Have You Ever Wondered How Corrugated Cardboard Is Formed?

Majority of the items in the supermarket, discount store, or even shopping mall are delivered in kraft mailer boxes. These boxes are made from corrugated cardboard and brown in color. Which brings us to the title of this post; how is the corrugated cardboard created? We will get to that soon but allow us to explain the importance of these cardboard boxes. Each year, millions of tons of these are used for protection and displaying of products. 

Corrugated cardboard is strong, stiff, and lightweight material. It is comprised of three layers of brown kraft paper. Since kraft paper is used, that is why they are known as kraft mailer boxes as well. Back in 1884, Swedish chemist, Carl F. Dahl came up with a process for pulping wood chips into a strong paper that was able to resist splitting, bursting, and tearing. The created rolls of kraft paper are taken to a corrugating or a converting plant where layers of them are crimped and then glued for forming of corrugated cardboard. This cardboard is then cut, printed, folded, and then glued for creating boxes. 

The primary raw material for corrugated cardboard comes from pine trees. For those of you who are not aware, pine trees grow really fast. Packaging companies own thousands of acres of land where these trees are matured, harvested, and replaced with seedlings. Once the trees have been harvested, their strips are stripped. Only the trunks of the trees are sent to the pulp mill. Such companies also have their own mills where these trees undergo conversion into kraft paper. 

At the mill, these trees trunks get subjected to the kraft process that is also known as the sulfate process owing to the chemicals used for breaking down the wood chips into fibrous pulp. Once pulping and other processing has been completed, the obtained fibers are fed to the paper machine where they get formed, pressed, dried, and then rolled into rolls. Corn starch glue is used for bonding the corrugated medium to the liner sheets. 

At the corrugating plant, only a small amount of other raw materials are required for achieving the finished product. Dry corn starch is mixed with water and other chemicals and then pumped via the corrugated to be applied onto the corrugated medium while layers of liner get added. Waxes that have been created from vegetable oils or paraffin are also applied for creating a water/grease resistant box for food products. Inks are used if the boxes are to feature any certain logos or designs. Dies are then used for cutting and printing specific box designs. Dies can be made to cater to any specific needs that any business might have in terms of sizes. 

Kraft paper production is an on-going process since 1906 and has become more and more effective over the years. As of today, manufacturers rely on the latest technology to create intricate designs and sturdy boxes that can be used for a variety of purposes. Furthermore, CAD programs are used for coming up with custom designs for the boxes as well.