Water-based Epoxy Flooring

For a long time, in the application field of industrial floor coatings in my country, there are mainly two types of solvent-based and solvent-free epoxy floor coatings. However, these two types of epoxy floor coatings always have certain defects. For solvent-based epoxy floor coatings, they contain too many organic solvents, which will cause great damage and pollution to the environment. For solvent-free epoxy floor coatings, their active diluents have certain toxicity, which will harm people’s health. It is based on this background that an environmentally friendly water-based epoxy floor coating has been produced. It can not only meet people’s needs for ground protection and decoration in various occasions, but also has low odor, no organic solvents, and is non-toxic, and has a broad space for promotion.

For water based epoxy floor coatings, its main components are water based epoxy primer, water based epoxy topcoat and water based epoxy mid-coat. These three components each play an important role. For water based epoxy primer, it can effectively improve the adhesion between water based epoxy floor coating and base layers such as cement mortar and concrete. Water based epoxy topcoat is at the top layer. In addition to rich colors, it also has obvious wear resistance and chemical corrosion resistance. As for water based epoxy mid-coat, it is between water based epoxy primer and water based epoxy topcoat. Naturally, it plays an important role in connecting the upper and lower parts. It can enhance the strength of the coating and give the epoxy coating good polishing properties, providing good conditions for obtaining a smooth and flat surface.

When designing water based epoxy floor coatings, on the one hand, attention should be paid to the selection of water based epoxy resins and curing agents, which will have an important impact on the final performance of water based epoxy floor coatings; on the other hand, in order to reduce the cost of coatings and improve the wear resistance and impact resistance of coatings, appropriate amounts of pigments and fillers can be added. In addition, various additives can be selected during the development process to improve the performance of water based epoxy floor coatings, mainly including dispersants, leveling agents, etc.

Water based epoxy floor coatings are generally used on concrete or cement mortar bases. Once the cement mortar and concrete bases are not properly treated, the adhesion of the water based epoxy floor coatings will be greatly affected, and even cracking, blistering and other prominent phenomena will occur. Therefore, in order to avoid these phenomena, it is necessary to pay attention to the construction technology of water based epoxy floor coatings on concrete and cement mortar. The specific construction process is:

(1) Careful inspection of the base
Before the construction of water-based epoxy floor coatings, it is a necessary process to inspect the base layer. The inspection mainly includes the determination of moisture content, flatness and strength. For the determination of moisture content, the moisture meter tool is mainly used, which is a more direct determination method. Of course, in addition to this, it can also be judged according to the experience of the construction personnel based on the maintenance time of the substrate. For the determination of flatness, a two-meter ruler and a wedge-shaped feeler gauge are used for inspection. During the measurement process, the error should be controlled within five millimeters as much as possible. In addition, when determining the strength of the base layer, a concrete rebound tester can be used. Of course, in terms of strength judgment, the construction personnel can also use a small hammer to gently tap the base layer to make a simple judgment based on experience.

(2) Precautions for base treatment
After careful inspection of the cement mortar and concrete base, the base should be further processed according to the corresponding requirements.

First of all, the good cement mortar or concrete base required for the construction of water-based epoxy floor coatings must meet the requirements of flatness, firmness, density, etc. Generally speaking, the base strength required for the construction of water based epoxy floor coatings must be above 20Mpa. If the requirements are not met, the base surface will be pulled apart after the construction of the water based epoxy floor coating, resulting in peeling;

Secondly, the moisture content of the base concrete cannot exceed 15%. If it is above 15%, appropriate drainage measures must be taken to drain the water before the water-based epoxy floor coating can be constructed. Common base drainage measures mainly include ventilation, heating, and lowering the dew point temperature in the air;

Third, the surface of the base must be clean. Before the paint is applied, the floating dust, cement residue and loose parts on the surface of the base should be cleaned. The surface treatment method of the base should be to grind the surface with a grinding wheel or wire brush, and then clean it with a clean soft brush, compressed air or vacuum cleaner. When conditions permit, a light sandblasting method can be used to make the base form a uniform rough surface. The absence of a rough surface on the base will affect the adhesion between the paint film and the base, but if the base is too rough, it will cause a lot of waste of materials. Therefore, the appropriate roughness is very critical to the construction quality of the paint. If there are grease impurities on the ground, they must be wiped clean with a solvent.
In addition to the above precautions, the main construction tools such as floor grinders, vacuum cleaners, mixers, brushes or rollers, scrapers or serrated trowels, defoaming rollers, etc. should also be checked to ensure that all the machines are in place. Then it should be noted that the construction environment of water-based epoxy floor coatings cannot be lower than 10 degrees Celsius, and it cannot be too high. Because too low a construction temperature will slow down the curing speed of water-based epoxy floor coatings, increasing the difficulty of construction. Excessive temperature will cause the water-based epoxy floor coatings to accumulate reaction heat in the container, making the curing speed faster and the use time shorter, and sometimes there is no time for leveling construction. In addition to temperature, humidity should also be below RH85%, especially to avoid water-based epoxy floor coatings in low temperature and high humidity environment.

(3) Construction technology of water based epoxy floor coating
After processing the cement mortar and concrete base, the construction process of water-based epoxy floor coating can begin. The specific construction process mainly consists of four main parts: primer construction, mid-coat construction, putty repair and topcoat construction, which are:

Primer construction. Primer construction is the first step in the construction of water-based epoxy floor coatings after the cement mortar and concrete base are treated. For primer construction, the primer must be prepared according to the relevant requirements. It is important to stir the primer thoroughly before construction. During construction, it must be applied evenly, not thick and thin at times. The primer and base can be fully moistened to increase the corresponding adhesion. Before starting the next process, ensure that the primer construction is completed and there is a 12-hour maintenance time to allow it to fully solidify.
Mid-coat construction. Mid-coat construction is a critical step in the construction process of water-based epoxy floor coatings. Its main function is to further deal with defects such as tiny voids on the base layer. The main measures taken are to add quartz sand and quartz powder to the prepared wate based epoxy floor coating to make water based epoxy mortar. After sufficient stirring, it is evenly applied to form a flat and dense layer of a certain thickness.

Putty repair and topcoat construction. After the middle coating is completed, the floor is polished with a grinder and sandpaper, and a number of coats of putty made of water-based epoxy paint and quartz powder are applied according to actual needs. The surface is required to be flat and free of holes, knife marks and sanding marks, so as to provide a good surface for topcoat. In addition, when performing topcoat construction, the paint should be prepared and mixed evenly, and then applied by troweling. The operator should wear spiked shoes to repair defects, and then use a defoaming stick to defoam to obtain a flat and uniform surface coating.

In summary, water based epoxy floor coatings can not only meet people’s needs for ground protection and decoration in various occasions, but also have low odor, no organic solvents, and are non-toxic, and are worthy of promotion in the field of industrial flooring. The author believes that in the construction of water based epoxy floor coatings, it is necessary not only to do a good job in the treatment of the base layer, but also to combine the actual situation of the project and mix the water based epoxy floor coatings to adapt them to specific decoration and protection requirements.