ISO 9136-2:1999 pdf free download.Abrasive grains – Determination of bulk density Part 2 : Microgrits.
1 Scope
This part of ISO 9136 specifies a test method for the determination of the bulk density of bonded and coated
abrasive microgrits.
2 Term and definition
For the purposes of this part 01 ISO 9136, the following term and definition apply.
2.1
bulk density
Pg
this, of a pourable abrasive grain which is poured in a certain way, is the quotient of the mass and the volume,
specified in g/cm3
3 Testing equipment
The Testing equipment is snown in Figure 1.
3.1 Metering Device
The metering device1) is isolated by rubber teet, so that vibrations are not transmitted to the surroundings. The most important components are:
a) vibration generator;
b) stainless steel funnel with a polished inner surface and the following main dimensions:
c) total height of funnel: 290 mm;
2) top diameter: 190 mm;
3) inside diameter of cylindrical outlet: 28 mm;
4) height of cyhndrical outlet: 38 mm;
c) stainless steel horizontal vibration channel, with the following dimensions (210 mm x 40 mm x 30 mm) ± 1 mm (length x width x depth). The distance from the lower edge of the funnel to the bottom of the vibration channel must be (8 ± 4) mm;
d) stand.
3.2 Measuring cylinder
The measuring cylinder has a polished inner surface and a volume V of (200 ± 0,5) cm3 this volume is achieved by an inner diameter of 64 mm and an inner height of 62,2 mm, The rneasunng cylinder is placed ceiitrally under the stream coming from the vibration channel.
The height of tall of the microgrit to be tested (from the upper edge of the channel bottom to the bottom of the measuring cylinder) shall be (140 ± 1) mm.
Calibration of the measuring cylinder can be achieved by the following two methods. Method A
The dry, empty measuring cylinder is weighed together with a flat glass plate. The measuring cylinder is filled with water and the glass plate placed on the cylinder in such a way that no air bubble is present. The glass plate is held in this position, the surplus water removed and the total weight determined.
The volume is calculated in the following way:
4 Procedure
4.1 Number of observations
For each microgrit to be tested, the bulk density shall be determined from three samples taken from one sampling.
4.2 Sample preparation
The microgrit to be tested shall be dried for 1 h at a temperature of 110 °C, and then cooled to room temperature before measuring.
4.3 Procedure
The test shall preferably take place at an air temperature of (23 ± 2) °C, and a relative humidity of (50±6) %.
The microgrit to be tested is placed, in its dried form, in the funnel of the metering device. The metering speed, determined by the amplitude of vibration of the built-in vibrator in combination with the distance from the lower edge of the funnel to the bottom of the vibration channel, is regulated according to the grains in such a way that
— an even uninterrupted and regular stream flows into the vibration channel, and
— the filling time of the cylinder is between 30 s and 90 s.
Before each measurement, the test conditions shall be verified.
The measuring cylinder shall be filled in such a way that the test material is heaped in the middle. 2 cm to 3 cm above the rim of the measuring beaker.
The test material heaped above the rim of the measuring cylinder shall be removed using a straight blade with the leading edge at an angle of approximately 450 to the rim of the measuring beaker (see Figure 2).
Vibration shall be avoided throughout the measuring procedure (risk of compaction). The measuring cylinder filled with microgrits shall be weighed to within 0,01 g.
5 CalculatIon
The bulk density. , expressed in grams per cubic centimetre, is calculated as follows:
PB =
where
rn1 is the net weight, in grams. of the microgrit held in the measuring cylinder; V is the volume of the measuring cylinder, in cubic centimetres,
6 Results of measurements
The resu’t of the test is the arithmetic mean of the three measurements.
7 Repeatability
Duplicate determinations by the same operator and apparatus shall not differ by more than ± 0,02 glcm3.