Cardboard coated: features, density and types

Many of us have to daily contact with products made of cardboard. Their main difference is the material itself - the cardboard differs in density, hue, size, price and surface roughness. One of the most common is cardboard coated.

What is chalking?

The coating process is the application of a special coating on cardboard or paper, which gives them gloss and specific properties. The composition applied to the surface consists of plasticizing and adhesive elements and different pigments, in the role of which kaolin or chalk act. Melting is done in several ways: machine, cast and extra-machine. The latter two types require the use of special equipment, while the latter can be carried out on conventional paper technology.

There is another kind of chalking - scab. This method consists in spraying on the surface of cardboard or paper an excess amount of coating, which is then smoothed out with a long thin plate - scraper.

Depending on the purpose, coated cardboard can be covered with several layers of composition. A large number of layers gives the material a shine, an attractive appearance, and its surface is a snow-white shade.

What is coated cardboard?

Cardboard coated, or chrome-cardboard - a material on the surface of which is applied a special coating consisting of glue, pigment and plasticizer. There can be several types: design, packaging and printing.

Depending on the purpose for which the chrome-cardboard is made, it can differ from the number of layers and thickness of the coating, mutual or one-sided coating.

Characteristics of coated board

The main properties of coated cardboard, which pay attention when buying it, are:

• Rigidity.
• Durability for delamination, fracture and rupture.
• Absorption.
• Weight, density, size.
• Resistance to bending, moisture, punching.
• The number of layers and the degree of whiteness of the surface.

The quality of the raw materials used and the method of processing the layers directly affect the mechanical properties of the cardboard.

A layer of adhesives and colorants is applied to the surface of the cardboard using special coating equipment. The composition is dispersed both in one and in several layers. In case of multilayer coating, a maximum of three layers are applied to the front surface of the cardboard, one is applied to the reverse one.

The thickness of the application of the layers varies from 4 to 40 g / m ² . Depending on the thickness of the coated layer, the printed characteristics of the cardboard change. Coated cardboard, whose density is 230-520 g / m ² , can be used in various areas of human activity.

Often, coated board is indicated by terms such as triplex and duplex.

1. Duplex is the most common type of cardboard. The number of coating layers does not exceed three, it is used mainly for packaging. Multilayer coating is performed according to the classical scheme: on the reverse side of the sheet one layer is applied, on the front side - three or two. The upper and lower layers are made from quality raw materials - bleached waste paper, cellulose or dumass. The insert is made of low-quality waste paper, cellulose or wood pulp;
2. Triplex is an expensive and high-quality type of cardboard. The quality and composition of the liner material does not change. The face and back layers are subjected to two-sided coating, because of what their properties are strikingly different from the characteristics of the duplex.

Differences between coated and uncoated cardboard

The main difference between coated cardboard is the application on its surface of a special composition. White coated cardboard with a smooth surface much better than uncoated analogs retains a printed image for a long time, since it is used mainly for marking, text marks and trade marks of the trademark.

Coated cardboard is often used for the production of products that can not be made from ordinary cardboard for aesthetic reasons, since it is possible to apply polygraphy or a varnishing coating to coated paper. The disadvantages of this cardboard can only be attributed to its high cost.

Classification of coated board

Cardboard coated according to the European classification is divided into several categories: SBB, FBB and WLC.

The first category - SBB, or SBS - means cardboard produced from bleached cellulose and coated with one or two sides with a coated coating. The density of the product is from 185 to 390 g / m ² .

The second type - FBB - is also called a chromoerz. Its density is 170-850 g / m ^2. It consists of three layers, the liner is made of wood pulp, the lower and upper layers are made from bleached chemical pulp. Both sides of the cardboard are chalked.

The third type is WLC. It is a coated cardboard from waste paper with a small addition of wood pulp. The insert is made of cheap cardboard, and high-quality waste paper is used for making the lower and upper layers. Chalking is performed with one or both sides.

In the German classification, coated cardboard is divided into four categories: uncoated, duplex, triplex and cardboard, produced from primary fibers. The manufacturer of the material establishes its own marking.

According to Russian standards, coated cardboard is marked with the letter "M" and some others, indicating additional properties. For example, MNO - coated cardboard on an unbleached basis, MO - cover, from which a cover is made. Coated cardboard from bleached cellulose - M.

Advantages of coated cardboard

The main advantage of coated cardboard is its versatility. The distinctive features of the chrome card include glossy gloss, whiteness, quality composition, the ability to use lacquers. Colored cardboard coated for a long time preserves the clarity, brightness and saturation of the hue. The quality of the materials used and the number of coating layers play an equally important role in preserving color.

Chromokarton is used very widely, due to which its production is profitable and fully pays off, not to mention the fact that in some production areas it is simply irreplaceable.

Scope of application

Originally, cardboard was created and used as an environmentally friendly and safe, affordable, cheap and convenient container for packaging, storing and shipping pharmaceutical, food, agricultural and light products, protecting it from various influences. In the course of time, cardboard packaging became widely used for advertising, marking and marking. Often a box of coated cardboard is manufactured for the production of high-quality packaging.

To create a high-quality coating, the top layers of the face are subjected to complete coating. This type of cardboard is used mainly for varnishing, embossing and transferring images with bright colors. This includes not only packing tubes, boxes and boxes, but also children's goods - toys, sets, printed products, booklets and covers.

High-quality cardboard is used in almost all industries that require special requirements for smoothness and whiteness of the product surface. Coated cardboard is often used as a gift wrapping and food packaging.

Cardboard processing

Coated cardboard is recycled in the same way as usual. Recycling of waste paper in Russia falls on those enterprises that have been working in this service for a long time. The capacities of such corporations allow each year to process about 50 thousand tons.