Characteristics of Corrugated Cardboard

Characteristics of Corrugated Cardboard

Corrugated cardboard is made of paper, in which the corrugated paper is pressed into corrugated core paper with different flute forms through flute rollers, and then bonded with surface paper, intermediate core paper, and lining paper made of kraft and white  kraft paper to form a multi-layer corrugated cardboard structure. Corrugated base paper can significantly improve its mechanical strength, enabling it to withstand collisions and falls during transportation.

According to the number of layers, corrugated cardboard can be divided into categories such as three layers, five layers, and seven layers. Among them, three layers of corrugated cardboard have one layer of corrugated core paper, five layers of corrugated cardboard have two layers of corrugated core paper, and so on. As the number of layers of corrugated cardboard increases, the compressive strength and impact strength of corrugated cardboard continue to increase, but the larger the weight of the corresponding board, the higher cost.

Low weight and high strength corrugated base paper is much more stable than low strength and high weight corrugated base paper, and the stability of the base paper reduces individual differences in physical properties of the cardboard, making it more stable. At the same time, enterprises need to do a good job in the inspection of raw paper, and qualified raw paper should have a good appearance and no damage; Uniform fiber distribution and thickness, without wrinkles; The physical properties such as strength meet the requirements. Only qualified base paper with stable performance can reduce the quality problems caused by paper shrinkage and breakage on the corrugated cardboard production line

If the production process is not properly controlled, even the best paper can not produce high-strength corrugated cardboard. For a specific production process, it is generally influenced by machines and operators, so the strength of corrugated cardboard cannot be greatly improved. However, an accurate and effective production process can improve the strength of corrugated cardboard.

Corrugated cardboard is sensitive to changes in environmental temperature and humidity, especially changes in humidity, which can have a significant impact on the physical strength of corrugated cardboard. Therefore, in the dry season, attention should be paid to preventing cardboard from bursting, and in the wet season, attention should be paid to reducing moisture regain. We can also apply special treatments to corrugated cardboard through methods such as coating to resist the influence of the external environment.

Because corrugated cardboard is made by bonding starch adhesive, it plays a crucial role as the blood of cardboard. If the adhesive strength of cardboard cannot meet the requirements, cardboard or surface paper can easily separate from corrugated paper, leading to many quality problems, such as decreased cardboard quality and thickness not meeting the standard. Therefore, this also needs to be noted.

Delivery moisture refers to the moisture content in the corrugated base paper or cardboard at the time of delivery, expressed as a percentage. During the production process, it is necessary to maintain a certain moisture content, which is generally controlled between 7% and 12%. After offline, the moisture content of cardboard will generally decrease by more than 2% or even more. If the moisture content of the cardboard is too high, the stiffness of the cardboard will deteriorate, and the indentation and bonding quality will also be poor; If the water content is too low, the paper will be too brittle, easy to break when pressed, and have good folding resistance