Carton Manufacturing Process Materials Part II

(b) Types and Characteristics of Varroa

The corrugated board performance is related to the corrugated type in addition to the type of corrugated board. Corrugated species are generally divided into A type, B type, C type and E type four types. Corrugated size and performance are shown in Table 1-1.

A type corrugated cardboard. This kind of paperboard has good elasticity, large height and large corrugation distance, which makes it have shock absorption performance. This type of cardboard is used to make fragile articles and packaging boxes that require high impact, impact, and dynamic loads. It can also be used to make a variety of liners, pads, and shock-absorbing components.

B type corrugated cardboard. This type of paperboard is used to make product packaging that is sufficiently rigid but does not require shock-absorbing protection. This kind of product is used for all kinds of canned goods, daily chemical products, all kinds of small packaged foods and other products - hardware, wood furniture and so on.

C type corrugated cardboard. C-type corrugated board is the most commonly used corrugated board. This type of cardboard combines the characteristics of A-type and B-type corrugations, and also has sufficient stiffness and good damping properties. It can be effectively used to package all kinds of fragile items, soft products and hard products that require protection of their surfaces.

E-type corrugated cardboard. At present, the use of such corrugated board is more and more widespread. The number of corrugations per meter length on the cardboard surface is high, resulting in a flat surface and high planar stiffness. This makes it possible to obtain high quality decor printing. This is especially important for the packaging of daily necessities. This paperboard takes up very little space during transportation and storage and can be used more economically for transportation tools and warehouses.

K-type corrugated cardboard. The K-type corrugated screed is a newly developed type of large corrugated file with a height of 6.6 to 7.0 mm and 24±2 turns/300 mm.

Tests have shown that Types A, B, and C corrugations have different bearing capacities for pressure from different directions. Three types of corrugated strength properties are shown in Figures 1-3 and Table 1-2.

From the table, it can be seen that there are three kinds of corrugation strengths and characteristics of Types A, B, and C. When using the same base paper and the same pressure, the result is:

Plane Pressure - When applying planar pressure to corrugated board, the strength of the B-type paperboard with the highest number of turns and the lower enthalpy type is the highest, followed by Type C and Type A.

Vertical pressure—When vertical pressure is applied in the 楞-type direction, the A-type corrugation with the lowest number of turns and the highest 楞-type corrugation has the highest strength, followed by C-type and B-type.

Parallel pressure—When parallel pressure is applied in the sigmoid direction, the type B with the most number of turns and the smaller height is the highest, followed by type C and type A.

In the production practice, it can be selected according to the characteristics of the above four types of corrugated and the specific conditions. However, in general, the uses and suitability of the four types of A, C, B, and E are shown in Table 1-3.

(III) Types and Characteristics of Corrugated Cardboard

Corrugated cardboard can be divided into four types: single-layer corrugated cardboard, three-layer cardboard, five-layer paperboard, and seven-layer cardboard. The structure is shown in Figure 1-4.

Single layer corrugated cardboard

It is a combination of a piece of paper and a corrugated paper, also known as a two-layer cardboard. Single-faced corrugated cardboard is seldom used as an outer packaging alone, and most of it utilizes its elasticity to protect the goods as an inner packaging and a packaging liner.

2. Three-layer corrugated cardboard

It is also called double-faced corrugated paperboard (or single-wall corrugated paperboard). It consists of a combination of corrugated paper and kraft paper. Mostly used in the production of packaging or packaging of small cartons. The proportion of three-layer cardboard in corrugated board is very high.

3. Five-layer corrugated cardboard

It is composed of three sides of paper, two cores of corrugated paper, and is called double-sided double corrugated cardboard. The composition sequence is face paper, corrugating medium, core paper, corrugated paper, and paper. Five-layer paperboard is generally composed of Type A and Type B. It can also be combined with AC-type, BC-type, AE-type, and BE-type by other types of corrugation. Five-layer cardboard is mainly used to make cartons. Because it has greater strength than the three-layer paperboard, the loading is stable, allowing the manufacture of larger cartons of larger size and higher load capacity. It has a high stacking strength and is widely used for heavier goods or easily broken goods. Burst resistance is approximately 1 400 to 4 200 kPa (≈14 to 42 kgf/cm2), depending on the weight of the paper, the strength of the paper, and the type of corrugation.

4. Seven-layer corrugated cardboard

Also known as two-sided three-ply corrugated cardboard, it consists of four sheets of paper, three sheets of corrugated paper. As for the combination of 楞 type, BAB type structure is generally used, and BAA, CAC, and BAC type structures may also be used. Recently, Japan has an EBA structure. The seven-ply paperboard has the same characteristics as the longitudinal compression strength in the transverse direction, which can increase the longitudinal strength and reduce the thickness of the paperboard. It is mainly used for the packaging of heavy goods, sometimes using its high strength to make some special pads.

For corrugated cardboard boxes for transportation and packaging, the cardboard code can be found according to Table 1-4, and then the technical specifications of the relevant cardboard can be found according to Table 1-5. Table 1-6 is the technical index of corrugated paperboard for export product packaging. (Text / Luo Guanglin)