waxed paper to prevent sticking to the pan surface and weigh to the nearest 002

Waxed paper to prevent sticking to the pan surface

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waxed paper to prevent sticking to the pan surface) and weigh to the nearest 0.02 lb (9 g). With the steel rule, measurethe bar (5.2 of Test Method C 179) for all dimensions to the nearest 0.02 in. (0.5 mm) and record the results. Label and make reference marks to indicate the exact length measurement points (Note 8).
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6. Procedure NOTE 1 Two support pieces are used against the sides of the bar during the lifting and moving operation to prevent flexing. 6.6 Drying of Specimens : 6.6.1 Placement in Dryer Using the handling procedure described in 6.4, move the bars to the dryer and place on a non-stick ventilated surface (Note 8). NOTE 8 Plastic film or waterproof paper is not recommended for this surface. They inhibit movement of moisture out of the bottom of the bar. Flat expanded metal grids, ceramic fiber paper, or similar materials are preferred because they do not act as vapor barriers.
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6. Procedure 6.6.2 Standard Drying Schedule (Note 9): 6.6.2.1 Drying Step (230 ° F (110 ° C)) Raise the temperature of the drying oven to 230 ° F (110 ° C) in 1 h. Hold for at least 18 h. NOTE 9 This drying schedule described in 6.6.2.1 is suitable for plastics and ramming mixes utilizing clay and /or organic or inorganic chemical binder systems and many plastic and ramming mixes based on phosphate binder systems. If excessive flaws are found after drying phosphate bonded plastics and ramming mixes, one of the alternate drying procedures outlined in 6.6.3 which have been found effective in minimizing flaws should be used. 6.6.3 Alternate Drying Procedures, Phosphate-Bonded Materials :
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6. Procedure 6.6.3.1 Alternate Procedure 1 Immediately after forming and measuring the specimen, place on a wire or metal mesh grid and allow the specimen to air dry for a minimum of 24 h. The wire or metal mesh grid should also be of sufficient strength and supported so as to not bend or sag under the weight of the specimens. The wire or metal mesh grid should be supported a minimum of 1-in. (25-mm) above the table top to allow air circulation. After the air drying is complete, the procedure outlined in 6.6.2.1 can be followed. 6.6.3.2 Alternate Procedure 2 Immediately after forming and measuring the specimen, place in the oven and raise the temperature of the drying oven from ambient to 170 ° F (75 ° C) in 1 h. Hold at least 12 h. Raise the temperature of the drying oven to 230 ° F (110 ° C) in 1 h. Hold for at least 18 h.
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6. Procedure 6.6.4 Cooling Cool the bars at the natural cooling rate of the drying oven. 6.7 Measurement of Weight and Dimensions of the Dried Specimens After the bars are dried, remeasure and reweigh them at room temperature as described in 6.5 and record the data. NOTE 10 Storage of Specimen If more than 8 h will elapse before other tests described in 3.3 are performed on the bars, they should be kept dry by replacing them in a drying oven, sealing them in plastic bags, or some other suitable procedure
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7. Report 7.1 Report the workability and material temperature at time of test, pressing pressure used, drying schedule used, green and dried specimen size and weight.
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  • Spring '18
  • Standard, ASTM International

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