Application of Waterborne Coatings in Railway Vehicles

Water-based paint is a paint that uses water as a diluent and does not contain organic solvents. It is non-toxic and non-irritating. It is harmless to the human body and does not pollute the environment. change, easy to use and so on. Water-based paints include water-soluble paints, water-dilutable paints, and water-dispersible paints.

Used for: Railway Vehicle Coatings

Most of the body painting uses traditional solvent-based coatings, which contain a large amount of organic solvents, which brings inconvenience and safety hazards to storage, transportation and construction. The harmful gases released during the production and use of solvent-based coatings will have a negative impact on the health of production employees and the atmospheric environment that cannot be ignored. At present, the localization and water-based process of coatings in the fields of high-speed trains, high-speed railways and rail transit have entered the work plan of the General Railways.

However, the following matters should be paid attention to in the use of water-based paint railway vehicles:

1. Coating environment

The best state of the coating environment is room temperature, relative humidity below 70%, and gentle ventilation. Under this condition, the water can be quickly evaporated. The temperature of the coating environment is lower than 10℃ or higher than 30℃, which will affect the coating effect, such as sagging, prickly heat, orange peel, air bubbles and other disadvantages.

2. Dealing with defects

Use a soft brush for brushing the sinker, which requires no shedding, softness, and strong water absorption. Before use, remove the hair that is not firmly fixed, wash it with water, and shake it dry before use. Before the brush is dipped in the paint, it must be moistened with water in advance, but there must be no dripping water, otherwise the paint brush will dry and solidify quickly, or the paint in the paint brush will dry and slag, which will affect the quality of the coating film.

3. Spraying facilities and tools

Parts of the spray equipment that come into contact with the paint should be protected with stainless steel or with a Teflon lining, preferably without aluminum parts. modified parrafin wax for paint Because water-based resins and additives in coatings may contain substances that can react with aluminum and aluminum alloys, these compounds can cause pitting corrosion, chalking, and paint contamination and discoloration on aluminum.

4. Pre-grinding treatment

The abrasive cloth used for sanding should not use abrasive cloth containing stearate, otherwise the residue of stearate after sanding may cause shrinkage cavities.

5. Preparation before using water-based paint

The paint liquid should be fully stirred before use, and the paint should not be mixed by shaking. In order to ensure the quality of the paint, the water-based paint must be filtered with a filter screen of more than 200 meshes before use.

6. Coating and film treatment of water-based paint

The number of coating passes depends on the quality and effect required by the product coating, and usually 2 passes can achieve good results. When high fullness is required, the number of coating passes should be increased, and the drying time should be appropriately extended to more than 4h. Before painting, the compatibility of the water-based paint and primer must be confirmed. The oil-based system should be dried for at least 24 hours before applying the water-based paint. Before applying the water-based paint, it should be fully polished and cleaned. Although the water-based paint surface dries quickly, it takes a long time for the water in the paint film to completely escape, usually after 7 days of drying to reach the final strength (the time should be appropriately extended in winter).