What Is Corrugated Cardboard

 What is corrugated cardboard?

Corrugated cardboard (or corrugated board, corrugating paperboard), is a multi-layer glued paperboard, consisting at least of a layer of fluted/corrugated paper (wavy) and a layer or more flat linerboard ( or facings). Corrugated cardboard has high mechanical strength and can well withstand collisions and drops during handling. 

The actual performance of corrugated cardboard depends on three factors: quality of corrugated paper, quality of linerboard and the cardboard structure (flute type). 

Corrugated Cardboard

The quality of linerboard can be categorized into K(kraft), A, B, C and, D, among which K or kraft is the best while D the poorest. Similarly, the quality of corrugated paper is also categorized into 4 classes: A, B, C and D, the quality level goes all the way from class A down to the class D. The paper grammage generally ranges from 110g to 350 g per square meter.

What are the corrugated flute types?

Flute Type	Flute Height & Count	Appereance	Characteristics & Applications
A	4.5-5.0mm; 34+/-3 per  length of 30cm	relatively high and sparse flutes	flexible with good cushioning, resistance to high pressure; suitable for fragile and intolerant items, such as glassware, ceramics and plastic toys, etc
B	2.5-3.0mm; 50+/-4 per  length of 30cm	lower and denser flutes	with high compressive strength; suitable for shock-resistant commodities such as beverages and food cans.
C	3.5-4.0mm; 41+/-3 per  length of 30cm	in between A and B	has both rigidity and shock absorption properties; suitable for packing fragile items,  and hard objects that needs to prevent from scratches, etc.
E	1.1-2.0mm; 93+/-6 per  length of 30cm	dense and thin	thinnest and with highest compressive strength & flat surface; good for high-quality printing.

Flute Types of Corrugated Cardboard

Corrugated cardboard are mainly used in the manufacture of cartons, carton sandwiches and other packaging materials for fragile commodities. It is mainly made of earthen straw pulp and waste paper through beating to make raw paperboard similar to yellow paperboard, which is then mechanically processed and rolled into a corrugated shape, and then glued to the cardboard paper with adhesives such as sodium silicate on the surface.