ASTM D7724 Standard Test Method for Carbon Black

Scope:

In some extruded items, the amount of non-dispersible carbon black is crucial since it may affect the product’s surface appearance. The maximum amount of non-dispersible materials allowed, the smallest possible size, and the number of particles to be studied in each application between the user and the producer are determined in this ASTM D7724 testing.

Procedure:

The following procedure is followed in ASTM D7724 testing:

The water pressure is adjusted. The pressure is changed after spraying. The sieve is connected to the equipment, and the “flush” button is pressed. Water is flushed through the nozzles for as long as the timer is set. The sieve is disassembled and inspected for particles. If there are no particles found, the sieve is reconnected. The sample is placed in a container and weighed. The sample is transferred into the test cylinder. The correct weight is noted for the computation. The lid is closed slowly while pressing the “start” button. There is no water cleansing while the spraying nozzle rotates. A vacuum application without any water flowing indicates the conclusion of the test. The measurement then comes to an end. The sieve is disassembled and dried. The non-dispersible substance is transferred quantitatively to a weighing dish, weighing close to 0.1 mg.

Video 01: Carbon black dispersion tester

Data:

The following data is calculated in ASTM D7724 testing:

R = (W/S) X 10⁶  

R = Non-dispersible matter 

W = mass of the sieve residue

S = mass of the sample

Conclusion:

The determination of non-dispersible materials following mechanical water flushing of ordinary untreated carbon blacks is covered by the test technique ASTM D7724.