The surface of glass exposed to the atmosphere is generally polluted. Any useless substance and energy on the surface are pollutants, and any treatment will cause pollution. In terms of physical state, surface pollution can be gas, liquid or solid, which exists in the form of membrane or granular. In addition, according to its chemical characteristics, it can be in ionic or covalent state, inorganic or organic matter. There are many sources of pollution, and the initial pollution is often a part of the formation process of the surface itself. Adsorption phenomenon, chemical reaction, leaching and drying process, mechanical treatment, diffusion and segregation process all increase the surface pollutants of various components. However, most scientific and technological research and application require clean surfaces. For example, before giving a surface mask, the surface must be clean, otherwise the film and surface will not adhere well, or even stick to it.
Glass Cleaning Method
There are many common methods of glass cleaning, including solvent cleaning, heating and radiation cleaning, ultrasonic cleaning, discharge cleaning, etc.
Solvent cleaning is a common method, using water containing cleaning agent, dilute acid or anhydrous solvent such as ethanol, C, etc., emulsion or solvent vapor can also be used. The type of solvent used depends on the nature of the contaminant. Solvent cleaning can be divided into scrubbing, immersion (including acid cleaning, alkali cleaning, etc.), steam degreasing spray cleaning and other methods.
Scrubbing Glass
The simplest way to clean glass is to rub the surface with absorbent cotton, which is immersed in a mixture of precipitated white dust, alcohol or ammonia. There are signs that the traces of chalk can be left on these surfaces, so these parts must be carefully cleaned with pure water or ethanol after treatment. This method is most suitable for pre cleaning, which is the first step of cleaning procedure. It is almost a standard cleaning method to wipe the bottom of lens or mirror with lens paper full of solvent. When the fiber of lens paper rubs the surface, it uses solvent to extract and apply high liquid shear force to the attached particles. The final cleanliness is related to the solvent and the pollutants in the lens paper. Each lens paper is discarded after being used once to avoid re pollution. A high level of surface cleanliness can be achieved with this cleaning method.
Immersion Glass
Soaking glass is another simple and commonly used cleaning method. The basic equipment used for soaking cleaning is an open container made of glass, plastic or stainless steel, which is filled with cleaning solution. The glass parts are clamped with forging or clamped with a special clamp, and then put into the cleaning solution. It can be stirred or not. After soaking for a short time, it is taken out of the container, The wet parts are then dried with uncontaminated cotton cloth and inspected with dark field lighting. If the cleanliness does not meet the requirements, it can be soaked in the same liquid or other cleaning solution again to repeat the above process.
Acid Pickling To Break Glass
Pickling is the use of acids of various strengths (from weak to strong acids) and their mixtures (such as the mixture of acid and sulfuric acid) to clean the glass. In order to produce a clean glass surface, all acids except hydrogen acid must be heated to 60 ~ 85 ℃ for use, because silicon dioxide is not easy to be dissolved by acids (except hydrofluoric acid), and there is always fine silicon on the surface of aging glass, Higher temperature is helpful to the dissolution of silica. Practice has proved that a cooling dilution mixture containing 5% HF, 33% HNO2, 2% teepol-l cationic detergent and 60% H1o is an excellent general liquid for sliding washing glass and silica. It should be noted that pickling is not suitable for all glasses, especially for glasses with high content of barium oxide or lead oxide (such as some optical glasses), These substances can even be leached by weak acid to form a kind of thiopine silica surface.
Alkali Washing And Glass Adjusting
Glass cleaning is to use caustic soda solution (NaOH solution) to clean glass. NaOH solution has the ability of descaling and removing grease. Grease and lipid like materials can be saponified into grease acid proof salts by alkali. The reaction products of these aqueous solutions can be easily rinsed out of the clean surface. It is generally hoped that the cleaning process will be limited to the contaminated layer, but the mild corrosion of the backing material itself is allowed, which ensures the success of the cleaning process. It must be noted that strong corrosion and leaching effects are not expected, which will damage the surface quality and should be avoided. Chemical resistant inorganic and organic glasses can be found in glass product samples. Simple and complex immersion and lavage processes are mainly used for moisture cleaning of small parts.
Post time: May-21-2021