Three-layer corrugated cardboard is used as a material for the manufacture of cardboard boxes and as a substrate between the pallet and corrugated boxes. It is used for moving, in construction, and in the furniture industry.

Corrugated cardboard consists of one fluting and two liners. Cut into sheets of various formats.

Our company produces white and brown corrugated cardboard.

Stamps

There are several grades of cardboard: T-21, T-22, T-23, T-24, T-25. The capital letter "T" indicates the number of layers "T" - three-layer. The numbers after the letter "T" indicate the quality of the raw materials. The higher the paper density, the stronger the corrugated packaging.

Qualitative characteristics corresponding to all types of corrugated cardboard are specified in GOST R 52901.

Profile

Our company produces corrugated cardboard of profiles “B” and “C”. Profiles differ in fluting height.

"B" (small) - corrugation height 2.2-3.3 mm. It has good strength characteristics, high shock-absorbing strength, and is able to withstand dynamic loads. Used for the manufacture of transport containers.

This standard applies to corrugated cardboard (hereinafter referred to as cardboard), intended for the manufacture of product packaging - consumer and transport packaging (boxes, boxes, trays, etc.), as well as for the manufacture of auxiliary packaging materials (inserts, grilles, shells, gaskets, shock absorbers ) and other products.
Requirements ensuring the safety of cardboard for human health are specified in 5.1.9, 5.2.2.

2. Normative references

This standard uses normative references to the following standards:
GOST 166-89 (ISO 5399-76) Calipers. Specifications
GOST 427-75 Metal measuring rulers. Specifications
GOST ISO 1924-1-96 Paper and cardboard. Determination of tensile strength. Part 1: Constant Speed ​​Loading Method
GOST 7377-85 Corrugating paper. Specifications
GOST 7420-89 Cardboard for flat layers of corrugated cardboard. Specifications
GOST 7502-98 Metal measuring tapes. Specifications
GOST 7691-81 Cardboard. Packaging, labeling, transportation and storage
GOST 8047-2001 (ISO 186-94) Paper and cardboard. Sampling to determine average quality
GOST 9078-84 Flat pallets. General technical conditions
GOST 9557-87 Flat wooden pallet measuring 800x1200 mm. Specifications
GOST 13523-78 Semi-finished fibrous products, paper and cardboard. Sample conditioning method
GOST 13525.8-86 Semi-finished fibrous products, paper and cardboard. Methods for determining bursting resistance
GOST 13525.19-91 (ISO 287-85) Paper and cardboard. Determination of humidity. Oven drying method
GOST 17052-86 Production of paper and cardboard. Terms and Definitions
GOST 17527-2003 Packaging. Terms and Definitions
GOST 19088-89 Paper and cardboard. Terms and definitions of defects
GOST 20683-97 (ISO 3037-94) Container cardboard. Method for determining end compression (non-waxed end method)
GOST 21102-97 Paper and cardboard. Methods for determining sheet dimensions and skewing
GOST 22186-93 (ISO 3034-75) Corrugated cardboard. Thickness determination method
GOST 22981-78 Corrugated cardboard. Method for determining delamination resistance
GOST 27015-86 Paper and cardboard. Methods for determining thickness, density and specific volume

3. Terms and definitions

This standard uses terms according to GOST 17052, GOST 17527 and GOST 19088, as well as the following terms with corresponding definitions:

3.1. corrugated cardboard with uncut width: Corrugated cardboard with a sheet or roll width that best matches the width of the corrugator.
Note - The edge of the sheet or roll across the corrugations is not cut.
3.2. corrugated cardboard with cut width: Corrugated cardboard with a sheet or roll width of a certain size.
Note - The edge of the sheet or roll across the corrugations is cut off.

4. Classification, main parameters and dimensions

4.1. Depending on the number of layers, corrugated cardboard is produced in the following types:

• - D - two-layer, consisting of one flat and one corrugated layer;
• - T - three-layer, consisting of two flat and one corrugated layers;
• - P - five-layer, consisting of three flat (two outer and one inner) and two corrugated layers;
• - C - seven-layer, consisting of four flat (two outer and two inner) and three corrugated layers.

4.2. Cardboard is produced in the classes and grades indicated in Table 1.
Table 1

	Class	Brand
		T11, T12, T13, T14, T15
		T21, T22, T23, T24, T25, T26, T27
		P31, P32, P33, P34, P35, P36, P37
		S41, S42, S43, S44, S45

The purpose of cardboard grades is given in Appendix A.

4.3. Cardboard is made with corrugations of types A, C, B, E, F (Figure 1).

Figure 1 - Image of corrugation

The name of the corrugations and their dimensions are indicated in Table 2.

table 2

Corrugation type	Name of corrugation	Corrugation height, mm	Corrugation pitch, mm
		From 4.4 to 5.5	From 8.0 to 9.5
	Supermicro

4.4. Cardboard is produced:

type D - in rolls or sheets with trimmed and untrimmed widths;

types T, P, S - in sheets with uncut width.

The dimensions of rolls or sheets are determined by agreement with the consumer.
No more than three breaks are allowed per roll. Places of breaks should be marked at the end of the roll with paper strips or colored pencil.

4.5. Maximum deviations in size should not exceed, mm:
- along the length of the sheet;
- according to the width of the sheet or roll.

The slant of the sheet should not exceed 10 mm per 1 m of the length of the cardboard sheet.

Examples of cardboard symbols:

5. Technical requirements

Cardboard must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.

5.1. Characteristics

5.1.1 Cardboard types D, T, P in terms of quality indicators must comply with the standards specified in Table 3; type C cardboard - to the standards specified in table 4.

Table 3

Indicator name	Standard for the brand																				Test methods
	D	Class 1					Class 2							P31	P32	P33	P34	P35	P36	P37
		T11	T12	T13	T14	T15	T21	T22	T23	T24	T25	T26	T27
1. Absolute punching resistance, MPa (kgf/cm2), not less																					According to GOST 13525.8
2. Specific tensile strength with the application of a destructive force along the corrugations along the scoring line after performing one double bend at 180°, kN/m, not less	-	8	10	12	14	16	4	6	7	8	9	10	11	7	10	13	15	17	19	21	According to 7.8 of this standard
3. End compression resistance along corrugations, kN/m, not less	-	3,0	3,0	3,2	3,6	4,0	2,2	3,0	3,8	4,6	5,4	6,2	7,0	5,0	6,0	8,0	10,0	12,0	15,0	17,0	According to GOST 20683
4. Resistance to delamination, kN/m, not less	-	0,2	0,2	0,2	0,2	0,2	0,2	0,2	0,2	0,2	0,2	0,2	0,2	-	-	-	-	-	-	-	According to GOST 22981
5. Humidity, %																					According to GOST 13525.19

Table 4

Indicator name	Standard for the brand					Test method
1. End compression resistance along corrugations, kN/m, not less						According to GOST 20683
2 Thickness, mm	From 12.00 until 27.00	From 12.00 until 27.00	From 12.00 until 27.00	From 12.00 until 27.00	From 12.00 until 27.00	According to GOST 22186
3 Humidity, %						According to GOST 13525.19
Note - The nominal value of the cardboard thickness, depending on the thickness of the cardboard for flat layers and the type of corrugation, is established by the cardboard manufacturer.

5.1.2. Cardboard is made in natural fiber colors, white or any other color.

5.1.3. The edges of the sheet or roll must be clean and even.

5.1.4. The corrugated and flat layers of cardboard must be glued together along the tops of the corrugations.
Non-glued areas in cardboard types D and T, outer layers of cardboard types P and C with an area of ​​no more than 20 cm each are allowed. The sum of the areas of non-glued areas should be no more than 50 cm per 1 m of cardboard area.
Unglued layers of cardboard along the edges of a sheet or roll are allowed for a length of no more than 10 mm from the edge of the edges in all types of cardboard.

5.1.5. The following are not allowed on the cardboard surface: scuffs with an area of ​​more than 80 cm; folds and wrinkles more than 50 mm long; dents and stains more than 15 mm long in greatest dimension; damage to the edge of a sheet longer than 10 mm.

5.1.6. Cardboard warping is allowed if its value does not exceed 20 mm per 1 m of cardboard sheet.

5.1.7. Corrugated layers in cardboard must have a full corrugation height profile. It is allowed to crumple the corrugated profile along the edge of the sheet or roll.

5.1.8. Cracks are allowed on the surface of the outer flat layers of cardboard without exposing the corrugated layer. The sum of crack lengths should not exceed 25 mm.

5.1.9. The intensity of foreign odors, the amount of migrating harmful substances released into model environments for cardboard intended for the manufacture of packaging in contact with food products, medicines, pharmaceutical and perfumery-cosmetic products directly and/or indirectly, must not exceed the standards established in the instructions and hygienic standards.

5.1.10. Cardboard must be recycled as secondary raw materials - paper and cardboard waste.

5.2. Requirements for raw materials and materials

5.2.1. For the manufacture of cardboard the following must be used:
- for flat layers - cardboard according to GOST 7420;
- for corrugated layers - corrugated paper in accordance with GOST 7377 and other similar paper and cardboard, provided that the cardboard quality indicators are ensured in accordance with the requirements of this standard;
- for gluing layers of cardboard - adhesives based on starch products.

5.2.2. Materials for the manufacture of cardboard intended for the manufacture of packaging in contact with food, medicines, pharmaceutical and perfumery and cosmetic products directly and/or indirectly must be approved for use by sanitary and epidemiological supervision authorities.

5.3. Marking

5.3.1. Cardboard marking - according to GOST 7691.

The marking of bales and rolls must contain the following information about the products:

- name of the manufacturer;
- trademark of the enterprise (if available);
- legal address of the manufacturer;
- product name, brand, type of corrugation (or product designation);
- designation of this standard;

- cardboard weight (net) or number of square meters per packaging unit;
- batch number;
- product bar code (if available);
- handling signs “Keep away from moisture”, “Do not handle with hooks”.

5.3.2. It is allowed to include additional information in product labeling that provides the necessary information for the consumer.

For example:
- method of product disposal;
- environmental labeling, etc.

5.3.3. The national mark of conformity for certified products is affixed to cardboard packaging and (or) shipping documentation.

5.4. Package

5.4.1. Cardboard packaging - in accordance with GOST 7691 with the following additions.

5.4.1.1. Rolls and bales of cardboard may be packaged without the use of packaging materials, and packaging is considered to be one sheet at the top and bottom of the bale or one top layer of cardboard in a roll.

5.4.1.2. Bales and rolls of cardboard, packaged according to 5.4.1.1, may be placed on pallets in accordance with GOST 9557, GOST 9078.

6. Acceptance rules

6.1. Cardboard is presented for acceptance in batches.

6.2. Determination of the batch and volume of samples - according to GOST 8047.

6.3. The batch must be accompanied by a quality document, which must contain:
- name of the country of origin;
- name of the manufacturer, its trademark (if any);
- symbol of cardboard;
- cardboard weight (net) or number of square meters in a batch;
- date of manufacture (month, year);
- results of tests performed or confirmation of product compliance with the requirements of this standard.

6.4. Testing of products for compliance with the requirements of this standard according to 5.1.9 is carried out periodically on a batch that has passed acceptance tests: when changing production technology, raw materials and materials, in case of disagreements between the manufacturer and the consumer, during certification tests, as well as at the request of sanitary authorities -epidemiological surveillance.

6.5. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a double sample from the same batch. The results of repeated tests are applied to the entire batch.

7. Control methods

7.1. Sampling - according to GOST 8047.

7.2. Conditioning of samples before testing and testing is carried out according to GOST 13523 at air temperature (23±1) °C and relative air humidity (50±2)%. Conditioning duration is at least 24 hours.
It is allowed to test samples indoors under room conditions if the time from the end of conditioning to the end of testing the sample does not exceed 10 minutes.

7.3. To control the quality of cardboard according to 5.1.3-5.1.8, ten sheets are randomly selected from sheets of cardboard selected from product units according to 6.2, excluding the top and bottom two sheets in the bale.
From each roll selected in the sample according to 6.2, a sheet of cardboard 1 m long is cut at a depth of 2-3 cm from the packaging.
Each sheet is visually inspected on both sides, defects are noted according to 5.1.4, 5.1.5, 5.1.8 and measurements are taken with a metal ruler in accordance with GOST 427 or a tape measure in accordance with GOST 7502 with an error of no more than 1 mm.

7.4. The dimensions and slant of the sheets are determined according to GOST 21102. The width of the cardboard sheets and rolls is measured along the direction of the corrugations.

7.5. To determine the amount of cardboard warping according to 5.1.6, each sheet of cardboard, selected according to 7.3, is placed on a flat horizontal plane with the convex side up and the maximum deviation of the cardboard sheet from the horizontal plane is measured with a ruler in accordance with GOST 427 or a tape measure in accordance with GOST 7502.
The amount of sheet warping, mm/m, is calculated using the formula

where is the maximum deviation of a sheet of cardboard from the horizontal plane, mm;

Actual width of cardboard sheet, m.
The arithmetic mean value of the obtained determinations is taken as the test result. The result, recalculated per 1 m of sheet length, is rounded to the nearest whole number.

7.6. The height profile of the corrugations according to 4.3, 5.1.7 is controlled at any place on the cardboard sheet selected according to 7.3. At a distance of at least 10 cm from its edges, a cut is made perpendicular to the direction of the corrugation. The cutting plane should be perpendicular to the plane of the cardboard sheet. Corrugated and flat layers should not be crushed when cutting.

7.7. The dimensions of the corrugations according to 4.3 are determined at any place in each of the 10 sheets of cardboard sample taken according to 7.1.
Make a cut on a sheet of cardboard as indicated in 7.6. Measurements of the height and pitch of the corrugation are carried out with a metal caliper in accordance with GOST 166 with an error of no more than 0.1 mm.
The test result is taken to be the arithmetic mean of the measurements obtained, rounded to the first decimal place.

7.8. Method for determining tensile strength by applying a destructive force along the corrugations along the scoring line after making one double bend at 180° along the scoring line
The essence of the method is to determine the force causing the destruction of a cardboard sample under the influence of a load after performing one double bend at 180° along the scoring line.

7.8.1. Equipment for crimping and scoring:
- a device (Figure 2), consisting of a scoring part into which a set of couplings is installed for crushing corrugations and scoring samples;

Figure 2 - Device for crushing corrugations and scoring samples

1, 2 - couplings for crushing corrugations or scoring; 3 - device for adjusting the gap between the couplings;
4 - drive device for regulating the speed of corrugation and scoring
Figure 2 - Device for crushing corrugations and scoring samples

Devices for adjusting the gap between couplings;
- a drive device for regulating the speed of corrugation crushing and scoring of samples;
- a set of couplings for crushing corrugations, including two couplings, as shown in Figure 3;

Figure 3 - Set of couplings for crushing corrugations

A set of couplings for scoring specimens, including two couplings, one with a recess and the other with a protrusion, as shown in Figure 4.

Figure 4 - Set of couplings for scoring samples

1 - coupling with a notch; 2 - coupling with projection
Figure 4 - Set of couplings for scoring samples

The dimensions of coupling sets for scoring samples must correspond to those indicated in Table 5.
Table 5

Serving coupling kit number

7.8.2. Preparing for the test

From the selected 10 sheets of sample according to 7.1, one sample is cut from each with a length of (250 ± 1) mm and a width of (200 ± 1) mm so that the larger size is perpendicular to the direction of the corrugations.
Samples must be free of dents, unbonded areas and tears in flat layers of cardboard, with smooth cut edges.
The samples are numbered and the thickness is determined according to GOST 22186 or GOST 27015.
Set the distance between the clamps of the tensile testing machine to 150 mm. It is possible to set a distance of 100 or 50 mm. The loading speed is selected so that the samples rupture occurs within (20±5) s from the moment the load is applied.

7.8.3. Carrying out the test
Tests are carried out under conditions according to 7.1.
The scoring lines are applied to the sample in the following sequence. In the scoring part of the device, a set of couplings is installed for crushing the corrugations with a gap between them of no more than 0.5 thickness of the cardboard being tested, and the corrugations are crushed in the cardboard sample (in several places). The thickness of the cardboard is determined according to GOST 27015.

The corrugations are crushed and scored at a linear speed of (50±5) m/min.

When the corrugations are crushed and when scoring, rupture of the flat layers of cardboard by the edges of the couplings is not allowed. If the cardboard breaks, the size of the gap between the couplings is specified, after which samples cut from the same test sheets are re-scored.

It is allowed to test samples with scoring produced on a corrugator.

After removing the couplings for crumpling the corrugations, a set of couplings for scoring the sample is installed in the scoring part of the device with a gap between them equal to the thickness of the cardboard along the crumple line in combination: the upper one with a recess, the lower one with a protrusion. The selection of a set of couplings is carried out in accordance with Table 6, depending on the thickness of the cardboard after crumpling.

Table 6

Strips with a width of (25±1) mm or (50±1) mm are cut from each sample and scored along the crumple line.
The scoring line should be in the middle of the strip's crease line. For testing, one (second) strip with scoring is taken from each sample, excluding the outer ones. The strips are numbered with the same number as the sample from which they are cut. Before the tensile test, each strip is manually subjected to one double bend along the scoring line by 180°. If the strip breaks after bending, the test is stopped and the cardboard is considered to have failed the test.
The strip is secured in the clamps of the tensile testing machine without distortion, it is loaded until it breaks, and the value of the breaking force in N (kgf) is measured to within one division of the scale of the tensile testing machine.
The test results of strips that break not along the scoring line are not taken into account. Strips cut from the same cardboard samples are tested again.

7.8.4. Processing the results
The breaking force in newtons along the scoring line is calculated as the arithmetic mean of ten determinations. The result is rounded to the nearest 10 N.
Specific tensile strength with the application of a destructive force along the corrugations along the scoring line after making one double bend at 180° along the scoring line, kN/m, is calculated by the formula

where is the breaking force, N;

Sample width equal to 0.025 or 0.05 m.
The result is rounded to the nearest whole number.
The relative error in determining the breaking force and tensile strength is no more than 4% with a confidence probability of 0.95.
The arithmetic mean of ten measurements obtained is taken as the test result.

8. Transportation and storage

8.1 Transportation and storage of cardboard - according to GOST 7691.

8.2 Cardboard must be transported by all types of vehicles in clean, dry, covered vehicles in accordance with the rules for the carriage of goods in force for the relevant type of transport. Cardboard should be stored indoors at a relative humidity of 40% to 80%.

Table A.1

Brand	Purpose
	For the production of packaging aids
	For the manufacture of containers and auxiliary packaging means for packaging products, capable of withstanding static (stack loads) and dynamic loads
T21-T27; P31-P34	For the manufacture of containers and auxiliary packaging means for packaging products that are not capable of withstanding static loads (stack loads)
	For the production of large-sized containers

Corrugated cardboard - what is it? When hearing this word for the first time, not everyone will understand what we are talking about. And this material is quite common in industry. Ordinary buyers meet it when purchasing equipment. You probably already guessed what kind of material this is. Right! Corrugated cardboard is used to make packaging. Why not ordinary and familiar cardboard? And everything is extremely simple. The special technology used in the manufacture of this material makes it possible to protect the contents of the boxes from deformation as much as possible.

Short description

So, corrugated cardboard - what is it? This is a material for the production of which paper and cardboard are used. It is worth noting that these resources are taken exclusively from waste paper, thereby showing concern for the environment. The only drawback of corrugated cardboard is its low level of moisture resistance.

A little history

Corrugated paper first appeared in 1856 in Great Britain. It was used as a lining for hats. And fifteen years later, corrugated cardboard was patented. What is it, how does it differ from ordinary cardboard and how did its production develop?

First of all, it consists of several even layers, between which there is a corrugated layer. Mass production began in 1874. After that, this material quickly gained popularity throughout the world. Currently, there are more than 1.5 thousand enterprises that produce corrugated cardboard.

Classification

Nowadays, enterprises offer several types to choose from, which differ in leaf structure.

Popularity of corrugated cardboard

A lot depends on the packaging of goods. Firstly, the container must protect the contents from any type of damage. In addition, it is where the main information about the product and its main characteristics is located.

One of the most common materials for making boxes and boxes is corrugated cardboard. It has a lot of advantages, which makes it stand out among other options. Corrugated cardboard is made from recycled waste paper, so the cost of the material is relatively low. A large selection makes it possible to choose the type of density that will be optimal in a particular situation.

Advantages

Corrugated cardboard is almost one hundred percent cellulose. This makes it extremely cheap. This fact, in turn, relieves the manufacturer from the need to increase the price of the product in order for the packaging to pay off. In addition, purchasing it in bulk is also beneficial. This material has proven itself well due to its protective properties. The special structure allows for excellent shock absorption, which ensures the safety of the product even after an impact. Of course, the larger the corrugation and the more layers, the higher the effect will be. There are types that can compete with plastic in their strength.

In addition, this material can be given any shape. To do this, you do not need to use complex, expensive technologies: boxes of even the most intricate design are assembled from one or several sheets (fastened together using staples or adhesive tape). Corrugated cardboard containers are very light. Even the strongest box made of dense material weighs so little that a child can easily lift it. This quality greatly simplifies the work of loaders. It is also extremely compact. When disassembled, the box will easily fit into a small niche, and when the need arises, it can be easily returned to its previous state and reused.

It should also be said that the production of corrugated cardboard is an environmentally friendly process, during which predominantly natural ingredients are used. Therefore, even if such containers are thrown away, they will not cause harm to the environment, since it only takes a few years for the material to completely decompose. In this case, destruction occurs naturally without the use of auxiliary means.

The ability to reuse raw materials (recycling) is a great advantage in our time. This makes it possible to reduce the cost of production and the products themselves.

A few words about the manufacturers

Russian corrugated cardboard manufacturers are divided into four groups. The first includes companies that produce only raw materials: OJSC Karavaevo, OJSC Bratsky KCC, LLC Alatyr Paper Mill, etc.

The second group consists of full-cycle production facilities, where the process takes place from the production of raw materials to the production of corrugated cardboard. This includes OJSC Perm Pulp and Paper Mill, OJSC Arkhangelsk Pulp and Paper Mill, etc.

The third group includes companies operating on the partial purchase of raw materials: OJSC PEF Soyuz (Moscow), CJSC Stora Enso Packaging, etc.

But the fourth is a production facility that produces finished containers from imported corrugated cardboard. An example of such a company is the Moscow Cardboard and Printing Plant.

How to make corrugated cardboard yourself?

Making corrugated cardboard with your own hands is not difficult. To do this, you will need to take cardboard of different thicknesses, scissors, a ruler and glue. We make an accordion from a thin sheet, that is, we bend the paper in the form of a fan. To make the ribs a little wider, you can place a small strip between them. It is important that the distance between the folds is as equal as possible. After this, carefully first glue one side of the ribs to thick cardboard. After this, wait until the glue dries. After waiting this time, you can proceed to the second side. Using this principle, corrugated cardboard is made with a different number of layers.

Cardboard in Russia accounts for about 35% of all packaging produced. In the eyes of the consumer, packaging made from corrugated cardboard is as convenient and practical as possible. In addition, it is durable, lightweight, compact, can be used for a wide variety of products, is highly environmentally friendly and is suitable for any printing method. In this article we will tell you what corrugated cardboard is in general, what it comes in and what it consists of.

Types and types of corrugated cardboard

Corrugated cardboard (corrugated cardboard) is a multilayer structure consisting of flat (in foreign literature they are called liners) and wavy corrugated layers of cardboard (they are called fluting), connected together with glue.

Thanks to this design, it has various properties. When forces are applied in the direction perpendicular to the corrugations, corrugated cardboard acts as a shock-absorbing material, and when loaded along the direction of the corrugations, it exhibits high rigidity, which is provided by the corrugated layer. Flat layers of corrugated cardboard fix the position of the wavy layers, therefore they absorb compressive, tensile and pushing loads.

The type and type of corrugated cardboard is selected based on the requirements for the strength indicators of containers and packaging, which ensure the safety of the product, the requirements for the appearance of the container, the quality and method of applying an image to it, the type and technology of finishing processes, the technology and equipment for mechanical forming processing, gluing and folding.

Corrugated cardboard is characterized by the following indicators:

• number of layers;
• type and brand, weight 1 m 2 and thickness of cardboard for flat layers;
• type and brand, weight 1 m 2 and thickness of cardboard for corrugated layers;
• geometric parameters of corrugated layers;
• thick.

Evolution of waves

The possibility of using corrugated cardboard as packaging for glass flasks and bottles was first identified by the US inventor Albert L. Jones in 1871. His patent No. 122023, entitled “Improved Paper in Packaging Plants,” needed improvement, and was issued on August 25, 1874. Patent No. 154498 was issued for double-layer corrugated cardboard. Its owner, American Oliver Long, proposed gluing a flat sheet of paper to corrugated cardboard, placing it on the surface of the container being packaged.

In 1875, the Thompson and Norris company was formed in New York, which began to master the technology of new packaging. In 1881, a mechanically driven machine for producing two-layer corrugated cardboard and winding it into a roll was released in the USA, and at the end of the next year the first machine for mechanized gluing of a paper layer was manufactured there. On January 17, 1882, American Robert Thompson received a patent for three-layer corrugated cardboard, which was originally made by manually gluing a flat layer onto the corrugation in the form of sheets or blank shapes. In the same year, Thompson and Norris begins production of two- and three-layer corrugated cardboard, and a year later opens Europe's first corrugated cardboard factory. In 1886, this company opened a corrugated cardboard production plant in Kirchberg in Germany, and in 1888 - in France. An important step in the further improvement of the design was the introduction of five-layer (double-wave) corrugated cardboard in 1916, and in 1953 - seven-layer (three corrugated layers and four flat).

The types and sizes of corrugations gradually changed. Initially, they roughly corresponded to the modern corrugation A, in 1905–1906. corrugation B appeared, in 1925 - corrugation C, in 1951 - corrugation E.

Depending on the number of flat and wavy layers, corrugated cardboard is divided into the following types:

A) double-layer corrugated cardboard, consisting of flat and wavy (corrugated) layers, symbol D.

This type of corrugated cardboard is flexible and rolls well, although it can also be produced in sheets.

b) three-layer corrugated cardboard(T).

It is made of one corrugated layer and two outer flat layers glued to it. This, as well as subsequent types of cardboard, is rigid and is produced only in sheets.

V) five-layer corrugated cardboard(P).

Consists of two corrugated, three flat (two outer and one inner) layers.

G) seven-layer corrugated cardboard(WITH).

Seven-layer corrugated cardboard consists of three corrugated, two flat outer and two flat inner layers.

The following classes and grades of corrugated cardboard are produced in Russia.

D	–	D
T	1	T11, T12, T13, T14, T15
	2	T21, T22, T23, T24, T25, T26, T27
P	3	P31, P32, P33, P34, P35, P36, P37

Double-layer corrugated cardboard I-D is made with corrugations B and E. It does not have the rigidity necessary for boxes, so it is used as a cushioning and wrapping material. Supplied in rolls.

Three-layer corrugated cardboard II-T is most widely used in the production of container boxes. It is distinguished by grades T21, T22, T23, T24, T25, T26, T27 (the letter T means three-layer; numbers 21, 22–27 are grades). The larger the number after the letter T, the higher the quality of the cardboard.

Examples of symbols in the drawings of two-layer corrugated cardboard boxes with corrugation A: Cardboard DA GOST 7376-89, three-layer 1st class brand T11 with corrugation C: Cardboard T11 C GOST 7376–89. The same with “chrome-ersatz” cardboard or cardboard with a white (cloudy) cover layer of five-layer grade P32 with corrugations A and B: Cardboard P32 EB AB GOST 7376–89.

Five-layer corrugated cardboard (III-P) is used in the construction of large container boxes with greater resistance to resistance and compression. This container box is used for packaging large and heavy products. III-P corrugated cardboard is produced only in sheets. The variety of grades of III-P corrugated cardboard is associated with a possible combination of the grades included in its composition: three flat and two corrugated layers. When symbolizing the relative position of corrugated layers, the first letter indicates the type of corrugation profile of the outer layer of the box, and the second letter indicates the type of profile of the inner layer. The most widespread is III-P corrugated cardboard with an outer corrugated layer of type B and an inner corrugated layer of type A (B-A). In technically justified cases, other options for the arrangement of corrugated layers are used: A-B; B-C; NE; S-S. Recently, to increase strength, various combinations with micro-corrugation have been used: A-E; B-E; S-E.

Seven-layer corrugated cardboard (IV-C) is used in the construction of especially strong boxes and container boxes with a load capacity of up to 200 kg with the order of corrugations S-A-K.

The most widespread is corrugated cardboard with the order of corrugations E-A-B. The outer layer with E corrugation provides high rigidity in both directions, absorbs strong impacts, and reduces surface warping. The middle layer with corrugation A improves elasticity and the ability to absorb shock loads. The inner layer with corrugation B has sufficient rigidity and resistance to in-plane compression to withstand the pressure of the packaged product from the inside of the box.

Cardboard for flat layers

Flat layers of corrugated cardboard (liners) ensure that its shape is retained, and their quality largely determines the properties of the finished product, including its ability to withstand various loads under operating conditions, as well as the appearance of the packaging. For them, you can generally use any cardboard that is suitable for gluing, but in practice special grades are used that provide high strength, resistance to impacts and other types of influences. They are called kraft cardboard (or kraft liner), which translated from German means durable or strength cardboard.

Kraft cardboard usually consists of two layers, bonded together in a glueless manner on a board making machine. The top layer has increased strength, smoothness and porosity. Strength ensures corrugated cardboard's resistance to abrasion and tearing during creasing and folding, while smoothness and porosity ensure good appearance and high printing properties. The bottom layer gives the kraft cardboard the required rigidity and strength, and also determines its ability to adhere to the corrugated layer.

The most attractive appearance and high printing properties are distinguished by kraft cardboard with a top layer of sulfate cellulose. The bottom layer consists of recycled waste material. Some brands of flat ply are made entirely from kraft pulp: this type of product is called whiteboard.

Recently, recycled waste mass has begun to be used more widely for the production of flat layers. The strength and rigidity of such materials is lower than that of kraft cardboard. But the possibility of using waste from the pulp, paper and printing industries makes them very promising for use as internal flat layers of corrugated cardboard.

To give corrugated cardboard and its containers special properties, the following types of flat layers are produced for external finishing:

• multi-colored, plain, and also with “marbled” or “cloudy” tints;
• laminated or with various other coatings that increase moisture resistance, resistance to abrasion, punctures, etc.

The most widely used cardboard is for flat layers with a specific weight of 1 m2 of 125, 150, 175 and 225 g/m2. For the most durable and rigid types of corrugated cardboard, flat layers with a mass of 1 m 2 from 200 to 450 g/m 2 are used. In Russia, 5 grades of cardboard are produced in accordance with GOST 7420–89E for the production of flat layers: K-0, K-1, K-2, K-3 and K-4. Cardboard grades K-0 and K-1 are produced from 100% sulfate cellulose. For K-2 grade cardboard, sulfate cellulose is used only for the top cover layer. Grades K-3 and K-4 are not standardized in terms of fiber composition.

Cardboard for corrugated layers

Cardboard for corrugated layers is required to preserve the profile and dimensions obtained during the corrugation process both when compressing the layers of corrugated cardboard and during the manufacture and operation of the container.

In Europe, cardboard for corrugated layers is most often produced with a weight of 112, 127 and 150 g/m2, and for severe operating conditions and critical container designs - with a higher specific weight: 175, 200 and 250 g/m2. In Russia it is called corrugating paper and is produced according to GOST 7376–89 in three grades: B-1, B-2 and B-3. Brand B-1 consists of 25% sulfate unbleached cellulose and 75% semi-cellulose, B-2 contains 25% sulfate cellulose and 75% high-yield semi-finished products (high-yield semi-cellulose), B-3 – 35% sulfate cellulose, the rest of the composition fibers are not standardized. The production of paper for corrugation in Russia is carried out by many enterprises, including those that previously specialized in other products.

As a rule, all physical and mechanical indicators comply with the requirements of GOST 7376–89, with the exception of the resistance to in-plane compression of a corrugated sample.

Micro-corrugated cardboard

This material has been used on the Russian market for more than 7 years as a starting material for the manufacture of individual packaging and is becoming increasingly popular. In recent years, the use of packaging made from it and its production have increased tenfold.

Microcorrugated cardboard is a three-layer corrugated cardboard with a thickness of 0.9–1.8 mm. This is its main difference from simple corrugated cardboard, the thickness of which is 2.5–5 mm. Both materials are used for individual and group packaging and, due to their rigidity and strength, act as transport containers, however, if corrugated cardboard is recommended for packaging products weighing more than 3 kg, then micro-corrugated cardboard is used for lighter goods.

Microcorrugated cardboard is used for the manufacture of product packaging with a colorful liner applied to it. Corrugated cardboard is more often used for transport packaging, although it is also customary to apply color printing to modern packaging for advertising purposes.

Microcorrugated cardboard varies in the quality of flat layers (brown, white, coated). White has high-quality white paper as a base (the bottom layer of open corrugation), brown has lower quality paper made from recycled materials (waste paper), which has a gray color.

With a thickness close to regular cardboard, micro-corrugated cardboard has a number of advantages:

• the box turns out to be light, but quite durable, it better protects the goods inside, and thanks to its multi-layer structure, it is less damaged;
• ideal for packaging both large and small products, for example in the food, cosmetics and pharmaceutical industries;
• “Microwaves” make it possible to make even very small boxes, for which only thin, and therefore fragile, varieties are suitable for producing from simple cardboard;
• its design capabilities allow you to create real designer “masterpieces” from it, which is very important, for example, when wrapping gifts.

These properties can be used to create small advertising forms and structures, up to shop windows and displays for placing goods in supermarkets. At the same time, microcorrugated cardboard is cheaper and more environmentally friendly than materials traditionally used for these purposes.

But even despite the obvious advantages over “standard” cardboard, micro-corrugated cardboard has only in recent years begun to occupy a leading position in the segment of packaging materials. A significant portion of industrial, household and personal goods are still packaged in familiar cardboard boxes.

In this situation, most likely, a significant role is played by the conservatism of manufacturers and the dubious desire to “save” on the packaging of their products. Standard cardboard boxes, compared to micro-corrugated cardboard packaging, have a number of significant disadvantages that significantly cover all the savings from their use: susceptibility to deformation during transportation; rapid loss of attractive appearance; fragility; low presentability.

Manufacturers, for whom their own image, convenience for customers and the attractive appearance of the packaging of the goods they sell play an important role, have long taken care of “eradicating” all of the above-mentioned shortcomings of packaging products for their products and switched to micro-corrugated cardboard, which has virtually no all the noted shortcomings. In addition, micro-corrugated cardboard is an inexpensive and promising type of packaging material, characterized by increased stability compared to cardboard boxes, which, combined with a number of other advantages, makes it almost ideal for the production of containers and packaging. In the price category under consideration, it has no direct competitors among packaging materials, with the exception of ordinary corrugated cardboard, which is far from the attractiveness that micro-corrugated cardboard laminated with a full-color liner gives. But the attractiveness of product packaging is the most important argument in favor of choosing a product. It should also be noted that for things that are used periodically (tools, household goods, seasonal toys, sporting goods), it is important to maintain the packaging intact for storage purposes.

Today, corrugated cardboard is the most popular packaging material. This is due to the fact that it is characterized by light weight and low cost. Thanks to these advantages, corrugated cardboard has been in high demand for a long time, both among consumers and among manufacturers of packaging and containers.

Depending on the structure characteristic of corrugated cardboard, the following types are distinguished:

1. Double-layer corrugated cardboard Includes one flat layer and one layer of corrugated paper. In the production of two-layer corrugated cardboard, starch or silicate glue is used. In accordance with GOST standards, this type is marked with the letter “D”. Double-layer corrugated cardboard is easily wound into rolls.

Its main areas of application are packaging for light bulbs, the furniture industry and it is used as a shock absorber during transportation. Colored two-layer corrugated cardboard is used to create gift packaging and in the production of souvenirs.

2. Three-layer corrugated cardboard consists of 2 flat and 1 corrugated layer. Numbered with the letter “T” in accordance with GOST. Currently, this type of corrugated cardboard is used in the production of packaging, cardboard boxes, in industry and construction.

3. Five-layer corrugated cardboard marked with the letter "P". This type of corrugated cardboard includes 3 flat and 2 corrugated layers, which alternate relative to each other. It is used for the manufacture of durable and reliable packaging for meat processing products, dairy products and for the production of large boxes for household appliances.

4. Seven-layer corrugated cardboard consists of 3 corrugated and 4 flat layers. This type of corrugated cardboard is numbered with the letter “C”. Seven-layer corrugated cardboard is the most durable and is used for the production of boxes for heavy products, as shock-absorbing gaskets, liners and in construction when installing partitions, to fill openings.

Corrugated cardboard is also classified by profile type

Corrugated cardboard profile– indicator characterizing the corrugated part. Corrugations of packaging material are characterized by two indicators: h – height and t – pitch. Various combinations of these indicators are usually called a profile.

Modern corrugated cardboard can be of the following profiles: A, N, B, D, K, C, E, N, G and O. Corrugated cardboard of profile E is in greatest demand, the pitch of which is 3.2-3.6 mm, and the height is 1 ,1-1.6 mm. Profile parameters: O, F and K are not described in the standards and are used conditionally.

The brand of corrugated cardboard refers to its strength characteristics: density, resistance to punching and end compression, wet strength, tensile elongation.

The most common brands of corrugated cardboard are:

• Three-layer corrugated cardboard: T-11, T-15, T-12, T-14, T-13 - these materials are used for the production of small and medium-sized boxes, which are subsequently decorated artistically. Corrugated cardboard grades: T-21, T-25, T-22, T-24, T-23 are used in almost all industries. Corrugated cardboard boxes made from such materials can withstand loads of up to 20 kg.
• Five-layer corrugated cardboard: P-31, P-33, P-32 - these packaging materials are characterized by excellent strength characteristics. Containers made of five-layer corrugated cardboard can withstand a load of no more than 100 kg.

The numbers in these markings indicate the density of corrugated cardboard; the color of the packaging material can be either white or brown. Things to consider when choosing corrugated cardboard.