View source for 106.3.2.1 TM-1, Alkalinity of Glass Fiber Mat Materials

This test method covers the procedure for determining the alkalinity of glass fibers and glass fiber mat materials.

===106.3.2.1.1.1 Equipment===
: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.

===106.3.2.1.1.2 Specimens===

: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.

===106.3.2.1.1.3 Procedure===

: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:
::% Na<sub>2</sub>O = (Normality of H<sub>2</sub>SO<sub>4</sub> x ml of H<sub>2</sub>SO<sub>4</sub> x 0.031 x 100) / Weight of Sample

===106.3.2.1.1.4 Report===

The laboratory report shall contain the following:

:a. Description of sample

:b. Test results vs. specification requirements

:c. Remarks

[[Category:106.3.2 Material Inspection Test Methods|106.3.2.01]]