Abstract:

This paper compared three test methods and standards of carbon black content at home and abroad and discussed the differences among the three test methods， including the tubular electric furnace method， muffle furnace method， and thermogravimetric analysis method. Based on the comparative studies， some suggestions were provided for the revision the GB/T 13021—1991 standard. The results indicated that the determination method included in the GB/T 13021—1991 standard was relatively simple. To revise the GB/T 13021—1991 standard， some regulations were recommended to be included. For example， if the nitrogen with an oxygen content of less than 0.002 %， oxygen removal may not be carried out in the tubular electric furnace method. The other regulations were also suggested to use， including the requirement for cleaning and weighting the sample prior to the formal test， appending a muffle furnace method （either a traditional muffle furnace method or a microwave muffle furnace method） and a thermogravimetric analyzer method. In muffle furnace method， weighing steps were recommended to adopt according to the provisions of the ISO 6964?2019 standard. In the thermogravimetric analyzer method， the sampling position and value description were recommended to be included in addition to the provisions of ISO 6964?2019.

Key words: polyethylene, pipe, carbon black, content, electrical tube furnace, muffle furnace, thermogravimetric analyzer