What is the production process of corrugated cardboard?

The production process of corrugated cardboard involves several steps, including papermaking, corrugating, gluing, cutting, and packaging. Here is a detailed explanation of each step:

1. Papermaking:

The process of making corrugated cardboard starts with the production of the two main components: linerboard and corrugating medium. The linerboard serves as the outer layers of the finished cardboard, while the corrugating medium provides the strength and rigidity.

The linerboard is made by blending wood pulp fibers with water to create a paper pulp. The pulp is then spread onto a moving screen to form a continuous sheet. The water is drained from the sheet, and it is then dried and rolled into large rolls.

The corrugating medium is made by passing the paper pulp through fluted rolls, which create a wavy, corrugated pattern on one side of the paper. The corrugating medium is also dried and rolled into large rolls.

2. Corrugating:

In this step, the linerboard and corrugating medium are brought together to form corrugated cardboard. The corrugating machine consists of a series of heated rollers that press the linerboard and corrugating medium together, creating the characteristic wavy pattern. The heated rollers also dry the adhesive used to bond the layers.

The size and spacing of the flutes can be adjusted to meet different requirements, such as strength and thickness of the finished corrugated cardboard.

3. Gluing:

After corrugation, the cardboard passes through a glue machine, where a starch-based adhesive is applied to bond the linerboard and corrugating medium together. The adhesive is evenly spread over the flat surface of the linerboard, and the corrugated medium is then pressed against it, forming a sandwich-like structure.

The adhesive is allowed to dry for a short period before proceeding to the next stage.

4. Cutting:

Once the corrugated cardboard has dried and solidified, it is fed into a rotary cutting machine, also known as a slitter-scorer. This machine cuts the large rolls of corrugated cardboard into smaller sheets of desired dimensions.

The cutting machine typically consists of multiple sets of rotary knives that score the sheets along predetermined lines. The sheets are then separated by a set of rotating wheels, ensuring clean and precise cuts.

5. Packaging:

The final step in the production process is packaging the corrugated cardboard sheets into stacks or bundles. The sheets are usually first stacked and aligned using automated machinery. They are then strapped or wrapped with plastic film to secure them in place during transportation.

The packaged corrugated cardboard is then ready to be shipped to various users, such as packaging manufacturers, retailers, or end consumers.

Overall, the production process of corrugated cardboard involves the steps of papermaking, corrugating, gluing, cutting, and packaging. Each stage requires specialized machinery and skilled operators to ensure the production of high-quality and durable corrugated cardboard products.