ASTM D716-86(R2019) pdf free download
ASTM D716-86(R2019) pdf free download.Standard Test Methods for Evaluating Mica Pigment
1. Scope
1.1 These test methods cover the evaluation of mica pig- ment. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the appli- cability ofregulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Apparatus
4.1 Volumeter—A Scott volumeter or similar apparatus modified as follows: The screen used shall conform to the requirements of a No. 40 (425-µm) sieve as prescribed in Specification E11. The funnel below the screen shall be replaced by a conical funnel having a bottom opening 25 mm (1 in.) in diameter. It may be found necessary to replace the top glass baffle with one that is longer to ensure that all ofthe sifted mica is caught.
5. Procedure
5.1 Transfer convenient quantities of the mica pigment to the funnel of the modified volumeter and brush the pigment through the screen with a camel-hair brush until the receiver is slightly more than full. Scrape off the excess and weigh the pigment. Care must be taken not to jar the apparatus during the procedure.
The foot of the tube shall be drilled to 4.4 mm (0173 in.) (No. 17 drill) in inside diameter for a depth of12.7 mm ( 1 ⁄ 2 in.). The tube shall be placed in the beaker with the long arm in the vertical position, and the foot of the L parallel to the bottom of the beaker and perpendicular to the radius of the bottom at a point such that there is about 1.5-mm ( 1 ⁄ 16 -in.) clearance between the tubing and both the bottom and side of the beaker. The center of the foot shall be placed 90° from the lip of the beaker.
11. Procedure
11.1 Transfer 10 g of the sample to the 600-mL beaker, add 100 mL of water, and swirl the beaker until the mica is dispersed. Insert the metal tubing into the beaker as described in 10.2 and connect the upper end to a water faucet. Regulate the flow of water by a constant head to a rate of 800 mL/min over the lip of the beaker. When the elutriation has progressed so that the body of the water in the beaker is clear, stop the flow, and lower the water level to prevent spilling. 11.2 Swirl the beaker again to bring the remaining mica pigment into suspension and repeat the elutriation procedure as described in 11.1 three times. After final clearing, decant part of the water, and filter the residue. Transfer the paper and residue to a weighed crucible, and ash slowly, cool, and weigh.
15. Procedure
15.1 Compare pastes made by rubbing a standard mica pigment and standard zinc oxide, mutually agreed upon by the purchaser and the seller, in linseed oil with a similar paste using the sample to be tested. Rub 9 g of zinc oxide, and 3 g of mica pigment on a glass plate with a glass muller or rubber spatula to avoid staining, with 4 mL of bleached linseed oil. Spread the pastes adjacently on a clear glass plate and determine the color by viewing the spreadouts on the glass.
16. Precision and Bias
16.1 Insufficient data are available to develop acceptable precision and bias statements. The information presented in Section 8 (Reproducibility of Results) was obtained in 1943, and no documentation is currently available. The information will remain in Section 8.
