A-A-501778
2.4.1 Commercial test. Ignite a 30 ml Vycor or equal micro-Kjeldahl flask at 1000° C, cool in a dessicator and weigh to the nearest 0.1 milligram. Support the flask in a water bath at 75° ±2° C, with the level of the water about half way up the neck of the flask. Above the flask, suspend a funnel with filter paper to allow maximum free space at the neck and mouth of the flask for vapor dissipation. Adjust the position of the funnel so that the tip rests against the wall of the flask. The effluent should not drip but flow gently down the inner wall of the flask.
Fit a 125 ml graduated separatory funnel with a Teflon (or equal) plug-cock and attach a spring tension adapter. Cut a 5 gram sample of lens cleaning tissue into ½ inch to 1 inch squares, weight to the nearest 0.1 milligram and place in the separatory funnel. Cover the tissue with 75 ml of methylene chloride and agitate for 1 minute. Support the funnel above the filter for 3 to 5 minutes to allow the liquid to flow gradually into the flask at a rate approximately equal to the loss of solvent by volatilization. Repeat to make three extractions of the tissue. Evaporate the solvent by heating the flask on a steam bath, allow to cool and add 1.5 fuming sulfuric acid and
10 drops of fuming nitric acid. Heat gently on a digestion rack until the material gels as indicated by no further bubble formation at the bottom of the flask. The heating to expel the acid should be done carefully in a vented hood in such a manner that the material does not spatter. Ignite the flask and residue at 1000° C, to constant weight. Cool and re-weigh to the nearest 0.1 milligram.
To confirm the residue as Si02, transfer the major portion to a platinum crucible. Add 3 ml of concentrated hydrofluoric acid and 3 drops of concentrated sulfuric acid. Carefully expel the acids and ignite. There will be no significant residue if the ask was Si02.
Determine the percent moisture content of the paper in accordance with TAPPI Test Method
T412. Then calculate the moisture free weight of the specimen as follows:
Wt. paper sample (moisture free) = Wt. paper sample - (Wt. paper sample X percent moisture) Determine a blank value by analyzing a sample of untreated paper by the same procedure.
8lank results are usually in the order of 2.5 mg Si02. Subtract the blank from the weight of the
Si02 and calculate the silicone content of the paper as follows:
Percent silicone content = (Weight silica ash - blank) x 1.233 (SiH(CH3)3)x 100
Weight paper sample (moisture free)
3. REGULAT0RY REQUIREMENTS
The offeror/contractor is encouraged to use recovered materials to the maximum extent practicable, in accordance with paragraph 23.403 of the Federal Acquisition Regulation.
4. PR0DUCT C0NF0RMANCE
The products provided shall meet the salient characteristics of this Commercial Item Description, conform to the producer's own drawings, specifications, standards, and quality assurance practices, and be the same product offered for sale in the commercial marketplace. The government reserves the right to require proof of such conformance.
3
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business