Corrugated boxes are a critical component in the packaging and shipping industry. Their versatility, strength, and environmental friendliness make them an ideal choice for a wide range of applications. Understanding their types, construction, and applications can help businesses and consumers make informed choices about their packaging needs.
A Comprehensive Guide to Corrugated Boxes
Corrugated boxes are a staple in both personal and professional settings. Often unnoticed, they are crucial in packaging, shipping, and storage.
The corrugated box industry is witnessing significant growth, driven by e-commerce and environmental considerations. With an estimated U.S. shipment volume of about 443 billion square feet in 2023, their ubiquitous presence is undeniable.
What Are Corrugated Boxes?
Corrugated boxes, commonly mistaken for cardboard boxes, are distinct in their construction. They comprise a liner (the flat outer layer) and a medium (the wavy inner layer known as flute), which together provide remarkable strength and durability. This structure is key to their widespread use in shipping and storage.
Manufacturing process
The journey of a corrugated box begins with tree harvesting. The wood is converted into chips, pulped, and then formed into sheets for corrugation and linerboards.
These sheets are then processed through corrugating rolling machines and corrugators, which flute the paper and glue it to the liners, creating the corrugated board. Post this, die-cutters shape the board into usable box forms.
Types of Paper Used
Kraft and test liners are the two primary types of paper used in corrugated boxes. Kraft paper, often used for the outer liner, is made from softwood trees and is known for its strength and printability. Test liners, usually made from hardwood trees or recycled paper, are cost-effective and used for the inner liner.
Flute Grades
Flutes provide corrugated boxes with their strength and durability.
They vary in size, with common types including:
1/4” thick, ideal for fragile items.
1/8” thick, used for canned goods and counter displays.
3/16” thick, used for shipping boxes.
1/16” thick, used for smaller retail packages.
1/32” thick,offers a smooth surface for printing.
Wall Types
Corrugated boxes come in different wall constructions:
Single face
A single sheet of liner attached to a corrugated medium, used for delicate items.
Single wall
The most common type, suitable for general shipping.
Double wall
Offers more durability and is used for heavier items.
Triple wall
The strongest, used for industrial parts or heavy produce.
Packaging Styles
The shape and size of corrugated boxes vary, with popular styles including:
Regular Slotted Container (RSC):
The most common style, suitable for varied uses.
Full Overlap Container (FOL):
Offers added strength due to overlapping flaps.
One Piece Folder (OPF):
Commonly used for books and flat items.
Full Telescope Design (FTD):
Comprises a separate top and bottom piece, offering additional strength.
Environmental Impact
Corrugated boxes are highly recyclable and are often made from a significant percentage of recycled content. They are favored in sustainable forestry practices and are a popular choice for companies and consumers looking for environmentally responsible packaging solutions.
Limitations
Despite their versatility, corrugated boxes have limitations. They are not inherently waterproof and may not be suitable for extremely heavy or bulky items. Additionally, their appearance can deteriorate over time, especially under rough handling.
Testing and Standards
To ensure reliability, corrugated boxes undergo rigorous testing. The Edge Crush Test (ECT) and the Bursting (Mullen) Test are standard methods to assess their strength and durability. These tests ensure that the boxes meet the required safety and quality standards for shipping and handling.
