The effect of kaolin and silica variation on the properties of porcelain insulators

  • H.E. Mgbemere
  • I.P. Onyeayana
  • A.B. Okoubulu
Keywords: Electrical porcelain, Shackle insulator, Kaolin, Feldspar, Processing.

Abstract

Clay, Al2O3, feldspar and silica have been used to produce shackle-type porcelain insulators using slip casting method. The amounts of silica and kaolin were varied from 10 to 30 wt. % while keeping the amounts of other constituents constant. The samples were bisque fired at 900 °C, sintered at 1200 °C for 1 hour glazed using borax fritz. The results showed that as the amount of kaolin decreased, apparent porosity and water absorption increased from 9-19 % and 7-12 % respectively. The bulk density and linear shrinkage decreased from 1.94-1.12 g/cm3 and from 12.5 % - 7 % respectively. Breakdown voltages ranging from 23 kV to 35 kV were obtained while the highest insulation resistance value of 50GΩ was for the sample with 55 % clay, 15 % silica and 25 % feldspar and 5 % Al2O3. The results indicate that moderate variations in kaolin and silica content can be used to produce porcelain insulators for commercial applications.

Keywords: Electrical porcelain, Shackle insulator, Kaolin, Feldspar, Processing.

Published
2019-12-11
Section
Articles

Journal Identifiers


eISSN: 2467-8821
print ISSN: 0331-8443