1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW3262 Finished Genuine Leather Copyright 2011 General Motors Company All Rights Reserved August 2011 Originating Department: North American Engineering Standards Page 1 of 13 1 Scope Note: Nothing in this standard supercedes applicable laws a
2、nd regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Material Description. Leathers covered by this specification include all interior automotive grade leathers. All leather is to be full, top grain unless otherwise
3、 specified in the Leather Construction Specification form and must come from steer, heifer or bull hides only. All soft quality leathers shall be milled full grain only. All leathers shall be flexible, free from tackiness, and conform to trim fabrications. Note: For requirements for vehicles without
4、 solar absorbing glass, contact the appropriate Materials Engineer. All interior materials are developed to be used in vehicles with solar glass; therefore, performance may be compromised if non-solar glass is used. 1.2 Symbols. This code defines the material construction and will be assigned by the
5、 responsible department. 1.3 Typical Applications. This specification describes leather material used for automotive interior trim applications, such as seat cushions and backs, seat inserts, doors, shift knobs, shift boots, steering wheel covers, instrument panels, consoles, and armrests. 1.4 Remar
6、ks. All materials covered by this specification are subject to part performance testing through part validation including GMW14444. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 105-A02 ISO 5402 ISO 105-A03
7、 ISO 11640 ISO 105-B06 ISO 11644 ISO 105-E04 ISO 13937-2 ISO 105-X12 ISO 15701 ISO 2589 ISO/IEC 17025 2.2 GM Standards/Specifications. GMW3010 GMW14124 GMW3059 GMW14126 GMW3182 GMW14127 GMW3205 GMW14130 GMW3208 GMW14132 GMW3211 GMW14134 GMW3220 GMW14136 GMW3221 GMW14140 GMW3232 GMW14146 GMW3235 GMW1
8、4162 GMW3259 GMW14296 GMW3390 GMW14364 GMW3402 GMW14444 GMW3405 GMW14445 GMW3417 GMW14864 GMW6992 GMW15058 GMW8081 GMW15717 GMW14102 2.3 Additional References. x Construction Specification Sheet x GM Appearance Manual x GM Global Leather Statement of Requirements x GM Natural Markings and Defects Ma
9、nual x Leather Natural Markings Standards Book x TMC003 Material Safety Data Sheet guidance documents (available at ). Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLD
10、WIDE ENGINEERING STANDARDS GMW3262 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 2 of 13 3 Requirements 3.1 General Requirements. 3.1.1 Requirements on Test Specimens. Reference GMW3221. 3.1.2 Standard Conditions GMW3221, Code A. All test specimens shall be conditioned t
11、o GMW3221, Code A, unless the test method indicates that standard conditioning is not required. 3.1.3 Sampling and Test Specimen Preparation. Test specimens shall be cut from random areas of the hide, as required in the test method. Cut specimens relative to the backbone direction as specified in th
12、e test method. If the backbone direction cannot be determined, cut specimens from random areas of the hide in the orientation as described by the test method. The test report should indicate the backbone direction could not be determined. 3.1.3.1 Specimens should not be cut within 50 mm of any edge
13、of the sample. 3.1.3.2 If all individual readings of a specific test meet or exceed the specified requirements, report the average. Unless otherwise stated, any individual reading outside the specified limit does not meet the requirement; report all individual test results that do not meet the requi
14、rements. 3.1.3.3 All test specimens shall be prepared from areas which are in accordance with the Leather Natural Markings Standards Book. 3.1.3.4 Unless otherwise specified in the material specification or test procedure, test three samples. 3.1.4 Visual Evaluation of Automotive Trim, GMW6992. The
15、color, pattern, aesthetics and other related qualities shall be approved by the appropriate engineering department as an acceptable match to the standard when viewed under conditions set forth in GMW6992. See the appropriate Construction Specification for Pattern and Finish information. 3.1.4.1 Hapt
16、ics and Surface Feel. The aesthetic haptics of the leather shall be approved by General Motors Company (GM) to the existing target hand of the originating leather construction, when one exists, or to GMs color and trim design direction as identified by GM for new construction developments. Aesthetic
17、 hand masters will be signed off by the GM Leather Construction Development Engineer in Appearance Materials Engineering as appropriate. GM and the leather supplier shall retain signed pieces representing the acceptable hand of the leather. The hand of the leather of every shipment shall be equivale
18、nt to the original approved construction piece, as well as not degrade from the originating source. 3.1.5 Deviations from Defined Test Methods. Deviations from the conditions of any test method shall have been agreed upon between supplier and vehicle manufacturer. All deviations shall be specified o
19、n the component drawings, material specifications, etc., and shall be indicated on test certificates, reports, etc. 3.1.6 Test Data. Lab testing shall be performed by a laboratory that conforms (meets requirements but may not be formally recognized by a third party), to ISO/IEC 17025 and is acceptab
20、le to the responsible GM department. Test reports must conform to 5.10.2 and 5.10.3 of ISO/IEC 17025. Supplier shall submit a letter of compliance. 3.1.7 Types. Where stated, tests may be specific to a certain type of leather. Otherwise all methods apply to all leather types. 3.1.8 Documentation. Sa
21、mples of components or material released to this standard shall be tested for conformity with the requirements of this standard and approved by the responsible GM department prior to the start of delivery of production level components or materials. 3.1.8.1 Any change to the component or material, e
22、.g., design, function, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for
23、 a new release. 3.1.8.2 If not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases, a shorter test can be agreed to between the responsible GM department and the supplier. 3.2
24、Construction Requirements. 3.2.1 Weight, GMW3182. See Construction Specification Sheet for requirement. Report the average in grams/meter2 (g/m2). 3.2.2 Thickness, ISO 2589. See Construction Specification Sheet for requirements. Use specimens from 3.2.1 to measure thickness, report the average of th
25、ree specimens. 3.2.3 Breaking Load and Elongation, GMW3010, Code B. Four (4) groups of five specimens, for a total of 20 specimens, must be tested. See Figure 1 for sampling. Each group of five must be sampled according to GMW3010, 5.2.1.2. Copyright General Motors Company Provided by IHS under lice
26、nse with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3262 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 3 of 13 Figure 1: Breaking Load Sampling 3.2.3.1 Breaking Load. See
27、Construction Specification Sheet for requirements. Report the average of all 20 specimens. The average must meet the minimum requirement. Additionally, 75% of the specimens must meet the minimum requirement. Report the minimum of the 15 highest results. All results are to be reported in Newtons (N).
28、 3.2.3.2 Elongation at Break. See Construction Specification Sheet for requirements. 3.2.3.3 Stress Strain Curve. Report the stress in Newtons at the following strains: 5%, 10%, 15%, and 25% for information only. 3.2.4 Tear Force, ISO 13937-2 (Preload 0.5 N). The electronic method of calculation sha
29、ll be used. Cut three specimens approximately parallel to the backbone and three specimens approximately perpendicular to the backbone. The strength shall be a minimum of 20 N. 3.2.5 Seam Fatigue, GMW3405 (Seating and Shift Boot Only). Use a number 23 (metric 160) round needle. Three (3) specimens s
30、hall be tested: Backbone to backbone, backbone to against backbone, and against backbone to against backbone. The joining seam shall have no needle holes measuring greater than 2 mm or an objectionable seam appearance after 2500 cycles. Seam appearance shall be judged on the sew line when observed f
31、rom the face. 3.2.6 Dimensional Stability, All Types. 3.2.6.1 Instrument Panel (IP) and Steering Wheel (SW) Leather. Requires six specimens. Test two specimens, one each direction per cycles R and M per GMW14124 and High Heat. Report the percent change in each direction of each sample. 3.2.6.2 Seati
32、ng Leather. Requires two specimens, test one each direction per Cycle M. Report the percent change in each direction of each sample. 3.2.6.3 Sample Preparation. Cut 300 x 300 mm specimens. One direction of the square specimen must be cut parallel to the backbone. Mark the backbone direction on the b
33、ackside of the specimens. Reference the shrinkage test specimen drawing in Figure 2. Test according to the specified requirements based on application. Leather is subject to GMW14444 part performance. Figure 2: Shrinkage Test Specimen 3.2.6.4 Exposure Cycles for Dimensional Stability. 3.2.6.4.1 Heat
34、/Humidity Cycle Test to GMW14124, Cycle R. Repeat cycle 20 times for a total of 240 h of exposure. See Construction Specification Sheet for requirement. 3.2.6.4.2 Environmental Cycling Test to GMW14124, Cycle M. Repeat for a total of two cycles. See Construction Specification Sheet for requirement.
35、3.2.6.4.3 High Heat. Expose samples to 102 C mechanically circulated air for 168 h. See Construction Specification Sheet for requirement. 3.2.7 Stretch and Set, GMW3211. See Construction Specification Sheet for requirements. Test two specimens parallel to the backbone and two specimens perpendicular
36、 to the backbone from both the butt and neck area of the hide for a total of eight specimens. Report the range and arithmetic mean value in percent. 3.2.8 Softness and Flexibility. 3.2.8.1 Leather Depression, GMW14134 (BLC Softness ST300 Tester). See Construction Specification Sheet for requirement.
37、 300 mm 200 mm 300 mm 200 mm Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3262 Copyright 2011 General Motors Company All Rights Reserv
38、ed August 2011 Page 4 of 13 3.2.8.2 Flexibility, GMW3390. Cut three specimens parallel to the backbone direction and three specimens perpendicular to the backbone direction. Measure all six specimens finish side up and finish side down for a total of twelve readings. See Construction Specification S
39、heet for requirement. 3.2.9 Resistance to Rubbing, ISO 11640, All Types. Test three specimens, wet and dry. For all evaluations, use the white felt. There shall be no rupture of the leather finish. Loss of gloss is acceptable, but a complete color change, or exposure of the russet at 10X magnificati
40、on, or grain loss is not acceptable. Upon completion of the test, use cheesecloth moistened with water to clean the surface of the abraded specimen. Moistening the specimen will cause a darkening of the russet in any areas where the topcoat has been ruptured. A rating of 4 is required when the felt
41、pad is evaluated using the gray scale for staining, ISO 105-A03. A rating of 4 is required when the leather is rated using the gray scale for color change, ISO 105-A02. Note: When evaluating perforated leathers after wet rubbing, only the durability of the finish shall be considered. Any distortion
42、to the shape or size of the perforated hole caused by the russet being exposed to water is acceptable. 3.2.9.1 Dry. Test to 2000 cycles. 3.2.9.2 Wet. Test to 1000 cycles. 3.2.9.3 Steering Wheel and Knob Constructions. 3.2.9.3.1 Acidic Perspiration Solution. Five hundred (500) cycles with acidic pers
43、piration solution per ISO 105-E04. 3.2.9.3.2 Basic perspiration solution. Five hundred (500) cycles with basic perspiration solution per ISO 105-E04. 3.2.10 Flammability GMW3232. Specimens are to be cut parallel to the backbone and perpendicular to the backbone. Report the BSTAT value of each direct
44、ion and condition. For initial approvals and routine quality control see 6.1.1.1 and 6.1.1.2 of GMW3232. Note: If material is a composite (as defined in the test procedure) or is to be used in composite, the composite must meet this requirement. 3.2.10.1 After Conditioning. Immediately prior to test
45、s, all test specimens shall be conditioned for a minimum of 24 h according to GMW3221-A. 3.2.10.2 After Aging. The test cycle shall commence with 48 1 h at 40 3 C and 93 5% relative humidity (RH), followed by 168 1 h at 90 3 C and completed without interruption. Repeat 3.3.10.1 before testing flamma
46、bility. 3.2.11 Odor, GMW3205. A rating of 6 is required for both wet and dry. Use a ratio of 1:100 test specimens to container volume. 3.2.12 Mildew Resistance, GMW3259. Test three specimens. No visible mildew or mildew odor is allowed. 3.2.13 Fogging, GMW3235 B, Gravimetric Method. Precondition by
47、desiccation for 168 2 h over P2O5 at room temperature, by electric desiccation, or according to GMW3235. 3.2.13.1 Test Temperature +90 C. The amount of fog shall be 4 mg maximum for perforated leathers, or 5 mg maximum for aromatic leathers. 3.2.13.2 Instrument Panel Leather. Test temperature +110 C
48、. The amount of fog shall be 4 mg maximum. 3.2.14 Interior Emissions (GMW8081 - Relative Emission). The relative emission shall be 2.0. 3.2.15 Flex Resistance, ISO 5402, (Bally Flex), Seating, Door and Shift Boot. Record any damage in the flexed area. Evaluate using 10X magnification. No cracks thro
49、ugh the finish to the russet, or lifting of the finish allowed. 3.2.15.1 As Received. See 3.2.15.1.1 thru 3.2.15.1.3 for test cycles based on construction type. 3.2.15.1.1 Standard Seating Constructions. Requirement is 100 000 cycles. Test six specimens: one specimen parallel and one specimen perpendicular to the backbone direction to 50 000 cycles. Test two specimens parallel and two specimens perpendicular to the backbone direction to 100 000
