Liquid packaging board is a multi-ply paperboard with high stiffness, strong wet sizing and a high barrier coating, e.g. plastic. Only virgin paper fibers are used. The barrier coating must hold the liquid and prevent migration of air and flavors through the paperboard. [1]
A liquid packaging board might be up to five plies and is formed on a multi-ply paper machine with online coating. The most common is to use three plies with a basis weight of about 300 g/m2. [2] The base or middle ply is normally made of pulp from bleached or unbleached chemical pulp, chemi-thermo-mechanical pulp (CTMP) or broke (waste paper from a paper machine). CTMP gives more bulk and stiffness. The top ply (inside) is made of bleached chemical pulp. The barrier coating depends on the application and might be applied on both sides. When induction welding is employed an aluminum foil layer is used for barrier protection and for heating. [3] The back side of the board is the printing side and might have an extra ply made from chemical pulp of quality that is suitable for the printing applications. Liquid packages are normally heat sealed.
Cartons filled with short-shelf-life dairy products use board that are barrier coated on both sides with one layer of low density polyethylene. For long-shelf-life products it is common to use aluminium foil as barrier coating together with polyethylene. Commonly the plastic coating on the top side is 12 - 20 g/m2 and on the reverse side 15 - 60 g/m2. [2]
Sanitary and aseptic processing of food contact products are critical. [4]
Liquid packaging board is used for two package types: brick and gable top cartons.[ citation needed ]
The most common application is packaging for beverages, including for milk and juiceboxes.
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemical or plant-based additives, pulp is the major raw material used in papermaking and the industrial production of other paper products.
Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker 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. Paperboard can be single- or multi-ply.
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.
Kraft paper or kraft is paper or paperboard (cardboard) produced from chemical pulp produced in the kraft process.
A paper cup is a disposable cup made out of paper and often lined or coated with plastic or wax to prevent liquid from leaking out or soaking through the paper. It may be made of recycled paper and is widely used around the world.
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.
Deinking is the industrial process of removing printing ink from paperfibers of recycled paper to make deinked pulp.
When recycling post-consumer paper, stickies are tacky substances contained in the paper pulp and process water systems of paper machines. Stickies have the potential to contaminate the components either within or around the equipment necessary in the Stages of Manufacturing that a Paper Mill follows in its Developed Process, but would have otherwise excluded it in its routine cleaning and maintenance procedures. Contaminations of paper that are classified as tacky are also called stickies. The main sources for stickies are recycled paper, waxes, and soft adhesives.
Electrical insulation papers are paper types that are used as electrical insulation in many applications due to pure cellulose having outstanding electrical properties. Cellulose is a good insulator and is also polar, having a dielectric constant significantly greater than one. Electrical paper products are classified by their thickness, with tissue considered papers less than 1.5 mils (0.0381 mm) thickness, and board considered more than 20 mils (0.508 mm) thickness.
Lamination paper is a paper used for laminates. Normally on particle or fiberboards giving a good-looking and resistant surface for use as furniture, decoration panels and flooring.
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.
Clearwater Paper Corporation is a pulp and paper product manufacturer that was created on December 9, 2008, via a spin-off from the real estate investment trust (REIT) company Potlatch Corporation. With its headquarters in Spokane, Washington, the new company started with four locations for the manufacture of bleached paperboard, consumer tissue, and wood products.
Woodfree uncoated paper (WFU), uncoated woodfree paper (UWF) or uncoated fine papers are manufactured using wood that has been processed into a chemical pulp that removes the lignin from the wood fibers and may also contain 5–25% fillers. Both softwood and hardwood chemical pulps are used and a minor part of mechanical pulp might be added. These paper grades are calendered.
Special fine paper is a classification of paper used for copying and digital printing.
Fine papers are printing and writing paper grades based mainly on chemical pulps. Normally the content of mechanical pulps are below 10% and the amount of fillers in the range 5–25%.
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.
Magazine papers are paper grades generally used in printing of magazines.
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.
A paper sack is a packaging type that can be constructed of one or several layers of high quality kraft paper, usually produced from virgin fibre. Paper sacks can also be referred to as industrial paper bags, industrial paper sacks or multi-wall paper bags or sacks. They are not to be confused with paper bags, the term which usually refers to paper carrier bags, or paper shopping bags.
Plastic-coated paper is a coated or laminated composite material made of paper or paperboard with a plastic layer or treatment on a surface. This type of coated paper is most used in the food and drink packaging industry.
