Creating cardboard from trees creates sulfur dioxide emissions while recycling cardboard after it has been used can cut those emissions in half. Below we will discuss the typical cardboard life cycle. How is it made, recycled, and repurposed for reuse?
To understand how cardboard is made, take a look at one of the flaps on a cardboard box. You’ll notice the inside and outside of a typical box is made of smooth cardboard pieces, called “liners.” Sandwiched between those two liners is a wavy-looking piece of cardboard. This is called “fluted cardboard.” Fluted cardboard absorbs impact and cushions whatever is inside the box. Together, liners and fluted cardboard made corrugated cardboard, which is often used for shipping and packaging.
The second most common type of cardboard is boxboard. This type of cardboard is most commonly found in the packaging of consumer products like food or health and beauty products. This type of cardboard is thinner than corrugated cardboard and made from a single sheet.
The process begins by cutting and lumbering softwood trees. These trees are stripped of bark and turned into wood chips. Any impurities are filtered out using a vibratory screen or air separator like the DE-STONER® Air Classifier for Wood. The wood chips are then reduced to cellulose fibers through a pulping process. These fibers are mixed with water and turned into a slurry, which allows the fibers to separate from natural oils. Sometimes the fibers are bleached white; if not, they remain a brown color. The fibers are given a final washing to eliminate any contaminants before they are pressed and rolled into paper. These rolls of cardboard paper are converted into boxes or made into different cardboard products.
Cardboard has many uses. We often think of corrugated cardboard boxes that are used to package or ship goods. Boxboard is also used to make cereal boxes, paper towel and toilet paper rolls, tissue boxes, and milk or juice cartons.
Once a piece of cardboard is thrown into a recycling bin or dropped off at a recycling facility, it is sorted by the recycling company by material type. Depending on where cardboard is recycled, however, the home or property owner may have to sort the recyclables before the recycling program will pick them up.
In many areas, cardboard, glass, plastics, and metals must go into their own separate bins. This is called dual stream recycling. In other areas, though, property owners may only use one recycling bin to collect all recyclables for pickup. This is called single stream recycling. There are pros and cons to both methods of recycling.
When cardboard arrives at a recycling facility via single-stream recycling, it may be sorted and separated using equipment like a rod deck for single stream. In other instances, cardboard that arrives via dual stream recycling is further sorted for contaminants with equipment like the FINGER-SCREEN™ 2.0 Primary Screen. Contaminants like grease and food particles in pizza boxes ruin the quality of paper fibers, so these types of cardboard should be composted or thrown away, not recycled.
Fun fact: Cardboard typically takes 2 months to decompose, so small pieces can be used in a compost heap instead of recycling.
After cardboard is sorted with screening equipment, they are re-pulped in a process similar to the initial pulping. Cardboard is turned into a slurry to separate and clean the fibers. Fibers are washed to eliminate any contaminants or leftover ink. Finally, the fibers are pressed and rolled into paper, which can be made into more cardboard products. The life cycle of cardboard is extended through recycling and it also decreases the number of trees used in the production — and waste — of cardboard.
One ton of brand-new cardboard requires 3 tons of wood, which is why recycling this material is so important and why General Kinematics is committed to improving our screening and sorting equipment for recycling and waste management of cardboard and other materials. For more information on the life cycle of cardboard or our recycling solutions equipment, contact us today.