Air-laid paper
Encyclopedia
Air-laid paper is a textile-like material categorized as a nonwoven fabric made from fluff pulp
.
and tissue, air-laid paper is very bulky, porous and soft. It has good water absorption properties and is much stronger compared with normal tissue.
Main characteristics are:
The raw material is long fibered softwood fluff pulp in roll form. The pulp are defibrized in a hammermill
. Defibration is the process of freeing the fibres from each other before entering the papermachine. Important parameters for dry defibration are shredding energy and knot
content. Normally an air-laid paper consists of about 85 % fibre. A binder must be applied as a spray or foam. Alternatively, additional fibres or powders can be added to the pulp which can then be activated and cured by heat.
Fluff pulp
Fluff pulp is a type of chemical pulp made from long fibre softwoods. Important parameters for fluff pulp are bulk and water absorbency.-Manufacture:...
.
Properties
Compared with normal wet-laid paperPaper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
and tissue, air-laid paper is very bulky, porous and soft. It has good water absorption properties and is much stronger compared with normal tissue.
Main characteristics are:
- Soft, does not scratch.
- Non-linting, no dust, no static.
- Strong, even when wet, can be rinsed and reused.
- Clean, hygenic, can be sterilizedSterilization (microbiology)Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media...
. - Textile- like surface and drape.
- Can be dyeDyeA dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
d, printedPrintingPrinting is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
, embossed, coated and made solvent resistant.
Manufacture
Unlike the normal papermaking process, air-laid paper does not use water as the carrying medium for the fibre. Fibres are carried and formed to the structure of paper by air. The air-laid structure is isotropic.The raw material is long fibered softwood fluff pulp in roll form. The pulp are defibrized in a hammermill
Hammermill
A hammermill is a machine whose purpose is to shred or crush aggregate material into smaller pieces. These machines have many sorts of applications in many industries, including:*Ethanol plants...
. Defibration is the process of freeing the fibres from each other before entering the papermachine. Important parameters for dry defibration are shredding energy and knot
Knot (papermaking)
Knots are unwanted, lage, dark aggregates of wood fibres when making chemical pulp.Knots are incompletely cooked wood chips coming out of the digester. Their origin is often dense parts of branches, such as compression wood or timber knots – hence the name. Knots can also stem from...
content. Normally an air-laid paper consists of about 85 % fibre. A binder must be applied as a spray or foam. Alternatively, additional fibres or powders can be added to the pulp which can then be activated and cured by heat.
History
The Danish inventor Karl Krøyer is considered to be the first who commercialized air-formed paper in the early 1980s. Others developed different processes independently at about the same time.Applications
- Disposable diapers as part of the inner absorbent
- Feminine hygieneFeminine hygieneFeminine hygiene is a general euphemism used to describe personal care products used by women during menstruation, vaginal discharge, and other bodily functions related to the vulva...
- Industrial wipes
- Personal care products
- Table top
- napkinNapkinA napkin, or face towel is a rectangle of cloth used at the table for wiping the mouth while eating. It is usually small and folded...
- table cloth
- napkin
- Wet wipes