What Is a Corrugated Box and How Is It Made

A corrugated box is one of the most common packaging and shipping choices. This box has a fluted medium between linerboards. The fluted part makes air pockets. These air pockets give the box strength and softness. The fluted layer works like tiny arches. This helps corrugated boxes hold heavy weight and survive rough treatment. They do this better than simple cardboard or folding carton boxes. Corrugated packaging is used in many industries, such as:

• E-commerce

• Food and beverage

• Electronics

• Automotive parts Corrugated packaging is now the most used type in the world. Slotted boxes are the most popular kind. The special design of corrugated boxes makes them the best for protecting things during shipping.

Key Takeaways

• Corrugated boxes have a wavy layer between two flat sheets. This layer makes the boxes strong. It helps protect things during shipping.

• These boxes use recycled and new materials. This makes them good for the environment. They are also easy to recycle after use.

• There are different types of corrugated boxes. Flute sizes can be different too. Some are for light things. Others are for heavy or breakable items.

• The boxes are made by joining paper layers with glue and heat. This makes strong boards. The boards are cut and folded into boxes.

• Corrugated boxes are strong and not too expensive. They can be made in many ways. They help companies keep products safe. They also help show off the company’s brand.

Corrugated Box Basics

What Is a Corrugated Box

A corrugated box is a container made from corrugated cardboard. Corrugated cardboard has three layers. There are two flat linerboards on the outside. The middle layer is fluted and wavy. This fluted part makes air pockets. These air pockets help the box take hits and keep things safe inside. Most shipping boxes use corrugated cardboard because it is strong. In North America, about 95% of shipped products use these boxes.

Corrugated cardboard is known for being strong and safe. It is also good for the environment. Many makers use recycled fibers to make it. You can recycle these boxes again after using them. Corrugated boxes come in many shapes and sizes. Some types are Regular Slotted Containers and Full Overlap Slotted Containers. Each type is made for different packaging needs.

Key features of corrugated cardboard are:

• Great at cushioning and absorbing shocks

• Strong against bending and crushing

• Thickness and flute grades can be changed for different uses

• Tests like the Edge Crush Test and Mullen Burst Test check its strength

Corrugated Box vs. Cardboard

Many people mix up corrugated boxes and regular cardboard boxes. But they are not the same. Corrugated cardboard has more than one layer. Regular cardboard, or paperboard, is just one thick layer.

Aspect	Corrugated Boxes	Cardboard Boxes (Paperboard)
Material Composition	Three layers: two linerboards with a fluted medium	Single layer of thick paper stock
Strength	High compression and burst strength	Lower strength, bends easily
Cushioning	Built-in shock absorption	No cushioning
Weight	Heavier and bulkier	Lighter and more flexible
Durability	Long-lasting, protects heavy or fragile items	Less durable, for lightweight products
Typical Use	Shipping, storage, industrial packaging	Retail packaging, displays

Corrugated boxes keep things safe during shipping and storage. Cardboard boxes are better for light or store packaging, like cereal boxes or displays. Corrugated cardboard protects better from crushing, hits, and water. Cardboard is lighter and costs less, but it does not keep valuable or breakable things as safe.

Corrugated Cardboard Structure

Linerboard and Fluting

Corrugated cardboard is strong because of two main parts. These are linerboard and fluting. Linerboard makes the flat outside parts of the cardboard. Fluting is in the middle and has a wavy shape. This wavy part helps the box take hits and keep things safe.

Different materials are used for linerboard and fluting.

• Most outer linerboards use kraft paper. Kraft paper is made from mostly new pulp fiber. This makes the linerboard stiff and tough. It is also better for the planet, but it costs more.

• Test paper is often used for the inside linerboard. It has more recycled fiber. This makes it weaker and harder to print on. But it helps cut down on waste.

• Fluting paper comes in two main kinds. Semi-chemical fluting uses new fibers and a special process. Waste-based fluting is made from only recycled fibers.

Corrugated cardboard always has two linerboards with fluting in the middle. This setup helps the box not get crushed and keeps things safe inside.

The fluted layer works like a cushion. It spreads out force and keeps breakable things safe when shipped.

Layers and Strength

The number of layers in corrugated cardboard is important. Each layer gives more protection and lets the box hold more weight. Boxes with more layers, like 7-ply, are much stronger. These boxes can handle more pressure and hits than boxes with fewer layers. That is why they are good for shipping heavy or breakable things.

Corrugated cardboard is strong because of how the fluting sits between the linerboards. This design spreads out stress and helps the box stay strong when stacked or moved. The ply value means how many layers the box has. More layers mean the box can hold more weight. More layers also mean less chance of things getting broken during shipping.

Corrugated cardboard is special because it uses strong materials and a smart design. The right number of layers keeps products safe from harm.

Corrugated Box Process

Raw Materials

Making a corrugated box starts with picking the right materials. The main things used are paperboard and kraft paper. These papers mostly come from wood fibers. Softwood trees like pine, spruce, and fir give long fibers for strength. Kraft paper is made from these fibers. It is used for the liners and outside layers of the board.

Other paperboard types, like solid bleached sulfate, coated unbleached kraft, and folding box board, have special uses. Recycled materials are also important. Factories use old paper, scrap cardboard, and sawdust to make chipboard. Chipboard is good for the planet. The pulping process uses machines and chemicals to get cellulose fibers from wood. Bleaching and refining make the paper brighter and better for printing. Fillers like clay and calcium carbonate help make the paper smooth for printing.

The corrugated industry cares about the environment. Over 80% of cardboard can be recycled and used again. Using fibers from managed forests and old boxes helps the earth. These forests take in carbon dioxide. Recycling stops greenhouse gases from landfills. The industry has cut greenhouse gases per box by half since 2006. Better energy, water, and air use show the focus on eco-friendly packaging.

Corrugating and Combining

The next step uses machines to turn paper into strong corrugated board. The main machine is called the corrugator. This machine puts linerboard and fluted medium together to make the wavy shape.

1. Workers put kraft paper rolls for the medium and liners into the corrugator.

2. The machine warms up the medium with rollers.

3. Corrugating rollers bend the medium into flutes.

4. Starch glue sticks one liner to the fluted medium at the single-facer.

5. The second liner goes on at the double-backer, making a sandwich.

6. Steam-heated rollers dry the glue and set the board.

7. A slitter-scorer cuts the board into big sheets called box blanks.

8. The machine stacks these blanks for the next step.

The corrugator can change flute shapes and board types, like singlewall or doublewall, for different needs. Automatic splicing connects new paper rolls during work, so the process does not stop.

• Corrugators are very important in making corrugated boxes. They make the flutes, glue the layers, and cut the sheets. This makes sure every board is strong and the same.

Box Forming and Finishing

After making the board, the next step is shaping and finishing the box. This part turns the board into the final box.

1. Designers and engineers make plans for each box, showing its shape and job.

2. Factories make special dies with sharp edges for cutting.

3. Workers pick the best materials for strength and quality.

4. Machines are set up with the right dies and settings.

5. The cutting presses the board against the die to make shapes.

6. Workers take away extra material and trim the boxes.

7. Assembly lines fold, glue, and sometimes add special parts to finish the box.

Printing often happens now. UV printing and foil stamping add logos, instructions, or brand names. Die-cutting includes scoring, creasing, perforation, and through cutting. These steps help the box fold and look neat.

Finishing steps, like lamination and coating, make boxes work better. Lamination adds a plastic film to protect from scratches and water. Gloss or matte lamination changes how the box looks and feels. Coating puts a liquid layer on the box to protect and make it look nice. Both help keep printed designs safe and improve the box.

New technology in making corrugated boxes includes automation, robots, and digital printing. Factories use smart sensors and AI to check quality and track boxes. New materials and coatings make boxes stronger, lighter, and better for the planet. These changes help meet rules and support recycling.

Rules in different places also change how boxes are made. Some rules need more recycled content, better glue, and smarter designs. Factories must follow rules for safe materials and fair work. These changes help the industry grow and improve.

Types of Corrugated Boxes

Board Types

Corrugated boxes use different board types for many needs. Each board type has its own strength and structure. The number of layers changes how much weight the box can hold. More layers also help protect what is inside. The table below shows the main board types and how people use them:

Type	Layer Structure	Typical Uses
Single Face	Fluting, liner	Interior packaging, extra cushioning
Single Wall	Liner, fluting, liner	Shipping cartons
Double Wall	Liner, fluting, liner, fluting, liner	Industrial cartons
Triple Wall	Liner, fluting, liner, fluting, liner, fluting, liner	Shipping crates, chemical containers

Single wall corrugated is used most for shipping and stores. Double wall and triple wall boards are stronger for heavy or breakable things. Single face board is good for wrapping items inside bigger boxes.

Flute Profiles

The flute profile changes how much the box can cushion and stack. Flutes are the wavy part between the liners. Big flutes like A and C give more cushion and support. Small flutes like B, E, and F are flatter for printing and save space.

Flute Profile	Thickness (inches)	Flutes per Foot	Cushioning Properties	Stacking Strength & Usage
A-Flute	1/4″	33	Greatest cushioning	Highest compression strength
C-Flute	3/16″	39	Good cushioning	Most used for shipping cases
B-Flute	1/8″	47	Less cushioning	Excellent crush resistance
E-Flute	1/16″	90	Thin, less cushioning	Used for folding cartons
F-Flute	1/32″	N/A	Minimal cushioning	Small retail packaging

Tests show that flute profile and edge stiffness matter for box strength. B-flute boxes get much stronger with stiff edges. C-flute boxes also get stronger, but not as much. Picking the right flute profile helps boxes protect things during shipping and stacking.

Common Box Styles

Corrugated boxes come in many styles for different products and shipping. The Regular Slotted Container (RSC) is the most used. It has four flaps that meet in the middle, making it strong and easy to close. Full Overlap Slotted Containers (FOL) have flaps that cover the whole top, giving more protection for heavy or breakable things. Die-cut boxes are custom boxes with special shapes, slots, or holes for unique products.

Box Style	Description	Advantages / Applications
Regular Slotted Container (RSC)	Four flaps meet in the middle on top and bottom	Efficient, versatile, minimal waste, used for many products
Half Slotted Carton (HSC)	Like RSC but open on one end	Easy access, can add a lid
Full Overlap Slotted Carton (FOL)	Flaps fully overlap across the box opening	Extra strength, good for rough handling
Die Cut Boxes	Custom shapes, slots, or holes	Fits special products, adds features like ventilation
Trays	Open boxes or lids	Holds products securely, used as trays or covers
Full-Telescoping Style	Two pieces fit over each other	Extra corner protection, adjustable depth
One-Piece Folders	Single piece folds into a box	Good for books, electronics, printed items
Pads/Partitions/Internal Packaging	Inserts to separate or cushion items	Protects and stabilizes products inside boxes

Many online and store companies use RSC, FOL, and die-cut styles. These styles help keep things safe and make shipping simple.

Benefits of Corrugated Boxes

Packaging Protection

Corrugated packaging is great at keeping products safe. The fluted layer between linerboards soaks up shocks and bumps. This design stops dents, scratches, and things from breaking. Corrugated inserts and corner protectors make boxes even stronger. They help stop crushing and damage from impacts. Many companies pick corrugated packaging because it is strong but not heavy. This means boxes are light but still protect what is inside.

• Corrugated packaging keeps products safe from getting hurt.

• Coatings that resist moisture keep things dry inside.

• The box structure helps with changes in temperature during shipping.

• Custom inserts, dividers, and padding stop items from moving and add extra cushion.

Corrugated packaging can be made to fit each product. This gives the best fit and the most protection. Companies trust corrugated packaging to work well every time.

Sustainability

Sustainable packaging is important for businesses and customers. Corrugated packaging uses mostly recycled paper and fibers that grow back. Most corrugated boxes can be recycled and break down in nature. This means less trash goes to landfills and helps the earth. In 2022, over 93% of cardboard boxes were recycled in the U.S. On average, a corrugated box has about 52% recycled material.

• Corrugated packaging helps make a circular economy.

• Its light weight lowers shipping costs and cuts carbon emissions.

• Using recycled and renewable materials means less need for new stuff.

• Eco-friendly packaging helps customers trust brands that care about the planet.

Corrugated packaging has a smaller carbon footprint than most plastic packaging. Cardboard makes 0.94 to 1.53 kg CO2e per kg. PET plastic can make up to 4.523 kg CO2e per kg. This makes corrugated packaging a good choice for people who want to help the planet.

Cost and Customization

Corrugated packaging gives a good mix of price and quality. It costs more than folding cartons but less than rigid boxes. The table below shows the average price for each packaging type:

Packaging Type	Average Cost per Unit (USD)
Corrugated Boxes	$2.7 – $3.5
Folding Cartons	$1.8 – $2.25
Rigid Boxes	$8.5 – $10.00
Flexible Packaging	$0.25 – $0.75

Corrugated packaging can be changed in many ways. Companies can print logos, colors, and designs on the boxes. Custom sizes and shapes help products fit just right and stop damage. Special finishes like matte or glossy coatings make boxes look cool. Creative inserts and dividers keep things organized and safe. These choices help brands look better and keep products safe.

Custom corrugated packaging helps with branding and shipping. It lets companies send good products and meet what customers want.

A corrugated box is a popular pick for packaging. Its special design makes it strong and tough. Companies use these boxes to keep products safe when shipping or storing them. Corrugated packaging has many good points:

• The fluted design makes the box strong and keeps out water.

• It uses recycled and renewable cardboard, which helps the planet.

• You can change the box to fit different needs and jobs.

• It is light, saves money, and stacks easily.

Many companies pick corrugated packaging to save money and cut down on waste. This box also helps make customers happy by keeping products safe and delivered in good shape.

FAQ

What makes corrugated boxes stronger than regular cardboard boxes?

Corrugated boxes have a fluted layer between two linerboards. This layer makes air pockets inside the box. The air pockets help the box take hits and stay strong. Regular cardboard boxes do not have this fluted layer, so they are weaker.

Can people recycle corrugated boxes?

Yes, most recycling centers take corrugated boxes. People should take off tape and labels before recycling them. These boxes often use recycled materials already. Recycling them helps save resources and cuts down on waste.

Are corrugated boxes safe for food packaging?

Corrugated boxes are safe for food if made with food-grade materials. Many food companies use them to ship fruits, vegetables, and other foods. The boxes keep food safe from damage while being moved.

How do companies choose the right type of corrugated box?

Companies think about the product’s weight, size, and how it will be shipped. They pick board types and flute profiles for the right strength. Custom inserts or coatings can give extra safety for breakable things.

What printing options work on corrugated boxes?

Corrugated boxes can use many kinds of printing. Flexographic, digital, and lithographic printing add logos, colors, and instructions. Printing helps brands get noticed and gives customers important details.