenO
. Accordingly, an object of the present invention is the :~ 10 provision of a postemulsifiable dye penetrant inspection system and method employing dye penetrant solution~ or compositions of the type noted above employing certain types of the o*yalkylated ~:: alcohols such dye penetrant compositions being biodegradable and , ~ having high sensitivity~ in conjunction with a postemuLsifier which : when applied to the dye penetrant, pe~mits ready wa~hability of ~--` the emulsified dye penetrant with a reduced volume of water and ~ at reduced pre~sure as compared to that which would ordinarily be :~
j, , f required for removing such dye penetrant composition in the absence . . ~ , . .
of the emulsifierO A particular object o~ the invention is to ;~
20 ~ovide a postemulsifiable dye penetrant inspection system and ~ method of the above noted type, and which employs as a liquid .. carrier or vehicle for the dye penetrant and as emulsifier, readilyavailable and biodegradable nonionic surfactants of the type di~
-:. clos~d above and which particularly render the amulsi~ied dye `~
penetrant easily removable employing modest volwmes of water at ~ :normal washing pressuresO ;
DESCR~PTION OF ~HE I~V~NTION ;
: The above o~ects and advantages can be accomplished accord- :
; ing to the invention, and an improved postemulsifiable dye,, ~,:
.: 5 ~
''' .' "".
1~574~5 :
penetrant in~pection method and ~y~tem employing biodegradable nonionic surfactants providsd, by trea~ment of a specimen or object whose surface conditions are to be inspected, with a po~temulsifiable dye penetrant containing as carrier for the dye, eOgO, fluorescent dye, the above biodegradable nonionic surfac- :
tants, followed by treatment of the penetrant covered object with an emul~ifier containing as essential component biodegradable nonionic surfactants of the same general class as employed as carrier for the dye in the dye penetrant composition~ but having greater water solubilityO The invention process permits use of certain biodegradable nonionic ~urfactants of the general ty~e noted above and de~cribed in detail hereinafter, which confer high .qensitivity on ths dye penetrant but which have lImited water ~olubility and rendering the dye penetrant difEicult to wash away with water, and hence would require substantial volume~ ;
of high pressure water for removal of excess dya penetrant, to-gether with an emulsifier containing biodegradable nonionic surfactants of the same general type as employed in the dye pene-trant, but of a somewhat different chemical composition and which are essentially wate~ soluble, 50 that when the emulsifier is ;~
applied to the dye penetrant on the surface of the object, it :
readily combines with the penetrant on the obj~ct surace, and ~ :
does not penetrate into the cracks or flaws in the surface of the object, and the emulsified penetrant on the ob~ect surface :
can be readily removed employing substantially lower volumes of . ~^-:. .
water at normal water pressureO For this purpo~e, a~ will be ~ .
. . ~ J
pointed out in further detail below, the second ~ur~actant in the emulsifier ha~ a higher number of oxyalkyl groups in the hydrophilic portion than the first surfactant in ths dye - 6 ~ .
, ~1~5746S
, penetrant compositionO
Thus there i~ provided according to the invention a po~te-emulsifiable dye penetrant process which permits the employment in both the dye penetrant and the emulsifier of biode~radable nonionic ~urfactants which axe unusually fa~t acting and stable, providing excellent defect-revealing ~ensitivity and affording brilliant indications of surface defects and crack~, ~uch dye penetrants generally having an extremely high fla~h point, eOg~, in excess of 400Fo~ are compatible and noncorrosive to most ~ 10 structural metals such as steel, aluminum, and titanium and are odorless, in conjunction with highly effective emulsifier~ for such dye penetrants, both the dye penetrants and emulsifiers being completely biodegradable and avoiding pollution o the delicate bacterial balance of sewage systems. .
The dye penetrant compositions employed in the process of the present invenkion otherwise have sub~tantially the ~ame im~
proved properties and advantages of the dye penetrants of the . ~ .
aforementioned patents in that they do not require the pra~ence ~:
of any additional vehicles, volatile or nonvolatile solvents, or 20 wetting agents, generally employed in prior art dye penetra~t :~
. solutions and compositionsO ~his i~ in contrast, for example, to `;:~
-: the above Patent NOD 3,716~492 which employs as its principal : :
. . .,: .
` liquid vehicle a methyl ester of a fatty acidO The employment of .~ -such dye penetrant compositiong containing th~ above described ` :
nonionic surfactant as the e sential and 501e vehicle in con- :
:: , junction with the emulsifier compositions, according to the invention permit instant washability of the emulsifisd dye penetrant ~ ~;
from the surface of parts to be inspected without loss of dye penetrant solution entrapped within the defect~ and cracksO
: .
1C~5746 .
The nonionic biodegradable solvent or carrier employed as a vehicle for the dye of the dye penetrant compo~ition according to the invention can be alkylene oxide condensation products pre-pared by the reaction of an organic compound having a reactive hydrogan atom9 such as an aliphatic alcohol, an alkylen~ oxide of 2 - 4 carbon atomsO More particularly, one class of such nonionic solventR or carrier~ can be define~ as straight chain, primary, aliphatic oxyalkylated alcohol~, generally in the form ~ of mixtures thereof, wherein the prLmary aliphatic alcohols can .~ 10 have from 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, :`~ and the oxyalkyl groups are ethylene oxide and propylene oxide, preferably in the form of a mixture thereofO :
; One class of nonionic carriers within the broad class of ~;~ materials def ined above is a congeneric mixture of compounds -represented by the formula:
~; R-O(A)H
.:
. wherein:
R is an essentially linear alkyl group having from 10 to 18 carbon atoms, with the proviso that at least 70 weight percent 20 of 9aid compounds in said mixture have an R of from 12 to 16 :~
car~on atoms, and A is a mixture of oxypropylene and oxyethylene - group~, said oxpropylene and oxyethylene groups bei.ng from 55~ to -~ 80% of the total weight of the compounds, the oxypropylene to oxyethylene ratio of said total weight being from 0085:1 to 2075:1 preferably 1~25:1 to 2025:10 Another preferxed class of condensation products or oxyalkylated alcohol3 within the above de~inition are those : wherein the aliphatic alcohols of the oxyalkylated alcohols, or :........................................................................ .
. R in the above formula, ranges from 12 to 18 carbon atoms, and '.: . : .. :
~057~65 the total number of ethylene oxide and propylene oxide groups in the mixture thexeof, or de~ignated A in the above formula, ranges from about 4 to about 140 The term "cogeneric mixture" as employed herein, designates a serie~ of clo~ely related homologues obtained by condensing a plurality of oxide units, with an alcohol or a mixture thereofO
As is known, when a mixture of this type i9 generated, various oxyalkylene chain lengths are obtainedO
Alcohols which may be employed in the preparation of the : ~ -products noted above are those essentially linear, primary, aliphatic alcohols having from ô to 20 carbon atoms, preferably :~
10 to 18 carbon atomsO MLxtures o alcohols ara usually preferred ;
since their u e provides for a good balance of properties in the ;~
re~ulting productsO Examples of alcohol~ which are operable in~
clude decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl `- ~.
. : .
. alcohol, tetradecyl alcohol, pentradecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, hydrogenated tallow alcohol~
and mixtu~es thereofO They may be naturally-derive~ such as from : .
coconut oil or synthetically-derived such as from linear alkane~
or linear olefin~0 ~he nonionic surface active agents described above and `~
.,: .~ :. ':
their me~hod of preparation are disclo~ed in UOSo Patent ~oO
: '~ .:
-~. 3,504,0410 These ~urface active agents are believed to include, . . .
.~ , , .
.; for example, that class of surfactants which are marketed as the ~
: . .
~ "Plurafac*" surfactants "RA-40" gradesO
.' Another class of biodegradable liquid, water miscible oxy-1~ alkylated alcohol condensation products within ~he above definitLon :; . .
- are those wherein the aliphatic alcohol~ or R, is a straight chain alkyl group having ~rom 8 to 20 carbon atoms, the number of . * Trade Mark - 9-.' ~
, . . . . . . . . .
1057~65 .
ethylene oxide groups in the mixture thereof with propylene oxide9 or A, ranges from 3075 to 12075, and the number of propylen0 oxide groups in such m$xture range~ from 107 to 700, the oxyethylene to oxypropylene ratio in such mixtures being from 108:1 to 202:10 Such cogeneric mixtures can be prspared in two steps, the first step being conden~ation of an alcohol mixture and ethylene oxide in the presQnce of an alkaline condensing agent or catalyst, to form an ethoxylated product, followed by condensing the resulting ethoxylated product with propylene oxideO There can be employed in such reaction a mixture of straight chain aliphatic alcohols having from 8 to 20 carbon atoms in the aliphatic chainO This cogeneric mixture of condensation products and the method of their preparation are disclosed in UOS~ Patent NoO 3,340,3090 The non-ionic oxyalkylated alcohols marketed as the "RA-20" grades of "Plurafac", are believed representative of the class o~ sur~ace ~ ~
active agents disclosed in the latter patentO ~ ~ .
Various other "~lurafac'~ grades which are marketed and are believed to be generally within the above-described classes of .~ .
oxyalkylated alcohol surfactants are tho e designated RA-43, A-24, A-25~ B-25-5, B-26 and D-25~
A class o~ particularly preferred nonionic biodegradable ~ ;
.: . solvents or carriers which can be employed as substantially the .. . .
sole vehicle for the dye o the dye penetrant compositions accord-ing to the present invention are ethoxylated of a mixture o -~
:, , ; linear secondary aliphatic alcohols, with the hydroxyl groups randomly distributed, the linear aliphatic hydropho~ic portion of .. . .
such alcohols being a mixture of alkyl chains containing in the .
range from 8 to 20 carbon atoms, preferably 10 to 17 c~rbon atoms ;, : :
and most preferably from 11 to 15 carbon atoms, and containing an .' - 10-~OS74~5 average of f rom 3 to 12 moles of an alkyl~ne oxide of from 2 to 4 carbon atoms or mixture thereofO
The above particularly preferred clas~ of nonionic bio-degradable surfactant employed as carrier for the dye penetrant of the invention i~ a mixture of compounds which can be represented by tha formula:
CH - (CH2 ) - CH
, l-(CH2-CH2~)m-H ;~, ` where n is in the range from 9 to 13, and m is 3 to 12O : -: 10 The linear alkyl hydrophobic portion of the above defined surfactant i5 a mixture o Cll to C15 linear alkyl chains, and can be derived from a mixture of Cll to C15 aliphatic secondary ., alcohols, for example the secondary undecyl, dodecyl, tridecyl, ; ` tetradecyl and pentadecyl alcohols O The hydrophilic portion of ;~
: ~he ~urfactant i5 a polyoxyethylene chain randomly attached to . .
: any carbon atom of the linear alkyl hydrophobic chains, other : .,~ ,, .~.. , than to the terminal carbon atoms thereof, through ~n ether llnkageO Such hydroph~lic polyoxyethylene chain is generally ~ ~.
expressed in terms o~ an average number of moles o~ ethylene oxids Illustrative examples of biodegradable nonionic surfactants .,.,: :
of the types defined in the above formula are ~ho~e consisting of~
a mixture of ethoxylates of from 11 to 15 carbon atoms in the ij ~ .
aliphatic hydrophobic chain, and which have an averag~ of 3, 59 ~ 7, 9 and 12 moles of ethylene oxide, respectively, as the :` hydrophilO
Materials corresponding to these ive examples of bio-....
. degradable nonionic surfactants are marketed, respectively as:
:' ., . ' ;',. - 11 -~" .
.'.~` ' .
74~5 , ~ergitol* 15-S-3 ' 15-S-5 .~ .
: " 15-S-7 " 15-S-9 :~
' 15-S-12 In each ca~e of the ~ergitol S series of surfactants listed above, the number to the left of the "S" indicates a hydrophobic ali-phatic chain of from 11 to 15 carbon atoms derived from a mixture of alcohols on Cll to C15 backbone chains, and the number to the ~ 10 right of the "S" designates the average number of moles of :
:` ethylene oxide as the hydrophilO Thus for example, Tergitol 15-S-5 is a mixture of linear aliphatic alcohols in the Cll to C15 range ethoxylated. with an average of 5 moles of ethylene oxideO
.. : .
: All of these commercially marketed Tergitol S serie~ of surfactants :
. are water soluble except for Tergitol 15-S-3, which is essentially - .:
water~ insolubleO MLxtures of the~e materials can al~o be employed ~ ~
i.n providing the dye penetrant of the lnVentiOn~ such as a mixture .`~ :
- of the above Tergitols 15-S-5 and 15-S-30 . .`
Any suitable dye general}y employed in dye penetrant com-~0 positions can be incorporated into the nonionic oxyalkylated ~ ;
:~, .
alcohol sur~actan~s described above for producing the dye penatrant ;~
. . .
: compositions employed in the invention processO Preferably, ~ however, a ~luorescent dye is employed for this purposeO The :~
. . . . .
:. ethoxylated surfactant vehicle for the dye i8 compatible therewith ~ : :
~- and has the ability to dissolve either small or relatively large :;
amounts of the dye and to hold a high concentration of dye in solutior. while providing good resolution and clarity of the dye trace in the cracks and flawsO
:. *Trade Mark ,~ ~
1.
: . : , : , , - : : .. : ~
~57~5 , :
As previously noted, the dye penetrant solution employed ;~
according to the invention preferably contain~ a fluorescent dyeO
Various ~ypes of fluorescent dyes can be employed including for example the dye marketed as Fluorol 7~A* as well as other fluores-cent dyes ~uch as those marketed a~ Calco1uor Yellow*, Azosol Brilliant Yellow 6GF~; Rhodanine B, Rhodanine 6 GDN~ Calcofluor White RW*; Blancophor White AW*; Auramine and Eosine G, and water soluble fluorescent dyes such as Blancophor FFG*.
The dye penetrant composition employ~d according to the in~
vention alternatively can contain non-fluore~cent or daylight type "
:. dyes such as azo type dye~, eOgo ~ xyleneazo-beta-naphthol, Mefford No. 322 dye, believed to be o-toluene-azoxyleneazo-beta-naphthol, ;-and the azo dyes marketed as Oil Red "O" and Sudan RedO These ~.
dyes conveniently can be employed where daylight or white light .
i~ only available, and particularly where the surface of the body ~ to be detected contains relatively gross cracksO However, it is : ~
preferred to employ fluorescent dyes having greater sensitivity or detectability~ a~ result of the high contra t obtained by the ,: .
;~ fluorescent indication~O ~
~`` If de~ired, small amounts of extenders ~uch as kerosene, ;;~ :, ~;
and volatile solvents such as methyl ethyl ketone, i~opropyl ..
alcohol, and the like, and water, can be added to the dye penetrant composition of the invention containing the oxyalkylated alcohol carrier, to vary the properties thereofO It is noted however that in preferred practice these ~dditives are not employed and -~
in effect a '!one liquid" solution is pro~ded according to the in- : -, , .
` vention, in which the oxyalkylated alcohol surfactant is essential- -: ly the 501e carrier for the dye~ Al-~o~ if desired, corrosion -inhibitors ~uch as, for example, morpholine, can be added in a : *Trade Mark -.
.
:: , .
1~57465 small amount such a~ OoOl to Ool~ by volume of the dye penetrant compositionJ particularly where the object being tested is highly ~usceptible to corrosion, such aY magnesiumO
The amount of dye which is incorporated into the oxyalkylated alcohol surfactant or carrler to produce the dye penetrant compo-sition of the invention, can range from about Ool to 15, pre~erably about 005 to about 10, parts of the dye, or mixtures thereof, per 100 parts of the oxyalkylated alcohol surfactant, by weightO In . ;`
~ preparing the dye penetrant composition employed according to the ; 10 invention, the dye is slmply added to the oxyalkylated alcohol carrier, in the desired proportionO The resulting dye penetrant composition has both high and low temperature stabilityO .
Where a developer com~osition is employedg any one o~ the .~ three general types of developer compositions, namely, dry powder, ~ wet aqueous (water-base) and wet non-a~ueous (volatile solvent base) .. developer compoaition~ can be employedO In each case~ the develo-:~i per composition contains a light colored powder~ forming a coating ~ which contrasts with the color of the dye in the penetrant and which acts as a wick or blotter, and causes liquid penetrant con-: . . .
taining the dye~ eOgO fluorescent dye, which was retained in the cracks or surface fl~ws, to be drawn up out of the ~urface defects by capillary action and to "bleed" through the powderO Pre~erred developer compo~itions for use in conjunction with the dye pene~
trant com~osition according to the invention, are those de~cribed in my Patent NoO 3,803,051, whi h is a dry powder developer con~
taining fumed alumina9 fumed silica, fumed titanium dioxide and talc, and in my P~tent NoO 3,748,469, and which is a wet non-aqueous developer composition con~isting essentially of isopropyl ;
alcohol, talc and glycol monsbutyl ether ., lL~
~........ .
.: . , - : '' - ~OS7465 The dye penetrant composition employed in the invention process, employi~g the above biodegradable nonionic oxyalkylated alcohol surfactants can be tailored to have varying degrees o~
sensitivity or detection of the smallest microcrack~ to gro~s cracks in a part surface by generally varying ~he amount of dye ~' incorporated~ and also by selecting particular surfactants or : com~inations thereofO This is illu~trated by the compositions I
: to rv below, containing Tergitol 15-S-3 as sole vehicleO
; TABLE 1 COMPOSrTIONS (parts by weight) ~.;, .. .:
:, I II III IV
Sensitivity Level :
`:, COMPONENTS . _ Super HighHigh Medium Low : ~;
T-rgitol 15-S-3 lOOoOlOOoO lOOoO lOOoO
:. ~ Calco~Luor White RW 5 2~5 1025 Oo675 . . .
.~ Fluorol ~GA lo 5 _ o7~ o375 0o187 Composition I particularly is a super high sensitivity ~. :
dye penetrant composition which requires a more rigorous water wash than somewhat less sensitive dyo penetrant compositions em- :
ploying other related above described Tergitols, due tv the pre-.l sence thereln o~ the above noted specific Tergitol 15-S-3, which . is Iess water soluble or has lower water solubility than ~orres~
, .~
ponding TergitolsO As a matter of fact, Torgitol 15-S-3 is sub~
;: stantially water insolubleO Thu3~ although composition I i5 ~'~
particularly advantageous for inspection of parts having a very ~ :
smooth ~urface with microcracks, and compo3itions II~ III and IV . : -are also highly advantageous for inspeckion of parts having cracks of intermediate 4ize and gross cracks, due to the substantially reduced water solubility of the Tergitol 15-S-3, large volume~ of ~ -. - 15 - ~
- iO57~65 high presqure water are needed to remove excess dyq penetrant from the surface of a part to which the penetrant ha~ been applied~
when employing compositions I to rv.
Corresponding dye penetrant compositions to those of Table ~.
1 can be made by substituting Plurafac A-24, for example, for the : Tergitol 15-S-3 thereinO
The invention process will be more clearly understood from the further description below taken in connection with the accom-panying drawing wherein Figure~ 1 to 4 illustrate the steps in the invention process O
~ Referring to the drawing, Figure 1 illustrates application ; of the biodegradable substantially non water soluble penetrant, e.g. composition I to the surface 10 of a part 12 containing cracks ~ :
`........ such as illustrated at 14. It will be seen that the dye penetrant solution 16 is contained on the part surface 10 and in the cracks ~: ~
.. 14. ~: :
,:....... .~, ': .
- Viewing Figure 2, a~cording to the po~temu~ifying penetrant ;.
: .~
~: process of the invention, there is then applied over the dye pene-: ~:
trant composition on the part surface, an emulsifier 18 to render .
: 20 the emulsified penetrant easily water washableO Such emulsifiers have as essential component a biodegradable nonionic surfactant, ~ e.g~, of the same class as the particular Tergitol of composition .. I, or the particular Pluraac of the corresponding dye penetrant .::
: compositionO Thus, as a general rule, for greater sensitivi$y of . the dye penetrant, where a dye penetrant compositlon is employed containing nonionic biodegradable surfactants in the form of ethoxy~
late of linear secondary aliphatic alcohols, as repre~ented by the above Tergitols, there can be employed in the dye penetrant composition, surfactants of this type containing from 3 to 4 `:-. .' ~ ' .. ,~ -.. . . :
1~57~65 ethyle~e oxide groups, which are o~ low water ~olubility or which with respect to Tergitol 15-S-3, ~pecifically~ are es~antially wa~er insoluble, as represented by Compoqitions I to rv above, in .
conjunction with an emul3ifi~r consisting essentially of the same class of nonionic biodegradable $ergitol-type surfactants which contain from 5 to 12 moles of ethylene oxide or ethylene oxide groups, and which are e~sentially water soluble. Similarly, the above defined Plurafac type surfactant, e.gO, formed of a mixture of straight chain, primary, aliphatic oxyalkylatæd alcohols, and wherein about 4 to about 8 total ethylene oxide and propylane oxide groups are present, aR represented by the material marketed as Plurafac A-249 and which are of comparatively lower water solubili~
ty, can be employed in conjunction with an emu~aifier consisting essentially of the same general class of Plurafac noted abov-, but wherein the total number of ethylene oxide and propylene oxide groups can range from about 9 to about 14, and which are of greater solubilityO
Thu3, for example, where Plurafac A-24, which is understood to contain a total number of ethylene oxide and propylene oxide . . .
groups ranging from about 4 to about 8, i~ employed as carrier in providing a high sensitivity dye penetrant composition, an emulsifier can be employed containing the same general class of :. ~
Plurafacs but wherein the total number of ethylene oxide and propylene oxide groups rangas from about 9 to about 14~ e~g., as represented by Plurafac A-25, Similarly, where, for example~
Tergitol 15-S-3 is employed as carrier for the dye in the dye penetrant composition, an emulsifier can be employed containing from about 5 to about 12 moles of ethylene oxide, e.g,, Tergitol 15-S-5, 15-S-7, 15-S-9 or 15-S-12, separately or in combinations _ ~7 _ : -: - . . , - ,- . , ' : : .:
'~: ' :, . , , ' ~L~)57465 of one or more of such Tergi~ols, eOgO, a combination of Tergitols 15-S-5 and 15-s-9, a combination of Tergitols 15-S-5 and 15-S-7, or a combination o~ Tergitols l5-s-g and 15-S-12, the respective Tergitols in each such combination being employed in varying ratios of from about 5 to about 95~ by volume The object or part to which the dye penetrant composition has been applied is contacted with the above described emulsifiers in any desired manner as by spraying with or by Immersion in the , emulsifier, for a relatively short period of time, eOgO,about 1 .
to 5 minutesO Referring to Figure 3 of the drawing, the spontaneous mixing of both the emulsifier 18 and the dye penetrant solution 16 - on the part surface forms a water soluble biodegradable mixture .,,., .~
20 which does not penetrate into the cracks 14 which contain dye penetrant solution 160 Referring to ~igure 4 of the drawing, the resulting - emulsified penetrant 20 on the surface of the object is then con- :
tacted with water in any suitable manner as by spraying the water at 22 from a water spray nozzle 24, to remove the excess emulsified dye penetrant 20 from the part surface without removing dye pene-20 t~ant 16 trapped in the cracks and ~laws 14 in the surface of the objectO The part i8 then dried~ for example, by a hla~t of airO If deQired, as noted above, but not necessarily, the part 12 can then be covered with a devsloper, eOgO a dry powder~ aqueous or nonaqueous developer, and the developer allowed to dwell on the surface for a ~hort period, eOgo about 1 to 3 minutesO Exces~
: developer i8 then removed from the surface of the part. The part ~:~
, ~ .
is then viewed under suitable lighting conditions, eOgO, black ~ ~
:: ~
. light or fluorescent light where a fluore~Rcent dye has been em- ~ .
ployed in the dye penetrant composition, for indication of the deects and cracks in the partO
1~57~;5 :
....
The following are example~ of practice of the invention but ars not limitative of the bene~its and advantage~ obtained by : ;
practice of the inventionO .
. The fluorescent dye penetrant composition I of Table 1 above, containing biodegradable Tergitol 15-S-3 as carrier was : applied as by spraying to a chromi~m-plated: brass test panel con- :
taining minute cracks of the order of 0.00002 to 0.0001 inch in ~; ..
widthJ closely distributed over its entire surface.
The test panel covered with the dye penetrant was then , immersed in biodegradable Tergitol 15~S-9 as emulsifier and .1 `
` allowed to remain immersed in the emulsifier for a period of about ;: `
~ 1 minute. The test panel containing the emulsified penetrant was .~ then sprayed with water applied by an air-water spray over the dye ~. :
... .
' penetrant-emulsifier coating, causing instantaneous washing away .;~
~, of the emulsified dye pcnetrant on the surface of the panel without dislodging the dye penetrant from the surface cracks and thus en- ~ :
;., trapping the penetrant therein, .' ~ The test panel was then covered with a powder developer ~ :
20 having the following composition, according to my above Patent ~`
No. 3,083,051.
COMPONENTS Percent by Weight Talc 52 .~. .
;.~ Alumina 35 Silica 1 ~:'i ::
: ' The above developer ~as permitted to dwell over the surface of the test panel for a period of about 2 minutes.
.`` Excess developer compos~tion was then carefully removed from the surface of the test panel by means of a gentle air blast.
,, . , . '' , ~ ;' :
, :, - :~
~5746;5 The panel wa~ then placed under black light (fluorescent) illumination and the above treated surface of the panel viewed in such illumination. It was observed that the panel surface dis-closed fluorescent indication~ from numerous readily defined micro-cracks therein, such fluorescent indications being sharp and brilliant and revealing all defective conditions on the surface of the test panel. ~:
The procedure of Example 1 was repeated but without treat-ment of the dye penetrant covered surface of the test panel with any emulsifier. Thus, following application of the dye penetrant composition I to the surface of the test panel, a water wash was applied às by an air-water spray over the coating of the dye penetrant composition I on the test panel, followed by application of the developer to the surface of the penetrantO ~ : .
. ~ , ~ It was found that a vigorous water wash re~uiring large : volumes of water at a pressure of about 80 - 100 psi and an ex- ~:
~` tended period of washing of about 4 to 5 mlnutes, was required in order to substantially completely remove excess dye penetrant 20 composmtion from the surface of tbe test panel, priox to appli- -cation of the developerO
EXAMPLE
- The procedure of Example l was repeated but employing an aluminum test panel containing microcracks, and wherein the emul-sifier was Tergitol 15-S 5.
Excellent results were obtained comparable to those obtained in Example lo ' ' "
~ ' ,' ' ' ' . ~ . ;' . ' ' , . ' "
. ' .; - ' ' ,' ' ' ' ' ~ ' :. ' , .. . ~ . . .
,. . '. . . . . . . .. . . . . .
1~57~6S
The procedure of Example 1 wa3 repeated but employing in place of compcsition I, a ~imilar composition but employing Plurafac A-24 as dye solvent or carrierO Also, in place of the Tergitol 15-S-9 emulsifier employed in Example 1, the emulsifier used was Plurafac A-25, comprised of a straight chain, primary aliphatic oxyalkylated alcohol mixture believed to contain about 12 to about 18 carbon atoms in the alcohol chains, and a total of ; from about 9 to 14 oxyethylene and oxypropylene group~, as des-cribed above, Bright fluore_cent indications of the crack~ and defects - . .
in the surface of the panel ware obtained similar to the results achieved in Example l ~ EXAMPLE 5 ~ -~` A test on an aluminun panel having cracks of intermediate ~ize was carried out following the procedure of Example 1-, but ~ utilizing composition III of Table 1, containing Tergitol 15-S-3, . :
.:~ and employing as emulsifier a mixture of approximately equal parts by volume of Tergitol 15-S-5 and Tergitol 15-S-9o :: 20 Excallen~ re~ults with respect to water washability of the penetrant emulsified surface of the panel, as well as excellent ~ .
. brilliant indiaations of the defects on the surface of the test - panel, were achieved~ .
. ; _ ~ The procedurs of Example 1 waq essentially folla~ed, but : ~
.
:; employing in place of compo~ition IanDn ~luorescant dye penetrant solution consisting o~ 15 parts of Tergitol 15-S-3 and 1 part of ~ Oil Red "O" dye, by volumeO
Excellent results of crack detectability were obtained , 7~65 ~mploying such non-fluorescent dye penetrantO ~owever, the brightness and sensitivity of the colored dye txaces obtained employing the non-fluorescent dye penetrant of this sxample were ~ :
not as yreat as for the fluorescent dye penetrant composition I
of ~xample lo The procedure of Example 1 was followed except that in place of the powder developer employed in Example 1, a nonaqueous developer having the following composition according to my above Patent NoO 3,748,469 was employed:
COMPONENTSPercent by Weight Isopropyl alcohol 70O5 Talc 28O6 Glycol ~onobutyl ether OO9 The above developer was pexmitted to remain on the panel ::
surfaces to which it was applied for a period of 2 minutes, until ~ ~
-~ substantially all of the i~opropyl alcohol had evaporated and a ~-:
.
substantially dry powder coating was formed < Results similar to the results of Example 1 were obtainedO `
` 20 In all of Examples 1 to 7 above, all of the dye penetrants ., .~ .
and the emulsifiers were biodegradable and hence avoided pollution `~
of the sewage disposal systems into which they were discharged.
From the foregoing, it is seen that the invention provides a highly effective postemul~ifiable penetrant inspection system :
and method employing as sole carrier or vehicle in the dye pene-trantJ and as essential component of the emulsifier, certain :., .
oxyalkylated alcohol biodegradable nonionic surfactants, and permitting substantially instantaneous removal of emulsified dye :. penetrant from the surface of the part in a single wash operation _ 22 -:' ,'~.
., ;. , . .. , . : ~: . :
' ~' ' ::' . . ' .,.. :. ,' ` ~5746~
employing ~odest amounts of water at normal water pressure, while maintaining the dye penetrant in the cracks or defect~ of the part, followed by further processing as desired in the convention- :
al manner for viewing under suitable, eOgO, fluorescent lighting conditions, to obtain highly brilliant dye traces from cracks and flaws in the part surfaceO The dye penetrants and emulsifiers employed according to the invention afford substantially non-flammable high performance dye penetrant compositions having a wide range of sensitivity and non-flammabls emulsifiers providing improved water washability characteristics of the resultant emulsified penetrantO The dye penetrant and emulsifiers employed according to ~he invention process avoid the u~e of volatile extenders and thinners Since various changes and modifications of the invention will occur to and can be made readily by those skilled in the art :
without departing.from the invention concept, the invention is not to be taken as limited except by the scope of the appended claimsO
.
. ' . .
`` ~ ' ~.
~ .
.,, ~ .
I
- _ 23 _ . '
,.. , , ; , , ., ~, : .: . . . .
, . . . . . .
~ 0579~65 lighting conditions such as invisible fluorescigenous lightj and the location of the surace flaw~ i5 revealed by the emission of -visible fluore~cent light by the penetrant dye which wa~ retained in the cracks or flaws after the penetrant composition was re-moved from the suxface of the partO
For best efficiency, particularly for the detectisn and lo-cation of minute ~urface cracks and flaws, as well a3 inter~
mediate size and gros~ cracks) it is neces~ary that the dye pene- ~ ~
trant composition have high sensitivityO ~ ~ :
Volatile type solvents are commonly employed for extending or thinning dyes penetrant inspection solutions or compo~ition~. This i9 done chiefly for the purpose of lowsring the viscosity of the ~; penetrant in order to adapt it ~or application in spraying systems ~hus for example solvents such as kero~ene, light fuel oils, and f . methyl e~hyl ketone, all highly volatile solvents, have heretofore been employed in prior art dye penetrant~O See for example UOSo Patent NoO 2,806,9590 ~urther, most dye penetrant ~olutions in ~ practice generally require the use of a combination of solvents, : including primary and secondary solvents, extender solvents and '~ 20 wetting agentsO
~ owever, $he use of volatile solvents in dye penetrant com-positions has certain disadvantage O Thus9 the use of volatile ~ .
solvent~ in dye penetrants results in the evolution of fumes and solvent vapors which are rapidly formed by the evaporating solvent.
Since the use of organic solvents as noted above in the dyepenetrant composition doe~ not render the excess dye penetrant com-position readily removable from the ~urface of the part by waS~er~
an emulsifier i~ often applied ov~.r the dye penetrant applied to the ~urface of the part, to render the emulsified excess dye : :
.. , . ., , ., . .. ~.. ,, . ~ ,, ~ ;, . :
~57~65 .
penetrant water washable7 followed by removal of the emulsified penetrant with a water washO
In these dye penetrant ~ystems an additional criterion has recently been developed with respect to both the dye penetrant ~olutions and emulsi~iersO Generally dye penetrant solutions and emulsifiers presently employed and containing solvents and wetting agents present a disposal problem in that they generally contain petroleum 301ven~s and oil3 which are substantially non-biodegrad-able, that i5J they are very difficult to decompo~e by bacteria and sewage disposal plants, and constitute seriou~ pollutersO
~ence the necessity ~or the development of dye penetrant ~olution~
and emulsifiers for use in a postemul~iiabla dye penetrant in-spection system, which penetrant solutions and emulsifiers employ dye solvents and carrierC which are biodegradableJ and are readily ~ ;
available despite the petrochamical shortage, and which render the emulsified penetrant readily water wa~hable, has attained con- ; :
siderable importanceO
UOSo Patent ~oO 3,716,492 disclo es a liquid penetrant com-position con~isting essentially of a major amount of methyl sster il of a fatty acid, such as Methyl Sperm, and which is essentially water insoluble, and a minor amount of a nonionic surfactant ~uch :~' as polyethoxylates o~ ~acondary linear alcohols, the methyl esker being the principal liquid vehicle and the nonionic surfactant ~: functioning to emuls if y the methyl e~ter to form a water base emulsion, the methyl ester and nonionic surfactant being biodegradableO . ::
` ln UOSo Patents 33915,885 and 3,9159886, here are dis-closed novel dye penetrant compositions having improved senYitivity characteristic~, and which are biodegradable, containing as the .
~`
, . .. .. .
, , . : .
vehicle for the dye, certain biodegradable nonionic oxyalkylated alcohols Although dye penetrants of this type have been tested ; extensively and have proved highly sati~factory and effective formost applications, certain of theqe formulations having high sensitivity, and containing certain of the above noted oxyalkylat- :
ed alcohols as -~urfactant9 require employment of relatively hi~h volumes of water and increased pressure to wa~h excess penetrant from the surface of the test specinenO
. Accordingly, an object of the present invention is the :~ 10 provision of a postemulsifiable dye penetrant inspection system and method employing dye penetrant solution~ or compositions of the type noted above employing certain types of the o*yalkylated ~:: alcohols such dye penetrant compositions being biodegradable and , ~ having high sensitivity~ in conjunction with a postemuLsifier which : when applied to the dye penetrant, pe~mits ready wa~hability of ~--` the emulsified dye penetrant with a reduced volume of water and ~ at reduced pre~sure as compared to that which would ordinarily be :~
j, , f required for removing such dye penetrant composition in the absence . . ~ , . .
of the emulsifierO A particular object o~ the invention is to ;~
20 ~ovide a postemulsifiable dye penetrant inspection system and ~ method of the above noted type, and which employs as a liquid .. carrier or vehicle for the dye penetrant and as emulsifier, readilyavailable and biodegradable nonionic surfactants of the type di~
-:. clos~d above and which particularly render the amulsi~ied dye `~
penetrant easily removable employing modest volwmes of water at ~ :normal washing pressuresO ;
DESCR~PTION OF ~HE I~V~NTION ;
: The above o~ects and advantages can be accomplished accord- :
; ing to the invention, and an improved postemulsifiable dye,, ~,:
.: 5 ~
''' .' "".
1~574~5 :
penetrant in~pection method and ~y~tem employing biodegradable nonionic surfactants providsd, by trea~ment of a specimen or object whose surface conditions are to be inspected, with a po~temulsifiable dye penetrant containing as carrier for the dye, eOgO, fluorescent dye, the above biodegradable nonionic surfac- :
tants, followed by treatment of the penetrant covered object with an emul~ifier containing as essential component biodegradable nonionic surfactants of the same general class as employed as carrier for the dye in the dye penetrant composition~ but having greater water solubilityO The invention process permits use of certain biodegradable nonionic ~urfactants of the general ty~e noted above and de~cribed in detail hereinafter, which confer high .qensitivity on ths dye penetrant but which have lImited water ~olubility and rendering the dye penetrant difEicult to wash away with water, and hence would require substantial volume~ ;
of high pressure water for removal of excess dya penetrant, to-gether with an emulsifier containing biodegradable nonionic surfactants of the same general type as employed in the dye pene-trant, but of a somewhat different chemical composition and which are essentially wate~ soluble, 50 that when the emulsifier is ;~
applied to the dye penetrant on the surface of the object, it :
readily combines with the penetrant on the obj~ct surace, and ~ :
does not penetrate into the cracks or flaws in the surface of the object, and the emulsified penetrant on the ob~ect surface :
can be readily removed employing substantially lower volumes of . ~^-:. .
water at normal water pressureO For this purpo~e, a~ will be ~ .
. . ~ J
pointed out in further detail below, the second ~ur~actant in the emulsifier ha~ a higher number of oxyalkyl groups in the hydrophilic portion than the first surfactant in ths dye - 6 ~ .
, ~1~5746S
, penetrant compositionO
Thus there i~ provided according to the invention a po~te-emulsifiable dye penetrant process which permits the employment in both the dye penetrant and the emulsifier of biode~radable nonionic ~urfactants which axe unusually fa~t acting and stable, providing excellent defect-revealing ~ensitivity and affording brilliant indications of surface defects and crack~, ~uch dye penetrants generally having an extremely high fla~h point, eOg~, in excess of 400Fo~ are compatible and noncorrosive to most ~ 10 structural metals such as steel, aluminum, and titanium and are odorless, in conjunction with highly effective emulsifier~ for such dye penetrants, both the dye penetrants and emulsifiers being completely biodegradable and avoiding pollution o the delicate bacterial balance of sewage systems. .
The dye penetrant compositions employed in the process of the present invenkion otherwise have sub~tantially the ~ame im~
proved properties and advantages of the dye penetrants of the . ~ .
aforementioned patents in that they do not require the pra~ence ~:
of any additional vehicles, volatile or nonvolatile solvents, or 20 wetting agents, generally employed in prior art dye penetra~t :~
. solutions and compositionsO ~his i~ in contrast, for example, to `;:~
-: the above Patent NOD 3,716~492 which employs as its principal : :
. . .,: .
` liquid vehicle a methyl ester of a fatty acidO The employment of .~ -such dye penetrant compositiong containing th~ above described ` :
nonionic surfactant as the e sential and 501e vehicle in con- :
:: , junction with the emulsifier compositions, according to the invention permit instant washability of the emulsifisd dye penetrant ~ ~;
from the surface of parts to be inspected without loss of dye penetrant solution entrapped within the defect~ and cracksO
: .
1C~5746 .
The nonionic biodegradable solvent or carrier employed as a vehicle for the dye of the dye penetrant compo~ition according to the invention can be alkylene oxide condensation products pre-pared by the reaction of an organic compound having a reactive hydrogan atom9 such as an aliphatic alcohol, an alkylen~ oxide of 2 - 4 carbon atomsO More particularly, one class of such nonionic solventR or carrier~ can be define~ as straight chain, primary, aliphatic oxyalkylated alcohol~, generally in the form ~ of mixtures thereof, wherein the prLmary aliphatic alcohols can .~ 10 have from 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, :`~ and the oxyalkyl groups are ethylene oxide and propylene oxide, preferably in the form of a mixture thereofO :
; One class of nonionic carriers within the broad class of ~;~ materials def ined above is a congeneric mixture of compounds -represented by the formula:
~; R-O(A)H
.:
. wherein:
R is an essentially linear alkyl group having from 10 to 18 carbon atoms, with the proviso that at least 70 weight percent 20 of 9aid compounds in said mixture have an R of from 12 to 16 :~
car~on atoms, and A is a mixture of oxypropylene and oxyethylene - group~, said oxpropylene and oxyethylene groups bei.ng from 55~ to -~ 80% of the total weight of the compounds, the oxypropylene to oxyethylene ratio of said total weight being from 0085:1 to 2075:1 preferably 1~25:1 to 2025:10 Another preferxed class of condensation products or oxyalkylated alcohol3 within the above de~inition are those : wherein the aliphatic alcohols of the oxyalkylated alcohols, or :........................................................................ .
. R in the above formula, ranges from 12 to 18 carbon atoms, and '.: . : .. :
~057~65 the total number of ethylene oxide and propylene oxide groups in the mixture thexeof, or de~ignated A in the above formula, ranges from about 4 to about 140 The term "cogeneric mixture" as employed herein, designates a serie~ of clo~ely related homologues obtained by condensing a plurality of oxide units, with an alcohol or a mixture thereofO
As is known, when a mixture of this type i9 generated, various oxyalkylene chain lengths are obtainedO
Alcohols which may be employed in the preparation of the : ~ -products noted above are those essentially linear, primary, aliphatic alcohols having from ô to 20 carbon atoms, preferably :~
10 to 18 carbon atomsO MLxtures o alcohols ara usually preferred ;
since their u e provides for a good balance of properties in the ;~
re~ulting productsO Examples of alcohol~ which are operable in~
clude decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl `- ~.
. : .
. alcohol, tetradecyl alcohol, pentradecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, hydrogenated tallow alcohol~
and mixtu~es thereofO They may be naturally-derive~ such as from : .
coconut oil or synthetically-derived such as from linear alkane~
or linear olefin~0 ~he nonionic surface active agents described above and `~
.,: .~ :. ':
their me~hod of preparation are disclo~ed in UOSo Patent ~oO
: '~ .:
-~. 3,504,0410 These ~urface active agents are believed to include, . . .
.~ , , .
.; for example, that class of surfactants which are marketed as the ~
: . .
~ "Plurafac*" surfactants "RA-40" gradesO
.' Another class of biodegradable liquid, water miscible oxy-1~ alkylated alcohol condensation products within ~he above definitLon :; . .
- are those wherein the aliphatic alcohol~ or R, is a straight chain alkyl group having ~rom 8 to 20 carbon atoms, the number of . * Trade Mark - 9-.' ~
, . . . . . . . . .
1057~65 .
ethylene oxide groups in the mixture thereof with propylene oxide9 or A, ranges from 3075 to 12075, and the number of propylen0 oxide groups in such m$xture range~ from 107 to 700, the oxyethylene to oxypropylene ratio in such mixtures being from 108:1 to 202:10 Such cogeneric mixtures can be prspared in two steps, the first step being conden~ation of an alcohol mixture and ethylene oxide in the presQnce of an alkaline condensing agent or catalyst, to form an ethoxylated product, followed by condensing the resulting ethoxylated product with propylene oxideO There can be employed in such reaction a mixture of straight chain aliphatic alcohols having from 8 to 20 carbon atoms in the aliphatic chainO This cogeneric mixture of condensation products and the method of their preparation are disclosed in UOS~ Patent NoO 3,340,3090 The non-ionic oxyalkylated alcohols marketed as the "RA-20" grades of "Plurafac", are believed representative of the class o~ sur~ace ~ ~
active agents disclosed in the latter patentO ~ ~ .
Various other "~lurafac'~ grades which are marketed and are believed to be generally within the above-described classes of .~ .
oxyalkylated alcohol surfactants are tho e designated RA-43, A-24, A-25~ B-25-5, B-26 and D-25~
A class o~ particularly preferred nonionic biodegradable ~ ;
.: . solvents or carriers which can be employed as substantially the .. . .
sole vehicle for the dye o the dye penetrant compositions accord-ing to the present invention are ethoxylated of a mixture o -~
:, , ; linear secondary aliphatic alcohols, with the hydroxyl groups randomly distributed, the linear aliphatic hydropho~ic portion of .. . .
such alcohols being a mixture of alkyl chains containing in the .
range from 8 to 20 carbon atoms, preferably 10 to 17 c~rbon atoms ;, : :
and most preferably from 11 to 15 carbon atoms, and containing an .' - 10-~OS74~5 average of f rom 3 to 12 moles of an alkyl~ne oxide of from 2 to 4 carbon atoms or mixture thereofO
The above particularly preferred clas~ of nonionic bio-degradable surfactant employed as carrier for the dye penetrant of the invention i~ a mixture of compounds which can be represented by tha formula:
CH - (CH2 ) - CH
, l-(CH2-CH2~)m-H ;~, ` where n is in the range from 9 to 13, and m is 3 to 12O : -: 10 The linear alkyl hydrophobic portion of the above defined surfactant i5 a mixture o Cll to C15 linear alkyl chains, and can be derived from a mixture of Cll to C15 aliphatic secondary ., alcohols, for example the secondary undecyl, dodecyl, tridecyl, ; ` tetradecyl and pentadecyl alcohols O The hydrophilic portion of ;~
: ~he ~urfactant i5 a polyoxyethylene chain randomly attached to . .
: any carbon atom of the linear alkyl hydrophobic chains, other : .,~ ,, .~.. , than to the terminal carbon atoms thereof, through ~n ether llnkageO Such hydroph~lic polyoxyethylene chain is generally ~ ~.
expressed in terms o~ an average number of moles o~ ethylene oxids Illustrative examples of biodegradable nonionic surfactants .,.,: :
of the types defined in the above formula are ~ho~e consisting of~
a mixture of ethoxylates of from 11 to 15 carbon atoms in the ij ~ .
aliphatic hydrophobic chain, and which have an averag~ of 3, 59 ~ 7, 9 and 12 moles of ethylene oxide, respectively, as the :` hydrophilO
Materials corresponding to these ive examples of bio-....
. degradable nonionic surfactants are marketed, respectively as:
:' ., . ' ;',. - 11 -~" .
.'.~` ' .
74~5 , ~ergitol* 15-S-3 ' 15-S-5 .~ .
: " 15-S-7 " 15-S-9 :~
' 15-S-12 In each ca~e of the ~ergitol S series of surfactants listed above, the number to the left of the "S" indicates a hydrophobic ali-phatic chain of from 11 to 15 carbon atoms derived from a mixture of alcohols on Cll to C15 backbone chains, and the number to the ~ 10 right of the "S" designates the average number of moles of :
:` ethylene oxide as the hydrophilO Thus for example, Tergitol 15-S-5 is a mixture of linear aliphatic alcohols in the Cll to C15 range ethoxylated. with an average of 5 moles of ethylene oxideO
.. : .
: All of these commercially marketed Tergitol S serie~ of surfactants :
. are water soluble except for Tergitol 15-S-3, which is essentially - .:
water~ insolubleO MLxtures of the~e materials can al~o be employed ~ ~
i.n providing the dye penetrant of the lnVentiOn~ such as a mixture .`~ :
- of the above Tergitols 15-S-5 and 15-S-30 . .`
Any suitable dye general}y employed in dye penetrant com-~0 positions can be incorporated into the nonionic oxyalkylated ~ ;
:~, .
alcohol sur~actan~s described above for producing the dye penatrant ;~
. . .
: compositions employed in the invention processO Preferably, ~ however, a ~luorescent dye is employed for this purposeO The :~
. . . . .
:. ethoxylated surfactant vehicle for the dye i8 compatible therewith ~ : :
~- and has the ability to dissolve either small or relatively large :;
amounts of the dye and to hold a high concentration of dye in solutior. while providing good resolution and clarity of the dye trace in the cracks and flawsO
:. *Trade Mark ,~ ~
1.
: . : , : , , - : : .. : ~
~57~5 , :
As previously noted, the dye penetrant solution employed ;~
according to the invention preferably contain~ a fluorescent dyeO
Various ~ypes of fluorescent dyes can be employed including for example the dye marketed as Fluorol 7~A* as well as other fluores-cent dyes ~uch as those marketed a~ Calco1uor Yellow*, Azosol Brilliant Yellow 6GF~; Rhodanine B, Rhodanine 6 GDN~ Calcofluor White RW*; Blancophor White AW*; Auramine and Eosine G, and water soluble fluorescent dyes such as Blancophor FFG*.
The dye penetrant composition employ~d according to the in~
vention alternatively can contain non-fluore~cent or daylight type "
:. dyes such as azo type dye~, eOgo ~ xyleneazo-beta-naphthol, Mefford No. 322 dye, believed to be o-toluene-azoxyleneazo-beta-naphthol, ;-and the azo dyes marketed as Oil Red "O" and Sudan RedO These ~.
dyes conveniently can be employed where daylight or white light .
i~ only available, and particularly where the surface of the body ~ to be detected contains relatively gross cracksO However, it is : ~
preferred to employ fluorescent dyes having greater sensitivity or detectability~ a~ result of the high contra t obtained by the ,: .
;~ fluorescent indication~O ~
~`` If de~ired, small amounts of extenders ~uch as kerosene, ;;~ :, ~;
and volatile solvents such as methyl ethyl ketone, i~opropyl ..
alcohol, and the like, and water, can be added to the dye penetrant composition of the invention containing the oxyalkylated alcohol carrier, to vary the properties thereofO It is noted however that in preferred practice these ~dditives are not employed and -~
in effect a '!one liquid" solution is pro~ded according to the in- : -, , .
` vention, in which the oxyalkylated alcohol surfactant is essential- -: ly the 501e carrier for the dye~ Al-~o~ if desired, corrosion -inhibitors ~uch as, for example, morpholine, can be added in a : *Trade Mark -.
.
:: , .
1~57465 small amount such a~ OoOl to Ool~ by volume of the dye penetrant compositionJ particularly where the object being tested is highly ~usceptible to corrosion, such aY magnesiumO
The amount of dye which is incorporated into the oxyalkylated alcohol surfactant or carrler to produce the dye penetrant compo-sition of the invention, can range from about Ool to 15, pre~erably about 005 to about 10, parts of the dye, or mixtures thereof, per 100 parts of the oxyalkylated alcohol surfactant, by weightO In . ;`
~ preparing the dye penetrant composition employed according to the ; 10 invention, the dye is slmply added to the oxyalkylated alcohol carrier, in the desired proportionO The resulting dye penetrant composition has both high and low temperature stabilityO .
Where a developer com~osition is employedg any one o~ the .~ three general types of developer compositions, namely, dry powder, ~ wet aqueous (water-base) and wet non-a~ueous (volatile solvent base) .. developer compoaition~ can be employedO In each case~ the develo-:~i per composition contains a light colored powder~ forming a coating ~ which contrasts with the color of the dye in the penetrant and which acts as a wick or blotter, and causes liquid penetrant con-: . . .
taining the dye~ eOgO fluorescent dye, which was retained in the cracks or surface fl~ws, to be drawn up out of the ~urface defects by capillary action and to "bleed" through the powderO Pre~erred developer compo~itions for use in conjunction with the dye pene~
trant com~osition according to the invention, are those de~cribed in my Patent NoO 3,803,051, whi h is a dry powder developer con~
taining fumed alumina9 fumed silica, fumed titanium dioxide and talc, and in my P~tent NoO 3,748,469, and which is a wet non-aqueous developer composition con~isting essentially of isopropyl ;
alcohol, talc and glycol monsbutyl ether ., lL~
~........ .
.: . , - : '' - ~OS7465 The dye penetrant composition employed in the invention process, employi~g the above biodegradable nonionic oxyalkylated alcohol surfactants can be tailored to have varying degrees o~
sensitivity or detection of the smallest microcrack~ to gro~s cracks in a part surface by generally varying ~he amount of dye ~' incorporated~ and also by selecting particular surfactants or : com~inations thereofO This is illu~trated by the compositions I
: to rv below, containing Tergitol 15-S-3 as sole vehicleO
; TABLE 1 COMPOSrTIONS (parts by weight) ~.;, .. .:
:, I II III IV
Sensitivity Level :
`:, COMPONENTS . _ Super HighHigh Medium Low : ~;
T-rgitol 15-S-3 lOOoOlOOoO lOOoO lOOoO
:. ~ Calco~Luor White RW 5 2~5 1025 Oo675 . . .
.~ Fluorol ~GA lo 5 _ o7~ o375 0o187 Composition I particularly is a super high sensitivity ~. :
dye penetrant composition which requires a more rigorous water wash than somewhat less sensitive dyo penetrant compositions em- :
ploying other related above described Tergitols, due tv the pre-.l sence thereln o~ the above noted specific Tergitol 15-S-3, which . is Iess water soluble or has lower water solubility than ~orres~
, .~
ponding TergitolsO As a matter of fact, Torgitol 15-S-3 is sub~
;: stantially water insolubleO Thu3~ although composition I i5 ~'~
particularly advantageous for inspection of parts having a very ~ :
smooth ~urface with microcracks, and compo3itions II~ III and IV . : -are also highly advantageous for inspeckion of parts having cracks of intermediate 4ize and gross cracks, due to the substantially reduced water solubility of the Tergitol 15-S-3, large volume~ of ~ -. - 15 - ~
- iO57~65 high presqure water are needed to remove excess dyq penetrant from the surface of a part to which the penetrant ha~ been applied~
when employing compositions I to rv.
Corresponding dye penetrant compositions to those of Table ~.
1 can be made by substituting Plurafac A-24, for example, for the : Tergitol 15-S-3 thereinO
The invention process will be more clearly understood from the further description below taken in connection with the accom-panying drawing wherein Figure~ 1 to 4 illustrate the steps in the invention process O
~ Referring to the drawing, Figure 1 illustrates application ; of the biodegradable substantially non water soluble penetrant, e.g. composition I to the surface 10 of a part 12 containing cracks ~ :
`........ such as illustrated at 14. It will be seen that the dye penetrant solution 16 is contained on the part surface 10 and in the cracks ~: ~
.. 14. ~: :
,:....... .~, ': .
- Viewing Figure 2, a~cording to the po~temu~ifying penetrant ;.
: .~
~: process of the invention, there is then applied over the dye pene-: ~:
trant composition on the part surface, an emulsifier 18 to render .
: 20 the emulsified penetrant easily water washableO Such emulsifiers have as essential component a biodegradable nonionic surfactant, ~ e.g~, of the same class as the particular Tergitol of composition .. I, or the particular Pluraac of the corresponding dye penetrant .::
: compositionO Thus, as a general rule, for greater sensitivi$y of . the dye penetrant, where a dye penetrant compositlon is employed containing nonionic biodegradable surfactants in the form of ethoxy~
late of linear secondary aliphatic alcohols, as repre~ented by the above Tergitols, there can be employed in the dye penetrant composition, surfactants of this type containing from 3 to 4 `:-. .' ~ ' .. ,~ -.. . . :
1~57~65 ethyle~e oxide groups, which are o~ low water ~olubility or which with respect to Tergitol 15-S-3, ~pecifically~ are es~antially wa~er insoluble, as represented by Compoqitions I to rv above, in .
conjunction with an emul3ifi~r consisting essentially of the same class of nonionic biodegradable $ergitol-type surfactants which contain from 5 to 12 moles of ethylene oxide or ethylene oxide groups, and which are e~sentially water soluble. Similarly, the above defined Plurafac type surfactant, e.gO, formed of a mixture of straight chain, primary, aliphatic oxyalkylatæd alcohols, and wherein about 4 to about 8 total ethylene oxide and propylane oxide groups are present, aR represented by the material marketed as Plurafac A-249 and which are of comparatively lower water solubili~
ty, can be employed in conjunction with an emu~aifier consisting essentially of the same general class of Plurafac noted abov-, but wherein the total number of ethylene oxide and propylene oxide groups can range from about 9 to about 14, and which are of greater solubilityO
Thu3, for example, where Plurafac A-24, which is understood to contain a total number of ethylene oxide and propylene oxide . . .
groups ranging from about 4 to about 8, i~ employed as carrier in providing a high sensitivity dye penetrant composition, an emulsifier can be employed containing the same general class of :. ~
Plurafacs but wherein the total number of ethylene oxide and propylene oxide groups rangas from about 9 to about 14~ e~g., as represented by Plurafac A-25, Similarly, where, for example~
Tergitol 15-S-3 is employed as carrier for the dye in the dye penetrant composition, an emulsifier can be employed containing from about 5 to about 12 moles of ethylene oxide, e.g,, Tergitol 15-S-5, 15-S-7, 15-S-9 or 15-S-12, separately or in combinations _ ~7 _ : -: - . . , - ,- . , ' : : .:
'~: ' :, . , , ' ~L~)57465 of one or more of such Tergi~ols, eOgO, a combination of Tergitols 15-S-5 and 15-s-9, a combination of Tergitols 15-S-5 and 15-S-7, or a combination o~ Tergitols l5-s-g and 15-S-12, the respective Tergitols in each such combination being employed in varying ratios of from about 5 to about 95~ by volume The object or part to which the dye penetrant composition has been applied is contacted with the above described emulsifiers in any desired manner as by spraying with or by Immersion in the , emulsifier, for a relatively short period of time, eOgO,about 1 .
to 5 minutesO Referring to Figure 3 of the drawing, the spontaneous mixing of both the emulsifier 18 and the dye penetrant solution 16 - on the part surface forms a water soluble biodegradable mixture .,,., .~
20 which does not penetrate into the cracks 14 which contain dye penetrant solution 160 Referring to ~igure 4 of the drawing, the resulting - emulsified penetrant 20 on the surface of the object is then con- :
tacted with water in any suitable manner as by spraying the water at 22 from a water spray nozzle 24, to remove the excess emulsified dye penetrant 20 from the part surface without removing dye pene-20 t~ant 16 trapped in the cracks and ~laws 14 in the surface of the objectO The part i8 then dried~ for example, by a hla~t of airO If deQired, as noted above, but not necessarily, the part 12 can then be covered with a devsloper, eOgO a dry powder~ aqueous or nonaqueous developer, and the developer allowed to dwell on the surface for a ~hort period, eOgo about 1 to 3 minutesO Exces~
: developer i8 then removed from the surface of the part. The part ~:~
, ~ .
is then viewed under suitable lighting conditions, eOgO, black ~ ~
:: ~
. light or fluorescent light where a fluore~Rcent dye has been em- ~ .
ployed in the dye penetrant composition, for indication of the deects and cracks in the partO
1~57~;5 :
....
The following are example~ of practice of the invention but ars not limitative of the bene~its and advantage~ obtained by : ;
practice of the inventionO .
. The fluorescent dye penetrant composition I of Table 1 above, containing biodegradable Tergitol 15-S-3 as carrier was : applied as by spraying to a chromi~m-plated: brass test panel con- :
taining minute cracks of the order of 0.00002 to 0.0001 inch in ~; ..
widthJ closely distributed over its entire surface.
The test panel covered with the dye penetrant was then , immersed in biodegradable Tergitol 15~S-9 as emulsifier and .1 `
` allowed to remain immersed in the emulsifier for a period of about ;: `
~ 1 minute. The test panel containing the emulsified penetrant was .~ then sprayed with water applied by an air-water spray over the dye ~. :
... .
' penetrant-emulsifier coating, causing instantaneous washing away .;~
~, of the emulsified dye pcnetrant on the surface of the panel without dislodging the dye penetrant from the surface cracks and thus en- ~ :
;., trapping the penetrant therein, .' ~ The test panel was then covered with a powder developer ~ :
20 having the following composition, according to my above Patent ~`
No. 3,083,051.
COMPONENTS Percent by Weight Talc 52 .~. .
;.~ Alumina 35 Silica 1 ~:'i ::
: ' The above developer ~as permitted to dwell over the surface of the test panel for a period of about 2 minutes.
.`` Excess developer compos~tion was then carefully removed from the surface of the test panel by means of a gentle air blast.
,, . , . '' , ~ ;' :
, :, - :~
~5746;5 The panel wa~ then placed under black light (fluorescent) illumination and the above treated surface of the panel viewed in such illumination. It was observed that the panel surface dis-closed fluorescent indication~ from numerous readily defined micro-cracks therein, such fluorescent indications being sharp and brilliant and revealing all defective conditions on the surface of the test panel. ~:
The procedure of Example 1 was repeated but without treat-ment of the dye penetrant covered surface of the test panel with any emulsifier. Thus, following application of the dye penetrant composition I to the surface of the test panel, a water wash was applied às by an air-water spray over the coating of the dye penetrant composition I on the test panel, followed by application of the developer to the surface of the penetrantO ~ : .
. ~ , ~ It was found that a vigorous water wash re~uiring large : volumes of water at a pressure of about 80 - 100 psi and an ex- ~:
~` tended period of washing of about 4 to 5 mlnutes, was required in order to substantially completely remove excess dye penetrant 20 composmtion from the surface of tbe test panel, priox to appli- -cation of the developerO
EXAMPLE
- The procedure of Example l was repeated but employing an aluminum test panel containing microcracks, and wherein the emul-sifier was Tergitol 15-S 5.
Excellent results were obtained comparable to those obtained in Example lo ' ' "
~ ' ,' ' ' ' . ~ . ;' . ' ' , . ' "
. ' .; - ' ' ,' ' ' ' ' ~ ' :. ' , .. . ~ . . .
,. . '. . . . . . . .. . . . . .
1~57~6S
The procedure of Example 1 wa3 repeated but employing in place of compcsition I, a ~imilar composition but employing Plurafac A-24 as dye solvent or carrierO Also, in place of the Tergitol 15-S-9 emulsifier employed in Example 1, the emulsifier used was Plurafac A-25, comprised of a straight chain, primary aliphatic oxyalkylated alcohol mixture believed to contain about 12 to about 18 carbon atoms in the alcohol chains, and a total of ; from about 9 to 14 oxyethylene and oxypropylene group~, as des-cribed above, Bright fluore_cent indications of the crack~ and defects - . .
in the surface of the panel ware obtained similar to the results achieved in Example l ~ EXAMPLE 5 ~ -~` A test on an aluminun panel having cracks of intermediate ~ize was carried out following the procedure of Example 1-, but ~ utilizing composition III of Table 1, containing Tergitol 15-S-3, . :
.:~ and employing as emulsifier a mixture of approximately equal parts by volume of Tergitol 15-S-5 and Tergitol 15-S-9o :: 20 Excallen~ re~ults with respect to water washability of the penetrant emulsified surface of the panel, as well as excellent ~ .
. brilliant indiaations of the defects on the surface of the test - panel, were achieved~ .
. ; _ ~ The procedurs of Example 1 waq essentially folla~ed, but : ~
.
:; employing in place of compo~ition IanDn ~luorescant dye penetrant solution consisting o~ 15 parts of Tergitol 15-S-3 and 1 part of ~ Oil Red "O" dye, by volumeO
Excellent results of crack detectability were obtained , 7~65 ~mploying such non-fluorescent dye penetrantO ~owever, the brightness and sensitivity of the colored dye txaces obtained employing the non-fluorescent dye penetrant of this sxample were ~ :
not as yreat as for the fluorescent dye penetrant composition I
of ~xample lo The procedure of Example 1 was followed except that in place of the powder developer employed in Example 1, a nonaqueous developer having the following composition according to my above Patent NoO 3,748,469 was employed:
COMPONENTSPercent by Weight Isopropyl alcohol 70O5 Talc 28O6 Glycol ~onobutyl ether OO9 The above developer was pexmitted to remain on the panel ::
surfaces to which it was applied for a period of 2 minutes, until ~ ~
-~ substantially all of the i~opropyl alcohol had evaporated and a ~-:
.
substantially dry powder coating was formed < Results similar to the results of Example 1 were obtainedO `
` 20 In all of Examples 1 to 7 above, all of the dye penetrants ., .~ .
and the emulsifiers were biodegradable and hence avoided pollution `~
of the sewage disposal systems into which they were discharged.
From the foregoing, it is seen that the invention provides a highly effective postemul~ifiable penetrant inspection system :
and method employing as sole carrier or vehicle in the dye pene-trantJ and as essential component of the emulsifier, certain :., .
oxyalkylated alcohol biodegradable nonionic surfactants, and permitting substantially instantaneous removal of emulsified dye :. penetrant from the surface of the part in a single wash operation _ 22 -:' ,'~.
., ;. , . .. , . : ~: . :
' ~' ' ::' . . ' .,.. :. ,' ` ~5746~
employing ~odest amounts of water at normal water pressure, while maintaining the dye penetrant in the cracks or defect~ of the part, followed by further processing as desired in the convention- :
al manner for viewing under suitable, eOgO, fluorescent lighting conditions, to obtain highly brilliant dye traces from cracks and flaws in the part surfaceO The dye penetrants and emulsifiers employed according to the invention afford substantially non-flammable high performance dye penetrant compositions having a wide range of sensitivity and non-flammabls emulsifiers providing improved water washability characteristics of the resultant emulsified penetrantO The dye penetrant and emulsifiers employed according to ~he invention process avoid the u~e of volatile extenders and thinners Since various changes and modifications of the invention will occur to and can be made readily by those skilled in the art :
without departing.from the invention concept, the invention is not to be taken as limited except by the scope of the appended claimsO
.
. ' . .
`` ~ ' ~.
~ .
.,, ~ .
I
- _ 23 _ . '
Claims (14)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A postemulsifiable dye penetrant inspection method for detecting cracks and flaws in the surface of an object, which comprises applying to said surface a biodegradable liquid dye penetrant composition which consists essentially of (1) a first biodegradable nonionic surfactant consisting essentially of an oxyalkylated alcohol, or a mixture thereof, and (2) a small amount of a dye soluble in said first surfactant, said first surfactant having limited water solubility and rendering the dye penetrant difficult to wash away with water, contacting the dye penetrant covered surface of said object with an emulsifier con-taining as essential component a second biodegradable nonionic surfactant consisting of an oxyalkylated alcohol, or a mixture thereof, said second surfactant being essentially water soluble, and rendering the emulsified penetrant water washable, contacting the emulsified penetrant on the surface of said object with water and removing said dye penetrant from said surface without re-moving said dye penetrant composition from said cracks and flaws in said surface, and viewing the surface of said object under lighting conditions to obtain colored traces from the dye in said cracks and flaws.
2. A method as defined in Claim 1, said first and second biodegradable nonionic surfactants being of the group consisting of (a) straight chain, primary, aliphatic oxyalkylated alcohols, wherein said alcohols can contain from 8 to 20 carbon atoms and the oxyalkyl groups are a mixture of ethylene oxide and propylene oxide groups, and (b) ethoxylates of linear secondary aliphatic alcohols, with the hydroxyl groups randomly distributed, the linear aliphatic portion of said alcohols being a mixture of alkyl chains containing in the range from 8 to 20 carbon atoms, and containing an average of from 3 to 12 moles of an alkylene oxide of 2-4 carbon atoms or mixture thereof, said second surfactant in the emulsifier having a higher number of oxyalkyl groups in the hydrophilic portion than said first surfactant.
3. A method as defined in Claim 2, wherein said first non-ionic surfactant in the dye penetrant composition is the sole liquid carrier for the dye therein.
4. A method as defined in Claim 2, wherein said surfactant (a) is a mixture of compounds having the formula:
R - O(A)H
wherein R is an essentially linear alkyl group having from 10 to 18 carbon atoms, at least 70 weight per cent of said compounds in said mixture having an R of from 12 to 16 carbon atoms, and A is a mixture of oxypropylene and oxyethylene groups, said oxypropy-lene and oxyethylene groups being from 55 to 80% of the total weight of said compounds, the oxypropylene to oxyethylene ratio of said total weight being from 0.85:1 to 2.75:1; and wherein said surfactant (b) are ethoxylates of a mixture of alcohols having the formula:
where n is in the range from 9 to 13 and m is an average of 3 to 12; and said dye is present in said composition in an amount ranging from about 0.1 to 15 parts, per 100 parts, by weight, of said surfactant, said composition being substantially non-flammable.
R - O(A)H
wherein R is an essentially linear alkyl group having from 10 to 18 carbon atoms, at least 70 weight per cent of said compounds in said mixture having an R of from 12 to 16 carbon atoms, and A is a mixture of oxypropylene and oxyethylene groups, said oxypropy-lene and oxyethylene groups being from 55 to 80% of the total weight of said compounds, the oxypropylene to oxyethylene ratio of said total weight being from 0.85:1 to 2.75:1; and wherein said surfactant (b) are ethoxylates of a mixture of alcohols having the formula:
where n is in the range from 9 to 13 and m is an average of 3 to 12; and said dye is present in said composition in an amount ranging from about 0.1 to 15 parts, per 100 parts, by weight, of said surfactant, said composition being substantially non-flammable.
5. A method as defined in Claim 4, wherein R in said sur-factant (a) can have from 12 to 18 carbon atoms, and the total number of A groups can range from about 4 to about 14; and where-in in surfactant (b) the linear alkyl hydrophobic portion of said surfactant is a mixture of C11 to C15 linear chains, and the hydrophilic portion of said surfactant is a polyoxyethylene chain randomly attached to the linear alkyl hydrophobic chains through an ether linkage, and wherein said surfactant (b) is selected from the group consisting of said ethoxylates of said mixture of alcohols, wherein n ranges from 9 to 13, and m is an average of 3, 5, 7, 9 or 12.
6. A method as defined in Claim 5, wherein said first sur-factant in said dye penetrant composition is said surfactant (a), the total number of said oxyethylene and oxypropylene groups A
ranging from about 4 to about 8, and wherein said second surfactant in said emulsifier is said surfactant (a), the total number of said oxyethylene and oxypropylene groups A in said last mentioned surfactant ranging from about 9 to about 14.
ranging from about 4 to about 8, and wherein said second surfactant in said emulsifier is said surfactant (a), the total number of said oxyethylene and oxypropylene groups A in said last mentioned surfactant ranging from about 9 to about 14.
7. A method as defined in Claim 5, wherein said first sur-factant in said dye penetrant composition is said surfactant (b), and wherein m is an average of 3 to 4, and wherein said sur-factant in said emulsifier is said surfactant (b), wherein m is an average of about 5 to 12.
8. A method as defined in Claim 7, wherein m in said first surfactant is an average of 3, and m in said second surfactant is an average of 5, 7, 9 or 12.
9. A method as defined in Claim 8, wherein said second surfactant (b) in said emulsifier is a combination of two or more said ethoxylates.
10. A method as defined in Claim 9, wherein said surfactant (b) in said emulsifier is a combination of said ethoxylates wherein m is 5 and m is 9.
11. A method as defined in Claim 1, wherein said dye is a fluorescent dye and said surface of said object is viewed under fluorescigenous light to obtain colored fluorescent traces from the dye in said cracks and flaws.
12. A method as defined in Claim 8, wherein said dye is a fluorescent dye and said surface of said object is viewed under fluorescigenous light to obtain colored fluorescent traces from the dye in said cracks and flaws.
13. A method as defined in Claim 1, including applying a developer to said surface after removing said dye penetrant composition from said surface and prior to said viewing the surface of said object.
14. A method as defined in Claim 7, including applying a developer to said surface after removing said dye penetrant com-position from said surface and prior to said viewing the surface of said object.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA257,887A CA1057465A (en) | 1976-07-27 | 1976-07-27 | Postemulsifiable dye penetrant system and method for using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA257,887A CA1057465A (en) | 1976-07-27 | 1976-07-27 | Postemulsifiable dye penetrant system and method for using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1057465A true CA1057465A (en) | 1979-07-03 |
Family
ID=4106521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA257,887A Expired CA1057465A (en) | 1976-07-27 | 1976-07-27 | Postemulsifiable dye penetrant system and method for using same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1057465A (en) |
-
1976
- 1976-07-27 CA CA257,887A patent/CA1057465A/en not_active Expired
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