During the fuse manufacturing process, the flowability of the filler and the diameter of the fuse tube jointly influence the actual filling density of the fuse, thereby affecting its interruption performance. This paper first experimentally investigates the flowability of mixtures comprising five types of inorganic materials and silica sand. It was observed that when small-particle-size inorganic materials are mixed with large-particle-size silica sand, agglomeration occurs, resulting in the flowability of the mixed filler being lower than that of pure silica sand. Furthermore, as the proportion of the inorganic material in the mixture increases, its flowability further decreases. To explore the impact of mixed filler flowability on the filling density of fuses, the five inorganic materials were each mixed into silica sand at a mass fraction of 20% as the mixed filler. Using pure silica sand as a control, fuse test samples with a tube diameter of 5 mm were prepared using a vibration-assisted filling process. Subsequently, interruption tests were conducted on the six groups of samples using an LC power source. The results indicate that the pure silica sand group exhibited the optimal interruption performance. The group using a mixed filler containing a specific silicate mineral showed the poorest interruption performance, with an excessively long arcing time at a current of 4 kA, leading to interruption failure. Compared to the silica sand group, the other four filler groups demonstrated increased peak current and arcing I²t, reduced arc voltage, and consequently, degraded interruption performance. Comprehensive analysis suggests that due to the poorer flowability of the mixed fillers, combined with the small tube diameter, their actual filling density remained low even after vibration-assisted filling supplemented by manual packing. This resulted in a reduced arc voltage during the interruption process, leading to degraded interruption performance and even failure. Therefore, when developing new arc-extinguishing materials for fuses, the influence of material flowability on the filling density must be thoroughly considered.
 

interruption performance,flowability,filling density