[China Glass Network] 1, Rainbow When the content of SnO absorbed in the surface layer of the glass is high, if the glass is subjected to tempering or hot bending at a temperature of 600 ° C, the stannous oxide in the surface layer of the glass partially absorbs oxygen in the air and is converted into Tin oxide: Thus, a plurality of oxygen ions having a large ionic radius are added to the surface layer of the glass, and the local volume expansion causes microscopic wrinkles to exhibit an interference color-rainbow. 2, dip tin Tin is a typical metal, while glass is a typical non-metal, and their properties are completely different. At the same time, the tin liquid has an infiltration angle of 175 to the glass. , close to not infiltrating at all. Therefore, under normal circumstances, the glass will not be tinned. However, when the stannous ions invade the surface layer of the glass, the non-metallic properties of the glass surface are changed. Since the outer layer of the tin atom has four electrons, in the metal state, the outer electrons between the atoms form electron pairs to form a covalent bond, and are tightly bonded to each other. In the tetravalent tin compound, the four electrons in the outer layer of the tin atom all form an electron pair with the outer electron of the non-metal atom, and the tin atom no longer exhibits a metallic property. Only two of the four electrons in the outer layer of stannous ion form a bond with a non-metal atom, and the remaining two electrons are likely to form a covalent bond with the outer electron of the metal tin atom, which is sticky to the metal tin. Attached to force. Of course, this adhesion is only shown when the concentration of stannous ions in the surface layer of the glass reaches a certain amount. · When the contamination in the tin bath is serious, the content of stannous oxide in the tin liquid is increased, and the surface layer of the invading glass is infiltrated. When the concentration of stannous ions exceeds a certain amount, tin staining occurs on the lower surface of the glass. This tin is usually in the form of fine-grained dots, and in severe cases it is in the form of flakes. 3, spots "Spot" or "light distortion point" is a tiny pit on the surface of the glass, which has a smooth circular shape with a diameter of 0.06 to 0.1 mm and a depth of 0.05 mm. This speckle defect impairs the optical quality of the glass and distorts the observed object image. The "spot" defect is mainly caused by the aggregation condensation of stannous oxide and stannous vapour vapor. Since stannous oxide is soluble in tin and also highly volatile, stannous sulfide is more volatile, and its vapor condenses at a lower temperature and gradually aggregates. When concentrated to a certain extent, due to the impact of airflow, The condensed stannous oxide or stannous sulfide will fall on the surface of the glass that is not completely hardened to form a "spot" defect. In addition, the aggregates of these tin compounds may also be reduced to metal tin by the action of reducing components in the shielding gas, which also causes the glass to form spots. 4, small ripples This is a kind of fine unevenness of the glass surface, which affects the optical quality of the glass to some extent. For float glass with a high surface flatness, the surface height and the lower point are only 0.3 mm apart, and the float glass with this defect has a peak-to-valley difference of up to 9 mm. There are many reasons for the formation of "small ripples". In addition to the uneven temperature of the glass in the high temperature region of tin bath, tin oxide is also an important factor in promoting its formation. Because of the stannous oxide in the surface layer of the glass, it is also possible to partially absorb the oxygen in the tin liquid in the tin bath to be converted into tin oxide, and the volume is locally expanded to generate stress. When the glass temperature is low and the viscosity is large, the stress is too late to disappear. Uneven shrinkage occurs during the continued cooling of the glass, thereby promoting the formation of "small ripples". Non Stick BBQ Grill Sheet,BBQ Grill Sheets Mat,Barbeque Grill Sheets,PTFE Barbecue Sheet NINGBO TIANSHUO (SUPERBRIGHT) TECHNOLOGY CO. LTD. , https://www.ptfe-supplier.com