1、 FORD LABORATORY TEST METHOD BZ 105-05 Date Action Revisions 2002 05 06 Activated A. Olejnik, A. Reaume Printed copies are uncontrolled Page 1 of 5 Copyright 2002, Ford Global Technologies, Inc. DETERMINATION OF SPECIATED PERMEATION RATES FOR POLYMERS Application This method is used to determine the
2、 permeation rates of fuel components through a polymer film using the trap and desorption method. Using a gas chromatograph the collected vapors are speciated to provide permeation rates in grams/m2 day for each component. Principle The small scale solvent permeability test determines the permeation
3、 rate of a solvent mixture through a test film (e.g. polymer, elastomer or complex layers). The film is sandwiched between two chambers of a sealed small scale test cell. The test solvent/solution (in liquid or gas phase) is in contact with one side of the test film, and high purity nitrogen purge g
4、as is in contact with the opposite side of the film. The volatile organic compounds (VOC) permeating through the test film from the solvent side to the nitrogen purge side are trapped onto Trap and Desorption (T to 1000g), 8. Precision thickness gage, (e.g. Logitech CG-10 or equivalent), T or mixtur
5、es of these, or other liquid solvents. The solvents should be stored in a flammable solvent cabinet. 3. Certified VOC mixture in vapor gaseous Nitrogen matrix: isooctane (ISO), toluene (TOL), ethanol (ET), or mixtures of these, or others (Scott Certified Gases or equivalent). Procedure Test Apparatu
6、s: The test cells can be operated with either vapor or liquid contact with the film. The cell should be vented through a 1.8m long, 1/16“wide metal tubing which drops pressure to atmospheric, but minimizes diffusive loss of solvent vapors. The typical test is conducted with the solvent mixture in va
7、por contact with the film. The flow of the purging gas is controlled by a gas flow controller. The typical purge gas used is high purity Nitrogen at about 20 cc/min flow. The cells are contained in an air circulating oven with uncertainty better than T= +/- 0.5C. The test can be run in an isothermal
8、 mode, or with a temperature ramp. The typical test temperature is 40C isothermal. FORD LABORATORY TEST METHOD BZ 105-05 Page 3 of 5 Copyright 2002, Ford Global Technologies, Inc. A piece of the film to be tested (minimum 6 cm diameter) should be as uniform in thickness as possible. Measure the film
9、 thickness with a precision thickness gage at several points across the film. Typically the mean of five measurements is used to determine the thickness and variability. The film is mounted between two flat GFLT Viton o-rings. The o-rings should be heated in an oven at about 105 C for at least 1 day
10、 prior to conducting the test to remove any retained VOC. The film to be tested should be cut in a circle fitting the outside diameter of the o-rings (d=5.1 cm 2 inches), and the area of the exposed film surface is 20.2 cm2 (3.1 inches2). The weight of test solvent is approximately 32 g. The film is
11、 mounted between the Viton o-rings into the test cell, which is sealed tightly to prevent leaking. The cell (including solvent mixture) can be weighed prior and after the test to evaluate the weight loss of the fuel mixture. The completed test cell is then placed into the test oven, and the inlet, o
12、utlet and vent lines are attached to the cell. Sampling: Blank T for less permeable materials the once a day (week) sampling is sufficient. The duration of T the absolute limits were not set. A lower LOQ could be established by using longer sampling times. A higher LOD of the sample/standard can be
13、verified by adding additional splitting in the instrumentation. The results from ATD/GC/FID system are reported as weight of VOC (“nanograms“) trapped into the T SAE Technical Paper Series. 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.
