Introduction to Corrugation: The Basics

       Corrugated Cardboard has been around for more than a century, first being patented in England in 1856. The original use for corrugated cardboard - also known as pleated paper - was for the inside of hat boxes to keep tall hats protected.
       Corrugated Cardboard consists of one to four flat sheets of liner paperboard glued to fluted paper. Corrugation falls under different categories based on thickness and whether one or four liner paperboard is used. The following is the structures of the few most common types of corrugation.

SINGLE-FACE CORRUGATED
       Single face corrugated is constructed of one flat layer of linerboard glued onto a sheet of fluted cardboard or "medium". Single face corrugated comes in rolls of various sizes and can either be purchaed in kraft or white, although kraft is the more popular choice. If you are looking for a different color other than the industry standard, there is the option of custom ordering the color of your choice. Single face corrugated is a main commodity in packaging utilized in a wide range of industrial, decorative and structural applications.



SINGLE WALL
        Single wall - also known as double-face - corrugated consists of one sheet of fluted paper glued in between two linerboards. This is the most common form used for corrugated boxes.


DOUBLE WALL
      When you add another sheet of corrugating medium and a third flat liner sheet, you will have what is called a Double Wall sheet. Double wall is stronger than its single wall counterpart as well as heavier and more expensive. This thickness is mainly used for heavier items such as furniture, appliances, heavy breakables, etc.


TRIPLE WALL
      Triple wall consists of four sheets of flat liner board and 3 sheets of corrugating medium. This makes for a heavy and durable corrugated sheet used for large and/or heavy items. This thickness is also very expensive in comparison to its thinner counterparts.


        With all that said, corrugation does not stop there. A major component in the construction of cardboard corrugation are the different flutes. What are corrugated flutes anyways? Flutes are the inverted S-shape arches or waves of the corrugational medium which gives it rigidity and crushing (stacking) strength. When these flutes are applied to a linerboard with a starch-based adhesive, it resists bending and pressure from all angles. There is much to be said about the different flutes and their uses which we will discuss in our next blog in continuing the series of "Introduction to Corrugation: The Basics".