Fracture post insulators

The main pillar insulator prepared by mixing the original aluminum silicate clay, feldspar and quartz, etc., are shaped after sintered at high temperature inorganic insulating material, insulator surface was covered with a layer of smooth vitreous thin glaze. Post insulators affected by the deterioration of many factors, both manufacturers and the choice of materials, formulations, process, but also with the operating environment and the operation of the electrical load to bear against the external force even relevant.

If you post insulators in the production process formula properly, uneven mixing process raw materials, lack of fire roasting, etc., are easy to form hygroscopic porosity post insulators. The structure is irrational, or molding failures, discontinuity equalization, post insulators will also exist within the internal stress, resulting in post insulator to crack, gap, even deteriorated. Post insulator is generally formed by the powder material, sintering. After these processes are obtained post insulator, it is composed of many crystallites aggregated polycrystalline structure, which inevitably exist grain boundaries. Not only plays in the grain boundary pillar insulator sintering process an important role, but also has a great influence on the sintered body physical and chemical properties. Microstructure post insulators are made of microcrystalline grain boundary, grain boundary precipitates, grain boundary pores, intragranular precipitates within grains such as pinholes formed. Crystallite size constituting the main component of the post insulator, generally from one micron to tens of microns, is arbitrary crystal axis direction, and the crystallite diameter particle diameter of raw materials, impurities, sintering conditions. Ceramic grain boundary dislocations, voids and other defects in the crystal lattice and lattice distortion exists. Thus it tends to concentrate impurities, formation of grain boundary segregation layer, layered precipitates. Generally in the grain boundary segregation of impurity ions by the formation of a layer called the grain boundary segregation layer, the grain boundary segregation layer thickness from 20 angstroms to 1 micron.

Production post insulator, usually with cement as a binder. After the cement itself absorbs moisture and CO2, the volume becomes large, cement absorbed moisture will freeze and thaw repeatedly, prompting the post insulators deteriorated. The cement dry, condensation, moisture will not only form pores, and will have a lot of cracks.

When the ambient temperature sudden changes, post insulators will face a big test. For example, the summer day, when suddenly heavy rains in various parts of the post insulator too late while expansion and contraction of the local position post insulators (such as the head) will be exposed to high mechanical stress, and even pieces of porcelain cracking. In this case, if the volume of the post insulator larger structure is more complex, the greater the likelihood and severity of cracking. Long-term operating experience shows that the poor quality of post insulators, in the summer, especially under the hot sun and then dump heavy rain the weather, post insulator degradation rates often several times higher than in winter. Similarly, directly affected by sunlight and rain by a multilayer ceramic pin post insulators upper skirt and head and parts of post insulators with plastic insulators are high degradation rate of the site. Post insulator damage caused by many factors, fracture, are:

Product quality is not high, defective products leave the factory. Some even worse system or the old charge of new products, do not get no quality assurance. Specific performance, crack, slag, mezzanine, such as porosity, cracks under the action of which have greater stress and expand covert.

Packaging, transport and installation damage.

Post insulators in the harsh operating environment, the expansion coefficient of porcelain, cement and cast iron flanges there are differences between the three, another reason for the temperature difference, resulting in cracking.

Operating stresses and installation stress is too large, the number of operations frequently cause post insulators fracture.