Types of UV-curing paints and rating of brands, method of application

Ultraviolet paints are distinguished by a special composition. Due to their specific components, these substances react to the influence of ultraviolet radiation. In most cases they are used for different types of printing - especially for flex, offset, stencils. In addition, with the help of such materials it is possible to reproduce raster graphics. You can apply this type of dyes on different types of surfaces - paper, plastic, polyethylene.

UV-curable inks: properties and characteristics

When using UV-cured paints, special lamps are used. With their help, it is possible to fix the applied substance. Some materials in this category are highly toxic. Therefore, their application on food packaging is prohibited.However, after drying, these materials do not release solvents, as solvent formulations do.

However, it is important to take into account that the use of lamps is accompanied by the synthesis of ozone. With an increase in the concentration in the air, this substance can be very toxic.

Ultraviolet paints differ from simple formulations that contain solvents in their ability to dry quickly. The other characteristics of this type of material are as follows:

• rigid structure;
• moisture resistance;
• sticky, viscous consistency;
• lack of rapid abrasion;
• drying only under the influence of ultraviolet radiation.

Composition and curing methods

In paints that harden under the influence of ultraviolet radiation, the following components are present:

• Dye or pigment - gives the coating a specific shade.
• A special binder in liquid form - helps turn the material into a solid film. It freezes under the influence of ultraviolet radiation.
• Photoinitiator - participates in the chemical solidification reaction.
• The UV hardener is an oligomer. This group includes viscous components that acquire a solid consistency under the influence of ultraviolet radiation.
• The monomers are vegetable oils and solvents.
• Additional components and wax.

Basically, UV ink is a powder that includes curable polymers. As it warms up, the composition melts, forming a solid film on plastic, paper or wood.

A peculiarity of this type of paints is that they fix quite quickly on a white surface, while on a dark coating the polymerization process is much slower.

The fact is that a bright background repels ultraviolet radiation, while a dark background absorbs it.

The final step in applying UV dyes is drying.The dispersion medium for drying stains and varnishes is air. The formation of a film is due to the fact that the solid fragments of polymer, which are included in the composition of the material, form a strong bond. They first melt, then they acquire a hard texture. When using the material, it is first heated to +115 degrees. Thanks to this, it dries in a few minutes.

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Scope

The unique characteristics of the material allow it to be used in various fields. Ultraviolet dyes are produced for different types of printing - digital, screen printing or offset. The properties of these materials help to embody non-standard design solutions.

They are often used in the production of furniture and interior decoration. Such materials allow printing on cardboard and paper. They can be applied to glass, metal, wood, ceramic surfaces.

Coating quality and durability

This type of paint contains curable polymers. Once dry, they form a very resistant film. At the same time, the quality characteristics of the coating do not depend on its thickness.

UV cured paints are characterized by the following characteristics:

• uniform application;
• no spread.

The quality of the coating depends on the following factors:

• coloring composition - it includes pigments, solvents, resin, synergists, photoinitiator;
• surface type;
• dye application conditions;
• radiation dose;
• the type of UV device used;
• distance between the lamps and the cover.

Advantages and disadvantages of UV curing

The UV curing method is considered environmentally friendly. Other advantages of this technology are:

• short drying time for products;
• economical consumption;
• the possibility of using parts - it is allowed to paint a certain part of the surface;
• the possibility of reusing paint residues or coating drippings;
• high degree of strength and durability of the painted surface;
• the possibility of applying a thin layer to obtain a high-quality coating;
• low level of risk of explosion;
• harmless to the human body.

It is important to take into account that these materials and technologies, which implies their use, differ in certain disadvantages. The main disadvantages are:

• poor return on investment in case of application on automatic lines - this is possible only with large production volumes;
• high price - UV-curable dyes are more expensive than folic or solvent products;
• long drying time when painting uneven surfaces;
• the need to slow down the curing process to obtain a high quality coating;
• the impossibility of eliminating defects on the painted surface - these include drops or drips.

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Varieties and recommendations for choice

Acrylic and aqueous formulations are often used in print shops. Polyester materials are also often used. Each of the varieties has certain advantages and disadvantages.

Acrylic

This type of stain dries in minutes. They are characterized by a high level of responsiveness. In addition, the paints contain almost one hundred percent dry residue. Such substances include an ultraviolet hardener. After applying this type of materials, it is possible to obtain a durable and hard layer. Therefore, the scope of their application is quite wide.

Acrylic paints meet environmental requirements. They give off almost no fumes when drying. However, if they come into contact with exposed areas of the body, the substances can be harmful. Therefore, when working, it is recommended to use personal protective equipment. Another feature of these substances is considered a high level of viscosity. Therefore, the materials cannot be applied by spraying.

The advantages of such paints include:

• high strength;
• safe composition;
• minimum amount of vapours.

At the same time, the substances differ in their disadvantages:

• high price;
• harmful effect on the skin;
• high degree of viscosity.

Polyester

These materials are affordable. However, for their complete drying, blowing is necessary. The dyes are cured with a variety of UV lamps. Such substances can be applied by spraying. In addition, their layers can acquire a yellow tint under the influence of ultraviolet radiation.

Benefits of polyester dyes include:

• little price;
• the possibility of application by spraying;
• good hiding power.

At the same time, the materials differ in some drawbacks:

• the need to use airflow;
• instability;
• yellowing under the influence of ultraviolet radiation.

water soluble

These dyes are considered expensive, but their composition is safe. They do not yellow and are suitable for spraying. As the materials dry, they form strong layers of high quality pigments. These substances are completely harmless even if they come into contact with the skin.

Benefits of water-soluble paints include:

• safe composition;
• stability;
• the possibility of applying by spraying.

In addition, the substances have a number of disadvantages:

• high price;
• the need for convection drying.

Ranking of the best UV ink brands

Today, various brands are engaged in the production of such paints. Popular brands include:

• VAN SON (Netherlands);
• MEGAMI (Japan);
• Excure (Belgium).

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What is needed for painting

It is important to ensure optimal climatic conditions during printing:

• temperature at the level of + 18-24 degrees;
• humidity - 50-60%.

Curing depends on the choice of UV emitter. They can be of the following varieties:

• mercury lamps;
• LED, electrodeless, quartz devices;
• LED lamps;
• xenon fluorescent devices.

When choosing a device, it is important to take into account that the frequency of its radiation should coincide with the frequency of absorption by the photoinitiator. This component is responsible for the required dose of ultraviolet rays and the ability of dyes to react.

For the purpose of polymerization of powder paints, it is allowed to use a wide range of lamps. But they have a few drawbacks:

• toxicity;
• high energy consumption.

Surface preparation rules

When applying paints to non-absorbent surfaces such as films, it is important to monitor the tension. The thing is, dye adhesion to film or plastic can be imperfect. As a result, over time, the probability of defects is high. Therefore, the degree of tension should be assessed with special ink or pencils.

Material application technology

It is necessary to apply the dye with special devices.At the same time, it is important to ensure that direct sunlight and light from fluorescent lamps do not fall on the machine used for printing and ink containers. To protect windows, yellow filters are commonly used. All lamps must have a safe spectrum. It is available in yellow or white.

Drying time

It is allowed to apply UV cured varnishes on the finished products. They protect the product and help to create special effects such as glossy or matte surfaces. The drying time of UV dyes is short. Quite often, their polymerization occurs instantly.

Storage conditions

In order for the paints to retain their properties longer, it is recommended to keep them at a temperature of + 5-25 degrees. They should not be exposed to direct sunlight.

Paint consumption per 1 square meter

1 kilogram of dyes is usually sufficient for 80 square meters of surface.

Precautionary measures

When using such funds, it is important to avoid contact with mucous membranes and skin. Work is required in well-ventilated areas.

Recommendations from the masters

Teachers are advised to follow these recommendations:

• choose the right type of paint;
• observe the technology of applying the material;
• use protective equipment;
• do not expose the products and the paint to the sun.

Ultraviolet dyes have many benefits. They help create a durable finish and are used in a variety of applications. To achieve high-quality staining, it is important to strictly follow the technology.