Different Shapes of Corrugated Board and There Characteristics
Paper carton box has three basic shapes of corrugations: U-shaped and V-shaped and UV-shaped as shown in the following picture.
The characteristics of U-shaped corrugations
a) They are soft and elastic. As long as the deformation does not exceed the elastic range, U-shaped corrugations can quickly recover their original shape after being released.
b) Due to the slow wear of corrugating rolls, the thickness of paper carton box with U-shaped corrugations is more consistent.
c) U-shaped corrugations are relatively smooth, so the phenomenon of cutting the corrugated core paper at the peak of the corrugations is less likely to occur. Therefore, relatively larger amounts of paper carton and adhesive can be used, but this is not economical.
The characteristics of V-shaped corrugations
a) V-shaped corrugations are relatively hard and have high strength, but once they are deformed beyond the elastic range, they will be crushed and lose their ability to recover.
b) Although less core paper and adhesive are used for V-shaped corrugations, the corrugating rolls are easily worn out, and the service life is short. In addition, the thickness of corrugated board with V-shaped corrugations is not stable, and the core paper is easily cut at the peak of the corrugations.
The characteristics of UV-shaped corrugations
a) The tooth arc is larger than V shape and smaller than U shape. It has the advantages of high compressive strength, good elasticity and recovery power, and high deepening strength.
b) It has good elasticity, is easy to recover from deformation, has good cushioning properties, and has good drying properties for the corrugated top and tissue paper. It is better to withstand plane pressure than V-shaped.
Advantages of Paper Carton Box
Cardboard made from 3 layers (single corrugated) of paperboard, with a basis weight of 175/150/150g/m2, weighs approximately 600g/m2. In comparison, wood of the same thickness and size weighs around 2000g/m2, which is over three times the weight of cardboard.
Cardboard is made from raw paper, which can be produced from wood pulp (wood scraps) or straw pulp, and can be easily recycled and reused without causing pollution (environmentally friendly).
Easy to process
Cardboard’s flat surface makes it easy to print on and process.
Convenient for storage and transportation
Cardboard boxes can be folded and take up very little space for storage and transportation, which is not possible with wood or metal packaging.
The corrugated structure (U, V, UV) of cardboard greatly improves its compressive strength and puncture resistance.
Production of Corrugated Board with Paper Carton Box Making Machine
- Paper cutting: This process includes trimming and creasing. Trimming and creasing are separate processes. A paper cutting machine is used to trim the cardboard to make the edges smooth and neat. The trimming blade must be sharp and without gaps. If the blade is not sharp, it may cause paper scraps or impurities, which will affect the quality of the product. Creasing is done with a creasing machine.
- Ink printing: Ink printing includes single-side printing, which is a simple printing method in which the cardboard is fed into the printer directly by a chain. There are also other types of printing, such as double-side printing, which depends on the different absorption properties of the raw materials. Some have low absorption properties, which results in slower drying of the ink, while others have high absorption properties, which leads to faster drying. During the printing process, many problems may occur, such as printing quality and errors. Some minor errors can be remedied. For example, if a word is printed incorrectly, the customer can be contacted to approve correcting the mistake. If the customer disagrees, then the batch of products is wasted because the printed cardboard cannot be reused.
- Slotting: A slotting machine is used to create slots in the printed cardboard. The principle is similar to that of a creasing machine.
- Nailing boxes or gluing boxes: When combining cartons, the boxes or gluing boxes are nailed or glued according to the customer’s needs. If you need to nail the box, use a carton nailing machine and a folder gluing machine for box gluing.
- Packaging: After the cartons are glued, they are distributed through the conveyor rack and packed and bundled.