What is cardboard made of?

17 March 2020  |  Admin

If you are curious about what cardboard is made of & can cardboard be recycled, then read this article.Cardboard boxes,Recyling cardboard,how to recycle cardboard

Cardboard is made up of two basic materials Flute & Liners. These two materials are initially made from trees that are pulped.


     This is the angular material that is present between the liners of cardboard boxes. This material is usually made up of recycled paper.


       These are the two sheets between which the flute is sandwiched. There are two types; One is placed at the inner side of the cardboard box (also known as test paper) and the other one on the outer side (known as Kraft paper).
Test paper liners are usually made of hardwood trees (Oak, Chestnut etc.) that have tiny fibres, or recycled paper which is why it is more affordable and has a rougher quality. The outer liner is durable and smooth as compared to the inner and because it has a smoother surface, it is easier to print on.
The Kraft is also better water-resistant material than the test, making it more suitable for the outer surface. The smoother finish of Kraft paper comes from softwood trees having long fibres, for example, Pine trees. But most of the paper produced nowadays for boxes, in particular, are made from recycled waste. The two types of liners and the flute are then glued together by a roller after hot steam is sprayed on the paper to allow it to be pressed together with the help of a corrugator plant. After this process, the corrugator cuts the cardboard into required sizes and stacks them. A trimmer or a die-cutter is then used to cut the board design such as handles and flaps. The boxes are then folded with the help of a bending machine and glue or stitches are used on the places which will come together to form the box. And once the Carboard boxes are finally made the fragments that are left are recycled and used to produce more boxes and other products, many corrugator machines are now producing boxes eco-friendly and every effort made to ensure that their methods are carbon-neutral.

Can Cardboard be recycled? 

                                               Yes, it can and it is one of the easiest & most extensively recycled materials in the UK. Read on to know how the whole process takes place.


          The first step in recycling cardboard is sorting. It needs some preparation before it can be recycled. Sorting is essential because not all cardboard boxes are made exactly the same way. Some are made for packing food materials others for shoes etc and some for house removal purposes. They are sorted based on their material quality. After that, it's shredded into small pieces ready for the next process.


              Water is added to the shredded cardboard by putting the cardboard into large tanks of water. Because of this method, the shredded cardboard becomes pulp and can then be prepared ready for further processing.


           The pulp is then filtered because it has impurities in it such as tape, plastic, glue etc. The pulp is filtered of these impurities by a centrifugal process, after that, the de-inking process starts. Any chemicals and inking is removed from the pulp and made suitable to store ready for the next process.

More Addition of Water:

              More water is added to the pulp and is stirred and pressed to get the required quality of cardboard. Chemicals are also added to make it more durable and water-resistant.

Vacuum & Drying:

              At this stage, the pulp is dried and vacuumed with the help of heating and vacuum rollers so that it may take a sturdy shape. After drying, it is pressed with the help of rollers to make it hard and sheet-like structured. Also, more layers are added depending on what type of cardboard is being made (Double walled cardboard Box-Triple walled cardboard box).

The Final Stage:

             After vacuuming and drying the cardboard takes a form of paper and sheet. If the intention is to make a corrugated cardboard box, then it is passed through rollers with small projections which give them wrinkles and stronger form. And now it is ready to cut and made into different sizes of boxes.

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