Paperboard

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Corrugated fiberboard made from paperboard Cardboard All Flutes.jpg
Corrugated fiberboard made from paperboard

Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.30 mm, 0.012 in, or 12 points) than paper and has certain superior attributes such as foldability and rigidity. According to ISO standards, paperboard is a paper with a grammage above 250 g/m2, but there are exceptions. [1] Paperboard can be single- or multi-ply.

Contents

Paperboard can be easily cut and formed, is lightweight, and because it is strong, is used in packaging. Another end-use is high quality graphic printing, such as book and magazine covers or postcards. Paperboard is also used in fine arts for creating sculptures.

Sometimes it is referred to as cardboard , which is a generic, lay term used to refer to any heavy paper pulp–based board, however this usage is deprecated in the paper, printing, and packaging industries as it does not adequately describe each product type.

History

In 1817, the first paperboard carton was produced in England. Folding cartons first emerged around the 1860s and were shipped flat to save space, ready to be set up by customers when they were required. The mechanical die cutting and creasing of blanks was developed in 1879. In 1911 the first kraft sulphate mill was built in Florida. In 1915 the gable top milk carton was patented and in 1935 the first dairy plant was observed using them. Ovenable paperboard was introduced in 1974. [2]

Terminology and classification

Crush-proof cigarette pack made of folding boxboard Pakje sigaretten.JPG
Crush-proof cigarette pack made of folding boxboard

Terminology and classifications of paperboard are not always uniform. Differences occur depending on specific industry, locale, and personal choice. In general, the following are often used: [3] [4]

Production

Metsa Board Tako paperboard factory near the Tammerkoski in Tampere, Finland Takon kartonkitehdas Tammerkoski.jpg
Metsä Board Tako paperboard factory near the Tammerkoski in Tampere, Finland

Fibrous material is turned into pulp and bleached to create one or more layers of board, which can be optionally coated for a better surface and/or improved appearance. Pulp board is produced on pulping machines that can handle higher grammage and several plies.

Raw materials

The above-mentioned fibrous material can either come from fresh (virgin) sources (e.g. wood) or from recycled waste paper. Around 90% of virgin paper is made from wood pulp. [5] Today paperboard packaging in general, and especially products from certified sustainable sources, are receiving new attention, as manufacturers dealing with environmental, health, and regulatory issues look to renewable resources to meet increasing demand. It is now mandatory in many countries for paper-based packaging to be manufactured wholly or partially from recycled material.

Raw materials include:

Pulping

Two principal methods for extracting fibres from their sources are:

Bleaching

Pulp used in the manufacture of paperboard can be bleached to decrease colour and increase purity. Virgin fibre pulp is naturally brown in colour, because of the presence of lignin. Recycled paperboard may contain traces of inks, bonding agents and other residue which colors it grey. Although bleaching is not necessary for all end-uses, it is vital for many graphical and packaging purposes. There are various methods of bleaching, which are used according to a number of factors for example, the degree of colour change required, chemicals chosen and method of treatment. There are three categories of bleaching methods:

Plies

(1) single-ply vs. (2) multi-ply Single vs multiply.svg
(1) single-ply vs. (2) multi-ply

Multi-ply paperboard generally has higher creasing and folding performance than single-ply as a result of layering different types of pulp into a single product. In cases where the same kind of pulp is being used in several layers, each separate layer is treated and shaped individually in order to create the highest possible quality. [6]

Coating

In order to improve whiteness, smoothness and gloss of paperboard, one or more layers of coating is applied. Coated paper is usually made up of:

Additional components could be OBA (optical brightening agents). [9]

Grades

The DIN Standard 19303 "Paperboard - Terms and grades" (Publication date : 2005-09) defines different grades of paperboard based on the surface treatment (first letter), the main furnish (second letter) and the colour (non-D grade) or bulk (D grade only) (numbering).

First letter
(surface treatment)
Second letter
(main furnish)
Number
  • A = cast-coated
  • G = pigment coated
  • U = uncoated
  • Z = bleached virgin chemical pulp
  • C = virgin mechanical pulp
  • N = unbleached virgin chemical pulp
  • T = recycled/secondary fibre with white, cream or brown reverse
  • D = recycled/secondary fibre with grey back

All except D grades:

  1. white reverse side
  2. cream reverse side
  3. brown reverse side

D grades only:

  1. bulk ≥ 1.45 cm3/g
  2. 1.3 cm3/g < bulk < 1.45 cm3/g
  3. bulk ≤ 1.3 cm3/g

Example: GC1 would be a "pigment coated", "virgin mechanical pulp" board with a "white reverse side". Often the used paperboard type would be FBB, which was coated on both sides.

Common terms

Basis weight (US): Is the weight in 1,000 square feet (93 m2) of paperboard.

Brightness: Brightness is a technical term that is defined as the amount of blue-white light that a paper reflects. [10] This property is very subjective and individual to each buyer and end use, as skin colour and food are better reproduced on 'warm' (yellow) whites and not blue whites.

Grammage: The grammage of the paperboard is assessed in accordance ISO 536. [11] Grammage expresses mass per unit area and is measured in g/m2. [10]

PH: Surface pH is measured on a water extract and is on a scale of 0–14. 0 is acidic, 7 is neutral and 14 is alkaline. [12]

Stiffness: Stiffness is one of the most important properties of paperboard as it affects the ability of cartons to run smoothly through the machine that erects, fills and closes them. Stiffness also gives strength and reduces the propensity of a carton to bulge under the weight of settling flowable contents such as cereals.

Although most paper strength properties increase with increasing sheet density, stiffness does not. A rule of thumb is that stiffness is proportional to the 1.6 power of sheet caliper.

The species of fiber used has an effect on stiffness, other things being equal. Northern softwood species impart superior stiffness compared to southern softwoods.

Other factors which affect board stiffness include coatings and moisture content. [10]

Smoothness: Smoothness is particularly important when being used for printing, the smoother the paperboard, the better the image quality, because of better ink coverage. Smoothness is measured using air leak methods – the greater the rate of air leakage, at a specific air pressure, from under a cylindrical knife placed on the surface, the rougher the surface. [10]

Caliper/thickness: In the United States caliper is usually expressed in thousandths of an inch (0.001”) or points, where a sheet of paperboard with a thickness of 0.024” would be 24 points. In Europe it is often sold in g/m2, however the thickness of the board is measured in micron (μm).

Paperboard also tends to be referred to with thickness rather than weight. [9]

Whiteness: It refers ideally to the equal presence of all colours, because a truly white sheet will reflect all wavelengths of visible light equally. [10]

Paperboard industry

The paperboard sector is mainly looked at in conjunction with the paper industry. The Paper & Paperboard market size (2007) had a value of US$630.9 billion and a volume of 320.3 million metric tons. [5] Of that market 40.1% is European. About 50% of all produced paper is used for packaging, followed by printing and writing. [5] According to ProCarton, the consumption of paper and paperboard seem to correlate with economic trends (GDP). [13] [14] Sales of carton in Europe sum up to around 8 billion Euros worth.

Over 1,100 printers produce 5.4 million tonnes of cartonboard yearly. Cartons make up one third of paper and board packaging and 15% of all packaging. A bit more than half (54%) of the European carton is produced using recovered fibre or waste paper. The paper and paperboard industry is quite energy and capital intensive. Just a coated board machine itself can cost around 90 - 120 million Euros [15] (about 125 - US$166 million in 11/2011). Economies of scale apply, because of which a few large players often dominate the market place. E.g. in North America the top 5 producers have a market share of 85%.

See also

Related Research Articles

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Corrugated fiberboard, corrugated cardboard, or corrugated is a type of packaging material consisting of a fluted corrugated sheet and one or two flat linerboards. 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.

<span class="mw-page-title-main">Box</span> Type of container

A box is a container with rigid sides used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides. Boxes can be very small or very large and can be used for a variety of purposes, from functional to decorative.

<span class="mw-page-title-main">Lamination</span> Technique of fusing layers of material

Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials, such as plastic. A laminate is a layered object or material assembled using heat, pressure, welding, or adhesives. Various coating machines, machine presses and calendering equipment are used.

<span class="mw-page-title-main">Carton</span> Type of domestic container

A carton is a box or container usually made of liquid packaging board, paperboard and sometimes of corrugated fiberboard. Many types of cartons are used in packaging. Sometimes a carton is also called a box.

<span class="mw-page-title-main">Cardboard box</span> Type of packaging

Cardboard boxes are industrially prefabricated boxes, primarily used for packaging goods and materials. Specialists in industry seldom use the term cardboard because it does not denote a specific material. The term cardboard may refer to a variety of heavy paper-like materials, including card stock, corrugated fiberboard, and paperboard. Cardboard boxes can be readily recycled.

<span class="mw-page-title-main">Kraft paper</span> Paper or paperboard produced from chemical pulp produced in the kraft process

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Tracing paper is paper made to have low opacity, allowing light to pass through. Its origins date back to at least the 1300s where it was used by artists of the Italian Renaissance. In the 1880s, tracing paper was produced en masse, used by architects, design engineers, and artists. Tracing paper was key in creating drawings that could be copied precisely using the diazo copy process. It then found many other uses. The original use for drawing and tracing was largely superseded by technologies that do not require diazo copying or manual copying of drawings.

Coated paper is paper that has been coated by a mixture of materials or a polymer to impart certain qualities to the paper, including weight, surface gloss, smoothness, or reduced ink absorbency. Various materials, including kaolinite, calcium carbonate, bentonite, and talc, can be used to coat paper for high-quality printing used in the packaging industry and in magazines.

Cardboard is a generic term for a heavy-duty paper.

<span class="mw-page-title-main">Paper</span> Material for writing, printing, etc.

Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses, or other vegetable sources in water, draining the water through a fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and cleaning. It may also be used as filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency, and security paper, or in a number of industrial and construction processes.

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<span class="mw-page-title-main">Liquid packaging board</span>

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<span class="mw-page-title-main">White-lined chipboard</span>

White-lined chipboard is a grade of paperboard typically made from layers of waste paper or recycled fibers. Most often it comes with two to three layers of coating on the top and one layer on the reverse side. Because of its recycled content it will be grey from the inside. The main end use for this type of board is for packaging of frozen or chilled food, cereals, shoes, toys and others.

<span class="mw-page-title-main">Folding boxboard</span> Paperboard grade made of multiple layers

Folding boxboard, also referred to as FBB or by the DIN Standard 19303 codes of GC or UC, is a paperboard grade made up of multiple layers of chemical and mechanical pulp. This grade is made up of mechanical pulp in between two layers of chemical pulp. The top layer is of bleached chemical pulp with an optional pigment coating. This is a low-density material with high stiffness and a slightly yellow colour, mainly on the inside. The major end uses of folding boxboard are health and beauty products, frozen, chilled and other foods, confectionaries, pharmaceuticals, graphical uses and cigarettes.

<span class="mw-page-title-main">Solid bleached board</span> Paperboard grade

Solid bleached board (SBB) or solid bleached sulphate (SBS) is a virgin fibre grade of paperboard.

<span class="mw-page-title-main">Solid unbleached board</span>

Solid unbleached board, also known as SUB, is a grade of paperboard typically made of unbleached chemical pulp. Most often it comes with two to three layers of mineral or synthetic pigment coating on the top and one layer on the reverse side. Recycled fibres are sometimes used to replace the unbleached chemical pulp.

<span class="mw-page-title-main">Corrugated box design</span> Process of matching design factors for corrugated fiberboard boxes

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The wet strength of paper and paperboard is a measure of how well the web of fibers holding the paper together can resist a force of rupture when the paper is wet. Wet strength is routinely expressed as the ratio of wet to dry tensile force at break.

<span class="mw-page-title-main">Cardboard</span> Heavy-duty paper of various strengths

Cardboard is a generic term for heavy paper-based products. The construction can range from a thick paper known as paperboard to corrugated fiberboard which is made of multiple plies of material. Natural cardboards can range from grey to light brown in color, depending on the specific product; dyes, pigments, printing, and coatings are available.

References

  1. Robertson, Gordon L. (2005). Food Packaging - Principle and Practice (2nd Ed.). CRC Press. p. 111. ISBN   978-0-8493-3775-8.
  2. Paperboard Packaging Alliance. "Paperboard Packaging" (PDF). Archived from the original (PDF) on November 21, 2008. Retrieved 2009-07-18.
  3. ASTM D996
  4. Soroka, W. Illustrated Glossary of Packaging Terminology (Second ed.). Institute of Packaging Professionals.
  5. 1 2 3 Datamonitor (June 2008), Global Paper and Paperboard - Industry Profile
  6. 1 2 3 Iggesund Paperboard AB (2008). "Paperboard the Iggesund Way": 10.{{cite journal}}: Cite journal requires |journal= (help)
  7. Federal Institute for Risk Assessment (Germany). "Migration of mineral oil from packaging materials to foodstuffs (BfR Opinion No. 008/2010 of 2009-12-09)" (PDF). Retrieved 2010-04-21.
  8. Bundesinstitut für Risikobewertung. "Übergänge von Mineralöl aus Verpackungsmaterialien auf Lebensmittel" (PDF). Retrieved 2010-04-21.
  9. 1 2 Kirwan, Mark J. (1998). Paper and paperboard packaging technology. London: Blackwell Publishing. ISBN   978-1-4051-6845-8.
  10. 1 2 3 4 5 Twede, Diana; Selke, Susan E. M. (2004). "Cartons, Crates and Corrugated Board: Handbook of Paper and Wood Packaging Technology". Lancaster, PA: DasTech Publications.{{cite journal}}: Cite journal requires |journal= (help)
  11. ISO: International Organization for Standardization (1995). "Paper and board -- Determination of grammage" . Retrieved 2009-07-18.
  12. Iggesund Paperboard (2008). "Product Catalogue: General Technical Information". Archived from the original on July 13, 2011. Retrieved 2009-07-18.
  13. Dr. Peter Ince (1999–2000). "Paper, Paperboard and Woodpulp – Production, Consumption and Trade ECE/FAO Forest Products Annual Market Review" (PDF). Archived from the original (PDF) on June 5, 2011. Retrieved 2009-07-18.
  14. ProCarton (2009). "The Carton Packaging Fact File: Cartons, Industry and the Environment" (PDF). Retrieved 2009-07-20.
  15. Metso Corporation's press release (2011). "Metso to supply coated board line to International Paper & Sun Cartonboard in China". Archived from the original on 2011-10-13. Retrieved 2011-11-04.

Further reading