WO2026008398A1

WO2026008398A1 - Non-woven structures, carpets, use and manufacturing method thereof

Info

Publication number: WO2026008398A1
Application number: PCT/EP2025/067795
Authority: WO
Inventors: Bart Marc Ernest DESMYTER; Koen Ivo Aime HUYGENS
Original assignee: Beaulieu International Group NV
Current assignee: Beaulieu International Group NV
Priority date: 2024-07-04
Filing date: 2025-06-24
Publication date: 2026-01-08
Anticipated expiration: 2027-01-04

Abstract

A non-woven structure comprising staple fibres is disclosed, the staple fibres being part of an entangled and bonded non-woven structure comprising thermally activated bonds between the staple fibres, wherein at least a portion of the staple fibres comprises a filler material; and associated carpet, uses and method of manufacturing.

Description

Non-woven structures, carpets, use and manufacturing method thereof.

Technical field

The present invention relates to bonded and entangled non-woven staple fibre structures for use, for example, in carpets. The present invention also relates to carpets comprising the non-woven staple fibre structures, uses of the non-woven structures, and associated manufacturing methods.

Background art

A non-woven structure is a fabric-like material made from fibres, e.g. bonded by chemical, mechanical, heat or solvent treatment, which are neither woven nor knitted.

WO2017162540A1 discloses a bonded and entangled non-woven structure made of at least 50% staple fibres by weight of the bonded and entangled non-woven structure, and at least a partial bonding of the fibres of the non-woven structure, the at least partial bonding comprising thermally activated bonds between a first polyolefin material produced with a catalyst comprising at least one metallocene catalyst and having a melting point in the range 130-170°C and a second material having a melting point which is at least 10°C higher than the melting point of the first material, the weight of the first material in the non-woven structure being at least 3% of the weight of the nonwoven structure.

Event carpets, for instance used for indoor tradeshows and other temporary events or arrangements, which comprise a bonded and entangled non-woven structure, for instance according to embodiments as described in WO2017162540A1 , often have the problem of thermal expansion of the carpet. Such event carpets typically have a length dimension of the order of 50 meters.

For instance, a wave pattern formation in the installed carpet can occur due to thermal expansion when the surrounding temperature increases with respect to the installation temperature.

For instance, carpets are often installed at low surrounding temperatures; for example, the venue is not yet heated, and the hall doors are left open, resulting in an installation temperature of 2 degrees. Four edges of the carpet can be fixed to the floor or support structure, e.g. by double sided tape, so that it lies flat and smooth on the floor or support structure. When the venue or hall is then heated to for instance 25°C, resulting easily in a temperature difference of e.g. more than 20°C, the carpet material expands, and since the edges are fixed, the excess material bulges and creates a wave pattern in the unattached carpet material. Also, there can also be a shrinking effect when the surrounding temperature is decreasing with respect to the installation temperature. An event carpet can for instance be installed at an ambient temperature of 45°C after which is cooled by e.g. more than 20°C.

Current non-woven carpets use a binding latex layer as backing layer. Such a latex layer is typically filled with e.g. CaCO3 (chalk) to reduce thermal expansion.

Especially in the field of event carpets, venues are more receptible for environmental sustainability.

In order to be recyclable, latex should be avoided as it is for instance associated with high water consumption and it is difficult to recycle a mix of polypropylene and latex.

There exists a need in industry for event carpets with reduced thermal expansion or shrinking, which can be recycled, and which have a reduced ecologic footprint.

Summary of the disclosure

It is an objective of the present disclosure to provide a non-woven structure according to claim 1 , and to provide associated carpets, uses and methods for manufacturing.

In a first aspect of the present disclosure, a non-woven structure is disclosed comprising staple fibres, the staple fibres being part of an entangled and bonded non-woven structure comprising thermally activated bonds between the staple fibres, wherein at least a portion of the staple fibres comprises a filler material.

The addition of the filler material enhances crystal formation in the, for instance polypropylene, staple fibres during manufacturing of the fibre, changing/reducing the thermal expansion coefficient of the respective fibre material. The filler embodies the role of heterogeneous nucleating agent during crystallisation of the fibre. It is also believed that fillers can reduce thermal expansion as they act as barriers to restrict the movement of polymer chains, reducing the overall expansion when temperature rises.

It is an advantage that the thermal expansion of the non-woven structure can be reduced by adding a filler to at least a portion of the staple fibres.

It is another advantage that due to the reduction of the thermal expansion of the non-woven structure itself, no additional backing layer is needed. Especially, no latex backing layer needs to be applied. This means that the non-woven structure as such can be used as a carpet. A carpet can thus also be provided that does not comprise a backing layer. It is another advantage that the amount of filler material needed can be a magnitude of 100 times smaller when compared to a prior art carpet comprising a latex backing layer with filler material.

It is another advantage that the non-woven structure can more easily be recycled and has a reduced ecologic footprint when compared to a prior art carpet comprising a latex backing layer.

Staple fibres are short, individual fibres that are typically a few centimetres long. For instance, they can have a length within the range of 40 to 120 mm, more preferably within the range of 60 to 90mm. Preferably, the staple fibres have a linear density within the range of 1 ,3 and 300 dtex (g/10000 linear meter), more preferably within the range of 3 to 17 dtex, or within the range of 3,3 to 17 dtex, or within the range of 5 to 17 dtex, or within the range of 5,5 to 17 dtex. Preferably, the staple fibres have a diameter between 13,6 and 206 microns, more preferably between 21 ,6 and 49 microns, more preferably between 27,9 and 49 microns.

According to preferred embodiments, the non-woven structure comprises staple fibres of a first type, for instance comprising a first material, and staple fibres of a second type, the first type and second type of staple fibres forming an entangled and bonded non-woven structure comprising thermally activated bonds between fibres of the first type and of the second type. The fibres of the second type comprise a third material preferably having a melting point which is at least 5°C or at least 10°C higher than the melting point of the first material.

The fibres of the first type and/or fibres of the second type comprise the filler material.

According to certain embodiments, the staple fibres of the first or of the second type comprise a material having a melting point in the range of 130-170°C. For instance, the staple fibres can comprise a first polyolefin material produced with at least one catalyst such as a metallocene catalyst or a Ziegler Natta catalyst, for instance having a melting point in the range 130-170°C.

According to preferred embodiments of a first type, the fibres of the first type are heterogeneous, multi-component fibres, preferably bi-component fibres, and the fibres of the second type are homogeneous fibres.

According to preferred embodiments, the fibres of the first type comprise a heterogeneous structure of at least the first material and a different, second material, exposing at least a portion of the first material at an external fibre surface.

According to preferred embodiments, a cross-section of the heterogeneous structure comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least the first material at the external fibre surface. Preferably, the cross-section of the heterogeneous structure comprises a sheath-core structure comprising a core of second material surrounded by a sheath of the first material. According to preferred embodiments, the filler material is only present in the fibres of the first type.

According to preferred embodiments, the filler material is only present in the second material and not in the first material. In case that the cross-section of the heterogeneous structure comprises a sheathcore structure comprising a core of second material surrounded by a sheath of the first material, that means that the filler material is only provided/present in the core of the fibres of the first type.

It has been found that it is sufficient to provide filler material only in the core of the fibres, and not in the sheath material. This further provides the advantage that the presence of the filler material does not interfere with the melt temperature and behaviour of the sheath material, and that the fibre bonding process is not affected or jeopardised.

According to preferred embodiments, the second material comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material.

According to preferred embodiments, the fibres of the first type constitute between 30 and 50% (or between 30 and 49%) in weight of the non-woven structure and wherein the fibres of the second type constitute between 50 and 70% (or between 51 % and 70%) in weight of the non-woven structure.

According to preferred embodiments, the fibres of the first type comprise between 20 and 40% in weight of the first material and between 60 and 80% of the second material.

According to preferred embodiments of the first type, the second material and the third material are the same material.

According to preferred embodiments of a second type, both the fibres of the first type and of the second type are heterogeneous, multi-component fibres, preferably bi-component fibres.

According to preferred embodiments, the fibres of the first type comprise a heterogeneous structure of at least the first material and a different, second material, exposing at least a portion of the first material at an external fibre surface, and the fibres of the second type comprise a heterogeneous structure of at least the third material and a different, fourth material, exposing at least a portion of the fourth material at an external fibre surface.

According to preferred embodiments, a cross-section of the heterogeneous structure of the fibres of the first type and/or of the second type comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least the first material at the external fibre surface. According to preferred embodiments, the cross-section of the heterogeneous structure of the fibres of the first type comprises a sheath-core structure comprising a core of second material surrounded by a sheet of the first material, and wherein the cross-section of the heterogeneous structure of the fibres of the second type comprises a sheath-core structure comprising a core of the third material surrounded by a sheet of the fourth material.

According to preferred embodiments, the filler material is present in the fibres of the first type and/or the fibres of the second type.

According to preferred embodiments, the filler material is only present in the second and/or the third material and not in the first or the fourth material.

According to preferred embodiments, the second material and the third material comprise a melting point which is at least 5 or 10°C higher than the melting point of the first material and of the fourth material.

According to preferred embodiments, the fibres of the first type comprise between 20 and 40% in weight of the first material and between 60 and 80% of the second material, and wherein the fibres of the second type comprise between 20 and 40% in weight of the fourth material and between 60 and 80% of the third material.

According to preferred embodiments of a third type the fibres are heterogeneous, multi-component fibres, preferably bi-component fibres.

According to preferred embodiments, the fibres comprise a heterogeneous structure of at least the first material and a different, second material, exposing at least a portion of the first material at an external fibre surface.

According to preferred embodiments, a cross-section of the heterogeneous structure comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least the first material at the external fibre surface.

According to preferred embodiments, the cross-section of the heterogeneous structure comprises a sheath-core structure comprising a core of second material surrounded by a sheath of the first material.

According to preferred embodiments, the filler material is only present in the second material and not in the first material. According to preferred embodiments, the second material comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material.

According to preferred embodiments, the fibres of comprise between 20 and 40% in weight of the first material and between 60 and 80% of the second material.

According to preferred embodiments of a fourth type, the fibres of the first type FT1 are homogeneous, also called regular, fibres, and the fibres of the second type FT2 are homogeneous, regular fibres.

According to any of the above preferred embodiments of the first, second, third or fourth type, the second and/or third material is selected from the group of synthetic or natural fibres.

According to any of the above preferred embodiments of the first, second, third or fourth type, the second and/or third material is selected from the group of a polyolefin, polyamide, polyester, polypropylene, or a polypropylene copolymer.

According to any of the above preferred embodiments of the first, second, third or fourth type, the first and/or fourth material comprises polypropylene or a polypropylene copolymer.

According to preferred embodiments, the first, second, third and fourth material can comprise or consist of polyolefins which are preferably each independently selected from: a polypropylene homopolymer; and a copolymer prepared from at least two monomers selected from the group consisting of C2-C5 alkenes, preferably selected from the group consisting of C2-C4 alkenes, most preferably selected from the group consisting of C2-C3 alkenes, more preferably selected from a polypropylene homopolymer; and a copolymer having a propylene content of at least 80 wt.%, more preferably at least 85 wt.%, still more preferably at least 90 wt.%, and prepared from at least two monomers selected from the group consisting of C2-C5 alkenes, preferably selected from the group consisting of C2-C4 alkenes, most preferably selected from the group consisting of C2-C3 alkenes, more preferably selected from

- a polypropylene homopolymer; and

- a copolymer having a propylene content of at least 90 wt.%, and prepared from at least two monomers selected from the group consisting of C2-C3 alkenes (in other words, prepared from ethylene and propylene).

According to any of the above preferred embodiments of the first, second, third or fourth type, the filler material in the fibres, for instance of the first and/or the second type, comprises any of chalk (Calcium Carbonate), Silica, Talc, Kaolin, Alumina oxide, Barium Sulphate, Magnesium Hydroxide, Zinc Oxide, Mica, Glass Fibres, Clay, Carbon black, Wollastonite, Graphite or Boron Nitride.

Preferably, the filler material in the fibres, for instance of the first type and/or the second type comprises chalk (Calcium Carbonate) or Talc.

According to preferred embodiments, the filler material is evenly distributed within the material where it is present.

According to any of the above preferred embodiments of the first, second, third or fourth type, a particle size distribution of the filler in the respective fibres or fibre types comprises a D98 value smaller than 15 micron, or smaller than 10 micron, or smaller than 5 micron.

According to any of the above preferred embodiments of the first, second, third or fourth type, a particle size distribution of the filler in the respective fibres or fibre types comprises a D50 value smaller than 2, more preferably or smaller than 1 micron.

The Dx notation of a particle size distribution is known in the art. It refers to the particle size corresponding to the cumulative frequency of x%. For example, if the D98 of a sample is 5pm by mass distribution, it means that the volume of particles less than 5pm accounts for 98% of the total sample mass, and likewise, the mass of particles greater than 5pm is 2%.

The particle size is typically the diameter for generally spherical particles, or can be an equivalent spherical diameter for irregularly shaped particles. In the latter case, the particle size can for instance correspond to the largest cross-dimension of the particles).

According to preferred embodiments, the particle size distribution is determined by a SEDIGRAPH method performed according to ISO standard ISO 13317-3:2001 “Determination of particle size distribution by gravitational liquid sedimentation methods”.

According to any of the above preferred embodiments of the first, second, third or fourth type, the filler material constitutes between any of 0.1%, 0.2%, 0.3%, 0.4% or 0.5% (lower boundary of the range) and any of 15%, 10% or 5% (upper boundary of the range) in weight of the totality of staple fibres in the non-woven structure.

According to any of the above preferred embodiments of the first, second, third or fourth type, the filler material constitutes between any of 0.1%, 0.2%, 0.3%, 0.4% or 0.5% (lower boundary of the range) and any of 15%, 10% or 5% (upper boundary of the range) in weight of the respective first and/or second type of fibre. According to any of the above preferred embodiments of the first, second, third or fourth type, the bonding is a pressure-less bonding made without applying pressure during heating and bonding of the non-woven structure.

According to any of the above preferred embodiments of the first, second, third or fourth type, entanglement is provided by needle punching or hydroentanglement.

According to any of the above preferred embodiments of the first, second, third or fourth type, the non-woven structure has a weight of 200 to 2000 grams per square meter. More preferably, e.g. for event carpets, the weight is between 200 and 900 grams per square meter, more preferably between 200 and 500 grams per square meter.

In a second aspect of the present disclosure, a carpet is disclosed comprising or consisting of the non-woven structure of any of the embodiments of the first aspect.

According to preferred embodiments, the carpet consists of the non-woven structure only.

According to preferred embodiments, the carpet does not comprise an additional layer, such as for instance a backing layer, which comprises a filler material.

According to preferred embodiments, the carpet does not comprise an additional layer, such as for instance a backing layer.

According to preferred embodiments, the carpet is an event or exhibition carpet having a dimension larger than 30m, preferably larger than 50m.

According to preferred embodiments, the total staple fibre content is at least 60%, preferably at least 70%, or at least 80% or at least 90% or at least 95% or at least 99% and up to 100% by weight of the carpet.

In a third aspect of the present disclosure, the use is disclosed of an non-woven structure according to any of the embodiments of the first aspect in any of the following products : hygiene and health care products, in disposable or single use products for use in hospitals, schools, and domestically, in diapers or wipes or tissues of any sort, in residential and contract carpet, structured carpet, automotive carpet or coverings or linings, geotextiles, hygiene products, medical products, filtration products, thermal insulation, clothing and pipe wrapping, acoustic absorption products, acoustic dampening products, contact sound dampening products, linings of shoes or luggage.

In a fourth aspect of the present disclosure, a method for manufacturing a non-woven structure or carpet according to any the embodiments of the first aspects is disclosed, comprising the steps of: - providing staple fibres;

- entangling the staple fibres in a non-woven manner;

- bonding the non-woven fibres by thermally activating bonds between the staple fibres; wherein at least a portion of the staple fibres comprises a filler material.

According to preferred embodiments, the staple fibres are heterogeneous, multi-component fibres, preferably bi-component fibres.

According to preferred embodiments, the step of providing staple fibres comprises providing staple fibres of a first type and providing staple fibres of a second type; and wherein the step of bonding comprises thermally activating bonds between fibres of the first type and of the second type.

According to preferred embodiments, the fibres of the first type are heterogeneous, multi-component fibres, preferably bi-component fibres, and the fibres of the second type are homogeneous fibres.

According to preferred embodiments, both the fibres of the first type and of the second type are heterogeneous, multi-component fibres, preferably bi-component fibres.

According to preferred embodiments the fibres of the first type are homogeneous, also called regular, fibres, and the fibres of the second type are homogeneous fibres.

According to preferred embodiments, the method does not comprise applying an additional layer which comprises filler to the non-woven structure.

According to preferred embodiments, the method does not comprise applying an additional layer to the non-woven structure.

Features and advantages disclosed for one of the above aspects of the present disclosure are hereby also implicitly disclosed for the other aspects, mutatis mutandis, as the skilled person will recognize.

For instance, features described for the non-woven structure are supposed to be disclosed also for the corresponding carpet structure comprising such non-woven structure.

Brief description of the drawings

The disclosure will be further elucidated by means of the following description and the appended figures.

Fig. 1 shows prior art fibre structures suitable for use in embodiments of the present disclosure.

Fig. 2 illustrates the bonding process and structure between fibres of the same or different types as present in preferred embodiments of the present disclosure.

Fig. 3 (a) (b) (c) and (d) illustrate preferred embodiments of the first, second, third and fourth type. Fig. 4 is a flow chart illustrating a non-woven structure manufacturing process according to the present disclosure.

Detailed description of preferred embodiments

The present disclosure will be described with respect to particular embodiments and with reference to certain drawings, but the disclosure is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the disclosure.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order.

The various embodiments, although referred to as "preferred" are to be construed as examples in which the disclosure may be implemented rather than as limiting the scope of the disclosure.

Methods for making needlefelt or for making bicomponent staple fibres are generally known to the skilled person. For instance, the disclosure of WO2017162540A1 , which is hereby incorporated by reference in its entirety, comprises such information and examples.

Fig. 1 shows cross-sections of some prior art bicomponent staple fibre structures that are suitable for use in various embodiments of the present disclosure. For instance, a cross-section of the heterogeneous structure comprises any of a (1) side-by-side, (2) sheath-core, (3) segmented pie, (4) islands-in-the-sea, (5) tipped or (6) segmented ribbon structure, exposing at least the first material at the external fibre surface. Preferably, the bicomponent staple fibres used are of the type of sheathcore, wherein a central core portion 2 of a second material M2 is surrounded by a sheath layer 1 of a first material M1 . Preferably, in cross-section view, the core 2 is positioned centrally with in the nonwoven fibre structure in a rotation-symmetric manner.

Entangled and bonded non-woven structures according to embodiments of the present invention can be needle punched or hydroentanglement. They can be produced for instance by using an industrial scale needle punch or hydroentanglement non-woven production line. This needle punched or hydroentangled non-woven structure is then bonded by passing the non-woven structure through an oven or an equivalent heating device, the temperature profile of the oven or heating device being chosen and predetermined in such a way that fibres keep some integrity after bonding. During this process, typically one or more materials comprised in the respective fibre types (FT1 , FT2) used in the non- woven structure melt and forms bonds B with other fibres in the non-woven structure, while some other fibre materials no not melt and provide structural stability of the respective fibres. When cooling down, the created bonds are permanently fixed, while the respective fibres remain generally intact.

Different options have been disclosed for the choice of fibre types in the bonded non-woven structure, as illustrated in Fig. 3 (a) (b) (c) and (d).

For instance, in embodiments of a first type (see Fig. 3(a)), the fibres of the first type FT1 are heterogeneous, bi-component fibres, and the fibres of the second type FT2 are homogeneous, also called regular, fibres.

The bicomponent fibres comprises a central core portion 2 of a second material M2 surrounded by a sheath-layer 1 of a first material M1 . The second material M2 comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material M1.

The fibres of the second type FT2 comprise a third material M3, forming a single “core” structure 3, which has also a melting point which is at least 5 or 10°C higher than the melting point of the first material M1 .

The filler material can be applied in the fibres of the first type and/or in the fibres of the second type. Preferably, the filler material is applied only to the fibres of the first type. It was found that more preferably, the filler material is applied to the core of the fibres of the first type. In certain embodiments, a filler material is additionally applied to the fibres of the second type.

Referring to the manufacturing process, it has been found that the oven is preferably an air circulating oven, and that the oven is preferably run at a temperature which is higher than the melting temperature of the first material M1 and at least 5°C below the temperature at which the second and third materials M2 and M3 melt. It is further preferred that at least 50%, more preferably at least 60%, still more preferred if at least 75%, even more preferred at least 90% of all the fibres of the non-woven structure maintain their integrity after this process of thermally activated bonding.

For instance, in embodiments of a second type (see Fig. 3(b)), the fibres of the first type FT1 are heterogeneous, bi-component fibres, and the fibres of the second type FT2 are different, heterogeneous, bi-component fibres.

The bicomponent fibres of the first type FT1 comprise a central core portion 2 of a second material M2 surrounded by a sheath-layer 1 of a first material M1 . The second material M2 comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material M1 .

The bicomponent fibres of the second type FT2 comprise a central core portion 3’ of a third material M3 surrounded by a sheath-layer 4 of a fourth material M4. The third material M3 comprises a melting point which is at least 5 or 10°C higher than the melting point of the fourth material M4. The filler material can be applied in the fibres of the first type and/or in the fibres of the second type. Preferably, the filler material is applied only in one of the fibres of the first type FT1 of the fibres of the second type FT2. It was found that more preferably, the filler material is applied to the core of the fibres of the first type FT1 or of the second type FT2.

Referring to the manufacturing process, it has been found that the oven is preferably an air circulating oven, and that the oven is preferably run at a temperature which is higher than the melting temperatures of the first material M1 and/or the fourth material M4 and at least 5°C below the temperature at which the second and third materials M2 and M3 melt. It is further preferred that at least 50%, more preferably at least 60%, still more preferred if at least 75%, even more preferred at least 90% of all the fibres of the non-woven structure maintain their integrity after this process of thermally activated bonding.

For instance, in embodiments of a third type (see Fig. 3(c)), only fibres of a single, first type FT1 are used, which are heterogeneous, bi-component fibres.

It was found that more preferably, the filler material is applied to the core 2 of the fibres.

For instance, in embodiments of a fourth type (see Fig. 3(d)), the fibres of the first type FT1 are homogeneous, also called regular, fibres, and the fibres of the second type FT2 are homogeneous, regular fibres.

The fibres of the first type FT1 comprise a first material M1 , forming a single “core” structure.

The fibres of the second type FT2 comprise a third material M3, forming a single “core” structure 3, which has a melting point which is at least 5 or 10°C higher than the melting point of the first material M1.

The filler material can be applied in the fibres of the first type and/or in the fibres of the second type FT2. Preferably, the filler material is applied only to the fibres of the second type, i.e. into the fibres having highest melting temperature.

Referring to the manufacturing process, it has been found that the oven is preferably an air circulating oven, and that the oven is preferably run at a temperature which is higher than the melting temperature of the first material M1 and at least 5°C below the temperature at which the second material M2 melts. It is further preferred that at least 50%, more preferably at least 60%, still more preferred if at least 75%, even more preferred at least 90% of all the fibres of the non-woven structure maintain their integrity after this process of thermally activated bonding. Fig. 4 is a flow chart illustrating a non-woven structure manufacturing process according to the present disclosure. It comprises the steps of:

(A) Provide a type 1 master batch of granules with filler and a type 2 masterbatch of granules (optionally also with filler);

(B) Extrude fibre type 1 from masterbatch 1 and fibre type 2 from masterbatch 2;

(C) Form a web of fibres of fibre type 1 and/or fibre type 2;

(D) Submit the web to a needling process to create a nonwoven material;

(E) Submit the nonwoven material to heat so that at least part of the (e.g. bicomponent) fibres melt and bond.

In Tables 1 and 2 below, comparative results are shown for the linear expansion coefficient of the same non-woven structure without filler and with filler in one type of staple fibre (Table 1 : talc; Table 2: chalk). The non-woven structure comprises staple fibres of a first type being bicomponent staple fibres of the sheath-core type and fibres of a second type being homogeneous, regular fibres. The staple fibres of both first and second type comprised polyolefin material. In the non-woven structure with filler, the filler was added into the core of the bicomponent fibres. It can clearly be seen that the linear thermal expansion coefficient decreased due to the presence of the filler in the first type of fibre. For a non-woven structure or carpet having a standard length dimension of 50m, the difference in thermal expansion in the length direction for a temperature increase of 30°C is about 15mm and is thus significant.

Preliminary results further seem to show, surprisingly, that adding additional filler material in the second type of fibre does not further decrease the thermal expansion coefficient.

Table 1

Table 2

Claims

1 . A non-woven structure comprising staple fibres, said staple fibres being part of an entangled and bonded non-woven structure comprising thermally activated bonds between said staple fibres, wherein at least a portion of said staple fibres comprises a filler material.

2. A non-woven structure according to claim 1 , comprising staple fibres of a first type and staple fibres of a second type, said first type and second type of staple fibres forming an entangled and bonded non-woven structure comprising thermally activated bonds between fibres of said first type and of said second type, said fibres of said second type comprising a third material having a melting point which is at least 5°C or at least 10°C higher than the melting point of the first material, wherein said fibres of said first type and/or fibres of said second type comprise said filler material.

3. A non-woven structure according to claim 2, wherein said fibres of said first type are heterogeneous, multi-component fibres, preferably bi-component fibres, and said fibres of said second type are homogeneous fibres.

4. A non-woven structure according to claim 3, wherein said fibres of said first type comprise a heterogeneous structure of at least said first material and a different, second material, exposing at least a portion of the first material at an external fibre surface.

5. A non-woven structure according to claim 4, wherein a cross-section of said heterogeneous structure comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least said first material at said external fibre surface.

6. A non-woven structure according to claim 5, wherein said cross-section of said heterogeneous structure comprises a sheath-core structure comprising a core of second material surrounded by a sheath of said first material.

7. A non-woven structure according to any of the previous claims 4 to 6, wherein said filler material is only present in said fibres of said first type.

8. A non-woven structure according to claim 7, wherein said filler material is only present in said second material and not in said first material.

9. A non-woven structure according to any of claims 4 to 8, wherein said second material comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material.

10. A non-woven structure according to any of the previous claims 2 to 9, wherein said fibres of said first type constitute between 30 and 50 % in weight of said non-woven structure and wherein said fibres of said second type constitute between 50 and 70% in weight of said non-woven structure.

11. A non-woven structure according to any of the previous claims 2 to 10, wherein said fibres of said first type comprise between 20 and 40% in weight of said first material and between 60 and 80% of said second material.

12. A non-woven structure according to claim 2, wherein both said fibres of said first type and of said second type are heterogeneous, multi-component fibres, preferably bi-component fibres.

13. A non-woven structure according to claim 2, wherein said fibres of said first type comprise a heterogeneous structure of at least said first material and a different, second material, exposing at least a portion of the first material at an external fibre surface, and wherein said fibres of said second type comprise a heterogeneous structure of at least said third material and a different, fourth material, exposing at least a portion of the fourth material at an external fibre surface.

14. A non-woven structure according to claim 13, wherein a cross-section of said heterogeneous structure of said fibres of said first type and/or of said second type comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least said first material at said external fibre surface.

15. A non-woven structure according to claim 14, wherein said cross-section of said heterogeneous structure of said fibres of said first type comprises a sheath-core structure comprising a core of second material surrounded by a sheath of said first material, and wherein said cross-section of said heterogeneous structure of said fibres of said second type comprises a sheath-core structure comprising a core of said third material surrounded by a sheath of said fourth material.

16. A non-woven structure according to any of the previous claims 13 to 15, wherein said filler material is present in said fibres of said first type and/or said fibres of said second type.

17. A non-woven structure according to claim 16, wherein said filler material is only present in said second and/or said third material and not in said first or said fourth material.

18. A non-woven structure according to any of claims 15 to 17, wherein said second material and said third material comprise a melting point which is at least 5 or 10°C higher than the melting point of the first material and of the fourth material.

19. A non-woven structure according to any of the previous claims 13 to 18, wherein said fibres of said first type comprise between 20 and 40% in weight of said first material and between 60 and 80% of said second material, and wherein said fibres of said second type comprise between 20 and 40% in weight of said fourth material and between 60 and 80% of said third material.

20. A non-woven structure according to claim 2, wherein said fibres are heterogeneous, multicomponent fibres, preferably bi-component fibres.

21 . A non-woven structure according to claim 20, wherein said fibres comprise a heterogeneous structure of at least said first material and a different, second material, exposing at least a portion of the first material at an external fibre surface.

22. A non-woven structure according to claim 21 , wherein a cross-section of said heterogeneous structure comprises any of a side-by-side, sheath-core, segmented pie, islands-in-the-sea, tipped or segmented ribbon structure, exposing at least said first material at said external fibre surface.

23. A non-woven structure according to claim 22, wherein said cross-section of said heterogeneous structure comprises a sheath-core structure comprising a core of second material surrounded by a sheath of said first material.

24. A non-woven structure according to any of claims 21 to 23, wherein said filler material is only present in said second material and not in said first material.

25. A non-woven structure according to any of claims 21 to 24, wherein said second material comprises a melting point which is at least 5 or 10°C higher than the melting point of the first material.

26. A non-woven structure according to any of the previous claims, wherein said fibres of comprise between 20 and 40% in weight of said first material and between 60 and 80% of said second material.

27. A non-woven structure according to any of the previous claims, wherein the second and/or third material is selected from the group of synthetic or natural fibres.

28. A non-woven structure according to claim 27, wherein the second and/or third material is selected from the group of a polyolefin, polyamide, polyester, polypropylene, or a polypropylene copolymer.

29. A non-woven structure according to any of the preceding claims, wherein the first and/or fourth material comprises polypropylene or a polypropylene copolymer.

30. A non-woven structure according to any of the preceding claims, wherein said filler material in said fibres, for instance of said first and/or said second type, comprises any of chalk (Calcium Carbonate), Silica, Talc, Kaolin, Alumina oxide, Barium Sulphate, Magnesium Hydroxide, Zinc Oxide, Mica, Glass Fibres, Clay, Carbon black, Wollastonite, Graphite or Boron Nitride.

31 . A non-woven structure according to claim 30, wherein said filler material in said fibres, for instance of said first type and/or said second type comprises chalk (Calcium Carbonate) or Talc.

32. A non-woven structure according to any of the preceding claims, wherein a particle size distribution of said filler in said respective fibres or fibre types comprises a D98 value smaller than 15 microns.

33. A non-woven structure according to any of the previous claims 2 to 32, wherein said filler material constitutes between 0,1 and 15% in weight of the respective first and/or second type of fibre.

34. A non-woven structure according to any of the preceding claims, wherein the bonding is a pressure-less bonding made without applying pressure during heating and bonding of the non-woven structure.

35. A non-woven structure according to any of the preceding claims, wherein entanglement is provided by needle punching or hydroentanglement.

36. A non-woven structure according to any of the previous claims, having a weight of 200 to 2000 grams per square meter.

37. A carpet comprising the non-woven structure of any of the preceding claims.

38. A carpet according to claim 37, not comprising an additional layer which comprises a filler material, such as for instance a backing layer.

39. Carpet according to any of the claims 37 to 38, not comprising an additional layer, such as for instance a backing layer.

40. Carpet according to any of the claims 37 to 39, wherein the carpet is an event or exhibition carpet having a dimension larger than 30m, preferably larger than 50m.

41 . A carpet according to any of claims 37 to 40, wherein the total staple fibre content is at least 60%, preferably at least 70%, or at least 80% or at least 90% or at least 95% or at least 99% and up to 100% by weight of the carpet.

42. Use of an non-woven structure according to any of the claims 1 to 36 in any of the following products: hygiene and health care products, in disposable or single use products for use in hospitals, schools, and domestically, in diapers or wipes or tissues of any sort, in residential and contract carpet, structured carpet, automotive carpet or coverings or linings, geotextiles, hygiene products, medical products, filtration products, thermal insulation, clothing and pipe wrapping, acoustic absorption products, acoustic dampening products, contact sound dampening products, linings of shoes or luggage.

43. A method for manufacturing a non-woven structure according to any of claims 1 to 36, comprising the steps of:

- providing staple fibres;

- entangling said staple fibres in a non-woven manner;

- bonding said a non-woven fibres by thermally activating bonds between said staple fibres; wherein at least a portion of said staple fibres comprises a filler material.

44. A method according to claim 43, wherein said staple fibres are heterogeneous, multi-component fibres, preferably bi-component fibres.

45. A method according to any of claims 43 to 44, wherein the step of providing staple fibres comprises providing staple fibres of a first type and providing staple fibres of a second type; and wherein the step of bonding comprises thermally activating bonds between fibres of said first type and of said second type.

46. A method according to claim 45, wherein said fibres of said first type are heterogeneous, multicomponent fibres, preferably bi-component fibres, and said fibres of said second type are homogeneous fibres.

47. A method according to claim 45, wherein both said fibres of said first type and of said second type are heterogeneous, multi-component fibres, preferably bi-component fibres.

48. A method according to claim 45, wherein the fibres of the first type are homogeneous fibres and the fibres of the second type are homogeneous fibres.