１. Application

This applies to test method of measuring agglomerate size ratio.

2. Definition:

Agglomerate size ratio of green sand is the mass ratio of each size of the dried substance after removing free water from green sand by the method described in TJFS-201 (Green sand moisture content test method).

3. Instrument and apparatus

3.1 Balance

A balance of the precision of 0.01g is used.

3.2 Sieve

Sieve frame diameter is 200mm and the sieves of the following nominal mesh sizes (μm) are selected from those ruled by JIS Z 8801 (standard sieves): 3350, 2360, 1700, 1180, 850, 600, 425, 300, 212, 150, 106, 75, 53, and pan.

Note: Pan is a dish that collects fine particles passed through the sieve of the nominal mesh size of 53 μm.

3.3 Sieve machine

A Rotap sieve machine is used as a rule. However, a machine with an equivalent sieving performance may also be used.

4. Testing procedure

4.1 Sample

The total volume of the dried substance after removing free water from green sand by the method ruled in TJFS-201 (Green sand moisture content test method) is used as the sample.

4.2 Operation

Sieves are stacked in the order of mesh size and the sample is put in the top sieve. The stacked sieves, after covered with a lid, is vibrated for 15 minutes by the machine in 3.2, where vibration is given by tapping the top of the stacked sieve in a specified manner. Then the sieves are removed from the machine and the sand on each sieve is weighed

4.3 Calculation of the agglomerate size ratio

Weight % of each agglomerate size is calculated by the following equation.

\[R = { E \over B } \times 100 \]

where

\[ \left\{ \begin{array}{l} R &= weight \ ratio \ of \ each \ agglomerate \ size \ (％) \\ E &= weight \ of \ the \ sand \ on \ each \ sieve \ (g) \\ B &= total \ weight \ of \ the \ sample \ (g) \end{array} \right. \]

5. Expression

Agglomerate size ratio is expressed in %.

6. Record

6.1 The result is calculated to the first decimal place. Test is repeated two times or more from the same batch of sand. In calculating the average size ratio, the size of the largest size ratio is taken and the one above and below are also taken. If their deviation of the size ratio is confirmed to be within 5%, the data is used for averaging.

6.2 Green sand agglomerate size distribution is expressed in weight % of each size.

6.3 Green sand agglomerate fineness number is obtained from the weight of the sand grains together with other substance adhering to the grain surface and the size factor in the Table 1 below by the following equation.

\[FNO = \frac{\sum ( Wn \times Sn )}{ \sum Wn} \]

where
\[ \left\{ \begin{array}{l} FNO &= agglomerate \ size \ number \\ Wn &= weight \ of \ sand \ grains \ and \ other \ substance \ adhering \ to \ grain \ surface \ on \ each \ sieve \ (g) \\ Sn &= size \ factor \ given \ in \ Table 1 \end{array} \right. \]

6.4 Green sand agglomerate ratio is obtained by calculating the ratio between the sand grain fineness number (TJFS-202) and the agglomerate fineness number