Cardboard is a versatile and widely used material available in various forms and thicknesses. The two most common types are corrugated board and solid board. It is practical, lightweight, and sustainable. But what exactly is it, how is it made, and what are its unique properties?

Producing cardboard almost always begins with recycling waste paper. In fact, cardboard is the most environmentally friendly packaging material available; no less than 85% of cardboard on the Dutch market is made from recycled paper.

From production to disposal, the lifecycle of cardboard is a prime example of sustainability. It starts as a tree (from sustainably managed forests), is processed into pulp, and then into cardboard. After use, it is recycled and reused. This cycle significantly reduces the need for new raw materials.
At the paper mill, waste paper is dissolved in water. This separates the paper fibres, creating pulp. Contaminants—such as staples, tape, and ink—are screened out. The pulp (consisting of 99% water and 1% paper fibre) is then sprayed onto a fast-moving wire mesh screen. As the water drains away, a smooth, even paper surface remains. This is known as sheet formation. The paper is then pressed between rollers and dried to evaporate the remaining water. The result is paper (containing about 6% water) or solid board (10% water). Although the basis is the same, the two end products differ vastly.
Corrugated board is the most well-known type of cardboard. It is composed of one or more layers of wavy paper ('the fluting') combined with one or more layers of flat paper ('the liners'). This ingenious structure offers excellent strength and durability while remaining relatively lightweight.
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Corrugated board is produced on a specialised corrugator machine. Paper is pressed between two heated corrugating rolls under high pressure to create the wave shape. Glue is applied to the tips of the flutes, after which the flat liner paper is pressed against them.

There are many types, ranging from A-flute to N-flute. The strength depends on the profile:
Solid board is a dense, heavy type of cardboard. It consists of three to six layers of paper pressed together.

Production of solid board
On the board machine, layers of wet paper are pressed onto one another. Solid board weighs between 500 and 1200 g/m². Depending on the application, the board can be finished with a moisture-resistant layer or even a Polyethylene (PE) coating to make it waterproof. This makes solid board highly resistant to impact and tearing, even in damp conditions.

Paper and cardboard are natural products with distinct characteristics:

Why buy your cardboard boxes from RENUBOX?