A-A-2370 Pad, Floor Polishing Machine (Thin)This commercial item description covers two types of thin, floor maintenance pads used for polishing, buffing, scrubbing, and stripping floors. The round, thin floor pads shall be suitable for mounting on power-driven, rotary-disc type floor maintenance machines, operating in a speed range between 150 and 350 rpm. The rectangular floor pads are for mounting on the oscillating type floor maintenance machines. The floor pads are intended for heavy duty floor care maintenance machines. The floor pads are intended for heavy duty floor care maintenance and shall be suitable for use on various type floors.

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A-A-2370

TABLE I – Classification of defects

Abrasive distribution examination. Sampling shall be in accordance with MIL-STD-105, inspection level S-2 with an acceptable quality level (AQL) of 4.0 percent defective. The lot size shall consist of all cartons containing one type and size pad offered or acceptance at one time. The sample unit shall be one pad. One or more defects per sample shall constitute a   defective carton.

Tests.

Test equipment. The test equipment required to accomplish the following tests is four vested sieves; one 100-mesh screen with a hole size of 149 microns; one 150-mesh screen with a hole size of 105 microns; one 200-mesh screen with a hole size of 74 microns; one 270-mesh screen with a hole size of 57 microns; and a bottom pan. Additional equipment shall include a gram scale calibrated in centigrams; leveling plate 89 mm (3-1/2 inches) in diameter weighing 100 grams (g); an 85- to 100-mm diameter ashing dish; and other items as specified in the test paragraphs.

Ashing procedure. Heat a suitably clean ashing vessel, such as a porcelain dish approximately 85 to 100 mm in diameter, at 600 degrees Celsius (C) for 15 minutes. Cool in desiccators and weigh to nearest centigram. Add samples of the floor pad to be analyzed, favoring pieces approximately 1/2 g each, confining each within the perimeter of the vessel by means of a screen or similar means. (This helps to prevent some types of pad samples from floating out of the vessel). Weigh the vessel and contents. Compute and record the sample weight with the appropriate identification data. Initial ashing to drive off obnoxious organic volatiles should occur under a fume hood until a dry char is obtained. Finish ignition of the ash in the muffle furnace. A furnace with regulated air ventilation is preferable because air circulation aids the ashing which may be completed in approximately 15 minutes. Without air circulation, one-half to one hour may be required. When ashing is complete, remove vessel with ash to a refractory plate to cool, finishing the final cooling in a desiccator. Be careful to avoid expulsion of fluffy ash particles. When cooled to room temperature, weigh the vessel with the ash and transfer the ash to a small plastic or glass vial, properly identify and refrain for the abrasive (particle size) distribution test.