SAE J 323-2009 Test Method for Determining Cold Cracking of Flexible Plastic Materials《软塑料材料的冷裂测定试验方法》.pdf

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4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SURFACE VEHICLE RECOMMENDED PRACTICE J323 NOV2009 Issued 1968-08 Revised 2009-11 Superseding J323 JAN2004 Test Method for Determining Cold Cracking of Flexible Plastic Materials RATIONALE Clarify scope, add tolerance

5、 to 3.13, 3.2 and 4.2. Clarify number of specimens in 5.2. Correct case error in Figure 1 note. Add footnote to 5.2 1. SCOPE This SAE Recommended Practice is applicable for determining the cold characteristics of flexible plastic materials, as applicable. It consists of three different methods for d

6、etermining low-temperature properties of materials depending on type of material and end use. The method used shall be as specified by the contractual parties. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of the specification to the extent specified herein. 2.1.1

7、ASTM Publication Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D 3574 Standard Test Methods for Flexible Cellular MaterialsSlab, Bonded, and Molded Urethane Foams 3. METHOD A, MANDREL TEST 3.1 Apparatu

8、s and Materials 3.1.1 Mandrel Steel mandrel nominally 6.35 mm in diameter and 152 mm long attached to a suitable stand. Other diameters may be specified depending on the thickness and rigidity of the material to be tested. 3.1.2 Oven Air-circulating oven capable of maintaining a temperature of 82 C

9、2 C. SAE J323 Revised NOV2009 Page 2 of 5 3.1.3 Cold Box A cold box capable of maintaining a temperature of 34 C 2 C and large enough to permit bending the test specimen while it remains in the box. 3.1.4 Gloves Heavy cloth gloves to prevent heat transfer when handling specimens. 3.2 Procedure Cut 5

10、0 x 200 mm specimens in the machine and across machine direction and condition in the oven at 82 C 2 C for 24 h 0.1 h or as specified. (The dimensions of the specimen may vary for extruded or molded parts.) Remove specimens from the oven and condition at room temperature until reaching equilibrium.

11、Place specimens, gloves, and mandrel with stand in the cold box at 34 C 2 C for 4 h 0.1 h or as specified. Put on gloves and grasp each end of the sample and bend, around the mandrel in approximately 0.5 s with a uniform motion. Remove specimens from cold box and examine visually for evidence of cra

12、cks. 4. METHOD B, IMPACT TEST 4.1 Apparatus and Materials 4.1.1 Impact Tester Impact tester capable of applying a 10.8 J impact with a spherical ball head having a radius of 23.81 mm. (See Figure 1.) NOTE: Both H and W may be varied as long as HW = 10.8 J and H is not less than 3.048 mm. Dimension r

13、 of projectile must be 23.8 mm and is not variable. FIGURE 1 - IMPACT APPARATUS SAE J323 Revised NOV2009 Page 3 of 5 4.1.2 Base A 102 x 102 x 19 mm thick wood base with an 89 x 89 mm square marked off in the center for stapling specimen and a 76 x 76 mm square marked off for positioning urethane foa

14、m pad.14.1.3 Oven Air-circulating oven capable of maintaining a temperature of 82 C 2 C. 4.2 Procedure Cut a 100 x 100 mm specimen of the flexible plastic material and age it in the oven at 82 C 2 C for 7 days (or as specified by the contractual parties). Place a 75 x 75 x 19 mm thick urethane or la

15、tex foam pad in the center of the wood base and attach the aged specimen to the base by stapling 6 mm from the edge of the specimen as indicated in Figure 2 (staples should be 8 mm minimum length). Place the composite in the cold chamber at 29 C 2 C for a minimum of 12 h (or as specified by the cont

16、ractual parties). While still at 29 C 2 C, the center of the test material shall be impacted with a force of 10.8 J energy criteria or as otherwise agreed upon by the contractual parties. The height of the drop and the mass of the impactor shall be such that it meets the 10.8 J energy criteria or as

17、 otherwise agreed upon by the contractual parties. Remove the composite from the cold box and examine the flexible plastic material for cracks. FIGURE 2 - SPECIMEN AND SPECIMEN ON BASE 1Unless otherwise specified, the foam base shall be either a urethane or latex foam with the following load deflect

18、ion characteristics. If using urethane the base material shall have the following load deflection characteristics when tested for CFD (Compression Force Deflection) per ASTM D 3574: the pressure on the specimen after compressing it 25% of its original thickness at room temperature and holding it the

19、re for one minute shall be 3.0 to 4.1 kPa. The foam shall also meet the following cold temperature requirement: After conditioning the specimen for 12 h at 29 C immediately compress it with a pressure of 2.59 + 0.07 kPa and hold it for a minute. The compressed height of the specimen shall be 82 to 9

20、2% of the original specimen thickness. If using latex the base material shall have the following load deflection characteristics when tested for CFD (Compression Force Deflection) per ASTM D 3574: the pressure on the specimen after compressing it 25% of its original thickness at room temperature and

21、 holding it there for one minute shall be 2.5 to 3.1 kPa. The foam shall also meet the following cold temperature requirement: After conditioning the specimen for 12 h at 29 C immediately compress it with a pressure of 2.59 + 0.07 kPa and hold it for a minute. The compressed height of the specimen s

22、hall be 73 to 83% of the original specimen thickness. NOTE: The wood and urethane foam base described previously was established primarily for vinyl-coated fabrics. Other flexible plastic materials may require modifications in the base depending on the flexibility of the material to be tested. SAE J

23、323 Revised NOV2009 Page 4 of 5 5. METHOD C, DYNAMIC FLEX TEST 5.1 Apparatus 5.1.1 Cold Box A cold box capable of maintaining a temperature of 29 C and large enough to hold flexing equipment. 5.1.2 Oven Air-circulating oven capable of maintaining a temperature of 82 C 2 C. 5.1.3 Flexing Equipment Dy

24、namic flex equipment with reciprocating motion (see Figure 3).25.2 Procedure Cut four specimens 75 x 50 mm, two specimens having the long dimension in the warp direction and the remaining two having the long dimension in the filling direction. Condition two specimens for 7 days at 82 C 2 C in an air

25、-circulating oven followed by 4 h at 29 C 2 C. Condition the remaining two specimens at 29 C 2 C for 4 h. Clamp the two ends of the unaged specimen(s) in the cold flex apparatus with the finished side facing out. Flex at 29 C 2 C for 700 cycles at 90 cycles/min. Remove and examine for cracks. Flex t

26、he heat aged specimens for 600 cycles at the same rate. Remove and examine for cracks. 6. NOTES 6.1 Marginal Indicia A change bar (I) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue

27、 of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE TEXTILES AND FLEXIBLE PLASTICS COMMITTEE 2Equipment used to be agreed upon by contractual parties. SAE J323 Revised NOV2009 Page 5 of 5 FIGURE 3 - BASIC DETAILS OF COLD FOLD TEST APPARATUS