The Rupp Report: Successful Technical Textiles (Part III)

For many traditional textile people, technical textiles in general, and nonwovens in particular, and its technical expressions are sometimes not easy to understand. With this glossary of technical terms from the sector — which is only the tip of the iceberg — The Rupp Report closes its short round-up of technical textiles.
 
Next week, The Rupp Report will start with previews from exhibitors at the next Techtextil, which will take place in Frankfurt, May 4-7, 2015. Exhibitors are invited to send it their previews to jrupp@textileworld.com
 
 Nonwovens/Technical Textiles Glossary
 

Airlaid
Airlaid is one of the dry nonwoven processes. The most important feature of the airlaid process is the processing of short fibers from 1 millimeter (mm). The basic principle is that the short fibers are passed through an airflow and manufactured into nonwoven material.
 
Aramid fibers
The fibers are very stable, have a high tensile strength and are resistant to acids and alkali. They are also very heat and fire resistant. Aramid fibers do not melt at high temperatures, and only start to char at temperatures around 400° C.
 
Basalt fibers
Melts at 1,450° C. Can be produced from natural basalt filament fibers, which are used as the basis for a wide range of textile technology processes and various applications.
 
Bionics
Interface between physics, technology and biology, in which structures and functionalities of living systems are researched and used for technical constructions.
 
Bonding
Bonding together a sheet or web structure. Can be achieved:

  • Mechanically — for example, needle punched;
  • Thermally — for example, by adding thermoplastic fibers; or
  • Chemically — for example, by spraying.
Carbon fibers
Using special technical processes, carbon is formed into fine fibers. The resulting fibers have a very high tensile strength, are electrically conductive, resistant to chemicals and temperature and easy to process (similar to glass fibers).
 
Carded processes
In a continuous process, the basic fibers are carded, aligned in parallel and needled into nonwoven material.
 
Composites
Composites are materials consisting of at least two coexistent components, i.e. which do not dissolve into each other and whose properties are combined to form a material which is very stable and stiff.
 
Cellulose wadding
Soft, thick material made from cotton or rayon fibers.
 
Cellulose
Natural polymer (macromolecular polysaccharide) that is the main component of plant cell walls.
 
Carbon Fiber Plastics (CFP)
Carbon fiber plastics (CFP) are a fiber composite which is manufactured by embedding carbon fibers in epoxy resin.
 
Coverstock
The outer layer of an absorbent hygiene product that is in direct intimate contact with the user’s skin. It allows instant transfer of the fluid from the point of contact to the inside of the product. Sometimes also referred to as topsheet.
 
Defibered wood pulp
Wood pulp that has been put through a hammer mill to separate the fibers into ‘fluff’ which increases the bulk and, as a result, can be used to form absorbent hygiene product (AHPs).
 
Diaper
Article worn by babies to absorb urine and contain faeces.
 
Disposable
Term used by the AHP industry to denote products intended for single use.
 
Dissolving grade wood pulp
Technical name for fluff pulp.
 
Double-blind
clinical study

Clinical trial in which the method for analyzing data is specified in the protocol before the study has begun and the study subjects have been randomly assigned for either application of the study material or an alternative material, and in which neither the study subjects nor the physician(s) conducting the study know which treatment is being given to the study subject.
 
Elemental chlorine-free (ECF)
Bleaching process that substitutes chlorine dioxide for elemental chlorine in the bleaching process. Compared to elemental chlorine bleaching processes, ECF bleaching reduces the formation of many chlorinated organic compounds.
 
Extrusion
Manufacturing process that allows continuous production of polymer materials for example into long objects of a fixed cross-sectional profile.
 
Fiberization
Separation of wood and other plant material into fibers or fiber bundles by mechanical (sometimes assisted by chemical) means.
 
Fiber spraying
In this process, pieces of glass fiber and impregnated resin are combined into one form. The fiber spraying process is used, for example, to produce parts for boats made from glass-fiber reinforced plastic (GFP).
 
Fluff pulp
Common name for wood pulps used in the absorbent core of absorbent hygiene products such as diapers, feminine absorbent pads and airlaid absorbent products.
 
Glass-fiber reinforced plastic (GFP)
GFP is a fiber/plastic composite consisting of plastic and glass fibers.
 
Glass fibers
A glass fiber is a long thin fiber made from glass. In the production process, thin fibers are drawn out of molten glass and processed further into a number of end products. Characteristic properties include high stability and chemical and thermal durability.
 
Hot-melt adhesives
Solid thermoplastic adhesive that melts rapidly when heated and sets to a bond when cooled. Unlike many other adhesives, hot melt adhesives do not set due to the evaporation of a solvent.
 
Lamination
Bonding sheets together.
 
Laying products
A laying is a special textile surface structure, which can be used, for example, to reinforce fiber composites. In contrast to woven materials, laid webs are much more drapeable and have better mechanical properties in composite structures, since the fibers are used in an attenuated form and the direction of the fibers can be defined specifically for the respective application.
 
Meltblown technology
In the meltblown process, the spun filaments are deposited randomly and reinforced directly after they are removed from the spinneret and the stretching unit. If the filaments are stretched to an extreme degree by a compressed airflow, the resulting product is known as meltblown.
 
Nappy
Term used for a diaper in the United Kingdom.
 
Nanotechnology
Nanotechnology is the investigation, application and production of structures, molecular materials and systems with a dimension or production tolerance of typically less than 100 nanometers. The nanoscale of the system components alone results in new functionalities and properties to improve existing or develop new production and application options” (BMBF definition).
 
Non-crimp fabrics (NCF)
NCF is the term used to describe laid web products for fiber composites. The fibers are not woven together, but are placed in layers, and held together by a filament. Layings have better mechanical properties than woven materials.
 
Nonwovens
Generic term for textile fabrics not produced by weaving or knitting (stitching), but from a random combination of synthetic fibers. Sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally or chemically. They are flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film.
 
Fabrics which are produced neither by weaving nor by stitching fibers, and are known as composites. Examples of textile composites are felts and fleeces.
 
Nonwoven fabric
A pleonasm. Wrong description of nonwovens. The nonwoven as such is already the fabric.
 
Polyester (PET)
Thermoplastic material that can be spun into fibers or continuous filaments. Its properties include strength and high modulus. It can be easily recycled.
 
pH
Measure of the acidity or alkalinity of a fluid or substrate. The pH of any fluid is the measure of its range from 0 to 14 on a logarithmic scale, where 0 is most acid, 14 most alkaline and 7 is neutral.
 
Polyethylene (PE) film
Thin plastic that comes in sheets of different thicknesses and sizes rolled or folded.
 
Polypropylene (PP)
Thermoplastic material similar to polyethylene but somewhat stiffer and with a higher softening point (temperature). Very often applied for nonwovens.
 
Plasma technology
Surface treatment using plasma (ionized gas), to which the textile structures are exposed in a chamber.
 
Polylactic acid
Polylactic acids or polylactides (PLA) are biodegradable polymers made from lactic acid. Polylactic acids are biocompatible.
 
Prepregs
A prepreg is a semi-finished product which consists of continuous filaments and an unhardened duroplastic plastic matrix, which is used in lightweight construction.
 
Pultrusion
The pultrusion process is a method of producing fiber-reinforced plastic profiles in a continuous procedure.
 
REACh
Registration, Evaluation, Authorization of Chemicals. The REACh regulation controls the production, marketing and handling of industrial chemicals. On 1 June 2007, legislation on chemicals came into effect throughout Europe.
 
Rovings
Bundles of continuous, untwisted, stretched filaments which are often used in the production of fiber composites and particularly for fiber/plastic composites. If individual filaments consisting of glass, aramid or carbon are combined without twisting, they are initially referred to as a smooth filament yarn, and, from a certain strength (fineness >68 Tex) as a roving.
 
Sheet Molding
Sheet Molding Compound (SMC) technology
 
Compound SMC  technology
SMC resin mats, consisting of duroplastic resins and glass fibers, are processed in pressing tools to make technically sophisticated components.
 
Spunbond process
With the spunbond process, the spun filaments are deposited randomly and reinforced directly after they are removed from the spinneret and the stretching unit. The nonwoven materials produced using this process is referred to as spunbond.
 
Spunlace process
This technology uses high-speed jets of water to strike a web to intermingle the fibers. Spunlaced nonwovens made by this method have specific properties such as soft hand and drapeability. It is the most common used mechanical bonding technology after needle punching. The process employs jets of water to entangle fibers and thereby provide web and eventually fabric integrity.
 
Web formation
Producing nonwovens with different technologies such as:

  • Drylaid;
  • Carded;
  • Airlaid;
  • Spunmelt;
  • Spunlaid (or spunbonded);
  • Meltblown;
  • Wetlaid;
  • Electrostatic spinning; or
  • Flash spun.
Wetlaid process
Applied to produce nonwovens, the fibers are mixed with water to create a suspension. The mixture is sieved and dried by passing the lengths of fleece over heated drums.
 

Sources: EDANA, Commerzbank and author’s own knowledge

March 3, 2015

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