First, the classification of cardboard materials

Paperboard materials are classified by weight per unit area.

In the mainland market, there are mainly the following kinds of paper plates.

K paper: 250g/M*M A paper: 175g/M*M B paper: 125g/M*M (these three kinds of paper are generally imported) 7 paper: 200g/M*M 8 paper: 260g/M*M C paper:/kloc.

Core paper: basic 100g/M*M machine105-10g/m * m reinforced core paper:+paper 1 15g/M*M Other reinforced cores depend on the customer's situation. In Taiwan Province Province, there are 65,438 people. 190g/M*M reinforced core paper, but Chinese mainland has 140 g, 150 g and 180 g/m * m reinforced core paper.

Two. Cardboard structure

1, cardboard structure refers to the number of cardboard combinations, which can be made according to customer requirements, from five layers of K ⅲ K and K ⅲ A to three layers of C ⅱ.

2. Pit (wave) refers to the hole in the cross section of cardboard. Common waves are A wave, B wave, C wave, D wave and E wave. The mainland generally uses B waves, C waves and E waves.

3. Wave height: A wave = 5 mm, B wave = 3 mm, C wave = 4 mm, D wave = 2 mm, E wave = 1.5mm, two waves of five-layer paper are composed of BC pits, and single-layer paper generally uses B pits.

3. Carton form

Cartons are generally divided into A-type, B-type and C-type, packaging cartons and beer boxes, knife cards and partitions.

1, type A: A 1 Common: general standard; A3: bottomless, with bottom and no cover or with cover; A5: Double covers are completely staggered.

2. The partition refers to the cardboard that protects the upper, middle, lower, left and right objects in the carton. A knife card refers to a paper card with a cut and a chain when objects on the same floor are packed in a honeycomb-like nest.

3. Type C is a paper box for shoes, with a top cover.

4. Packing carton: It is similar to A5 carton, but generally it is directly packed with adhesive tape, which is divided into middle opening or side opening without nailing.

Carton material introduction, if good, you should get extra points.

So K paper seems to be the best paper.

Generally, B=B is used, and the paper thickness is about 6mm. This material is the lowest. If the guest has a request, you can also use a = b. This material has better strength and higher price than B = B

The paper quality of A=A is better than that of A=B and B=B, with a thickness of 6mm and a high price, unless otherwise specified.

The first letter (such as K A B) indicates the outer paper, the middle symbol (such as =) indicates the number of layers, and the last letter indicates the inner paper.

W- white outer box A- good yellow box B- slightly worse yellow paper K- paper is the best and the most expensive.

W=A five-layer good paper white box W=B five-layer slightly poor paper white box W=A=B five-layer good outside and slightly poor inside white box (this is universal)

A=B five-story yellow box (this is universal) 3A=B three-story yellow box (middle) 3B three-story yellow box (poor) doll car

A=B Five layers of yellow A=A Five layers of yellow W=A Five layers of white W=B Five layers of white.

A3A three-layer yellow W3A three-layer white outer box W3K three-layer white outer box 3A three-layer yellow outer box (good)

Tissue paper: W stands for160g white cow card; K stands for 230 grams of cattle card; A stands for 175g Niuka; B stands for127g Niuka; C stands for127g of cowhide vermicelli (imitation cow card);

Development of packaging carton printing technology

Printing process is an important process in the post-processing of corrugated boxes. For a long time, corrugated box has been widely used as the main form of single transport packaging, which also determines that its printing technology stays in the simple line-mounted printing stage and has not developed rapidly.

However, with the continuous development of the packaging market, the single transportation function of cartons has gradually changed to the sales function, and consumers' purchasing psychology and aesthetic concept have also changed. The continuous growth of export commodities also forces domestic carton production to go international. On the one hand, the requirements for post-press processing are getting higher and higher, on the other hand, there are also requirements for the environmental protection performance of products. A wallpaper box shoulders the dual tasks of commodity transportation, commodity display and promotion. Its colors are more and more bright and dazzling, and the pattern printing is more and more exquisite. Only in this way can we attract customers' interest and stimulate their desire to buy. This requires that corrugated boxes should not only meet the strength, but also have excellent surface printing quality. Multicolor printing will gradually become the development direction of carton printing in the future.

Introduction of carton printing technology

At present, there are various printing methods of corrugated boxes in China, mainly including offset printing, flexographic direct printing, flexographic or gravure pre-printing, screen printing and digital printing which has just emerged in recent years. Among them, flexographic printing of corrugated box ink occupies the main market of carton printing with its advantages in plate, ink, printing pressure and printing efficiency. Each printing method has its advantages and disadvantages and applicable printing range, and the appropriate printing process should be selected according to the actual situation and the characteristics of carton products.

Carton offset printing technology

Offset printing has the advantages of simple plate-making process, low cost and high speed. It is the most widely used indirect printing technology at present, and has always occupied a leading position in book, newspaper and paper packaging printing. The graphic part and blank part of the printing plate are almost on the same plane. When printing, water is supplied to the printing plate to wet the blank part, and then ink is applied. By applying the principle of oil-water repulsion, the ink is transferred to the blanket and then to the substrate, thus completing the printing process.

Offset corrugated box printing is divided into offset indirect printing and direct printing. Indirect printing method is to print corrugated box paper first, and then reload corrugated paper with a single machine. The number of screen lines of offset printing products can reach 200 lines/inch, with exquisite patterns, stable quality and superior quality. PS version is easy to make plate, and can also be used for surface finishing processes such as laminating and glazing, which occupies a considerable proportion in the printing of high-end sales packaging cartons at present.

Although offset printing technology is mature and printing speed is fast, this method is not suitable for paperboard linkage production line, and the production efficiency of finished products is low, the process is complicated and the cycle is long. Due to the use of fountain solution in offset printing, the water content of the base paper will increase, and improper control will easily lead to overprinter ban. In addition, the pressure of offset printing is high and the printing format is limited, which can not meet the needs of mass carton production.

From the processing technology of cardboard, the process of mounting after offset printing will also leave too much water in the glue, which makes it difficult for the technical indexes such as flat compressive strength and adhesive strength of cartons to meet the requirements of high-end goods for packaging. In addition, relatively environmentally friendly ink has not been used in offset printing at present, which is another obstacle affecting its use and promotion.

The development and use of micro corrugated paper products is the development trend of carton industry in the future, and offset printing is the best way for its printing processing. At present, the direct offset printing technology of corrugated boxes is relatively mature abroad, and corrugated boards can be printed directly on special offset presses during production. This process can not only ensure the formability of the carton, but also complete the exquisite printing of tissue paper. However, the printing press is demanding and expensive, so it will not be widely used in domestic small and medium-sized enterprises for a long time.

Carton flexo printing technology

Flexographic printing technology adopts elastic photosensitive resin plate, in which the graphic part is convex and the blank part is concave, and the ink is transferred by short ink path printing with scraper and anilox roller, which belongs to relief printing technology.

The production technology of flexographic cartons is also divided into two ways: flexographic direct printing and preprinting. Direct printing is printing directly on corrugated board with water-based ink, which is widely used in carton printing in China at present.

Flexographic printing has the advantages of large format, multi-color and high quality. The maximum width of wide flexographic printing machine can reach 2.5m~2.8m, and the satellite flexographic printing unit can print six colors at the same time. Flexo printing uses different screen numbers to express patterns, which can make the dots delicate, colorful and consistent. In addition, the flexographic printing method is light pressure printing, which has little damage to the strength of corrugated board. Printing with water-based ink is low in price, environmentally friendly and suitable for packaging export commodities. This method can be linked to production, printing, slotting, indentation and other processes can be completed at one time, which is more efficient than the processing method of offset printing first and then mounting.

However, due to the deformation of flexography under pressure, the problems of ink transfer and printing pressure are difficult to control, and the highlights of patterns are easily lost or seriously increased. In the dark tone part, the dot will be in the field state around 85%, and the range of reproducible tones is narrow, only about 8% ~ 85%. Therefore, some manuscripts with rich levels are difficult to present their rich levels and colors with flexography. When using flexography to process cartons, the general production speed is about1000-300m per minute. Although the speed of many flexographic printing machines can reach 600m per minute, if cartons are printed at this speed, many printing failures will occur due to many factors such as ink formula and substrate surface treatment. In addition, in the process of high-speed printing, it is difficult to maintain the stability of the equipment, so it is difficult to overprint beautiful patterns of various colors. This makes the printing quality of most cartons directly printed by flexography in the middle and low level, and the printing speed needs to be improved.

With the development of flexographic printing technology and the improvement of ink quality, the problem of flexographic printing speed will be gradually improved. For example, the closed ink scraping system can fully ensure that the surface area of ink contacting the anilox roller is small, and the diamond, hexagonal and other edge meshes can provide better ink flow, which can better maintain the effective ink supply of the ink system in high-speed printing machines.

Carton preprinting technology

Pre-printing methods mainly include intaglio pre-printing and flexographic pre-printing, among which intaglio pre-printing is the main method, which is a process of printing on a web with an intaglio or flexographic printer, collecting materials into a web after printing, then making the printed web into corrugated board as carton face paper, and then die-cutting into boxes. Pre-printing is done directly on smooth paper. Compared with printing on the surface of cardboard, it can carry out exquisite color printing with richer layers and brighter colors, and the quality is more stable and reliable. Pre-printing technology avoids the damage of direct printing to the strength of cartons, and the printing quality of cartons is relatively high. By using the web printing method, the paper can be changed without stopping, which is suitable for producing high-quality and large-scale products. Pre-printed patterns are used in the production of corrugated cardboard, and pattern factors should be considered when cutting. Therefore, the photoelectric tracking crosscutting control system should be installed on the crosscutting knife to make the cardboard cut accurately at the border of the pattern.

China Inspection Standard for Packaging Cartons

The base paper used by carton production enterprises in China can be simply divided into imported base paper and domestic base paper if it is divided according to the origin; According to the variety of base paper, it can be divided into kraft paper board (also called kraft paper board in China), corrugated base paper, high-grade white board for packaging and printing, dried kraft paper, coated kraft paper board and so on. Due to the rapid development of carton industry in China, the demand for base paper is increasing year by year, especially coated kraft paper board. Because it not only has the advantages of kraft paper board and coated white board, but also has the strength of kraft paper board and printability of white board, the import volume is increasing significantly. In recent years, although the overall quality of domestic base paper has been greatly improved, there is still a gap compared with the quality of foreign base paper, and even if individual paper mills can reach the same level abroad, some low-gram-weight, high-strength kraft paper and corrugated paper production can not meet the demand at present because of limited production capacity. Most of them still rely on imports. China's inspection and quarantine departments have specific regulations on imported base paper: according to the provisions of the Commodity Inspection Law, the goods listed in the category catalogue must be inspected by the inspection and quarantine institution or its designated inspection department, and may not be sold or used without inspection. Most of the carton base paper imported from China belongs to legal inspection, so it must be inspected. At present, the inspection standards followed by the inspection and quarantine departments in inspecting these papers are roughly as follows:

1. Mandatory standards of laws and regulations or other inspection standards that must be implemented;

2. If there are no mandatory standards or other inspection standards that must be implemented in laws and regulations, the inspection can be carried out according to the standards agreed in the contract between the two parties to the transaction. (If the mandatory standards of laws and regulations are lower than those agreed in the contract, the standards agreed in the contract shall prevail);

3. Neither of the above two points can be inspected according to the standards of the producing country, relevant international standards or the standards designated by the national inspection and quarantine institutions. If there is no suitable testing standard, the approved internal standard method should be selected.

The second point above needs special explanation here. During the actual inspection, we found that most domestic users did not have enough stipulations on the quality terms of imported base paper in the trade contract, or even no stipulations. They often only recognize the brand and origin, but ignore the quality fluctuation of the product itself. In the first half of this year, several batches of imported paper were found to have quality problems after inspection by China's inspection and quarantine departments. However, because the customer has not agreed on the quality requirements and inspection standards for receiving goods in advance in the contract, it is difficult for the inspection and quarantine department to issue unqualified certificates, which brings trouble to the customer's claim for return. Therefore, we call on enterprises that import base paper to stipulate quality clauses in their contracts to protect their own interests.

The specific inspection contents of paper include: safety, hygiene, environmental protection, quality, quantity, weight, packaging and other items. Due to the limitation of space, we only introduce the routine physical detection items, methods and standards used.

1. Appearance inspection:

The appearance inspection of paper is one of the important inspection items, which generally consists of on-site sampling inspection by inspectors and laboratory inspection. The appearance defects of paper not only affect the appearance of paper, but also affect the use of paper. We adopt ISO and TAPPI standards, as well as SN/T 0874-2000 and GB/T 154 1 dust detection. It mainly adopts aiming inspection, head-up inspection, strabismus inspection and palpation inspection. The paper is required to be flat and clean, and no passbook is allowed.

2. Physical performance test

Before the physical performance inspection, the paper must be pretreated at constant temperature and humidity according to the standard. Because different papers need different inspection items, here are mainly listed:

(1) whiteboard paper

Good whiteboard paper generally requires dense texture, smooth surface, uniform thickness, lint-free, good absorption and low shrinkage, which can meet the requirements of multi-color overprinting. In order to meet the requirements of box making, whiteboard paper should also have the characteristics of high stiffness and good folding resistance. Major importing countries: Korea, Indonesia, the United States, Japan, etc. Especially the white board made in Japan is of better quality. Test items include: basis weight, thickness, whiteness, smoothness, breaking length, bursting strength, folding endurance, sizing degree, stiffness and IGT.

(2) Cowhide cardboard:

Cowhide cardboard, called box board paper in China, is one of the main types of carton paper. Domestic cardboard is divided into three grades: excellent, first-class and qualified. Kraft paper must be tough in texture, with high bursting strength, ring crush strength and tearing strength, and also with high water resistance. Generally speaking, the quality of most imported kraft paper is better than that of domestic kraft paper, especially the cow card made in the United States, because of the differences in technology and materials, the quality is the best. Test items include: basis weight, thickness, compactness, bursting strength, bursting index, ring crush strength, transverse ring crush index, breaking length, tear degree, sizing degree, moisture, difference in basis weight of banners, transverse folding endurance, etc.

(3) The inspection items of coated kraft paper and dried kraft paper refer to kraft paper and paperboard.

(4) corrugated base paper:

Corrugated base paper is one of the important components in corrugated board production. Corrugated base paper requires good fiber bonding strength, smooth paper surface, good tightness and stiffness, and certain elasticity to ensure that the manufactured carton has shock resistance and pressure resistance. In addition, it is necessary to control the moisture index. If the moisture is too small, the paper will be fragile and will break during corrugated paper processing. Too much moisture and too soft paper will bring difficulties to processing and molding. Generally, the water content of paper should be controlled at about 10%. Domestic corrugated paper is divided into four grades: A, B, C and D.

Test items include basis weight, thickness, compactness, bursting strength, ring compressive strength, transverse ring compressive index, flat compressive strength, breaking length, sizing degree, moisture, etc. The methods and standards used in testing mainly include: GB, SN, ISO, TAPPI, SCAN, JIS, etc. Here is a simple example of China inspection standard:

1.GB/T 45 1.2-2002 Quantitative Determination of Paper and Board

2.GB/T 451.3-2002 Determination of paper and paperboard thickness

3.GB/T 453-2002 "Determination of tensile strength of paper and paperboard (constant speed loading method)"

4.GB/T 454-2002 "Determination of bursting strength of paper"

5.GB/T 455-2002 "Determination of Tear Degree of Paper and Board"

6.GB/T 456-2002 Determination of Smoothness of Paper and Board (Buick Method)

7.GB/T 457-2002 Determination of folding endurance of Paper (Sauber Method)

8.GB/T 458-2002 Determination of air permeability of paper and board (Sauber method)

9.GB/T 459-2002 "Determination of flexibility of paper and paperboard"

10.GB/T 462-2003 determination of moisture in paper and paperboard

11.GB/t13024-2003 "Boxboard"

12.gb/t13023-1991corrugated medium

13.SN/T0874-2000 Inspection Rules for Import and Export Paper and Board

The above mentioned are some conventional inspection methods for carton paper. With the rapid development of science and technology and people's increasing concern for environmental protection, carton paper is developing towards functionality and environmental protection. Such as anti-corrosion, anti-bacterial, oil-proof, high-temperature resistant and other functional paper. At present, China's national standards for this kind of specialty paper are not complete, and some standards are being revised and formulated. For the detection of this kind of paper, the inspection and quarantine department will generally refer to the relevant international standards, the standards of exporting countries or the standards of manufacturers. In addition, some base paper used for food packaging cartons must also meet the relevant health standards in China, which is the focus of our inspection and quarantine work now, because it is directly related to the health and safety of our people. The inspection standards involved in these documents mainly include:

1.gb11680-89 Hygienic standard for food packaging base paper.

2.GB 18 192-2000 Paper-based Composite for Aseptic Packaging of Liquid Food

3.GB 18706-2002 Paper-based Composite Materials for Fresh-keeping Packaging of Liquid Food (Roof Pack) For some printing paper used for food packaging, the contents of related heavy metal elements such as lead, chromium, cadmium and mercury must also be detected.

In addition, EU countries now strictly control the total amount of heavy metals in imported packaging cartons. The scope of inspection covers a wide range, including the carton itself, box nails, adhesives, contents and so on. Relevant test standards are:

1. Paper and paperboard in contact with food. Determination of cadmium, lead and chromium in water extract ("water extraction method for determination of cadmium, lead and chromium in paper and paperboard in direct contact with food");

2. Paper and cardboard in contact with food. Determination of mercury in water extract ("water extraction method for determination of mercury in paper and paperboard in direct contact with food"); With the strengthening of people's awareness of environmental protection, all countries in the world have their own laws and regulations to restrict imported packaging. Our carton manufacturers should pay special attention to international trade to prevent unnecessary losses.

Classification and price of carton materials

Unit price of imported materials and domestic materials.

K=K 2.65 2.5

K=A 2.35 2.3

K=B 2.2 2. 15

A=A 2. 1 2.00

A=B 1.9 1.90

B=B 1.75 1.72

B=C 1.68 1.65

W=A 2.45 2. 1

w = B 2. 1. 1.97

W=C 2.05 1.9

C=C 1.65 1.6

C=3 1.6 1.55

K3K 2. 1. 1.95

K3A 1.75 1.67

K3B 1.6 1.58

A3A 1.5 1.45

A3B 1.32 1.32

B3B 1. 15 1.2

B3C 1. 10 1.09

B33 1.07 1.02

W3A 1.65 1.47

W3B 1.50 1.35

W3C 1.40 1.28

Remarks: 1. Carton formula: (length+width +2)* (width+height+1)*2 unit price/1000.

2. Flat card formula: (length+1)* (width+1)* unit price/1000.

3. Beer boxes and cards depend on the processing cost and style.

4. The formula for converting centimeters into inches is: inches = centimeters *2.54.

K paper is the best paper, and so on. W paper is white paper.

I believe you know something about this, so I will say more here.

Besides, I don't want to type. I copied it from outside. Let's see:

The structure of the carton is expressed as follows: face paper: paper name, weight/tile paper: tile paper strength, weight, corrugated paper/core paper: tile paper strength, weight/inner paper: paper name, weight.

For example: 300g kraft paper card/180g high tile (A/B)/ 180g core paper /280g lining paper.

Pricing formula of corrugated box

Carton price (yuan) = ex-factory price of corrugated board per square meter (yuan/square meter) × expanded area of carton (square meter)

I. Calculation of ex-factory price of corrugated board per square meter

1. Composition of corrugated board

Corrugated board is mainly divided into three layers of corrugated board, five layers of corrugated board and seven layers of corrugated board.

Three-layer corrugated box is mainly used for packaging lighter inner packaging materials, also known as single corrugated box. Its structure is composed of a piece of corrugated paper with tissue paper on both sides.

Five-layer corrugated box is mainly used for packaging light and fragile contents in one piece; Five-layer corrugated box is also called double corrugated box, formerly referred to as three yellow and two tiles. The structure of five-layer corrugated box consists of face paper, inner paper, two-layer core paper and two-layer corrugated paper. The combination of corrugated boxes usually adopts AB type (this type is most widely used in Chongqing pharmaceutical packaging), AC type, BC type, AE type or BE type.

Seven-layer corrugated box consists of the following three layers of corrugated box boards (mainly used for packaging heavy goods, such as motorcycles, etc.). );

Composition: composed of face paper, corrugated paper, core paper, corrugated paper, core paper, corrugated paper and inner paper. The combination of corrugated type usually adopts BAB type, BAA type, CAC type or BAC type.

2. Unified unit of measurement for corrugated board

1). Generally, when purchasing paper, liner paper, core paper and corrugated base paper, it is calculated at the ton price. That is, how many yuan per ton of various kinds of face paper, inner paper, core paper and corrugated base paper, whose unit is expressed as "yuan/ton", must be converted into "yuan/kg" when calculating.

If the purchase price is 5200 yuan/ton, it is 5200 yuan/1000kg=5.20 yuan /kg.

2). Generally speaking, the weight of paper is grams, and how many grams per square meter should it actually be, that is, the weight of all kinds of face paper, liner paper, core paper and corrugated base paper is expressed by "grams per square meter". In order to calculate, its dosage unit must be unified, and the "gram/square meter" here must be converted into "kilogram/square meter".

If you buy 300g kraft paper, that is, 300g/m2 kraft paper, you can get 0.3kg /m2 by converting "300g/m2" into (300/ 1000)kg/m2 ".

3) Determination of the coefficient of corrugated base paper made of corrugated base paper.

The ratio of shortening of corrugated base paper in the paper length direction due to corrugated pressure is called compression ratio. There is no uniform standard for this coefficient among manufacturers, because the production capacity and management level of each manufacturer directly affect the output of corrugated paper, but the packaging industry generally defaults to the following coefficient;

The compression ratio of a corrugated board is 1.59, that is, the corrugated length of 1.59 m is1m..

The compression ratio coefficient of B Leng is 1.36, that is, the corrugated length of 1.36m corrugated paper is1m..

The compression ratio coefficient of C-notch is 1.50, that is, the corrugated length of 1.50m is1m..

E the cold compression ratio coefficient is 1.27, that is, the corrugated length of 1 .27m is1m..

3. Calculation of paper price per square meter of corrugated box.

(1)( 1) Algorithm for Face Paper, Inner Page Paper and Core Paper

Example: The purchase price of 4800 yuan/ton tissue paper is 350 g /m2, and its price per square meter should be:

(4800/ 1000)×(350/ 1000)

=4.8×0.35

= 1.68 (Yuan/m2)

(2)(2) Algorithm of corrugated paper

Example: the purchase price of high-strength tile is 1800 yuan/ton, and its price per square meter should be:

( 1800/ 1000)×( 180/ 1000)× 1.59

= 1.8×0. 18× 1.59

=0.5 16 (Yuan/m2)

4. Calculation of cost price per square meter of corrugated board raw materials

The existing customer wants to make a five-layer corrugated box, and the facial paper is required to be 300g kraft paper card/180g high tile (A/B)/ 180g plain paper /280g tea board paper. Try to calculate the cost price of cardboard per square meter.

List calculation:

Price per gram of paper (yuan/ton) calculation formula layer coefficient (yuan/square meter)

Tissue kraft card 300 520011(300/1000) × (5200/1000 )×1.56.

High strength ceramic tile paper180 2250 2 (1.56+1.39) (180/1000) × (2250/1000) ×

Core paper180170011(180/1000) × (1700/1000).

Lined paperboard 280 250011(280/1000) × (2500/1000 )×1= 0.70.

Total (RMB/m2) =4.96

5. The main factors and coefficients of corrugated board ex-factory price calculation.

The ex-factory price of cartons shall include the sum of the cost price of raw materials of cartons and other amortized expenses.

Other amortized expenses include auxiliary materials (adhesive, ink, flat wire, power), equipment depreciation, workers' wages, taxes, etc.

In the ex-factory price of cartons, the general raw material cost of cartons accounts for 0.5 ~ 0.7, and other amortized expenses account for 0.5 ~ 0.3. The average manufacturer's value is that the cost of carton raw materials accounts for 0.65, and other amortized expenses account for 0.35. However, a simple calculation uses a coefficient of 0.5 to estimate the quantity.

6. Ex-factory price of corrugated board

The ex-factory price of cardboard = the cost price of cardboard raw materials per square meter /0.65.

According to "4. Calculation of the cost price of raw materials per square meter of cardboard, it can be calculated that the ex-factory price of cardboard should be;

The ex-factory price of cardboard =4.96/0.65=7.63 yuan/square meter.