1、 FORD LABORATORY TEST METHOD BO 101-06 Date Action Revisions 2001 03 28 Revised Editorial no technical change A. Cockman 1996 10 22 Printed copies are uncontrolled Page 1 of 5 Copyright 2001, Ford Global Technologies, Inc. ADHESION STRENGTH OF COEXTRUDED BLOW MOLDED PLASTIC FUEL TANK MATERIAL BY T-P
2、EEL TEST METHOD Application This procedure is used to determine the adhesive strength of coextruded blow molded plastic fuel tank material. It specifies the procedure for initiating layer separation in a specimen and for preparing it for the adhesion strength test. The relative peel resistance of th
3、e adhesive bond between the adherands (barrier layer (EVOH), virgin high density polyethlene (HDPE) and regrind layer (HDPE with reground flash) in plastic fuel tank material is determined from a peel test of a T-type specimen. This peel test follows the procedure outlined in ASTM D 1876 (T-Peel Tes
4、t) with the exception of the modifications which are specified in the “Procedure“ section herein. Commonality This is a CONTROL TEST and can be used to qualify vehicles or components throughout the world. The test may be conducted at any location having the necessary equipment and facilities. Materi
5、als and Apparatus Required Tensile bar die 12.7 x 127 mm Press for cutting specimens Wood chisel 12.7 mm wide and modified to taper at approximately 12 Hammer Pliers Flat vice 30 cm long Illuminated magnifier (2 - 5 X) Band saw Scalpel FORD LABORATORY TEST METHOD BO 101-06 Page 2 of 5 Copyright 2001
6、, Ford Global Technologies, Inc. Testing Equipment and Facilities A tension testing machine (Instron, MTS or analogous systems) which will apply a tensile load with the following prescribed conditions: The machine and loading range shall be so selected that the maximum load on the specimen is within
7、 15 - 85 % of the upper limit of the load measuring device. The specimen will be clamped firmly and without slippage throughout the test with suitable grips attached to the machine. The rate of movement between the crossheads of the machine shall remain constant. The displacement and tensile load sh
8、all be measured with an accuracy of +/-1 %. A sufficient number of load and displacement measurements must be taken to ensure that significant characteristics of the specimen response are recorded. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in
9、 a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure 1. Specimens 12.7 x 127 mm are to be obtained from flat regions of blow molded bottles or fuel tanks. Specimens a
10、re to be cut in accordance with ASTM D 3183 (cutting knife procedure preferred) a. If using bottles, cut off the bottom and conical upper parts of bottle using the band saw. b. Cut off the front and back panels of the bottle, and discard the rest of the bottle. c. Cut out the specimen from the front
11、 and back panels using the tensile bar die and press. Five specimens can be obtained from each panel of a 1 L rectangular offset oil bottle. 2. Label each specimen. 3. Secure a specimen in the vice lengthwise. FORD LABORATORY TEST METHOD BO 101-06 Page 3 of 5 Copyright 2001, Ford Global Technologies
12、, Inc. 4. Using the scalpel, initiate a separation between the two layers of polyethylene (Figure 1). This layer can be made more visible by staining the edge with iodine and wiping off the excess. The barrier layer between the polyethylene layers will appear as a dark line. Use an illuminated magni
13、fied lamp to improve visibility. Initiate a cut in this layer using an oscillatory motion of the blade edge and applying slight pressure. (Beware of the extreme sharpness of the scalpel blade.) 5. After initiating a separation at the edge of the specimen, turn the specimen and secure it in the vice
14、in the vertical position. 6. Using the same technique, continue to extend the separation until its length is 3 - 5 mm. 7. Use the hammer and chisel to extend the separation to a length of 12 15 mm. Keep the chisel vertical and on the crack edge between the polyethylene layers, and apply short, gentl
15、e hammer blows (Figure 2). 8. With the specimen still secure in the vice, grip one side of the split specimen with the pliers and pull outward. When the crack (separation) length reaches 25 - 30 mm, cease pulling. The specimen is now ready for the adhesion test. 9. The specimens should be tested at
16、23 +/- 2 C and 50 +/- 5 % relative humidity. The time elapsed since removal of the specimen source (coupon, bottle or tank) from its loading environment (fuel soak) should be short enough to ensure that the specimens continue to reflect the conditions of their loading (fuel soak) history. 10. Clamp
17、15 mm of the bent separated ends of the test specimen in the test grips of the testing machine. 11. Apply tension by separating the crossheads at constant rate of 50 mm/ minute. 12. Continue the test for at least 76 mm of separation after the initial peak load (Figure 3). Record the load and displac
18、ement measurements throughout the test. Note that this adhesion test is in accordance with ASTM D 1876, with the exception of the following modifications: a. the 7 day conditioning period prior to testing is omitted in order to retain the loading (fuel soak) history; b. the total specimen size is 12
19、.7 x 127 mm, with 25 - 30 mm preparatory separation of the bond length; c. the separated layers mounted in the machine grips are separated at a crosshead speed of 50 mm/minute; and d. the adhesive strength is the average load per unit bond width which is required for layer separation to continue for
20、 76 mm after the initial peak (Figure 3). FORD LABORATORY TEST METHOD BO 101-06 Page 4 of 5 Copyright 2001, Ford Global Technologies, Inc. Presentation of Data Prepare a comprehensive test report which includes: 1. Statement of objectives. 2. Reference to procedure(s) used and/or deviation(s) from s
21、tandard. 3. Complete identification of the adhesive tested, including type, source, manufacturers code number, batch or lot number, form, etc. 4. Complete identification of the adherands used, including thickness, material, source, manufacturers code, batch or lot number, form, etc. 5. Average thick
22、ness of adhesive layer within 0.025 mm. Describe the method of measuring the thickness and the range of measurements. 6. Complete description of the test specimens, including dimensions and construction, conditions in which the specimens were cut, prepared and tested, orientation of the specimens re
23、lative to extrusion direction, and the number of specimens tested. 7. Type of testing machine and measuring devices used, and crosshead separation rate used. 8. Method of determining the average adhesive strength (i.e. visual or statistical average). 9. Average, maximum and minimum peeling load valu
24、es for each specimen. (Number specimens according to Procedure Item B.) 10. Average T-peel strength (load per unit width of specimen) for each combination of materials, construction and loading history (including fuel soak). 11. The type of failure for each specimen. Cohesive failure is separation w
25、ithin either the adhesive layer or the adherence layer. Adhesive failure is separation at the surfaces between the adhesive and adherand. Failure may also be a combination of cohesive and adhesive. 12. Any important phenomena observed during the test. 13. Test locale and date. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BO 101-06 Page 5 of 5 Copyright 2001, Ford Global Technologies, Inc.
