What is the difference between cardboard and fiberboard boxes?

Composite paper material

This article is about the paper-based material used to make boxes. For the product made of wood fibers, see fiberboard

Corrugated board

Corrugated fiberboard, corrugated cardboard, or corrugated is a type of packaging material consisting of a fluted corrugated sheet and one or two flat linerboards.[1] It is made on "flute lamination machines" or "corrugators" and is used for making corrugated boxes. The corrugated medium sheet and the linerboard(s) are made of kraft containerboard, a paperboard material usually over 0.25 millimetres (0.01 in) thick.

History

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Corrugated (also called pleated) paper was patented in England in 1856, and used as a liner for tall hats, but corrugated boxboard was not patented and used as a shipping material until 20 December 1871. The patent was issued to Albert Jones of New York City for single-sided (single-face) corrugated board.[2] Jones used the corrugated board for wrapping bottles and glass lantern chimneys. The first machine for producing large quantities of corrugated board was built in 1874 by G. Smyth, and in the same year Oliver Long improved upon Jones' design by inventing corrugated board with liner sheets on both sides,[3] thereby inventing corrugated board as it came to be known in modern times.

Scottish-born Robert Gair invented the pre-cut paperboard box in 1890 – flat pieces manufactured in bulk that folded into boxes. Gair's invention resulted from an accident. He was a Brooklyn printer and paper-bag maker during the 1870s. While he was printing seed bags, a metal ruler used to crease bags shifted in position and cut them. Gair discovered that by cutting and creasing in one operation he could make prefabricated paperboard boxes. Applying this idea to corrugated boxboard was a straightforward development when the material became available in the early 20th century.[4][5]

The corrugated box was first used for packaging glass and pottery containers. In the mid-1950s, the corrugated fiberboard case enabled fruit and produce to be shipped from farm to retailer without bruising, improving the return to producers and opening export markets.

Properties

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Several properties and characteristics can be measured for corrugated board. Some of these include:

• Moisture content ranges from 6.5 to 9.5%. If moisture is below a certain limit it will cause cracking in corrugated board and if it is above then it will reduce the compression strength of board.
• Edge crush test measures force per unit width and predicts Box compression strength. It is reported in KN/m or lb/inch.
• Burst strength is the pressure required to rupture corrugated sheet. It is reported in KPa or lb/inch2.
• Box Compression strength is the direct measurement of performance of corrugated boxes. It is reported in kgf or N.
• Flat crush test measures flutes rigidity and reported in KPa.
• Bending resistance
• Impact resistance
• Cushioning, shock absorption[6]
• Tear resistance
• Grammage is the weight per meter square of any material. It is reported in g/m2

Corrugated fiberboard is anisotropic; many of its properties are highly directional. For example, edge crush, bending stiffness, tensile, and surface characteristics are different, depending on the orientation to the flutes and the machine direction of manufacture.

Manufacturing

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Main flutes for corrugated fiberboard

Corrugated board is manufactured on large high-precision machinery lines called corrugators, usually running at about 500 feet per minute (150 m/min) or more. These machines, over time, have become very complex with the objective of avoiding some common problems in corrugated board production, such as warp and washboarding.

The key raw material in corrugating is paper, different grades for each layer making up the corrugated box. Due to supply chain and scale considerations, paper is produced in separate plants called paper mills. Most corrugating plants keep an inventory of paper reels.

In the classical corrugator, the paper is softened with high-pressure steam. After the board is formed it is dried in the so-called dry-end. Here the newly formed corrugated board is heated from the bottom by hot plates. On the top, various pressures are applied by a load system on the belt.

The corrugated medium is often 0.026 pounds per square foot (130 grams per square metre) basis weight in the US; in the UK, a 90 grams per square metre (0.018 lb/sq ft) fluting paper is common. At the single-facer, it is heated, moistened, and formed into a fluted pattern on geared wheels. This is joined to a flat linerboard with a starch based adhesive to form single face board. At the double-backer, a second flat linerboard is adhered to the other side of the fluted medium to form single wall corrugated board. Linerboards are test liners (recycled paper) or kraft paperboard (of various grades). The liner may be bleached white, mottled white, colored, or preprinted.

Common flute sizes are "A", "B", "C", "E" and "F" or microflute. The letter designation relates to the order that the flutes were invented, not the relative sizes. Flute size refers to the number of flutes per linear foot, although the actual flute dimensions for different corrugator manufacturers may vary slightly. Measuring the number of flutes per linear foot is a more reliable method of identifying flute size than measuring board thickness, which can vary due to manufacturing conditions. The most common flute size in corrugated boxes is "C" flute.

Standard US corrugated flutes[7] Flute designation Flutes per foot Flute thickness (in) Flutes per meter Flute thickness (mm) A flute 33 ± 3

3

⁄

16

108 ± 10 4.8 B flute 47 ± 3

1

⁄

8

154 ± 10 3.2 C flute 39 ± 3

5

⁄

32

128 ± 10 4.0 E flute 90 ± 4

1

⁄

16

295 ± 13 1.6 F flute 125 ± 4

1

⁄

32

420 ± 13 0.8

Corrugated fiberboard can be specified by the construction (single face, singlewall, doublewall, etc.), flute size, burst strength, edge crush strength, flat crush, basis weights of components (pounds per thousand square feet, grams per square meter, etc.), surface treatments and coatings, etc. TAPPI and ASTM test methods for these are standardized.

The choice of corrugated medium, flute size, combining adhesive, and linerboards can be varied to engineer a corrugated board with specific properties to match a wide variety of potential uses. Double and triple-wall corrugated board is also produced for high stacking strength and puncture resistance.

Most corrugators are two knife corrugators, which means that they can produce two different sheet lengths side-by-side. This leads to an optimisation problem, known as the cutting stock problem.

Box manufacture process

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Box design

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Packaging engineers design corrugated boxes to meet the particular needs of the product being shipped, the hazards of the shipping environment (shock, vibration, compression, moisture, etc.), and the marketing needs of retailers and consumers.

The most common box style is the Regular Slotted Container (RSC). All flaps are the same length from the score to the edge. Typically, the longer major flaps meet in the middle and the minor flaps do not. However, with the rise of E-commerce and a more competitive retail environment, box designs are becoming more dynamic and functional, straying away from typical shipping box designs.

The manufacturer's joint is most often joined with adhesive but may also be taped or stitched. The box is shipped flat (knocked down) to the packager who sets up the box, fills it, and closes it for shipment. Box closure may be by tape, adhesive, staples, strapping, etc.

The size of a box can be measured for either internal (for product fit) or external (for handling machinery or palletizing) dimensions. Boxes are usually specified and ordered by the internal dimensions.

• Regular Slotted Container (RSC)

• RSC blank showing score lines, slots, and manufacturer's joint at the leftmost edge

Box maker's certificate

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A box maker's certificate is typically printed on what will become the underside of the box

A box maker's certificate (also known as "box certificate", or "box certificate of maker") is a seal printed on an outside surface, typically the bottom of the box, that includes some information about how strong the box is. The certificate is not required, but if used, it implies compliance with regulations relating to the certificate.[8] Significant information includes:[9][10]

• Bursting Test or Edge Crush Test
• Size Limit (the maximum outside dimensions of a finished box when the length, width and depth of the box are added together)
• Gross Weight Limit

Manufacturing

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Boxes can be formed in the same plant as the corrugator. Such plants are known as "integrated plants". Part of the scoring and cutting takes place in-line on the corrugator. Alternatively, sheets of corrugated board may be sent to a different manufacturing facility for box fabrication; these are sometimes called "sheet plants" or "converters".

The corrugated board is creased or scored to provide controlled bending of the board. Most often, slots are cut to provide flaps on the box. Scoring and slotting can also be accomplished by die-cutting. Along with the print being produced on the box in these plants. These conversions are produced on different machines, depending on the conversion being made: "Flexo Folder Gluers (FFG)", "Rotary Die Cutters (RDC), "Printer Slotters" or " Printing Presses".

Single-face laminate

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A limitation of common corrugated material has been the difficulty in applying fine graphic print for informative and marketing purposes. The reasons for this stem from the fact that prefabricated corrugated sheets are relatively thick and spongy, compared to the thin and incompressible nature of solid fibre paper such as paperboard. Due to these characteristics of corrugated, it has been mainly printed using a flexographic process, which is by nature a coarse application with loose registration properties.

A more recent development popular in usage is a hybrid product featuring the structural benefits of corrugated combined with the high-graphics print of lithography previously restricted to paperboard folding cartons. This application, generally referred to as "Single-Face Laminate" (SFL), begins its process as a traditional fluted medium adhered to a single linerboard (single-face), but in place of a second long-fibered liner, a pre-printed sheet of paperboard such as SBS (solid bleached sulfate) is laminated to the outer facing. The sheet can then be converted with the same processes used for other corrugated manufacturing into any desired form.

Specialized equipment is necessary for the material construction of SFL, so users may expect to pay a premium for these products. However, this cost is often offset by the savings over a separate paperboard sleeve and the labor necessary to assemble the completed package.

Recycling

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Used boxes bundled for recycling

Old corrugated containers (OCC) are an excellent source of fiber for recycling. They can be compressed and baled for cost effective transport. The baled boxes are put in a hydropulper, which is a large vat of warm water for cleaning and processing. The pulp slurry is then used to make new paper and fiber products.

Mill and corrugator scrap, or "broke", is the cleanest source for recycling. The high rates of post-consumer recycling reflect the efficiency of recycling mills to clean and process the incoming materials. Several technologies are available to sort, screen, filter, and chemically treat the recycled paper.

Many extraneous materials are readily removed. Twine, strapping, etc. are removed from the hydropulper by a "ragger".[further explanation needed] Metal straps and staples can be screened out or removed by a magnet. Film-backed pressure-sensitive tape stays intact: the PSA adhesive and the backing are both removed together.[11]

Materials which are more difficult to remove include wax coatings on corrugated boxes and "stickies", soft rubbery particles which can clog the paper maker and contaminate the recycled paper. Stickies can originate from book bindings, hot melt adhesives, pressure-sensitive adhesives from paper labels, laminating adhesives of reinforced gummed tapes, etc.[12][13]

Corrugated fiberboard shredders are now available which convert post-consumer corrugated board into packing/cushioning materials by means of a specialized shredding process.

ASTM standards

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The following standards are in practice among others:

• D1974 Standard Practice for Methods of Closing, Sealing and Reinforcing Fiberboard Boxes
• D4727 Standard Specification for Corrugated and Solid Fiberboard Sheet Stock (Container Grade) and Cut Shapes
• D5118 Standard Practice for Fabrication of Fiberboard Shipping Boxes
• D5168 Standard Practice for Fabrication and Closure of Triple-Wall Corrugated Fiberboard Containers
• D5639 Standard Practice for Selection of Corrugated Fiberboard Materials and Box Construction Based on Performance Requirements
• D6804 Standard Guide for Hand Hole Design in Corrugated Boxes

See also

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References

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Further reading

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• Asian Corrugated Carton Association
• European Corrugated Board Industry
• Good Manufacturing Practices for Corrugated and Solid Board Packaging This GMP-standard allows packaging for the food industry to be made to the highest standards of consumer safety. All details at the website of the European Federation of Corrugated Board Manufacturers (FEFCO)

Corrugated Definition

Corrugated fiberboard, most commonly referred to as "corrugated," by definition is a packaging material formed by gluing a fluted corrugated sheet, or the "medium," to one or two sheets of flat linerboard, or the "liner."

Corrugated fiberboard is often called "cardboard," although cardboard is a broader term that refers to any heavy paperboard, even if not corrugated.

Even though it is such a commonly used material, in order to understand benefits, it is important to know the composition as well as the different options corrugated can offer.

The composition, customization, packaging advantages, and eco-friendly benefits all work together to create an interesting material that is used to help products stand out every day.

Corrugated packaging has many benefits that can efficiently support your product.

Corrugated Composition

While corrugated packaging and cardboard are both primarily made of paper-based materials, they are completely different. Corrugated material is composed of an inside liner and outside liner with fluting in between. It is commonly used for shipping boxes, retail display, and retail packaging.

However, cardboard is any type of board made from heavy, one-layer paper-pulp stock. Popular uses of cardboard include cereal boxes and other smaller consumer goods.

Fluting was inspired by the architectural use of curves to span a given space in the strongest way. The inventors of corrugated fiberboard used this principle to resist bending and pressure from all directions.

Fluting is glued onto the paperboard to maximize the strength and durability of the material. Many different types of fluting are available ranging from 33 flutes per foot to 125 flutes per foot based on their purpose.

Corrugated fiberboard, also known as combined board, is composed of the liner and the medium, but there are many options for types using a variety of flute structures.

The type of structure affects the durability and graphics capabilities. Here are some commonly used flute structures:

• Single Face: One sheet of flat linerboard is glued to one piece of corrugated paperboard.
• Single Wall: One piece of corrugated paperboard is glued in between two sheets of flat linerboard.
• Double Wall: Three sheets of flat linerboard with two pieces of corrugated paperboard glued in between.
• Triple Wall: Four sheets of flat linerboard with three pieces of corrugated paperboard glued in between.

Corrugated Packaging Advantages

Corrugated fiberboard packaging has huge advantages including unmatched protection for the product, flexibility, and different treatments based on the need.

Protecting your product is one of the most important aspects in packaging, and corrugated is one of the most protective options. The fluting within the material allows for high durability and strength, to ensure your package arrives safely.

Combining structural soundness of the fluting with the cushioning qualities of a linerboard, corrugated packaging can be designed to fit specific protection needs. Protecting against shocks and jerks, it is extremely useful for the packaging of fragile objects.

Corrugated material is a versatile medium that is commonly used for packaging because of its widely varying capabilities. 

There is an infinite number of customizing possibilities from different shapes and uses to varying levels of protection. They can come in all sizes and be easily folded into whatever shape makes it a perfect fit.

There is a multitude of options for coatings and treatments that can support the product in the most efficient way possible. Combined board can be coated with different materials, and various adhesives can be selected in order to fit the specific needs of the product. It can even be made flame resistant if more protection is required.

Considering what options are most important for your product ensures that corrugated fiberboard will be the most successful option in getting your product from point A to point B.

Corrugated Is Cost-effective

Maximizing usage and minimizing waste allows for corrugated fiberboard to be the most economical choice for packaging. Lower raw material costs and the ability to be mass produced supports lower labor costs and lower machinery expenses.

Used widely for everything from shipping to packaging this material is readily available.

Minimize freight and handling costs by optimizing wasted space. Shipping costs are lower due to the lightweight material and higher fill density. Corrugated packaging can be customized so easily that it is simple to minimize the amount of excess material needed to get the job done.

Corrugated cartons serve as the most diverse solution to ensure your product remains safe in the most cost-effective manner. On a larger scale, it is used for shipping containers to display mediums in retail stores. It is also used residentially—think moving boxes and storage solutions.

Corrugated Is Sustainable

Corrugated fiberboard is the most recycled packaging material and is continuously being recycled more and more. In 1993 only 54% of corrugated packaging was recycled; however, in 2016 the recovery rate was up to 93%. Recycling corrugated materials helps reduce the amount of waste disposed of and allows for a constant cycle of reusable material.

Corrugated packaging is not only recyclable but it is also renewable. Most corrugated material is made up of 70% to 100% of recycled material. Further reducing the cost and environmental impact of producing corrugated fiberboard.

Another benefit of corrugated packaging is its ability to be reused. Many case styles are designed to be collapsible and used repeatedly. Consumers use this material through its entire life cycle, from moving and shipping packages to using old packaging pieces as floor protectors.

Then when it is no longer usable it can be easily recycled to continue the cycle.

Related: How To Find A Corrugated Box Manufacturer

Corrugated Is Customizable

Continuous research and investment into the industry of printing on corrugated materials have created incredible printing options. The capabilities are growing consistently, and technology is constantly being improved upon. Today we are able to provide sharper, cleaner graphics on corrugated fiberboard than ever before.

Corrugated material is a blank canvas that just requires the right technology to convey the most successful consumer engagement. Bennett offers multiple printing options based on your product’s needs, including flexo, litho, and digital printing.

We are committed to providing state-of-the-art technology options that will assist in making sure your product is not only supported but communicating the most impactful message.

In fact, Bennett was the first to invest in a high-speed, single-pass, direct-to-corrugate, 6-color digital press of its kind in North America. With increasing demand, we strive to be at the top of our game and create innovative solutions perfect for every product.

To ensure your product makes the most impact when it reaches stores, pairing it with a custom corrugated retail display can help your product stand out. Corrugated displays are easily set-up making them perfect for temporary solutions, but also strong enough to be able to serve as a permanent solution.

The possibilities of corrugated fiberboard are endless, and so are the benefits it can provide. From shipping to shopping, this material plays an important role in all phases supporting your product.

Corrugated fiberboard is the most economical and natural choice for your packaging—protecting your product from harsh environments and conveying a strong message.

Bennett Makes Custom Boxes

Bennett is a premier packaging and retail displays manufacturing company striving to protect and promote our clients' products with customized corrugated solutions. With our fully-integrated design-to-delivery process, we can be the single supplier source.

We are an award-winning manufacturer of virtually anything corrugate. We offer everything from plain brown shipping boxes to sophisticated, high-graphic printed point-of-purchase displays, and everything in between.

Frequently Asked Questions

What Is Corrugated Cardboard?

Corrugated cardboard is made up of "corrugated paperboard", which contains rows of open-air columns inside the walls of the two or more layers. The open-air columns are what make the paper stronger than average cardboard, with the air acting as a cushion for any items inside of them. The ridges inside the wall offer strength and flexibility, which is usually needed in packaging.

What Does Corrugation Mean?

In cardboard packaging, corrugation is the process of combining layers of paper to create a structure that is strong enough for safe shipping / handling. A middle layer of paper is steamed, and pressed into a "wavy" shape to create columns of air in between the outer layers. This creates a "flute". Then all three layers are combined to create the shape of the box.