High Refractive Index Round Borosilicate Glass Tubing 1250-1800mm Length

Has A High Refractive Index Borosilicate Glass Tubing

raw material

Including main raw materials and auxiliary raw materials. The former refers to the introduction of raw materials such as the oxides that form the network structure of the glass, the intermediate oxides and the oxides outside the network; the latter can accelerate the melting of the glass or make it obtain certain necessary properties.

main ingreadient

According to the nature of the introduced oxides, it is divided into acidic oxide raw materials, alkali metal oxide raw materials and alkaline earth metal oxide raw materials.
① Acidic oxide raw materials: raw materials such as SiO2, B2O3, Al2O3, etc. SiO2 is the skeleton of the glass structure in silicate glass. It gives the glass high strength, good chemical stability, heat resistance and low expansion, but it will increase the melting temperature of the glass and increase the viscosity. The cited raw materials of SiO2 are silica sand, sandstone, and quartzite. Adding B2O3 to the glass can reduce the thermal expansion of the glass, increase the refractive index, thermal shock resistance and chemical resistance, reduce the viscosity of the glass when the temperature is higher, and increase the viscosity of the glass when the temperature is lower. The cited raw material for B2O3 is borax or boric acid. Adding Al2O3 to the glass can reduce the tendency of glass to crystallize and enhance the chemical stability, increase the strength, and increase the viscosity of the glass. The cited raw materials are usually feldspar with K2O or Na2O and SiO2, and industrial alumina can also be used. Cangzhou Tianchang Craft Glass Products Factory specializes in the production of various types of high borosilicate glass tubes
② Alkali metal oxide raw materials: raw materials with Na2O and K2O. Adding Na2O and K2O to the glass can reduce the melting temperature and viscosity, but it will make the chemical stability of the glass worse. The cited raw materials are soda ash (Na2CO3) and potash (K2CO3).

It mainly includes the steps of batch preparation, melting, forming, annealing and post-processing.

Batch preparation

forming
Process glass liquid into products with fixed geometric shapes. When the glass cools down, it changes from liquid state to plastic state to solid state, which connects the production stages of glass supply and retrieval, shaping and setting. When manually picking the material, the viscosity of the glass liquid is usually 102.2 Pa·s; when the material is automatically fed by the machine, it is 102～103 Pa·s, which is equivalent to 10-100 times the viscosity when the glass liquid is clarified. The suitable viscosity of the glass drop into the mold is usually 103.5 Pa·s, and the viscosity should be 106 Pa·s during demolding. In this plastic range, the glass frit is subjected to shaping operations such as shearing, bonding, blowing, and calendering. If the production time is longer, the glass composition must be adjusted so that the viscosity transition tends to be slow and the crystallization tendency is small, so as to avoid hardening too fast and crystallization during the molding process. Commonly used glass forming methods include blowing method, pressing method, drawing method, pouring method, calendering method and so on.
Glass tube blowing method: used to manufacture hollow glass products, such as drinking glasses, utensils, bottles, jars, bulbs, etc. For manual blowing, use a 1.5m hollow iron blowing tube, one end is dipped in glass liquid (material picking), and one end is a blowing nozzle. After picking the material, roll it evenly and blow on the rolling plate (bowl) to form a glass froth, which is blown into a product in the mold; it can also be blown freely without a mold, and finally knocked off from the blow tube. When forming large-scale products, it is necessary to repeatedly pick and roll evenly to collect enough material. During mechanical blowing, the molten glass flows out from the outlet of the glass melting furnace, and forms gobs of set weight and shape through the feeder, which are cut into the preliminary mold to be blown or pressed into the preliminary shape, and then transferred to the forming mold to be blown into the shape. Products. The weighing-blowing method of blowing into an initial shape and then blowing into a product is suitable for making small mouth utensils and bottles. The weighing-blowing method of pressing into a preliminary shape and then blowing into a product is suitable for making large-mouth utensils and thin-walled bottles and cans.