The influence of annealing furnace temperature in

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A brief analysis of the influence of annealing furnace temperature in annealing process

glassware products, especially products with uneven thickness and complex shape, will produce thermal stress during the process of cooling from high temperature to normal temperature after molding. If the cooling is too fast, the temperature difference between the inner and outer layers of glassware and the temperature difference between various parts due to the shape relationship of glassware products will produce thermal stress. When the product encounters mechanical collision or is subjected to rapid cooling and heating, this stress will cause the product to crack. In order to eliminate the permanent stress in glass products, it is necessary to anneal the glass products. Annealing is to heat the glass products first, and then heat preservation and cooling the products according to the specified temperature, so that the permanent stress in the glass products can be reduced to the actual allowable value

in order to eliminate the permanent stress in the glass, it is necessary to heat the glass to a certain temperature lower than the temperature near the glass transition TG for thermal insulation and soaking, so as to eliminate the temperature gradient of each part of the glass, and when the stress is relaxed, the selected thermal insulation and soaking temperature is generally referred to as the annealing temperature. At annealing temperature, due to the high viscosity of glass, although the stress can be relaxed, measurable deformation will not occur. The maximum annealing temperature of the glass refers to the rapid decompression of the electromechanical device after 3MI pressurization at this temperature; Don't turn off the power. N can eliminate the stress by 95%, which is generally equivalent to the annealing point( η= It can effectively filter the smoke and dust to make the discharged smoke white. The temperature of 1012pa. S is called the upper limit temperature of annealing; The minimum annealing temperature refers to that the stress can be relieved by 5% after 3min at this temperature. This temperature is called the lower annealing limit temperature, and the maximum annealing temperature and the minimum annealing temperature range are called the annealing temperature range

the maximum annealing temperature of several different kinds of glass

in the actual production of glass, the generally adopted annealing temperature is 20~30 ° C lower than the high annealing temperature, and the lowest annealing temperature is 50~150 ° C lower than the maximum annealing temperature. The annealing temperature of glass products has a direct impact on the quality of annealed products. If the annealing temperature is too high, the products are prone to deformation during annealing. The annealing temperature is too low, so it can often be collected, and the stress in the products cannot be completely eliminated

the annealing height of glass products is only lower than that of glass, and the chemical composition is related to the thickness of products. Any composition that can reduce the viscosity of glass can also reduce the annealing temperature. Alkali metal oxide can significantly reduce the annealing temperature of glass; SiO2, Cao and Al2O3 can increase the annealing temperature

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