188.8.131.52 TM-1, Alkalinity of Glass Fiber Mat Materials
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This test method covers the procedure for determining the alkalinity of glass fibers and glass fiber mat materials.
- a. Analytical Balance capable of weighing to accuracy of 0.0001 grams.
- b. 250 ml Erlenmeyer flask with 24/40 T glass joint.
- c. Burette, 10 ml. with .02 ml subdivisions.
- d. Filtration rack with 75 mm Pyrex funnels.
- e. 30 cm air condenser with 24/40 T glass joint.
- f. 12.5 cm No. 41 Whatman filter paper.
- g. Methyl purple indicator, pH range 4.4-6.0.
- h. N/50 sulfuric acid.
- a. Glass Fiber: Specimens shall be taken from at least four representative areas and combined to form a sample weighing approximately 5 grams.
- b. Glass Fiber Mat: Four specimens shall be taken from one square foot of sample material by means of a cork borer having a diameter of approximately 1 in. The borings shall be made 4 in. apart and parallel to the material so that each boring will include portions of both surfaces of the sample.
- a. Weigh a 1 gram test specimen to an accuracy of .0001 grams and place in a clean 250 ml pyrex Erlenmeyer flask.
- b. Add 100 ml of boiling distilled water and attach the air condenser the flask.
- c. Place the flask with condenser on the hot plate. Adjust the temperature so that the liquid is heated almost to boiling.
- d. After simmering for three hours, filter and collect the filtrate in a clean 250 ml Erlenmeyer flask. Wash the residue with three portions of 25 ml of hot distilled water, allowing each portion drain.
- e. Cool the filtrate, add three drops of methyl purple indicator and titrate to a permanent red end point with N/50 sulfuric acid.
- f. Run a blank determination on the same amount of distilled water in the same manner and correct for any alkalinity shown.
- g. Calculations:
- % Na2O = (Normality of H2SO4 x ml of H2SO4 x 0.031 x 100) / Weight of Sample
The laboratory report shall contain the following:
- a. Description of sample
- b. Test results vs. specification requirements
- c. Remarks