Corrugated paperboard is currently the world's largest and most commonly used packaging material. Corrugated boxes, on the other hand, are one of the most common packaging methods in the transportation of goods.
Since 1856, two British brothers invented the corrugated corrugated paper pressed on paper, which was not used as a packaging at first, but as a liner for high hats, and since then, after continuous exploration, development and application, there are today's rich corrugated paper types!
1
What is a corrugated box?
Corrugated box (Corrugated Box) is a three-dimensional carton that is processed and formed by corrugated cardboard. Corrugated cardboard is a strong packaging material, the outer layer is called face paper, the wavy layer is called core paper or corrugated paper, and the bottom layer is called inner paper.
In short, these cartons are made of corrugated cardboard after a certain structural design, and in transportation, corrugated cardboard has a good protective cushioning effect.
There are two major categories of box type standards for international corrugated boxes, one is the international carton box type standard jointly developed by the European Federation of Corrugated Cardboard Manufacturers (FEFCO) and the Swiss Paperboard Association (ASSCO) approved by the International Corrugated Board Association; The other category is the national standards of Japan and the United States.
In the international carton box type standard, the text name of the box type is represented by a simple 4 ~ 8 digit code, such as 0201, click the figure below to view the commonly used carton box type.
2
Material
Corrugated cardboard: also known as corrugated cardboard. It is a multi-layer adhesive, which is at least composed of a wavy core paper sandwich and a layer of paper, with good cushioning and elongation.
Foreign base paper is generally made of ground wood pulp or semi-chemical pulp, and there are also partially recycled pulp; Domestic base paper is generally based on straw pulp, with part of the chemical pulp or recycled pulp, the quality is worse than foreign base paper, kraft paper is the most in line with the concept of sustainable development of all available paper types, but it is also the most expensive.
Commonly used for corrugated cardboard paper are kraft paper and coated paper.
Kraft paper: A type of stronger paper made from sulphate softwood pulp, commonly used to make corrugated cardboard.
Coated paper: A type of paper coated with a smooth coating on the surface, such as single copper, double copper, dust, etc., which is usually used to print high-quality color pictures or photos.
3
Corrugated type
The corrugated pit type provides cushioning, strength and compression resistance to packaging according to different grades, allowing for more customization of packaging. The commonly used types of corrugated cardboard are A, B, C, E, F, and their thickness is different. In addition, there are common pit type combinations, AC pit, BC pit, EB pit, etc.
Single-sided corrugated cardboard (also known as pits) is often used as a protective layer for product packaging, or to make a protective layer and pad to protect goods from vibration or shock during storage and transportation.
Three- and five-layer corrugated cardboard is used a lot when making corrugated boxes. Usually the surface of the corrugated box can be printed with beautiful graphics and text. Not only the goods inside are protected, but also the internal goods are promoted and beautified.
At present, many corrugated color boxes or corrugated boxes made of three- or five-layer corrugated cardboard have been placed directly on the sales counter or shelf to become sales packaging.
Seven-layer or eleven-layer corrugated cardboard is mainly used to make packaging boxes for mechanical and electrical appliances, furniture, motorcycles, large household appliances, etc. For some specific products, this combination of corrugated cardboard can also be used to make inner and outer boxes, which is not only convenient for production, but also suitable for packaging, storage and transportation of goods.
In recent years, according to the needs of environmental protection and the requirements of relevant national policies, such commodity packaging made of corrugated cardboard has gradually replaced the trend of wooden box packaging.
4
Corrugated box calculation
The weight of paper is calculated in units of how many grams (g) per square meter (㎡) per sheet of paper, the weight of general paper is usually calculated in grams, and the weight of various facial paper, lining paper, core paper, corrugated base paper is represented by "g / ㎡, the unit is g / ㎡. People used to refer to it simply as "gram". For example, 300 grams of kraft paper, that is, 300g/㎡ kraft paper,
1. Calculate the area of the carton (total length * total width)
Total length = (carton length + carton width) * 2 + connector (one barge)
Total length = (carton length + carton width + joint) * 2 (double barge)
Total width = (carton width + upper cover size + lower cover size is the cardboard ordering area = paper degree * paper length
2. Calculate the weight per unit area: AB pit = face paper base weight + B flute base weight * 1.36 (corrugation rate) + core paper base weight + A flute paper base weight * 1.51 (corrugation rate) + base weight of the bottom paper
B pit = base weight of face paper + base weight of B flute paper * 1.36 (corrugation rate) + backing paper
Corrugation rate is a description of the length of cardboard consumed additionally by corrugated core.
The corrugation rates of different corrugated cardboards are usually as follows:
A=1.51,B=1.36,C=1.44,E=1.29,F=1.23。
Due to the different initial specifications of the corrugated rollers used by manufacturers and the different cardboard consumed on the machine, the corrugation rate of different machines is also different.
5
Test & BMC
Some standard tests include edge pressure tests, box pressure tests, and burst resistance tests.
1. Edge pressure test: it is one of the basic tests of corrugated packaging. As the name suggests, force is applied perpendicular to the edge of the corrugated cardboard until it bends. The result ensures the strength and durability needed to handle heavy loads and stacking resistance.
2. Box pressure test: similar to edge pressure test. The force is applied directly to the surface area of the corrugated plate until the groove flattens and destroys its structure. The test likewise determines the crush resistance and stacking resistance of the corrugated cardboard required to carry heavy loads.
3. Bursting strength test: the maximum pressure that the cardboard can withstand per unit area perpendicular to the surface of the specimen uniformly increased.
4. BMC Quality Assurance Chapter
After comprehensive testing, the corrugated box is ready to obtain its BMC Quality Assurance Chapter, we have talked about it in previous issues, here is just an explanation, interested partners click the following review to understand the content of the BMC Quality Assurance Chapter.