Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/005—Synthetic yarns or filaments
  • D04H3/009—Condensation or reaction polymers
  • D04H3/011—Polyesters
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4274—Rags; Fabric scraps
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4326—Condensation or reaction polymers
  • D04H1/435—Polyesters
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
  • D04H3/147—Composite yarns or filaments
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion

Definitions

• the present disclosure generally relates to nonwovens made with the addition of a
• supplementary composition which may comprise recycled polymeric material, and more particularly to spunbond nonwovens made with addition of a supplementary composition, which may comprise recycled polyester and methods of making the same.
• Aromatic polyesters are well known in the field to be used in filament formation, typically polyethylene terephthalate (PET) is often used to create filaments, or at least one component of the filaments. Often the PET component is combined with a so called bonding component with lower bonding temperature, typically a type of copolymer of PET (coPET). In5 the industry, there are known combinations of PET and coPET for filament production. The difference between Polyethylene Terephthalate (PET) and Co-Polyethylene Terephthalate (coPET) lies in their chemical structures and properties. PET is a semi-crystalline polymer with high melting point, good mechanical strength, and excellent chemical resistance.
• the second component comprises at least 1 mass % of supplementary polyester composition, preferably at least 2.5 mass % of supplementary polyester composition, with an advantage at least 4 mass % of supplementary polyester composition, more preferably at least 5 mass % of supplementary polyester composition.
• the second component comprises up to 90 mass % of supplementary polyester composition, preferably up to 85 mass %, more preferably up to 75 mass %, most preferably up to 50 mass %.
• the carrier polyester composition comprises one or more carrier polyesters.
• the carrier polyester is polyethylene terephthalate.
• the carrier polyester has full width at half maximum of crystallization peak at first cooling of at least 12°C.
• the carrier polyester has full width at half maximum of crystallization peak at first cooling of at most 50°C.
• the carrier polyester or the carrier polyester composition has heat of fusion of at least 35 J/g.
• the carrier polyester composition in the filament component provides complex shear viscosity in the range of 250-500 Pa.s under amplitude of shear strain deformation of 5% at angular frequency of 1 rad.s-1 at temperature of 270°C defined within 5 minutes of experiment run under nitrogen atmosphere.
• the bonding polyester composition comprises one or more bonding polyesters.
• the bonding polyester is a copolymer of polyethylene terephthalate.
• the bonding polyester is a polyester having crystallization enthalpy at first cooling of at most 10 J/g, preferably at most 8 J/g, with an advantage at most 5 J/g, most preferably at most 2 J/g.
• the supplementary polyester com position has crystallization enthalpy at first cooling of at least 2 J/g, preferably at least 4 J/g, with an advantage at least 6 J/g, most preferably at least 10 J/g.
• the supplementary polyester composition has full width at half maximum of crystallization peak at first cooling of at most 12°C.
• the supplementary polyester composition has heat of fusion of at least 35 J/g.
• the supplementary polyester composition is provided for step A) in the form of fibers and/or nonwoven substantially formed of PET/coPET composition.
• the supplementary polyester composition comprises recycled carrier polyester composition and recycled bonding polyester composition.
• the supplementary polyester composition comprises at least 20 mass % of recycled carrier polyester composition, preferably at least 30% of recycled carrier polyester composition, with an advantage at least 40% of recycled carrier polyester composition, most preferably at least 50% of recycled carrier polyester composition.
• the supplementary polyester composition comprises at least 5 mass % of recycled bonding polyester composition, preferably at least 10 mass % of recycled bonding polyester composition, with an advantage at least 15% of recycled bonding polyester composition, most preferably at least 20% of recycled bonding polyester composition.
• the supplementary polyester composition comprises at least 20 mass % of recycled PET, preferably at least 30 mass % of recycled PET, with an advantage at least 40 mass % of recycled PET, most preferably at least 50 mass % of recycled PET.
• the melting temperature of the supplementary polyester composition is lower than melting temperature of the bonding polyester composition by at most 10°C.
• the melting temperature of the supplementary polyester composition is preferably higher than the melting temperature of the bonding polyester composition, wherein the difference is at most 50°C, preferably at most 30°C, with an advantage at most 20°C, most preferably at most 10°C.
• the difference of supplementary polyester composition crystallization enthalpy at first cooling and at least one bonding polyester present in the bonding polyester composition crystallization enthalpy at first cooling is at least 10 J/g, preferably at least 20 J/g, with an advantage at least 30 J/g.
• the difference in full width at half maximum of crystallization peak at first cooling between the carrier polyester composition and the supplementary polyester composition is at least 2°C, preferably at least 3°C, with an advantage at least 5°C.
• the difference of the carrier polyester composition heat of fusion and the bonding polyester composition heat of fusion is at least 5 J/g, preferably 7 J/g, with an advantage 10 J/g.
• the second component forms at least 10% of filament mass, with an advantage at least 15% of filament mass, preferably at least 20% of filament mass and / orthe second component forms at most 60% of filament mass.
• steps B) to D) filaments with concentric core-sheath or eccentric core-sheath or side-by-side cross-section are produced.
• the first component comprises the supplementary polyester composition in an amount of at least 2.5% of mass of the first component, preferably at least 5% of mass, with an advantage at least 7.5% of mass, more preferably at least 10% of mass of the first component; and / orthe first component comprises the supplementary polyester composition in an amount of up to 90% of mass of the first component, preferably up to 85% of mass, with an advantage up to 75% of mass, more preferably up to 50% of mass of the first component.
• step F) thermally bonding the filamentary batt is performed by air-through-bonding.
• the "Fiber diameter” is expressed in microns (micrometers). It is possible to use, for example, an optical or electronic microscope (depending on the diameter of the measured fibres). At least 50 individual fibers were measured to calculate the average value.
• the terms "number of grams of filament per 9000 m” (also denier or den) or “number of grams of filament per 10000 m” (dTex) are used to express the degree of fineness or coarseness of a filament as they relate to the filament diameter (a circular filament cross-section is assumed) multiplied by the density of the material or materials used.
• the term “mono-component”" relates to a filament formed from a single polymer or from a single polymer blend, whereby it is differentiated from a bi-component filament or multi-component filament.
• Recycled polyester suitable for use, as described here, is in general intended to fulfil the standard requirements for filament or spunmelt nonwoven virgin polymer (e.g., color stability, pellet size (if applied), melt flow rate, thermostability or other requirements) set by filament or spunmelt nonwoven production companies for their production lines.
• Recycled materials are typically generated from two different waste streams.
• Post-industrial recycled (PIR) materials otherwise considered as pre-consumer waste stream is essentially the waste generated from the original manufacturing process that is in-turn used for producing new products.
• Post-consumer recycled (PCR) materials refers to everything that gets tossed into the recycling bin by a consumer. PCR is generally known to have higher levels of contamination and variability, due to additional life cycle of the product by the consumer and exposure of materials to uncontrolled conditions post manufacturing process.
• multi-component designates a fiber or filament of which the cross-section incorporates more than one individual partial component, whilst each of these independent components in the cross-section consists of a different polymeric compound or a different blend of polymeric compounds.
• multi-component is thus a superior term, that includes, but is not limited to "bi-component ".
• the different components of multi-component filaments are arranged essentially in clearly defined areas arranged along the cross-section of the filament and extend out continuously along the length of the filament.
• a multi-component filament may have a cross-section divided into several partial areas consisting of various components of selectable shapes or arrangements.
• the partial components of the cross-section can be arranged in a coaxial arrangement in the form of core and sheath, radial or so-called islands-in-the-sea arrangement, etc.
• the terms "two-component” and “bicomponent” used to describe filaments are herein used interchangeably.
• the design used to produce multi-component filaments has a determining impact on the resulting longitudinal shape of the filament, for example its propensity to crimp.
• a good way to recognise the design of a multi-component filament is to see and evaluate its cross-section which makes visible the position of different components of a filament.
• the different components are made out of different polymer formulations which are selected and characterized by e.g.
• crimpable crosssection refers to multicomponent fibers, wherein components with different shrinkage properties are arranged across the cross-section so, that either these filaments will self-crimp during the filament drawing and solidification or, when heated to or above an activation temperature and then slowly cooled down, the fibers crimp, which causes these fibers to follow the vectors of the shrink forces. Thereby, when the fiber is released, it creates a so-called helical crimp, although when contained within a fiber layer the mutual adhesion of the fibers does not permit the creation of ideal helixes.
• the fiber is "non-crimpable".
• the center of mass is in the center of the cross-section (see the Fig. 1).
• bonding points relate to the bonds that usually connect two filaments in a location where these filaments intersect each other or in a location where they come into contact or alternatively where they adjoin each other. By means of bonding points it is possible to connect more than two filaments or to connect two parts of the same filament.
• bonding point here represents the connection of two or more fibers or filaments at the point of contact by the interconnection of their components having the lower melting characteristic (melt temperature).
• the formed component of the filament with the higher melt temperature is in general less impacted than the formed component of the filament with the lower melt temperature.
• the sheath polymer may soften and start to flow while the core remains essentially unchanged.
• bonding impression represents a surface upon which the boss of a calender roller has acted.
• a bonding impression has a defined area given by the size of the emboss on the bonding roller and compared to the adjacent area typically has a smaller thickness.
• the area of the bonding impression is typically subjected to significant mechanical pressure, which together with temperature may affect the shape of all filament components within the area of the bonding impression.
• Bonding impressions can be formed by protrusions of embossed roller, impressing engraved pattern into nonwoven batt.
• Combination of embossed roller and smooth roller can be used as well as combination of two embossed rollers or combination of two smooth rollers. In case of combination of two smooth rollers, bonding impression represents typically whole nonwoven surface.
• Nonwoven material or “nonwoven fabric” is a batt or fibrous formation produced from directionally or randomly oriented filaments that are first formed during the creation of a layer of filaments and then consolidated together by means of friction, or cohesive forces or adhesive forces, and finally consolidated by the creation of bonds points, whilst this consolidation is accomplished thermally (e.g. by the effect of flowing air, calendering, effect of ultrasound, etc.), chemically (e.g. using an adhesive), mechanically (e.g. hydroentanglement, etc.), or alternatively by a combination of these methods.
• the term does not refer to fabrics formed by weaving or kniting or fabrics using yarns or fibers to form bonding stitches.
• the fibers may be of natural or synthetic origin and may be staple yarns, continuous fibers or fibers produced directly at the processing location.
• Commercially available fibers have a diameter ranging from approximately 0.001 mm or even less to approximately 0.2 mm or even more and are supplied in various forms: short fibers (known as staple or cut fibers), continuous individual fibers (filaments or mono-filament fibers), nontwisted bundles of filaments (combed fibers) and twisted bundles of filaments (yarns).
• a nonwoven fabric can be produced using many methods, including technologies such as meltblown, spunbond, spunmelt, spinning using solvents, electrostatic spinning, carding, film fibrillation, fibrillation, air-laying, dry-laying, wet-laying with staple fibers and various combinations of these processes as known in the art.
• the basis weight of nonwoven fabrics is usually expressed in grams per square metre (g/m2 or gsm).
• the "spunbond” or “spunlaid” or “spunmelt” process is a nonwoven fabric production process, which includes a direct conversion of polymers to filaments, which is directly followed by the deposition of such created filaments, thereby creating a layer of nonwoven filaments containing randomly arranged filaments. This nonwoven layer of filaments is subsequently consolidated in such a way as to enclose the nonwoven fabric by the creation of bonds between the filaments.
• the consolidation process can be performed using various methods, for example by the effect of passing air, calendering, etc.
• bath refers to layer(s) of filaments that are found in the state prior to bonding, a process that can be performed in various ways, for example, air-through-bonding, calendaring etc.
• the "batt” consists of individual filaments between which a fixed mutual bond is usually not yet formed even though the filaments may be pre-bonded / pre-consolidated in certain ways, where this pre-consolidation may occur during or shortly after the laying of the filaments in the spunlaying process. This pre-consolidation, however, still permits a substantial number of the filaments to be freely moveable such that they can be repositioned.
• the above mentioned “batt” may consist of several layers created by the deposition of filaments from several spinning beams in the spunlaying process.
• the term "layer” relates to the partial component or element of a fabric.
• a “layer” may be in the form of multiple filaments produced on a single spinning beam or on two or more consecutively arranged spinning beams, which create essentially the same filaments.
• two consecutively arranged spinning beams intended for performing the spunbond procedure have essentially the same setings and process polymers of essentially the same composition, can combine to produce a single layer.
• two spunbond-type spinning beams of which one produces, for example, single-component filaments and the other produces, for example, bi-component filaments will form two different layers.
• composition of a layer can be ascertained on the basis of knowledge of the individual setings and components determining the resin (polymer) composition used for the creation of the layer or by means of analysis of the nonwoven fabric itself, for example, by using electron microscopy, or alternatively by analysis of the composition used in the production of the filaments contained in the layer using the DSC method.
• Adjacent layers of filaments do not necessarily have to be strictly separated, the layers in their border region may blend in together as a result of the filaments of a later deposited layer falling into the gaps between the filaments of an earlier deposited layer.
• Machine direction in relation to the production of nonwoven fibrous material and the actual nonwoven fibrous material itself, the term “machine direction” (MD) represents the direction that essentially corresponds to the forward motion direction of the nonwoven fibrous material on the production line on which this material is produced.
• CD Cross direction
• z-direction in relation to the production of nonwoven fibrous material is the vertical direction to the plane MD x CD.
• the extension in z-direction describes the thickness of the nonwoven material.
• Fig. 1A Examples of crimpable cross-sections
• Fig. IB Examples of non-crimpable cross-section
• Fig. 2 Examples of filament cross-section shapes used in industry (source: Lecture: Textile and clothing basics production 2, MUNI, CZ;
• Fig 5 A-G Exemplary DSC measurement results of carrier polyester composition, bonding polyester composition and supplementary polyester composition.
• Fig. 6 examples of bonding impressions in nonwoven fabric with and without supplementary polyester composition in first and second component of the filament.
• Fig. 7 simplified sketch of spunmelt production line
• Nonwoven fabric production can be in general described as a sequence of major steps: melting polymer composition, fiber creation including cooling and drawing, batt formation, bonding step. There are two general possibilities - either all steps are performed at once (spunmelt technology) or some steps are performed separately and for example formed fibers are cut to defined length, treated, mixed and after the batt is formed and bonded together (carded technology). Both principles can be used to produce nonwoven according to invention.
• the nonwoven produced according to the invention is formed of filaments suitable for thermal bonding.
• each filament comprises at least two components, where one of the components (second) has lower melting temperature and acts as a bonding component and another component (first) acts as a carrier component.
• Bonding component (second) is typically at least on a part of the surface of the filament.
• bonding component (second) can be added in the form of filaments or other suitable form mixed with other filaments in a batt.
• a bonded nonwoven according to the invention comprises filaments containing first component comprising carrier polyester composition, wherein the filaments are connected with other filaments containing first component comprising carrier polyester composition by means of bonding polyester composition.
• the subject matter of the invention is a thermally bonded nonwoven textile made from endless spunmelt-type filaments and/or carded staple fibers containing at least one first component comprising carrier polyester composition and at least one second component comprising bonding polyester composition, wherein the bonding polyester composition comprises at least one bonding polyester and supplementary polyester composition.
• the subject matter of the invention is thermally bonded nonwoven textile made from endless spunmelt-type filaments comprising at least one first component and at least one second component, wherein the second component comprises at least one bonding polyester and supplementary polyester composition.
• the subject matter of the invention is thermally bonded nonwoven textile made from staple fibers, wherein at least some staple fibers comprise at least one first component comprising carrier composition and at least some staple fibers comprise at least one second component comprising bonding polyester composition, wherein the second component comprises at least one bonding polyester and supplementary polyester composition.
• a bi-component filament contains 2 components arranged within the cross-section of the filament.
• a core-sheath (C/S) type of bi-component filament contains two components, where one represents the core of the filament and the other wraps around it and forms the surface of the filament.
• the carrier composition is used here with an advantage for the core, wherein it can consist of a polyester composition or a blend comprising a more than 50 mass % of polyester.
• Bonding component contains a bonding polyester composition with a lower melting point as a predominant input material, wherein the bonding component forms the sheath of the filament.
• S/S side-by-side
• eC/S eccentric core-sheath
• Carrier polyester composition is formed of at least one carrier polyester.
• a carrier polyester is a thermoplastic polymer suitable for processing on a spunmelt production line or staple fiber production line belonging to the polymer groups of polyesters or copolyesters, preferably polyethylene terephthalate (PET) or copolymer of polyethylene terephthalate (coPET).
• PET polyethylene terephthalate
• coPET copolymer of polyethylene terephthalate
• PET polyethylene terephthalate
• a bonding polyester is a thermoplastic polymer suitable for processing on a spunmelt production line or staple fiber production line belonging to the polymer groups of polyesters or copolyesters, preferably polyethylene terephthalate (PET) or copolymer of polyethylene terephthalate (coPET).
• PET polyethylene terephthalate
• coPET copolymer of polyethylene terephthalate
• An advantageous solution represents, for example copolymer of polyethylene terephthalate (coPET).
• the bonding polyester composition has a lower melting temperature than the carrier polymer polyester composition by at least 5°C, preferably by at least 10°C, more preferably by at least 15°C, and most preferably by at least 20°C.
• the difference between the melting temperatures of carrier polyester composition and the bonding polyester composition also influences the manufacturing process.
• Lower melting polymers exposed to a temperature required to melt the higher melting polymer can, for example, undergo thermo-degradation or other unwelcome changes.
• the carrier polyester is preferably a semi-crystalline polymer.
• the bonding polyester is preferably semi-crystalline or an amorphous polymer.
• the carrier polyester composition is preferably more crystalline than bonding polyester composition.
• DSC differential scanning calorimetry
• first cooling carrier polyester performs a typical curve for slow crystallization (rather wide, not too high peak).
• Bonding polyester performs a typical curve for no or very limited crystallization (no or small indistinctive peak).
• supplementary polyester composition performs curve typical for fast crystallization (rather narrow peak typically higher than carrier polyester).
• crystallization enthalpy (He) can be used to describe the difference.
• the crystallization enthalpy of the bonding polyester composition at first cooling is at most 10 J/g, preferably at most 8 J/g, with an advantage at most 5 J/g, most preferably at most 2 J/g.
• the crystallization enthalpy of the carrier polyester at first cooling is at least 2 J/g, preferably at least 4 J/g, with an advantage at least 6 J/g, most preferably at least 10 J/g.
• full width at half maximum of crystallization peak at first cooling was chosen to define the difference between wide and narrow peak.
• full width at half maximum (FWHM) is the difference between the two values of the independent variable at which the dependent variable is equal to half of its maximum value. In other words, it is the width of a spectrum curve measured between those points on the y-axis which are half the maximum amplitude (fig. 4).
• Full width at half maximum of crystallization peak at first cooling is set from DSC measurement and expressed in °C.
• the carrier polyester has full width at half maximum of crystallization peak at first cooling of at most 50°C.
• the difference in full width at half maximum of crystallization peak at first cooling between carrier polyester composition and supplementary polyester composition is at least 2°C, preferably at least 3°C, with an advantage at least 5°C.
• the bonding polyester or bonding polyester composition has heat of fusion of at most 35 J/g.
• the carrier polyester or carrier polyester composition has heat of fusion of at least 35 J/g.
• the supplementary polyester composition has heat of fusion of at least 35 J/g.
• the difference of carrier polyester composition heat of fusion and bonding polyester composition heat of fusion is at least 5 J/g, preferably 7 J/g, with an advantage 10 J/g.
• the carrier polyester composition of a filament component provides complex shear viscosity in the range of 250-500 Pa.s under amplitude of shear strain deformation of 5% at angular frequency of 1 rad.s 1 at temperature of 270°C defined within 5 minutes of experiment run under nitrogen atmosphere.
• the required parameters of the supplementary polyester composition can be achieved by using material from recycled nonwoven products formed substantially of carrier and bonding polyester composition.
• the supplementary polyester composition is some form of reused polymer, its properties shall be evaluated at the point when it is dosed to virgin polymer (in form of granules, nonwoven or even in a melt form).
• nonwoven fabric is dependent on the combination of filaments properties and bonding properties. Especially, but not limited to, tensile strength of produced nonwoven is a good example.
• the fabric produced according to the invention can be formed of multicomponent filaments comprising first component and second component. Strength of the fabric is given by many factors, for the purpose of this invention we focus on combination of strength of single filaments and strength of formed bonds.
• any additional element will be considered an impurity when it causes a lower filament tensile strength due to an influence on the filament formation, including crystallization rate, total degree of crystallinity, or polymer chain orientation. If the additional element does not impact the tensile strength, it is not considered an impurity.
• TiOz a commonly used white pigment, can be in one composition considered as supportive nucleating agent improving filament tensile strength and in a different composition an impurity, that decreases filament tensile strength.
• the supplementary polyester composition can be considered an impurity when added to bonding polyester composition due to its neutral to negative effect on tensile strength of filament, while still providing positive effects in other aspects.
• the filament components cohesivity describes the strength of the interface after the components are process into a filament. Without being bound by theory, itis believed to have minor effect on the filament tensile strength but a major effect on the tensile strength of the nonwoven. For example, if the bonding polyester composition and the carrier polyester composition have a high level of cohesivity, a higher level of energy is needed to separate them as a result, with a reasonable level of simplification, both components will break simultaneously when subject to a tensile deformation and therefore, both component contribute to the overall tensile strength. If the level of cohesivity is low, the interface between the two components will be weak, and require low energy to separate them.
• the cohesivity of the components is dependent on the chemical affinity between the components but also on the physical interaction, or a mechanical connection.
• Component shaping can be provided in various ways, for example supplementary polyester composition added to bonding polymers can contain substance with great compatibility to carrier polyester composition and for example due to fast cooling and drawing, some of domains close to components interface can partially connect with carrier polyester composition or its part and form something like "puzzle structure" increasing component to component cohesivity.
• Thermally induced bonding of batts can result for example in the formation of individual bonding points (typically so-called air-through-bonding as described for example in W02020103964) or for example in the formation of bonding impressions (typically so-called calender-bonding as described for example in W02017190717).
• the combination of the bonding polyester composition, the carrier polyester composition, and their level of cohesivity is beneficial to the nonwoven textile, no matter which form of thermo-bonding is used. The better the cohesivity is, the higher the nonwoven tensile strength is.
• a supplementary polyester composition added to bonding polymer composition has neutral to positive effect on tensile strength of filament, by enhancing the cohesivity between the bonding component and the carrier component.
• a supplementary polyester composition added to carrier polymer composition has neutral to positive effect on tensile strength of stretched filament.
• a supplementary polyester composition added to bonding polyester composition has neutral to positive effect on tensile strength of the nonwoven fabric.
• thermo-bonding process of multicomponent filaments is in general built on the principle of softening and/or melting the bonding part of filaments and puting them in contact leading to the merge or fusion bonding part of the same or other filaments at the contact points, and then leting them cool and solidify, which forms a bond, resulting in the bonded filaments being connected together.
• the bonding polymer has to be able to spread or flow when heated during thermo-bonding process to form effective bonds of required properties.
• a calendering process with an embossing roll provides a typical patern formed of multiple bonding impressions in the bonded fabric. Even though some characteristics are given by design of bonding patern, the effectivity of the filament-to- filament connection is key factor.
• the filaments in contact with the calender are heated to a temperature at which at least the bonding polyester has a specific level of softening and surface adhesive characteristics, while, at the same time the filaments are compressed together, resulting in a bonding impression.
• fluid-through-bonding typically air-through-bonding performs bonding throughout the entire fabric, where each individual fiber-to-fiber contact may form a bond. Bonds are small, formed at the contact points where two or more filaments touch.
• Hot fluid flows around the filaments of the bat and a part of the heat carried by the hot fluid is transferred into the colder filaments.
• bonding polyester needs to accept so much energy (heat), that it comes to its specific level of softening and surface adhesive characteristics where when bonding components of two filaments touch each other they sticks together, and bond is formed.
• heat energy
• bonding polyester is able to spread more, stronger filament to filament bond can be formed and overall nonwoven tensile strength can be expected to grow.
• a specific level of softening and surface adhesive characteristics state differs based on chosen thermal bonding method. Surprisingly, combination of supplementary composition according to the invention with bonding composition according to the invention improves its ability to spread and results in better and more solid formed bonds and to improvement in overall nonwoven fabric tensile strength properties.
• additive polymer according to the invention added to bonding polymer has positive effect on tensile strength of thermal bonded nonwoven fabric.
• bonding polyester composition shall preferably be kept at lower level of crystallinity to reach desired effective bonding.
• bonding polyester composition shall preferably be kept at lower level of crystallinity to reach desired effective bonding.
• the supplementary polyester composition added to second component in filament improves nonwoven fabric tensile strength for at least 5%, preferably at least 7%, with an advantage at least 10%.
• the second component comprises at least 1 mass % of supplementary polyester composition, preferably at least 2.5 mass % of supplementary polyester composition, with an advantage at least 4 mass % of supplementary polyester composition, more preferably at least 5 mass % of supplementary polyester composition.
• Supplementary polyester composition can be designed as virgin polymer or blend of virgin polymers, or recycled material can be used. For example, during nonwoven production edges can be cut and fed to the production line extrusion system. For example, filament or nonwoven scrap can be shredded and fed to the production line extrusion system.
• supplementary polyester composition is in the form of fibers substantially formed of carrier/bonding polyester composition.
• supplementary polyester composition is in the form of nonwoven substantially formed of carrier/bonding polyester composition.
• supplementary polyester composition is in the form of fibers and/or nonwoven substantially formed of PET/coPET composition.
• supplementary polyester composition comprises recycled carrier polyester and recycled bonding polyester.
• supplementary polyester composition comprises at least 5 mass % of recycled bonding polyester, preferably at least 10 mass % of recycled bonding polyester, with an advantage at least 15 mass % of recycled bonding polyester, most preferably at least 20 mass % of recycled bonding polyester.
• supplementary polyester composition comprises at least 20 mass % of recycled PET, preferably at least 30 mass % of recycled PET, with an advantage at least 40 mass % of recycled PET, most preferably at least 50 mass % of recycled PET.
• PET/coPET bi- and/or multi-component fiber and/or nonwoven scrap is collected, dosed through the dosing unit into extrusion system comprising zone of pre-heating with temperature set to 100 - 150°C, several heated extrusion zones with temperature set to 200 - 300°C, preferably graduating from 200 - 250°C at the beginning to 250°C - 300°C at the end.
• Melted polymer blend is filtered, cooled and formed to pellets cooled further to ambient temperature.
• the amount of bonding composition can influence bonding quality and so also tensile properties of nonwoven fabric. If, for example, there is just a small quantity of bonding polyester composition, bonds can be formed, but their strength will be limited, especially at lower cohesivity level. On contrary, high amount of bonding polyester composition assure strong bonds, but providing same fiberdiameter as previous case, amount of carrier polyester would be limited, and so fabric stability and also tensile strength.
• bonding polyester composition forms at least 10% of filament mass, with an advantage at least 15% of filament mass, preferably at least 20% of filament mass.
• bonding polyester composition forms at most 60% of filament mass.
• carrier polyester composition forms at least 40% of filament mass, with an advantage at least 50% of filament mass, preferably at least 60% of filament mass.
• carrier polyester composition forms at maximum 90% of filament mass, preferably at maximum 80% of filament mass, with an advantage at maximum 70% of filament mass.
• Islands in the sea composition does not require bonding polyester composition to spread as much as in case of side-by-side composition to form strong bonds among bonding components of filaments. Also providing supplementary polymer composition acts as impurity as described above in view of polymer tensile strength, its effect on overall strength would be different for coresheath structure with carrier part present in the form of one backbone and different for example in segmented pie shape, where carrier part is divided into several parts divided by bonding polyester composition.
• Recycling is in general desired in industry. Providing supplementary polyester composition which comprises recycled polymers (for example recycled carrier polyester, recycled bonding polyester, and possibly also recycled supplementary polyester composition) it might be advantageous to dose higher amount into filament composition.
• recycled polymers for example recycled carrier polyester, recycled bonding polyester, and possibly also recycled supplementary polyester composition
• supplementary polyester composition can be present in the second component of filament in an amount of up to 90% of its mass, preferably up to 85% of its mass, with an advantage up to 75% of its mass, more preferably up to 50% of its mass.
• supplementary polyester composition is present in the second component ofthe filament in an amount lowerthan 50% of its mass, preferably lower than 40% of its mass, with an advantage lower than 30% of its mass, more preferably lower than 20% of its mass.
• any additive in carrier polymer might bring neutral to negative effect concerning carrier polyester composition tensile strength.
• adding of supplementary polyester composition to the carrier composition might bring positive effect on filament component cohesivity.
• we do not expect straight effect on bonding polymer to spread for example by slight increase of carrier polymer flexibility, it might bring effect on bonding.
• core-sheath filament composition even a slight increase of core, formed of carrier polyester, flexibility allows it to become more elliptic oval under pressure, decrease its diameter and just by its shape help bonding polymer to spread more.
• supplementary polyester composition can be added to first component of filament to form at least 2.5% of its mass, preferably at least 5% of its mass, with an advantage at least 7.5% of its mass, more preferably at least 10% of its mass.
• supplementary polyester composition can be added to first component of filament to form up to 90% of its mass, preferably up to 85% of its mass, with an advantage up to 75% of its mass, more preferably up to 50% of its mass.
• supplementary polyester composition can be added to both first and second component of the filament provided the supplementary polyester composition mass concentration would be the same or lower in the first component than in the second component.
• a method for producing a nonwoven fabric from continuous filaments, in particular from continuous filaments of thermoplastic material is used to describe the invention.
• Person skilled in the art would appreciate that described principles would work also for carded technology where nonwoven fabric is created substantially from staple fibers, which have much shorter lengths, for example 10 mm to 60 mm.
• the multicomponent or bicomponent filaments of the nonwoven fabric layer are spun by a spinning device or spinneret and then passed preferably for cooling through a cooling device.
• the filaments are conveniently cooled using a fluid medium, in particular by means of cooling air.
• the spun filaments are then passed through a drawing device, and the filaments are drawn.
• the drawn filaments are then deposited on a tray - preferably laid on a formation moving belt to form a nonwoven bat.
• a diffuser interposed as a storage device managing the laying down of the filaments is installed between the drawing device and the deposition location.
• a particularly recommended embodiment of the method according to the invention is characterized by a nonwoven fabric that is produced from multicomponent filaments, in particular bicomponent filaments, having core-sheath, eccentric core-sheath or side-by-side composition of filament.
• filaments having so called crimpable cross-section can (self)crimp during cooling, drawing or laying down on the belt, possibly later on due to activation by additional thermal energy. It should be also noted that filaments with so called non-crimpable cross-section can form irregular crimp based for example on controlled shrinkage effect, as disclosed e.g. in W02020103964. Person skilled in the art would understand what process conditions would support crimping and what would keep fibers uncrimped.
• the bonding polyester composition has a lower melting temperature than carrier polyester composition by at most 200°C, preferably at most 180°C, with an advantage at most 160°C, most preferably at most 150°C.
• Bonding polymer composition is formed of at least one bonding polyester.
• the carrier polyester is a thermoplastic polymer suitable for processing on a spunmelt production line or staple fiber production line belonging to the polymer groups of polyesters or copolyesters, preferably polyethylene terephthalate (PET) or copolymer of polyethylene terephthalate (coPET).
• PET polyethylene terephthalate
• coPET copolymer of polyethylene terephthalate
• PET polyethylene terephthalate
• the bonding polyester is a thermoplastic polymer suitable for processing on a spunmelt production line or staple fiber production line belonging to the polymer groups of polyesters or copolyesters, preferably polyethylene terephthalate (PET) or copolymer of polyethylene terephthalate (coPET).
• PET polyethylene terephthalate
• coPET copolymer of polyethylene terephthalate
• An advantageous solution represents, for example copolymer of polyethylene terephthalate (coPET).
• the supplementary polyester composition is a thermoplastic polymer or polymer blend suitable for processing on a spunmelt production line or staple fiber production line belonging, with an advantage, to the polymer groups of polyesters or copolyesters.
• the preferred bicomponent filaments have the ratio of the mass of the first component to the mass of the second component from 40:60 to 90:10. It is in the context of the process according to the invention that the mass ratios of the core-sheath configuration can be freely varied during production without stopping the machine.
• bonding polyester composition forms at least 10% of filament mass, with an advantage at least 15% of filament mass, preferably at least 20% of filament mass.
• carrier polyester composition forms at least 40% of filament mass, with an advantage at least 50% of filament mass, preferably at least 60% of filament mass.
• carrier polyester composition forms at most 70% of filament mass, preferably at most 80% of filament mass, with an advantage at most 90% of filament mass.
• the resulting nonwoven layer is thermally pre-bonded, i.e. pre-consolidated, possibly thermally activated and then thermally bonded.
• the formed nonwoven fabric consists of one or several layers, each formed on a spunbond beam (1). It is understood that multiple layers are laid on top of each other and transported together on at least one forming belt (2) to a final bonding device (3). It is within the invention that other layers can be part of nonwoven composite, including meltblown layer.
• the filaments 4 are spun using a spinneret 5.
• the arrangement of the filaments is optimized by a staggered arrangement so that each filament gets a very similar mass and a very similar temperature of cooling air.
• the spinnerets can vary in number of capillaries as well in the diameter (d) and the length (I) of the capillaries.
• the length (I) is typically calculated as multiple of the capillary diameter and for this application is in the range from 2 to 10 l/d.
• the number of capillaries must be chosen based on the required final filament diameter and the required or planned total polymer throughput together with the required filament spinning speed.
• the number of capillaries can be varied from 800- 7000 capillaries per meter, providing a filament diameter range from 8 to 45 pm.
• Filament speed should be defined between 3000 and 5500 m/min, the capillary diameter should be in between 200 and 1000 pm for round capillaries.
• Non-round capillaries show typically higher draw down ratios, greatly dependent on the capillary shape and its surface-to-volume ratio.
• the volume and temperature of the cooling air is set to achieve the correct draw down ratio and cooling conditions.
• the volume and temperature of the cooling air is controlled in the cooling device (6).
• the filaments are guided through the draw down zone (7).
• the filaments are drawn down by pulling forces created by the air speed of the cooling air.
• the volume of cooling air and the adjustable geometry of the draw down zone results in an air speed, which is also converted into filament speed.
• the filament speed together with the polymer throughput also defines the filament diameter.
• the filaments are guided to the diffuser 8 which has divergent side walls in relation to the flow direction of the filaments. These walls can be adjusted and are adjusted in a way to achieve a uniform nonwoven fabric in which single filaments create a filament laydown arrangement exhibiting omnidirectional orientation in the MD/CD plane.
• a filament laydown is influenced by the air guiding the filaments in the diffuser.
• the air can be adjusted to create arrangements from distinct zigzag lay down arrangements to real round loops, and furthermore CD-orientated elliptical structures.
• the filaments are laid down on the formation belt and transported into at least one preconsolidation device (9). Cooling air is moved through the filament lay down layer and the formation belt out of the process. The volume of suction air can be adjusted to help the filament lay down and also to ensure that the filament batt is fixed on the formation belt.
• the pre-consolidation device is located close to the diffuser. The filament batt is controlled on the way from the diffuser to the pre-consolidation device by suction air.
• Pre-consolidation can be performed by various methods including compact rolls, flow of fluid (e.g. air) or any other suitable forms. Pre-consolidation can be performed at cold, ambient, increased or high temperature.
• flow of fluid e.g. air
• Pre-consolidation can be performed at cold, ambient, increased or high temperature.
• Final bonding can be performed by multiple methods in bonding device (3).
• procedure of treating the filament batt with hot air in a bonding device is applied.
• the filament batt of a single layer and/or more layers is bonded together, preferably without reducing the diameter of the filament batt significantly and having almost no bonding gradient throughout the thickness of the nonwoven.
• the bonding temperature and forces applied to the filament batt need to be adapted to the required process effect of low softening and low forces but sufficient to affect the integrity of the nonwoven filament batt. This can be achieved in multiple different devices like an Omega drum bonding device, a flat belt bonding device as well as a multiple drum bonder.
• the bonding time for the batt is recommended between 200 and 20000 ms, preferably between 200 and 15000 ms and most preferably between 200 and 10000 ms.
• the bonding air speed used in this bonding unit device is adjustable between 0.2 and 4.0 m/s, preferably between 0.4 and 1.8 m/s.
• the bonding temperature for thermal bonding is between 100°C and 250°C, preferably between 120°C and 220°C. In one embodiment, the bonding temperature is 90°C to 140°C, in particular 110°C to 130°C.
• the nonwoven layer of bicomponent filaments has a core component comprising carrier polyester composition, preferably polyethylene terephthalate (PET) and a sheath component comprising bonding polyester composition, preferably a polyethylene terephthalate copolymer (CoPET), and supplementary polyester composition, the bonding temperature is preferably 140°C to 230°C.
• carrier polyester composition preferably polyethylene terephthalate (PET)
• sheath component comprising bonding polyester composition, preferably a polyethylene terephthalate copolymer (CoPET)
• the bonding temperature is preferably 140°C to 230°C.
• pair of heated rolls can be applied to the batt.
• nonwoven batt can be consolidated by means of heated calender rollers with one smooth roll and opposed embossed roll forming by its protrusions bonding impressions creating a pattern repeated in direction of the nonwoven web movement (MD).
• MD nonwoven web movement
• Various pattern designs are known in industry (for example, W02017190717).
• a pairs of smooth rolls, a pair of embossed rolls or any combination thereof can be used.
• the nonwoven layer of bicomponent filaments has a core component comprising carrier polyester composition, preferably polyethylene terephthalate (PET) and a sheath component comprising bonding polyester composition, preferably a polyethylene terephthalate copolymer (CoPET), and supplementary polyester composition, the bonding temperature is preferably 140°C to 240°C.
• carrier polyester composition preferably polyethylene terephthalate (PET)
• sheath component comprising bonding polyester composition, preferably a polyethylene terephthalate copolymer (CoPET), and supplementary polyester composition
• the bonding temperature is preferably 140°C to 240°C.
• nonwoven batt can be thermobonded first, and hydroentagled or hydroenhanced in following step (for example WO2022235648; WO2022235652; WO2018112259 or W02006031656).
• air-through-bonding can be combined with calander bonding or 3D shaping or any combination of above. Person skilled in the art would be able to choose suitable combination to reach desired fabric properties.
• the bonded nonwoven is finally wound up on a winder 11.
• a spraying device or kiss roll is placed either in between the forming belt and the final bonding device or in between the final bonding device and the winder.
• one layer of bicomponent fibers was prepared using a spunbond-type spinneret with round capillaries using a REICOFIL 4 technology on a pilot line at STFI (Sachsisches Textilforschunginstitut e.V.).
• the core carrier polyester composition
• the core was produced from Type 5520 resin (PET2) in examples 1-8 and XPURE Polyester V062 (PET1) resin in examples 9-11 from Indorama and the sheath (bonding polyester composition) was produced using coPET XPURE Polyester 701K (PET3) resin from Indorama. Core/Sheath ratio was set to 70/30 (mass). Cabin pressure was set to 8 000 Pa.
• the invention is applicable wherever a polyester nonwoven fabric is required — for example in the hygiene industry as various components of absorbent hygiene products (e.g. baby diapers, incontinence products, female hygiene products, changing pads, etc.) or in healthcare, for example, as a part of wound sponges and/or protective garments, surgical cover sheets, underlays and other barrier material products. Further uses are also possible in industrial applications, for example, as a part of protective garments, in filtration, insulation, packaging, sound adsorption, footwear industry, automotive, furniture, etc.
• the invention is usable with an advantage particularly in applications, where there is a requirement for polyester fabric and also stress on sustainability.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Multicomponent Fibers (AREA)
• Nonwoven Fabrics (AREA)

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• 2024
  • 2024-03-29 CZ CZ2024-115A patent/CZ2024115A3/cs unknown
• 2025
  • 2025-03-28 WO PCT/CZ2025/050028 patent/WO2025201584A1/en active Pending

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