1、Designation: D2210 13Standard Test Method forGrain Crack and Extension of Leather by the Mullen Test1This standard is issued under the fixed designation D2210; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the determination of the
3、 resis-tance of leather to grain cracking and for measuring theextension of the leather. It is limited to light leathers such asshoe uppers, garment, gloves, and upholstery. This test methoddoes not apply to wet blue.1.2 The values stated in inch-pound units are to be regardedas standard. The values
4、 given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establ
5、ish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD1813 Test Method for Measuring Thickness of LeatherTest Specimens3
6、. Terminology3.1 Definitions:3.1.1 extensionthe amount of stretch of leather over thediaphragm under pressure.3.1.2 grain crackingthe appearance of cracks on thesurface of the leather as the leather is extended over adiaphragm under pressure to form a sphere.4. Significance and Use4.1 The test metho
7、d is designed to measure the forcerequired to crack the grain of leather by steady hydraulicpressure on a diaphragm of definite diameter applied to theflesh side of the specimen to form a sphere. The cracking of thegrain is a result of failure under elongation or stretch. Theelongation or stretch of
8、 the leather can be measured at differentloads or at the failure of the grain to determine if the stressleather will withstand under lasting conditions. Cuts, scratches,and other defects will cause considerable variation in theresults by concentration of the applied force to the weak points.This tes
9、t method is excellent for manufacturing control, speci-fication acceptance, and service evaluation in the lastingproperty of leather. This test method may not apply when theconditions of the test employed differ widely from thosespecified in the test method.5. Apparatus5.1 Testing Machine,3as shown
10、in Fig. 1. The machine shallbe hand- or power-driven. The machine shall hold the speci-men firmly, without slippage, between two annular, plane,unpolished (matte) surfaces that may have fine, spiral toolmarks not over 0.010 in. (0.25 mm) in depth.5.2 Upper Clamping SurfaceThe upper clamping surface(
11、clamping ring) shall have a circular opening 1.240 6 0.010 in.(31.50 6 0.25 mm) in diameter and shall be connected to theclamping mechanism through a swivel joint to ensure an evenclamping pressure.5.3 Lower Clamping SurfaceThe lower clamping surface(diaphragm plate) shall be 0.219 6 0.003 in. (5.56
12、 6 0.08 mm)thick and have an opening of 1.240 6 0.01 in. (31.50 6 0.52mm) in diameter. The circular edges of the openings that comein contact with the specimen and the rubber diaphragm shall berounded to a radius of not over 0.025 in. (0.64 mm) to preventany cutting action. During the test, the circ
13、ular edges of the1This test method is under the jurisdiction ofASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.03 on Footwear. This testmethod was developed in cooperation with the American Leather Chemists Assn.(Standard Method E58 1965).Current edition approved No
14、v. 1, 2013. Published November 2013. Originallyapproved in 1963 as D2210 63T. Last previous edition approved in 2012 asD2210 00(2012). DOI: 10.1520/D2210-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
15、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of the apparatus known to the committee at this timeis B. F. Perkins, 939 Chicopee St., Chicopee, MA 01013-2797, (413) 536-1311. Ifyou are aware of alternative suppliers, please
16、 provide this information to ASTMHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1openings in the t
17、wo clamping plates shall be substantiallyconcentric with no overlapping of any point.5.4 Diaphragm, of rubber, 0.034 6 0.002 in. (0.86 6 0.05mm) thick, clamped under the lower clamping plate so that,before the diaphragm is stretched by pressure underneath it, thecenter of its upper surface is below
18、the plane of the clampingsurface.5.5 Dial Gage, as shown in Fig. 2, to measure the extensionof the leather specimen and mounted on the machine throughscrew shaft or on side of clamps on platform. This gage shallbe calibrated to read directly to the nearest 0.001 in. (0.03 mm).It shall be equipped wi
19、th a flat anvil and a presser foot.5.6 Bourdon TubeThe apparatus shall be equipped with aBourdon tube, maximum-reading-type, pressure gage gradu-ated in pounds-force per square inch and accurate throughoutthe entire range of its scale to within a value of 1 % of itsmaximum capacity. The capacity of
20、the gage shall be such thatthe individual readings will be not less than 25 % nor morethan 75 % of the total capacity of the gage.5.7 Pressure ControlThe machine shall be equipped withmeans of applying controlled increasing hydraulic pressure tothe underside of the diaphragm until the specimen crack
21、s. Thispressure shall be generated by a piston forcing a liquor (usuallyglycerin) into the pressure chamber of the apparatus. Formachines shown in Fig. 1 where the cracking pressure is theonly measurement, the pressure will be generated by pumpingliquid at a rate of 170 6 10 mL/min or by turning a h
22、andwheelat approximately 30 r/min. Record pumping rate or crankingrate. For machines shown in Fig. 2 where cracking pressureand extension are measured, the pressure will be generated bypumping liquid at a rate of 15 6 2 mL/min or by turning ahandwheel at approximately 3 r/min.NOTE 1When equipment do
23、es not have a gauge to measure the flowrate or uses a hand crank method, consult the equipment manufacturer oroperating manual. Results from the different tester may not be comparablebecause of the different flow rates.5.8 Thickness GageA dead-weight type of thickness gageas described in Test Method
24、 D1813.6. Test Specimen6.1 The specimen shall be a square of leather 3 by 3 in. (76by 76 mm) cut from the test unit of leather.6.2 The specimen shall be free of mechanical damage andsurface defects.7. Conditioning7.1 All specimens shall be conditioned in accordance withPractice D1610.8. Procedure8.1
25、 Determine the thickness of the specimen by taking threemeasurements in the area to be cracked and determine theaverage value.FIG. 1 Mullen Tester, Model AFIG. 2 Mullen Tester with Dial GageD2210 1328.2 Place the flesh side of the specimen in contact with therubber diaphragm of the testing machine.8
26、.3 Clamp the specimen securely in the apparatus in such amanner that the leather will not be damaged.8.4 Rest the presser foot of the extension gage on the flatsurface of the specimen and set the gage at zero.8.5 Apply pressure to the specimen until the specimencracks.8.6 At the moment the first cra
27、ck appears in the specimenstop the machine, note the applied pressure from the gage, andrecord the value as the cracking strength of the specimen.9. Report9.1 The report shall include the following:9.1.1 Cracking pressure to the nearest 5 psi (35 kPa) foreach specimen or averaged and reported as the
28、 average of thetest unit,9.1.2 Extension of the leather to the nearest 0.001 in. (0.03mm), converted to percentage (see Annex A1) and reported aspercentage stretch, and9.1.3 Thickness to the nearest 0.001 in. (0.03 mm) reportedfor each specimen or averaged and reported as the thickness ofthe sample.
29、9.1.4 Speed the liquid was pumped to build pressure to thenearest 10 % (see 5.7). Record revolutions per minute.10. Precision and Bias10.1 The following criteria may be used to judge theacceptability of the results if at least 15 units have been tested:10.1.1 One Operator, Duplicate Specimens, Same
30、SkinResults by the same operator in duplicate adjacent specimensin a skin taken from the official sampling position should not beconsidered suspect unless the coefficient of variation exceeds:Leathers Cracking Pressure, psiExtension at GrainCrack, %Shoe upper 26 13Upholstery 17 14CalfskinA16 22Glove
31、 11 20A3 1 oz, 0.0468 0.0156 in. (1.189 0.396 mm).10.1.2 Two Laboratories, Duplicate Specimens, SameSkinResults for the same group of light leathers listed in10.1.1 submitted by each of two laboratories on duplicateadjacent specimens in a skin taken from the official samplingposition should not be c
32、onsidered suspect unless the twoaverage results differ by more than 5 %.NOTE 2The reproducibility reported in 10.1.2 is based on dataobtained at two laboratories, and a different operator. The results showclose correlation between laboratories.NOTE 3The results given in Section 10 are based on tests
33、 on 30 sidesof leather and do not apply to findings and cut parts.NOTE 4The precision data for between skins are not included becausethe results were based on different skins from several production lots. Thevariables in leather for between skins will give a higher variation of theresults, but this
34、factor should not affect the precision of the method.11. Keywords11.1 burst strength extension; grain crack; leather; MullenANNEX(Mandatory Information)A1. DERIVATION OF EQUATION FOR PERCENTAGE STRETCHA1.1 Referring to Fig. A1.1, h = deflection (measured by Mullen tester), andFIG. A1.1 Geometry for
35、Derivation of Equation for Percentage StretchD2210 133TABLE A1.1 Conversion Table From h to Percentage Stretch (2.56h2 100) (for Values of hBetween 0.2 and 0.5 in.)h, in. Stretch, % h, in. Stretch,% h, in. Stretch, % h, in. Stretch, %20010310.24 276 10319.50 352 10331.72 428 10346.90201 10.34 277 19
36、.64 353 31.90 429 47.11202 10.45 278 19.78 354 32.08 430 47.33203 10.55 279 19.93 355 32.26 431 47.55204 10.65 280 20.07 356 32.44 432 47.78205 10.76 281 20.21 357 32.63 433 48.00206 10.86 282 20.36 358 32.81 434 48.22207 10.97 283 20.50 359 32.99 435 48.44208 11.08 284 20.65 360 33.18 436 48.66209
37、11.18 285 20.70 361 33.36 437 48.89210 11.29 286 20.94 362 33.55 438 49.11211 11.40 287 21.09 363 33.73 439 49.34212 11.51 288 21.23 364 33.92 440 49.56213 11.61 289 21.38 365 34.11 441 49.79214 11.72 290 21.53 366 34.29 442 50.01215 11.83 291 21.68 367 34.48 443 50.24216 11.94 292 21.83 368 34.67 4
38、44 50.47217 12.08 293 21.98 369 34.86 445 50.69218 12.17 294 22.13 370 35.05 446 50.92219 12.28 295 22.28 371 35.24 447 51.15220 12.39 296 22.43 372 35.43 448 51.38221 12.50 297 22.58 373 35.62 449 51.61222 12.62 298 22.73 374 35.81 450 51.84223 12.73 299 22.89 375 36.00 451 52.07224 12.85 300 23.04
39、 376 36.19 452 52.30225 12.96 301 23.19 377 36.39 453 52.53226 13.08 302 23.35 378 36.58 454 52.77227 13.19 303 23.50 379 36.77 455 53.00228 13.31 304 23.66 380 36.97 456 53.23229 13.42 305 23.81 381 37.16 457 53.47230 13.54 306 23.97 382 37.36 458 53.70231 13.66 307 24.13 383 37.55 459 53.93232 13.
40、78 308 24.29 384 37.75 460 54.17233 13.90 309 24.44 385 37.95 461 54.41234 14.02 310 24.60 386 38.14 462 54.64235 14.14 311 24.76 387 38.34 463 54.88236 14.26 312 24.92 388 38.54 464 55.12237 14.38 313 25.08 389 38.74 465 55.35238 14.50 314 25.24 390 38.94 466 55.59239 14.62 315 25.40 391 39.14 467
41、55.83240 14.75 316 25.56 392 39.34 468 56.07241 14.87 317 25.73 393 39.54 469 56.31242 14.99 318 25.89 394 39.74 470 56.55243 15.12 319 26.05 395 39.94 471 56.79244 15.24 320 26.21 396 40.14 472 57.03245 15.37 321 26.38 397 40.35 473 57.27246 15.49 322 26.54 398 40.55 474 57.52247 15.62 323 26.71 39
42、9 40.76 475 57.76248 15.75 324 26.87 400 40.96 476 58.00249 15.87 325 27.04 401 41.17 477 58.25250 16.00 326 27.21 402 41.37 478 58.49251 16.13 327 27.37 403 41.58 479 58.73252 16.26 328 27.54 404 41.78 480 58.98253 16.39 329 27.71 405 41.99 481 59.23254 16.52 330 27.88 406 42.20 482 59.47255 16.65
43、331 28.05 407 42.41 483 59.72256 16.78 332 28.22 408 42.61 484 59.97257 16.91 333 28.39 409 42.82 485 60.22258 17.04 334 28.56 410 43.03 486 60.47259 17.17 335 28.73 411 43.24 487 60.72260 17.31 336 28.90 412 43.45 488 60.96261 17.44 337 29.07 413 43.67 489 61.21262 17.57 338 29.35 414 43.88 490 61.
44、47263 17.71 339 29.42 415 44.09 491 61.72264 17.84 340 29.59 416 44.30 492 61.97265 17.98 341 29.77 417 44.52 493 62.22266 18.11 342 29.94 418 44.73 494 62.47267 18.25 343 30.12 419 44.94 495 62.73268 18.39 344 30.29 420 45.16 496 62.98269 18.52 345 30.47 421 45.37 497 63.23270 18.66 346 30.65 422 4
45、5.59 498 63.49271 18.80 347 30.82 423 45.81 499 63.74272 18.94 348 31.00 424 46.02 500 64.00273 19.08 349 31.18 425 46.24 . .274 19.22 350 31.36 426 46.46 . .275 19.36 351 31.54 427 46.68 . .D2210 134TABLE A1.2 Conversion Table From h to Percentage Stretch (2.56h2 100) (for Values of hBetween 5.08 a
46、nd 12.70 mm)h, mm Stretch, % h, mm Stretch,% h, mm Stretch, % h, mm Stretch, %5.08 10.24 6.99 19.36 8.89 31.36 10.80 46.245.11 10.34 7.01 19.50 8.92 31.54 10.82 46.465.13 10.45 7.04 19.64 8.94 31.72 10.85 46.685.16 10.55 7.06 19.78 8.97 31.90 10.87 46.905.18 10.65 7.09 19.93 8.99 32.08 10.90 47.115.
47、21 10.76 7.11 20.07 9.02 32.26 10.92 47.335.23 10.86 7.14 20.21 9.04 32.44 10.95 47.555.26 10.97 7.16 20.36 9.07 32.63 10.97 47.785.28 11.08 7.19 20.50 9.09 32.81 11.00 48.005.31 11.18 7.21 20.65 9.12 32.99 11.02 48.225.33 11.29 7.24 20.70 9.14 33.18 11.05 48.445.36 11.40 7.26 20.94 9.17 33.36 11.07
48、 48.665.38 11.51 7.29 21.09 9.19 33.55 11.10 48.895.41 11.61 7.32 21.23 9.22 33.73 11.13 49.115.44 11.72 7.34 21.38 9.25 33.92 11.15 49.345.46 11.83 7.37 21.53 9.27 34.11 11.18 49.565.49 11.94 7.39 21.68 9.30 34.29 11.20 49.795.51 12.08 7.42 21.83 9.32 34.48 11.23 50.015.54 12.17 7.44 21.98 9.35 34.
49、67 11.25 50.245.56 12.28 7.47 22.13 9.37 34.86 11.28 50.475.59 12.39 7.49 22.28 9.40 35.05 11.30 50.695.61 12.50 7.52 22.43 9.42 35.24 11.33 50.925.64 12.62 7.54 22.58 9.45 35.43 11.35 51.155.66 12.73 7.57 22.73 9.47 35.62 11.38 51.385.69 12.85 7.59 22.89 9.50 35.81 11.40 51.615.72 12.96 7.62 23.04 9.53 36.00 11.43 51.845.74 13.08 7.65 23.19 9.55 36.19 11.46 52.075.77 13.19 7.67 23.35 9.58 36.39 11.48 52.305.79 13.31 7.70 23.50 9.60 36.58 11.51 52.535.82 13.42 7.72 23.66 9.63 36.77 11.53 52.775.84 13.54 7.75 23.81 9.65 36.97 11.56 53.005.87 13
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