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How Is Cardboard Recycled?

Cardboard is the most widely used material in packaging. Whether it’s secondary corrugated boxes, paper void-filling, or primary packaging — cardboard has been in use since the early 1800s. Like any other packaging material, however, it’s important to understand the environmental impact that cardboard has, and what can be done to limit its footprint. Therefore, it begs the question:

With all of that cardboard being produced and used, how is it being recycled and reused?

stacks of cardboard sheets on top of each other close up

Step 1: Collection and Sorting

To start the recycling process, cardboard is first collected from businesses and residents. There is often a wide variety of cardboard and paper types mixed together into one recycling bin.  The most common types are corrugated cardboard and paperboard (which is technically not a cardboard). Since these two materials have unique properties and require specific recycling, the collected mixture needs to be sorted before the process can continue. Sorting is typically done once the boxes arrive at the recycling facility.

Step 2: Processing

In order to be re-used, cardboard must first be broken down. This is achieved by shredding the cardboard down into small pieces, which is then mixed together with a liquid solution containing water and various chemicals. Once mixed, the solution becomes pulpy. However, before moving on, the mixture needs to become firmer. To do this, new pulp — most commonly broken down from wood chips — is added the recycled pulp.

Now, the mixture is ready to be filtered and prepared for re-use. The pulp gets put through an intensive process that filters out tape, glue, staples, or plastics that may have been added in the cardboard’s previous life. It’s crucial that these materials are removed, as they could impact the structural integrity of the recycled cardboard.

Ink is also removed from the pulp during the processing stage. Commonly, a strong chemical solution is mixed in with the pulp that separates any ink that remains. Once that step is done, the pulp is fully filtered and ready to be re-used.

Step 3: Reuse

The pulp is pressed, heated, and drained to remove all excess liquid. Once dry, the pulp gets pressed into sheets that can be layered and glued together to re-create cardboard. From there, the cardboard gets measured, cut, and distributed.

 Sustainability is an increasingly important reason to understand how your single-use packaging materials are recycled. Cardboard, when recycled properly, can be re-used effectively — limiting consumption and reducing environmental waste.