Autoglass Black Enamel

Auto Glass Black Enamel1.INTRODUCTIONGeneralIn the automotive industry two kinds of glass enamels are used, laminated and toughened. Toughened products are used for side lights, back lights and sunroofs; laminated products for windshields.Side LightsThe side lights are in fact the less technical demanding with respect to the glass enamel. Semi-mat shine and printability on both the air and tin side of the glass, without any change in color are the main characteristics of this kind of glass enamel. There are heavy metal-free glass enamels in all kind of media systems available for side light printing, but also side light designers are more and more requiring complex bending. Again non-stick properties of the glass enamel are becoming more important. The tendency to use conductive pastes on side lights is already noticeable(burglar alarms and antennas).For the short term the enamel for side lights will need a fair amount of research and development work in order to live up to the new requirements. Back LightsThe back light is traditionally the most complex piece of glass in the car. It can have a very complex shape and therefore the enamel must have very good non-stick properties, as the glass is bent by a press at about 700ºC.A large amount of black enamel is used for obscuring and styling aspects. The glass enamel has to be overprinted with a conductive ink for the defrosting/defogging circuit. The glass enamel has to hide the silver bus bar (when seen through the glass).The strength of the soldered electrical connectors onto the circuit must not be affected by the glass enamel. And last but not least, the glass enamel must keep its' neutral black color.Knowing all this, it is hardly surprising that a lot of research and development has been put into enamels for toughened glass. Heavy metal free glass enamels for press and sag bending have been available on the market for quite some time.2. PRODUCT CHARACTERISTICS The core range exists of 3 products, which covers a wide firing range (680-720ºC) and has very good anti stick properties. For special applications we can offer two others, which have different characteristics.In general it can be said that it has a neutral black color (a-and b-value close to zero) is very opaque, has very good silver hiding under intense light and has very good non-stick properties.CharacteristicsThe main characteristics are:Pb & Cd freeBismuth basedSilver hidingNo blue discoloration when over firedWide working rangegood acid resistanceAnti stick suitable for deep press system Media IR medium oil solvent basedBending temperature : 580-650ºCTempering Temperature:680~720ºCAverage Particle Size: 5 ~ 6 umPrinting Environment: It is very important to keep the printing environment clean and good environment can bring good printing result. The room temperature should be control at 25±2ºC, humidity at 60% and make sure no dust in printing.Coefficient of Thermal Expansion (CTE): (85~95)×10-7/K-1(50-300ºC)Screen Printing· Standard printing conditions 200~250 of Mesh· Minimum wet layer/thickness required of 24μm to obtain perfect silver hidingStorageEnamel should be stored in its original package preferably tightly closed and in a clean dry place at 5~25ºC.Store material away from heat and direct sunlight .When storing more than one batch, use first-in and first-out system. Cold pastes should always be shaken well prior to use. This product should be used within 12 months of production date for optimum results.3.TESTAcid durabilityImmersed the fired sample partly in 0,1N H2SO4 at 80ºC,during 4 hours. Clean afterwards with water and dry the glass.Grade 3Alkaline durabilityImmersed the fired sample partly in 0,1N NaOH at 80ºC,during 4 hours. Clean afterwards with water and dry the glass.Grade 3Water durabilityImmersed the fired sample partly water at 25ºC, during 7days. Clean afterwards with water and dry the glass.Grade 3