Advantages and disadvantages of polyvinyl acetate paints

Polyvinyl acetate paints (PVA) are emulsion formulations made on an oil-in-water basis. Such paints are widely used for painting interior surfaces in residential and industrial buildings.

Content:

• Advantages and disadvantages of PVA compounds
• The composition and characteristics of the paint
• Acrylic waterborne paints
• Surface application
• GOST, prices and form of release

PVA paints and varnishes can be purchased in one of two varieties:

1. One-pack composition, which is a completely ready-to-use paint. It is stored and transported in hermetically sealed containers at positive temperatures.
2. Two-pack composition. It is a semi-finished product, which includes paint in the form of a paste, as well as a plasticizer. The composition is prepared by mixing immediately before use.

Advantages and disadvantages of PVA compounds

The benefits of polyvinyl acetate paints include the following:

• Applicability even to highly porous materials (some types of wood, plaster, cardboard);
• high drying rate;
• simple preparation of the composition and simple application to the surface;
• high explosion safety and fire safety;
• lack of unpleasant odors, as there are no solvents in the composition
• non-toxicity of paint material;
• the existence of additives, despite the limited color palette, due to which it is possible to obtain a matte or glossy surface;
• competitive product prices;
• great option for drywall staining and other smooth surfaces (due to high adhesive ability);
• the possibility of using for re-painting after surface treatment with oil paints;
• water solubility;
• resistance to ultraviolet radiation;
• ability to resist fungus and mold;
• the elasticity of the formed coating.

The PVA composition has a number of disadvantages:

1. Slight color palette.
2. Instability of PVA to low temperatures during staining, as, according to the recommendations of manufacturers, the minimum air temperature should be 6 degrees above zero (the paint freezes at temperatures below zero).
3. For interior finishing work, not just any paint is suitable, but only containing acrylate and verstate components.
4. There is a tendency to increase the cost of PVA inks, as manufacturers often add new components to their compositions.
5. Coloring with polyvinyl acetate aqueous emulsion compositions is carried out only after preparation of the rough layer, since PVA gives a high surface tension (objects need to be cleaned several times and then sanded).
6. The paintwork material is unstable to high humidity, therefore it is rarely used for painting the exterior of buildings (the problem is partially solved by adding an acrylic component to the composition).
7. PVA can not be applied to Cretaceous whitewashing, alumina, alum and vitriol priming materials.

The composition and characteristics of the paint

The cost of PVA paints is low, because they do not contain complex components. Polyvinyl acetate compositions include the following components:

1. An aqueous emulsion based on polyvinyl acetate. It is a solution of creamy consistency.Since the composition of the emulsion contains water, do not forget about the freezing temperature - zero degrees Celsius. An unplasticized emulsion is able to withstand no more than 3-4 cycles of complete freezing.
2. Pigmenting substances, due to which the paint conveys the color of the surface.
3. Stabilizers - components that improve certain performance characteristics of the paint material.
4. Plasticizers - components that regulate the physical and mechanical properties of the paint, as well as contribute to the formation of a film.

As mentioned above, PVA paints are quick drying.

Aqueous emulsion formulations dry for about 2-3 hours, provided that the air temperature is 17-23 degrees above zero.

The reason for quick hardening is that the emulsion contains up to 40% water, which evaporates easily after application to the surface. The composition of the emulsion also includes up to 60% of resins and pigmenting substances. If there is a need to reduce the viscosity of the composition, water is added to it, and vice versa.

In the process of evaporation, tar particles (their size varies from 1 to 4 microns) first approach each other, creating a dense ring around the pigments, and then merge with them. The result is a dense mass formed from pigments and resin. In the mass there are very small pores through which water evaporates. After staining, the water eventually evaporates, and the plasticizers become hard and hydrophobic.

After drying, the film decreases in size - up to approximately 60% of the original volume. Since the surface of the film has many pores, it acquires a slightly matte, silky sheen. Due to this, excellent decorative qualities are transmitted to the painted surface. In many cases, subject to the staining technology, it is quite possible to replace opaque oil coatings with polyvinyl acetate paint.

Polyvinyl acetate paints may be color-coded. Use tinting substances in accordance with the manufacturer's instructions.

Acrylic waterborne paints

In order for the paint to acquire moisture protective properties, an acrylic component is added to the water-dispersed polyvinyl acetate compositions. This polymer gives the coloring material the following characteristics:

1. The surface begins to "breathe", letting in air, but not moisture.
2. The hydrophobicity of the surface increases.
3. Increases the ability to resist aggressive environmental influences.

Thanks to the use of acrylic polymers, improved PVA paints can be used for application on exterior facades, as well as for surface treatment in damp rooms (for example, kitchen, bathroom). To add gloss or dullness to coatings, special additives are used.

Surface application

Coloring with polyvinyl acetate aqueous emulsion formulations is carried out in a certain sequence:

1. We select the most suitable paint and varnish material for the existing conditions.
2. We carry out a set of preparatory measures before painting the surface: remove dirt and dust, close up all defects (seams, cracks, tubercles, etc.), remove whitewash (if any). To save on paint and improve adhesion, it is recommended that the surface be primed.
3. Stir PVA paint well, removing previously dried clods from the container. We dilute the emulsion mass.
4. We apply paint with a brush, roller or with a spray gun.
5. We wait for the first layer to dry and apply the next layer. If necessary, the procedure is repeated for the third time.

GOST, prices and form of release

PVA paints are produced in accordance with the rules prescribed in GOST 28196-89.It is worth noting that the certification of paints for compliance with GOST is at the discretion of the manufacturer. On the packaging with the paint, the consumption rate, components, and also the method of creating the solution are indicated.

The price per kilogram of paint can vary greatly depending on the popularity of the brand and additives. The cost is also affected by the remoteness of the region.

However, it is believed that high-quality PVA paint in any case cannot cost less than the ruble equivalent of a dollar per liter.

Despite the obvious disadvantages listed above, polyvinyl acetate paints and varnishes are in high demand. High drying speed, compatibility with different types of materials, as well as affordable prices provide PVA paints unchanged popularity among consumers.