Have You Ever Wondered? How Is Cardboard Made? Learn Cool Paper Facts

Rajnandini Roychoudhury
Nov 28, 2022 By Rajnandini Roychoudhury
Originally Published on Dec 09, 2021
Edited by Monisha Kochhar
Knowing the answer to how is cardboard made helps to learn new facts about the commonly used material.
Age: 3-18
Read time: 8.5 Min

Be it for packing parcels or making an art project, cardboard is ever-present in our lives.

Cardboard has to be one of those materials that are used in almost all industries, but we seldom think about it. The first cardboard box is said to have been made in 1817, and since then we haven't stopped manufacturing this wonderful product.

There isn't much difference in the initial process of cardboard production. After all, everything is about making thick paper to form a paperboard. But it's amazing how when several paperboards are bunched together and flutes are added, it turns to be quite strong.

Cardboard has been repeatedly declared as the best packaging material. Moreover, as cardboard boxes are 100% recyclable, you can make lots and lots of paper and cardboard from past carbon products. This does help in reducing the footprint of a company while also making it cost-effective.

Only a handful of people know about the process in which box cardboard is made. Hence, keep reading to know all the things associated with cardboard. If you enjoy this article, why not also read about how aluminum is made or how cement is made here on Kidadl?

How is corrugated cardboard made?

Cardboard or corrugated cardboard is one of the essential packaging materials that is used these days.

It is usually made in a factory, where paperboard and glue come together in the manufacturing process to make the finished product. The quality of cardboard is based on the number of layers present in it, but usually, there is a single piece of the crinkled board called a flute sandwiched between two flat paper boards.

You will be astonished to visit a cardboard-making factory by seeing the numerous rolls of paper in the facility.

Making The Paper Pulp: The first step of any paper making industry is to make cellulose pulp from timber, recycled wood chips, or wood shavings which are the raw materials of papermaking.

Before making the paper pulp, you need to cut down trees to turn the timber into wood chips in a mill, which will then be turned into pulp using a machine.

Usually, chemical pulping is used to derive the cellulose needed to make strong cardboard used for packaging. The common chemical used for the is liquid sodium hydroxide along with other substances and involves cooking the wood chips.

Usually, the process of making kraft paper liners requires chemical pulping, while test paper liners can be made by mechanical pulping which involves grinding.

Making Paper: Once the chemical pulping or mechanical pulping process is over, the pulp is fed into the paper making machine, rolls and fibers extracted from the pulp are turned into reels of paper.

Now, the produced paper is made to pass through heated rollers to extract any moisture, and then it is packed up in rolls to be made into the cardboard used for packaging.

The paper will be used as a liner as well as a flute to give the corrugated cardboard its strength.

Fluting: Once the paper rolls reach the mill where corrugated cardboard will be made, the paper is divided into grades to be used as a liner or a flute, and this is known as fluting. Moreover, there are different types of cardboard based on the paper quality.

In the process of fluting, the medium layer of paperboard is first heated and then fed into the corrugator machine to give it a wrinkled or waved appearance.

This medium layer is called the flute and it goes between the flat liner layers in the cardboard. Sometimes the flute is also called the inner liner.

Assembly: There are different types of machines used in producing cardboard, but the corrugator helps to make the final finished product, so we can call it one of the most crucial machines for accomplishing the process. Depending on the type of cardboard selected by the client, there can be two to three layers of the corrugated medium present.

However, the most basic design includes one corrugated inner liner or flute glued to two outer liners.

The papers used as liners are made to go through rollers to flatten them out and all three layers including the flute meet at the gluing station.

Here rollers apply glue to the inner side of the liners as well as on the flutes coming from the corrugator machine. All the layers are then typically made to go through a steaming station that binds the glued layers to turn them into a corrugated board.

Then, the finished board is fed through a heavy-duty oven to dry out any moisture from the boards. At times, a plastic layer or a corn starch layer can be applied to make the paper water-resistant.

And then the cardboard is cooled for 10 seconds in a drying machine to let all the materials harden and get into place. After this process, the corrugated board or paper is ready to be turned into a cardboard box.

How is cellulose made for cardboard?

When trees are alive, cellulose plays a vital role in the structural integrity of a cell. Similarly, when making kraft paper or cardboard, the cellulose needs to be broken to bring flexibility.

The basic component of any cardboard is paper pulp. This pulp is often made by grinding down wood chips, so there's a need to break down the cellulose before you can make the cardboard.

This is either done by the mechanical process where the wood chips are ground through a revolving stone, and this breaks down the individual cellulose fibers which are then removed with water.

The mechanical pulping costs less, but the output generates a higher lignin content.

On the other hand, there is also the chemical pulping process where the production of pulp for kraft paper is done using chemicals so that the individual cellulose fibers or lignin can disintegrate easily. Usually, alkaline chemicals like sulfate or sulfite are used to produce the pulp with a low amount of lignin making the cardboard high quality.

Several processes are involved in making cardboard.

What is cardboard used for?

When we think about it, cardboard is used for many things. However, the most common use of it is in the form of cardboard boxes needed for the process of packaging.

As you may know, cardboard boxes are one of the best ways to transport things. Huge cardboard boxes are prepared to carry things from manufacturing facilities.

The way cardboard is made makes the containers quite strong making them great for shipping. Cardboard is also the material you will find in packing boxes used for moving things from home.

One of the best things is that the cardboard boxes can be manufactured using recycled paper which makes it a great material when it comes to being environmentally friendly. Also, cardboard can be easily used instead of plastic and can be recycled quickly and then turned into recycled paper cardboard.

However, that's not all. Cardboard can also be used to make furniture, used as mulch in gardening, and it's also widely used in crafting by children and adults.

Tailors may even use cardboard to create a stencil for size measurement. On top of that, cardboard or kraft paper has been used as liners in collars, and even in baseball caps. The easiest way to tell if your baseball hat has cardboard in it is to test if its brim is bendy or flexible.

Baseball hats brims are usually manufactured with cardboard or plastic. So, tapping on plastic will give you a more solid sound, compared to the hollow sound produced by paper.

Where is cardboard made?

Cardboard is either made in a single facility from start to finish, as in from pulp to cardboard. At times, the same facility will also turn the cardboard into packing boxes.

However, in some cases, the facilities are different depending on the extent of a factory. Usually, cardboard factories need a lot of space to accommodate all the machines used in the process.

Often, the same facility will also have sections needed for pulping, then setting the paper, and then a machine to create the final cardboard with the corrugated liner. The initial paper is collected in a roll and fed into the machines to make the final corrugated board.

There are two types of machines that are used in the process of making corrugated or cardboard boxes.

The Rotary Die Cutter machine helps to precisely cut the grooves into cardboard boxes without assembling them, while the Flexcil or Flexible Die machine makes finished cardboard boxes. Moreover, the Rotary Die Cutter can make multiple boxes or containers from one sheet, while the Flexcil can only make one box per sheet.

In both processes, the boards are first fed into a printing plate and then the boards move towards the slotter and die cutter to be turned into finished boxes or kept flat to be assembled later.

In some places, the printing is done at a later stage. The waste cutting of the cardboard box is recycled.

After the corrugated boxes are made, it goes into a machine that stacks up the packaging boxes according to the specified load to finally reach the customer.

Did You Know...

Even though chipboards are referred to as cardboard, both aren't the same. In most cases, chipboard is made from leftover wood chips. These chipboards are also referred to as manufactured or engineered boards and are used to make cheap furniture.

To create these boards, first, the wood chops are cut and sorted into different sizes. And resins or other additives are used to make the final board.

You'll notice that the outside of these boards has a smoother texture, which is created by using smaller wood chips, while the bigger chips are present on the inside. After applying glue, the wood chips are fed into a pressing machine, where pressure is applied so that the wood chips can turn into a board.

Then, it's sanded to produce a smooth texture as well as laminated to retain its quality for a long time. However, these chipboards cannot be used to make packaging or cardboard boxes.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for facts about how cardboard is made then why not take a look at why people blush or when kittens start pooping.

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Written by Rajnandini Roychoudhury

Bachelor of Arts specializing in English, Master of Arts specializing in English

Rajnandini Roychoudhury picture

Rajnandini RoychoudhuryBachelor of Arts specializing in English, Master of Arts specializing in English

With a Master of Arts in English, Rajnandini has pursued her passion for the arts and has become an experienced content writer. She has worked with companies such as Writer's Zone and has had her writing skills recognized by publications such as The Telegraph. Rajnandini is also trilingual and enjoys various hobbies such as music, movies, travel, philanthropy, writing her blog, and reading classic British literature. 

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