Bicomponent fibres

Pilot line for research and prototyping

bicoschema.pngCentexbel's extrusion line is at the industry's disposal to carry out private or collective research projects in collaboration with us.
You may also rent the extrusion line (paying service) to create prototypes or to perfect a certain product. Also in this case, the extrusion line will be serviced by our experienced operators.
During the set-up of the line, we have paid much attention to flexibility and a minimal use of resources. Although we can simulate high production speeds, the line is not designed to produce large quantities of yarns.

However, we have learned that yarns, developed and optimised on the Centexbel extrusion line, are being produced on an industrial scale very soon afterwards.

What are bicomponent fibres?

Bicomponent fibres are made from two components distributed over the entire length of the fibre. Each component may have different physical or chemical properties. They may either belong to the same type of polymer or be totally different polymer types. By "co-extruding" two polymers into one single fibre, the different properties of both polymers are combined. The newly created bicomponent fibre will have new properties and can be applied in many new applications. The properties and possible applications depend on both the properties and combination of the different polymers and additives and on the specific configuration (shape) of the bicomponent fibre.

Concentric Sheath/Core

concentrisch-mantel-kern.pngThis configuration is mainly used in melt fibres with a sheath made from polymers with a low melting point around a core with a high melting point. When heated, the sheath will melt; the consequent cooling will bind the nonwoven or composite structure. Concentric sheath/core fibres are also applied to produce fibres with a quality (expensive) and/or weaker external polymer layer around a cheaper but more resistant core.

Eccentric Sheath/Core

excentrisch-mantel-kern.pngIn contrast to the concentric sheath/core configuration, the core here is out of centre. Due to the different shrinking ratios of both polymers, the fibre will curl when it is heated in a relaxed state.
By doing so, it is possible to add crimp and volume to the fibre.


side-side.pngBoth polymers occupy an equal part of the fibre surface.
Depending on the chosen polymers, the fibre may develop more crimp than the excentric sheath/core configuration.

Pie Wedge

This construction is made of sixteen adjoining "pie wedges". pie-wedge.pngEach pie wedge of polymer A is flanked on both sides by a polymer B.
The fibres are designed in such a way that mechanical action causes the different pie wedges to split into microfibres of 0.1 to 0.2 denier.


island-sea.pngIn this configuration, polymer A represents the islands, and polymer B the sea. This fibre structure allows that a lot of fine yarns of a fibre polymer configuration are placed into the matrix of a soluble polymer. By dissolving the latter, a fabric is produced on the basis of very fine microfibres. In this way it is possible to obtain finer fibres than by directly extruding fine fibres.

These five basic configurations can be adapted in function of the desired fibre or yarn properties. It is for example possible to limit the number of islands to produce conductive yarns. On the other hand, it is possible to provide a hole in the pie-wedge configuration (hollow pie wedge) to split the filaments even more easily. The yarn diameter can be adapted to produce trilobal (instead of round) filaments with a sheath/core or side/side structure for carpet applications.

Bicomponent fibres are actually being applied in the production of :

  • microfibres (hygiene)
  • conductive fibres
  • antimicrobial textiles
  • autocrimp fibres
  • elastic fibres
  • composites
  • non-wovens…