During the glass tempering process, because of the special properties of the glass coating material, the coated surface of the Low-E glass has higher requirements on the cleaning brushes in the washing machine unit; the cleaning brushes must be made of high-quality nylon wire such as PA1010 and PA612. The preferable diameter of the wire is between 0.1-0.15mm; the brush wire should be flexible, elastic, and resistant to acid, alkali, and high temperatures. It should be able to easily remove the dust and dirt on the surface of the Low-E glass without causing any harm to the coating.