Scope:

ASTM D4218 test method is used to determine the carbon black content in polyethylene compounds by the Muffle-Furnace technique. The muffle furnace is an important laboratory testing tool that is used to test a variety of materials. With this technique, ASTM D4218 is aimed to provide improved temperature uniformity and isolate heated materials from combustion pollutants. This test method provides high performance and is appropriate for quality control in manufacturing, technical support, and research. The test is conducted at high temperatures ranging from 600°C to 900°C.

Procedure:

For ASTM D1418, a black polyethylene compound enclosed in a disposable aluminum weighing dish is pyrolyzed for a brief period in a muffle furnace. The air in the muffle furnace becomes oxygen-deficient during the pyrolysis of the polymer, preventing the residual carbon black from being burned. Any soot generated during the early combustion of the gasses is consumed before the carbon black. After cooling, the carbon black residue is weighed. The dish and contents can be reinserted into the muffle furnace to determine the ash content, with the findings being used to calculate the true carbon black content.

Specimen size

The ASTM D1418 test specimen may be in the form of granules or pieces cut from an article such as a pipe, jacket, film, molding, etc.

Data:

In ASTM D1418, the percent carbon black content is calculated as follows :

where, 

W1, W2, W3, and W4 are the weights of the dish at four different times during the whole test procedure.

Conclusion:

ASTM D4218 test method is used to determine the carbon black content in polyethylene compounds by the Muffle-Furnace technique.