IT202300008229A1 - Compact multilayer material and its preparation process, padding comprising the multilayer material, and garment comprising the padding - Google Patents

Description

TITLE: ?Compact multilayer material and its preparation process, padding comprising the multilayer material, and garment comprising the padding?

DESCRIPTION

FIELD OF INVENTION

The technical field to which the invention belongs is that of methods of preparing multilayer non-woven materials.

STATE OF THE ART

?Non-woven fabric? (TNT) is a generic term for an industrial product similar to a fabric, consisting of staple fibres (short) and long fibres (long continuous), bonded together by chemical, mechanical, thermal or solvent treatment. In particular, a non-woven fabric is a fabricated surface (web) of fibres (natural or synthetic), oriented in a particular direction or randomly, bonded by friction and/or cohesion and/or adhesion.

The term "non-woven fabric" is used in the textile manufacturing industry to indicate fabrics that have neither been woven nor knitted.

The term "non-woven fabrics" first appeared in 1965: "Non-woven fabrics are products consisting of strips laid parallel, crossed or randomly, bonded by the application of adhesives or thermoplastic fibres under the application of heat and pressure."

Nonwoven materials are used for numerous applications: from surgical masks to liquid filters, road underlay, packaging, or trendy clothing.

Almost all known fibers can be compacted; for example, synthetic fibers, such as Tyvek or Nylon, or high-strength fibers, such as fiberglass, Kevlar, or carbon fiber.

The production of non-woven fabric essentially takes place in two phases:

i) creation of the veil;

ii) compaction of the veil.

In phase i) of creating the veil, the fibres are combined into a veil, usually very thin and delicate, which does not yet have good mechanical characteristics. The first veil can be created starting from:

- a group of short fibres (up to 7 cm);

- continuous threads.

Short fibers can be treated in a humid environment (similar to paper), or in a dry environment, thanks to machines called ?carding machines?. The plies are generally very thin and must be overlapped to obtain greater thicknesses.

At this stage, the non-woven veil is not yet ready to be used, since the fibres are not well cohesive and compact.

In phase ii) of veil compaction, the veil multilayers are reduced in thickness with the aim of increasing their density and resistance. In this sense, it is possible to use chemical, mechanical, or thermal processes.

In general, the mechanical compaction process occurs through the repeated action of numerous small needles, which are inserted into the veil with the aim of binding the fibres together.

The needles are, therefore, the elements that actually perform the compaction process. They are generally made of high-performance steel, by specialized companies. The most used needles are ?shaving needles? and ?fork needles?.

The general principle is that some roughness on the tip of the needle captures and drags the fibres during the movement of the needle itself.

Mechanical compaction with a needle puncher generally has a horizontal development. The fabric is made to slide parallel to the support surface and passes through the machine from one side to the other. During the passage inside the machine, the fibers are hit by the needles and, consequently, subjected to needling.

The tape is usually carried by rollers or moving carpets towards the entrance of the machine, up to the exit, where it is extracted. During the passage inside the machine, a traction force can be applied to the web.

The needles are firmly inserted into a perforated table that moves with an alternating vertical motion, allowing the needles to repeatedly penetrate the fibers. Generally, the vertical movement is generated by a connecting rod type kinematics and is driven by an electric motor.

SUMMARY OF THE INVENTION

The object of the present invention is a compact multilayer material 1 comprising at least three layers, of which at least one layer is a mattress comprising a mixed textile fibre comprising at least two natural fibres, and the remaining at least two layers, in addition to the at least one layer which is the mattress comprising the mixed textile fibre, are independently selected from: a polylactic acid (PLA) layer, a hard needled layer of mixed textile fibre, a medium needled layer of mixed textile fibre, a mattress comprising the mixed textile fibre, a hemp layer.

A further object of the present invention is a process for preparing the compact multilayer material 1 comprising the following steps:

A. prepare at least three layers, of which at least one layer is the mattress comprising the mixed textile fibre;

B. overlapping said at least three layers, forming a non-compact multilayer;

C. compact the non-compact plywood by needle punching, obtaining the compact multilayer material.

A further object of the present invention is a thermally insulating padding comprising the compact multilayer material 1 according to the present invention.

A further object of the present invention is a garment comprising thermally insulating padding comprising the compact multilayer material 1 according to the present invention.

Advantages of the invention

The preparation process according to the present invention allows the preparation of a compact multilayer material, through a mechanical compaction step, carried out by needling, of a non-compact multilayer.

Advantageously, the preparation process according to the present invention, thanks to the use of a mixed textile fiber comprising different plant fibers alternative to the natural fibers commonly known for the same uses, allows the exploitation of greater biodiversity and, at the same time, guarantees a constant availability of raw material. This advantageously allows to prevent potential and possible shortages of raw materials, resulting from the impact of seasonality and current climate changes on the growth and/or production of specific plant species.

Furthermore, the preparation process according to the present invention allows to obtain compact multilayer materials, which can be advantageously employed in the production of thermally insulating padding, as a replacement for materials commonly known to be used for the same purposes, such as wool.

Advantageously, the preparation process according to the present invention, adopting a mechanical compaction method, is more eco-sustainable than similar processes involving thermal compaction, since it requires less energy consumption.

Advantageously, compared to processes based on chemical compaction, the preparation process according to the present invention allows to obtain compact multilayer materials, avoiding the use of additional components, such as adhesives and/or binding agents, potentially polluting and/or dangerous for the user. Consequently, the process according to the present invention is particularly respectful for the environment and safe for the user.

Advantageously, the preparation process according to the present invention allows to drastically reduce the control on the final quality of the product, since it guarantees the obtaining of compact multilayer materials having an excellent structural homogeneity.

A further advantage of the preparation process according to the present invention lies in the possibility of combining non-woven fabrics with other non-woven materials, such as foams, leathers, papers, and/or films, having variable chemical-physical, morphological and mechanical properties. Consequently, the preparation process according to the present invention allows, by appropriately choosing the raw materials, to obtain compact multilayer materials with similar thermal properties, but with variable chemical-physical, morphological and mechanical properties, depending on the intended uses of interest.

In this regard, always advantageously, the process in accordance with the present invention, thanks to the possibility of joining non-woven fabrics with further non-woven materials, allows the creation of compact multi-layered materials with high performance, in terms of mechanical resistance, thermal insulation, compatibility with environmental agents, pleasantness to the touch and to the sight.

Always advantageously, this possibility of using different non-woven materials allows the selection, based on availability and the applications of interest, of low-cost raw materials, reducing the overall production costs of multilayer materials.

DESCRIPTION OF THE FIGURES

Figures 1-a and 1-b schematically represent two standard (or single-side process) configurations of needling machines, while Figure 1-c schematically represents a non-standard (or double-side process) configuration of needling machines.

Figures 2-a and 2-b schematically represent respectively a standard and non-standard configuration of needle-punching machines.

Figures 3-a, 3-b, 3-c, schematically show three embodiments of the compact multilayer material according to the present invention.

Figures 4-a, 4-b, and 4-c, schematically show three further embodiments of the compact multilayer material according to the present invention.

Figures 5-a, 5-b, schematically show two further examples of embodiment of the compact multilayer material according to the present invention.

Figures 6-a, 6-b, 6-c, schematically show three further embodiments of the compact multilayer material according to the present invention.

Figures 7-a, 7-b, and 7-c, schematically show three further embodiments of the compact multilayer material according to the present invention.

Figure 8-a and 8-b schematically show a standard and a non-standard configuration of needle-punching machines respectively.

Figures 9-a and 9-b schematically show an example of application of the mixed textile fibre, used in the manufacturing process according to the present invention, in two different conditions of use.

Figures 10-a and 10-b schematically show an example of application of the thermally insulating padding comprising the compact multilayer material according to the present invention, in two different conditions of use.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

By ?natural fibre? we mean a fibre obtained from plant materials, or from materials of animal origin from which it is possible to take hair or skin.

By ?veil? we mean a layer of non-woven material, usually thin and delicate, obtained from a group of fibres generally up to 7 cm long and/or from continuous threads.

By ?mattress? we mean a non-woven biodegradable and/or compostable structure, based on cellulose fibres with high thermal capacity.

By ?fermented protein fibres? we mean fibres obtained from natural protein substances, produced through fermentation processes promoted by microorganisms, such as yeasts, bacteria, and/or fungi.

By ?fermented cellulosic fibres? we mean fibres made from cellulosic materials or derivatives of cellulosic materials, where the cellulosic materials are obtained through fermentation processes promoted by microorganisms, such as yeasts, bacteria, and/or fungi.

By ?degraded bacterial cellulose? we mean a product obtained through degradation processes promoted by microorganisms, preferably bacteria and/or fungi, starting from bacterial cellulose.

By ?airlaid structure? we mean a non-woven material structure, obtained from fibres subjected to carding and air dispersion processes.

A ?spunbond structure? refers to a non-woven material structure created through a process of spinning polymer filaments which are then arranged randomly.

Process of preparing a compact multilayer material

The object of the present invention is a process for preparing a compact multilayer material 1. The steps of the preparation process according to the present invention are reported in detail below.

A. Prepare at least three layers

In a phase A of the preparation process of the compact multilayer material 1, at least three layers are prepared, of which at least one layer is the mattress 2 comprising a mixed textile fibre comprising, in turn, at least two natural fibres.

Preferably, in phase A of the preparation process three to five layers are prepared, preferably three or five layers.

Preferably, each of the at least three layers is in the form of an airlaid or spunbond structure, more preferably in the form of an airlaid structure.

Note that the airlaid structure and/or the spunbond structure can be obtained by the person skilled in the art using state-of-the-art methodologies.

Preferably, the mattress 2 comprising the mixed textile fibre is prepared in phase A of the preparation process in a quantity between 150 and 250 g, preferably equal to 200 g or 250 g.

Preferably, the mattress 2 comprising the mixed textile fibre is obtained by carding the mixed textile fibre. Note that the carding of the mixed textile fibre can be carried out by the person skilled in the art with methodologies known to the state of the art.

Preferably, the at least three layers comprise one to two layers, preferably one layer, which is the mattress 2 comprising the mixed textile fibre.

Preferably, the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, are independently chosen from: a layer of polylactic acid (PLA) 3, a layer of mixed textile fibre, the mattress 2 comprising the mixed textile fibre, a layer of hemp 5.

Optionally, the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, are independently chosen from: a layer of para-xylene, a layer of polyethylene furanoate (PEF), a layer of polybutylene adipate terephthalate (PBAT), a layer of polybutylene succinate (PBS), a layer of polycaprolactone (PCL), a layer of polyvinyl alcohol (PVOH), a layer of poly(trimethylene terephthalate) (PTT), a layer of polyhydroxyalkanoates (PHA), a layer of Azlon.

Optionally, the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, are independently chosen between a layer of fermented protein fibres and/or a layer of fermented cellulosic fibres.

Please note that natural protein substances suitable for the production of fermented protein fibres are preferably recombinant spider silk proteins.

Note that microorganisms suitable for the production of natural protein substances are preferably chosen from bacteria, yeasts, and/or fungi, preferably bacteria and/or fungi.

Please note that the bacteria suitable for the production of natural protein substances, preferably recombinant spider silk proteins, are preferably chosen from the following species: Komagataella pastoris, Escherichia coli, Bacillus subtilis, Trichoderma reesei.

Note that cellulosic materials suitable for the production of fermented cellulosic fibres are preferably chosen from bacterial cellulose and/or bacterial nanocellulose.

Note that the derivatives of cellulosic materials suitable for the production of fermented cellulosic fibres are preferably chosen from bacterial cellulose aerogels and/or degraded bacterial cellulose.

Note that microorganisms suitable for the production of degraded bacterial cellulose can be, for example, Trichoderma reesei.

Preferably, the fermented cellulosic fibres are chosen between tree-free Lyocell and Lyocell.

Please note that microorganisms suitable for the production of cellulosic materials are preferably chosen from the following species: Komagataeibacter xylinus (also known as Gluconacetobacter xylinus), Aerobacter xylinum.

Advantageously, bacterial cellulose and, consequently, fermented cellulosic fibres are biodegradable, renewable and highly resistant materials; in particular, fermented cellulosic fibres have characteristics similar to protein fibres such as, for example, silk.

Advantageously, the fermented protein fibres can be woven into corresponding woven materials, which can be used in the production of clothing and/or new woven materials.

Preferably, the fibres of each ply are treated in a humid environment, according to a process similar to those known for the production of paper, or they can be subjected to carding, using special conventional carding machines, in a dry environment. It should be noted that the carding of the fibres of each ply can be carried out by the person skilled in the art with methodologies known to the state of the art.

Preferably, each of the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, is prepared in phase A of the preparation process in quantities between 80 and 150 g, preferably equal to 100 g.

Note that the individual mixed textile fibre veils are preferably obtained from mixed textile fibre in the form of hollow staple fibres.

Preferably, the PLA 3 veil has a weight between 20 and 50 g/m<2>, preferably equal to 30 g/m<2>.

Preferably, the hemp veil 5 has a weight between 40 and 80 g/m<2>, preferably equal to 50g/m<2>.

Mixed textile fibre

Preferably, the mixed textile fibre is obtained through a production process comprising phases 1, 2, 3, described below.

Preferably, at least two natural fibres are used in phase 1 of the mixed textile fibre production process.

Preferably the at least two natural fibres are in yarn or staple form.

Preferably, the at least two natural fibres are chosen from: fibre of a plant of the genus Asclepias, preferably Asclepias syriaca, kapok fibre, cattail fibre (Typha latifolia), balsa fibre (Ochroma pyramidale).

Preferably, the at least two natural fibers include Asclepias fiber and kapok fiber, or cattail fiber and balsa fiber.

Preferably, the Asclepias fiber has a length between 18.32 mm and 27.48 mm, preferably 22.9 mm.

Preferably, Asclepias fiber has a diameter between 14.8 and 27.9 ?m, preferably between 18.4 and 19.1 ?m, preferably equal to 18.6 ?m.

Preferably, Asclepias fiber has a wall thickness of 1.1 to 2.3 μm, preferably 1.4 to 1.8 μm, preferably 1.6 μm.

Preferably, Asclepias fiber has a relative crystallinity of between 31 and 38%, preferably 35%.

Preferably, the Asclepias fiber has a crystallite width between 3.70 and 4.70 nm, preferably equal to 4.20 nm.

Preferably, the kapok fiber has a length between 13.78 and 18.86 mm, preferably 16.32 mm.

Preferably, kapok fiber has a diameter between 13.87 and 21.31 ?m, preferably 17.59 ?m.

Preferably, kapok fiber has a wall thickness of between 0.57 and 2.11 ?m, preferably 1.34 ?m.

Preferably, kapok fiber has a relative crystallinity of between 31 and 38%, preferably equal to 35.65%.

Preferably, kapok fiber has a crystallite width between 3.76 and 5.64 nm, preferably 4.70 nm.

Preferably, the cattail fibre has a length between 2.25 and 10.65 mm, preferably between 2.25 and 8.65 mm, preferably between 6.25 and 8.25 mm, preferably equal to 7.9 mm.

Preferably, the cattail fibre has a fineness of between 10 and 22.5 ?m, preferably between 10 and 17.5 ?m, preferably between 10 and 15 ?m, preferably equal to 12.5 ?m.

Preferably, the balsa fiber has a length between 10.32 and 15.7 mm, preferably 13.01 mm.

Preferably, the balsa fiber has a diameter between 16.56 and 21.94 ?m, preferably 19.25 ?m.

Preferably, the balsa fiber has a wall thickness of between 1.43 and 3.37 ?m, preferably 2.40 ?m.

Preferably, balsa fiber has a relative crystallinity of between 27.95 and 34.85%, preferably equal to 31.40%.

Preferably, balsa fiber has a crystallite width between 3.30 and 4.10 nm, preferably 3.70 nm.

Preferably, in step 2 of the mixed textile fibre production process, blowing and cleaning are carried out separately for each of the at least two natural fibres, in order to obtain clean fibres. This means that each natural fibre is subjected, independently, to step 2 of the mixed textile fibre production process. Therefore, for each natural fibre a clean fibre is obtained. Since at least two natural fibres are prepared in step 1, at least two separate clean fibres will be obtained at the end of step 2.

Preferably, the blowing and cleaning phase 2 for each of the natural fibres from phase 1, comprises the following sub-phases:

2-a) blowing the natural fibres using a continuous flow of air, obtaining blown fibres;

2-b) clean the blown fibres, separating the impurities and dust, obtaining clean fibres.

Preferably, phase 2 of blowing and cleaning of the natural fibres is performed independently for each natural fibre cyclically, for a number of sequential cycles between two and four, preferably for three sequential cycles.

Preferably, phase 2 is conducted using a dedicated fiber blowing and cleaning apparatus comprising at least three chambers, preferably three chambers, preferably cylindrical, fluid-dynamically connected in series, each configured to receive the fibers.

Preferably, each chamber includes at least one rotating blade configured to generate airflow.

In use, in sub-phases 2-a and 2-b, the air flow passes through at least three chambers in series, blowing the fibres from a first chamber to a last chamber, in series, separating the impurities and dust through special sieves or filters placed between one chamber and the next.

Preferably, said sieves or filters have a pore size of between 2 and 10 mm, preferably 5 mm.

The air flow produces a vortex movement of the fibers inside each chamber. The fiber blowing and cleaning apparatus is able to control the speed at which the fibers are moved inside each chamber. In addition, the apparatus is able to control the residence time of the fibers in each chamber, for each conduction cycle of phase 2.

Preferably, the residence time of each natural fiber for each conduction cycle of phase 2 is between 3 and 7 seconds, preferably 5 seconds.

Preferably, each clean fiber is loaded and stored separately in a dedicated tank or silo, preferably a silo.

Preferably, in a stage 3 of the mixed textile fibre production process, each of the clean fibres from stage 2 are mixed together to obtain the mixed textile fibre.

Preferably, in stage 3 of the mixed textile fibre production process, each clean fibre is mixed in a quantity by weight, with respect to each other clean fibre, of between 10 and 40%, preferably equal to 20%.

Preferably, the production process of the mixed textile fiber comprises a step 4, subsequent to step 3, of mixing a carded polylactic acid (PLA) fiber with the mixed textile fiber, to obtain a mixed textile fiber with PLA.

Advantageously, the use of PLA fiber in combination with mixed textile fiber is able to improve the filling power of the latter, making the mixed textile fiber with PLA thus obtained particularly suitable for use in the production of padding.

It is worth noting that the textile fibre mixed with PLA obtained through the production process is particularly suitable for the creation of thermally insulating padding, given its ability to vary its volume as a function of temperature.

Note that, starting from a resting condition, i.e. from a given volume at a temperature above 10°C, the mixed textile fibre, preferably with PLA, is able to increase in volume at temperatures below 5°C and, vice versa, starting from an expanded condition, i.e. from a given volume at a temperature below 5°C, this fibre is able to gradually decrease in volume, until it returns to the resting condition, as a function of the increase in temperature above 10°C.

Preferably, the PLA-blended fiber expands from the resting condition to the expanded condition, according to a volume increase of between 50% and 100% compared to the initial volume of the fiber itself, where initial volume means the volume of the fiber in the resting condition.

Preferably, the carded PLA fiber is obtained by carding from a PLA fiber. This carding process is carried out with industrial methods known to those skilled in the art, preferably using a special machine configured to open the fibers.

Preferably, the PLA carded fiber has a length between 24 and 30 mm, preferably between 25 and 27 mm, preferably equal to 26 mm.

Preferably, PLA fiber is in yarn or staple form.

Preferably, in step 4 of the mixed textile fiber production process, the PLA carded fiber is mixed in a weight ratio, relative to the mixed textile fiber, of between 60 and 90%, preferably equal to 80%.

Preferably, the ratio of the length of each of the natural fibers to the PLA carded fiber is between 1:2.5 and 2.5:1, preferably between 1:2 and 2:1, preferably equal to 1:1.

Preferably, the production process of the mixed textile fiber comprises a step 5, of spraying and drying the mixed textile fiber or the mixed textile fiber with PLA.

Note that spraying may consist of coating the fiber and is preferably carried out using aerogel microparticles, preferably silica, alumina and/or carbon aerogels, or cellulose aerogels. Preferably, the aerogel microparticles are silica microparticles, obtained from silica gel. Preferably, the cellulose aerogel is obtained from recycled paper.

Preferably, the spraying comprises 2 to 4 consecutive sprays, preferably 3 consecutive sprays. Preferably, each individual spray is conducted for a time preferably between 15 and 20 seconds, preferably 18 seconds.

Please note that drying consists of a temperature curing treatment. Preferably, this treatment is carried out at a temperature of 60?C, for a time preferably between 40 minutes and 2 hours. The humidity level and the temperatures of the external environment influence the drying times.

Advantageously, spraying and drying confer thermal insulation and buoyancy properties to the textile fiber, thanks to the high porosity of the aerogel and its ability to retain air inside it. In this regard, it is worth noting that spraying with aerogel microparticles advantageously confers better thermal insulation compared to cellulose aerogel.

Advantageously, cellulose aerogel, in addition to being lightweight, resistant and water-repellent, is also a better choice from the point of view of eco-sustainability, compared to traditional aerogels, given its perfect biodegradability. Furthermore, cellulose aerogels have potential applications in various fields, including construction, energy and environmental protection, thanks to their unique combination of mechanical, thermal and optical properties.

Optionally, spraying and drying phase 5 includes a mixed textile fiber carding phase 5a. Phase 5a is conducted using industrial methods known to those skilled in the art, preferably using a special machine configured to open the fibers.

Preferably, the mixed textile fibre has a thermal insulation value between 3.84 and 4.04 Clo, preferably equal to 3.94 Clo.

This thermal insulation value is determined according to the ASTM D1518 standard and can be expressed in International System units in m<2>K/W, where:

1 Clo = 0.155 m<2>?K/W.

The term ?thermal insulation? refers to a quantity that measures the reduction of heat transfer (transfer of thermal energy between objects at different temperatures) between objects in thermal contact or within the radius of radiative influence.

Preferably, the blended textile fiber has a fill power value between 550 and 650 in<3>/oz, preferably equal to 600 in<3>/oz.

This fill power value (mass volume) is determined according to the European standard EN12130 and can be expressed in cm<3>/g, where:

1 in<3>/oz = 0.578037 cm<3>/g.

Advantageously, having optimal thermal insulation and fill power values, the mixed textile fibre is particularly suitable for use in the production of padding, which can constitute a more ecologically sustainable choice than those known and commercially available, such as for example those made with fibres of animal origin, such as wool.

Preferably, the mixed textile fibre has a length between 24 and 30 mm, preferably 26 mm.

Preferably, the mixed textile fibre has a wall thickness of between 1.6 and 3.1 ?m, preferably equal to 2.0 ?m.

Preferably, the mixed textile fibre has a relative crystallinity of between 31 and 38%, preferably equal to 35%.

Preferably, the mixed textile fiber has a crystallite width between 3.70 and 4.70 nm, preferably equal to 4.00 nm.

B. Overlap at least three layers together

In a phase B of the preparation process of the compact multilayer material 1, at least three layers are superimposed on each other to form a non-compact multilayer.

Preferably, the overlapping of the layers occurs by using a special machine, called a crosslapper. It should be noted that the overlapping of the layers by means of a crosslapper machine can be carried out by a person skilled in the art according to procedures known in the state of the art.

Preferably, the non-compact plywood comprises a first outer surface and a second outer surface opposite each other, said first outer surface and said second outer surface being spaced apart from an X-direction.

It is worth noting that, once the layers have been superimposed, the non-compact multilayer is preferably transported on a conveyor belt, connected in series with the machine(s) used in the subsequent phase(s) of the preparation process in accordance with the present invention.

C. Compact non-compact plywood by needle punching

In a step C of the preparation process according to the present invention, the non-compact multilayer is compacted by needling, to obtain the compact multilayer material 1.

It is worth noting that, following the compaction phase C, each of the individual layers prepared in phase A of the preparation process retains its chemical composition, although compaction modifies some of its chemical-physical and mechanical properties, such as, for example, mechanical resistance, density, thickness, structural homogeneity and breathability. Therefore, below we will refer to each layer of the compact multilayer material 1, adopting the same terminology with which the individual layers were defined in the preparation process.

Preferably, the needling is carried out using special machines, commonly known as needling machines. It should be noted that the needling can be carried out by a person skilled in the art using procedures known to the state of the art.

Preferably, the needling machines can operate in two different configurations: a standard configuration (or with a single process side), or a non-standard configuration (or with a double process side). In use, the machines in the standard configuration act on the first external surface or on the second external surface of the non-compact multilayer, using a single table of needles 9,11; vice versa, in use, the machines in the non-standard configuration (or with a double process side) act simultaneously on the first external surface and on the second external surface of the non-compact multilayer, using two tables of needles 9,11, which operate with a double kinematic mechanism.

Note that the non-standard configuration (or with double process side) is more complex, but advantageously allows to control the homogeneity of the product more efficiently, ensuring a greater uniformity; furthermore, it allows to generate non-symmetrical materials from the point of view of the density distribution along the thickness of the multilayer material.

Preferably, the needle table 9 comprises a plurality of first needles 12.

Preferably, the needle table 11 comprises a plurality of first needles 12 and a plurality of second needles 13, wherein each needle extends between a portion fixed to the needle table 11 and a free portion, wherein the free portion of each of the first needles 12 projects beyond the free portion of each of the second needles 13 along the X direction.

By way of example, figures 1-a and 1-b schematically represent two standard configurations of needle-punching machines with a needle table 9, positioned respectively above and below the position of a generic non-woven material 10. Figure 1-c schematically represents a non-standard configuration of a needle-punching machine with a needle table 9.

Again by way of example, in figure 2-a a standard configuration of needle-punching machines with a needle table 11 is schematically represented, in which the needle table 11 is positioned above the position of a generic non-woven material 10; in figure 2-b a non-standard configuration of a needle-punching machine with a needle table 11 is schematically represented.

It is worth noting that the length of each of the first and second needles 12,13 can be calibrated in such a way that, in use, said first and second needles 12,13 act only on the layers of interest, depending on the chemical-physical and mechanical characteristics of the compact multilayer material 1 that one intends to obtain.

Advantageously, the use of the needle table 11 allows to obtain compact multilayer material having a more uniformly distributed density.

Advantageously, the mixed textile fibre, both when included in the mattress 2 and when included in the mixed textile fibre veil, is particularly suitable for being subjected to mechanical compaction by needling.

Advantageously, the preparation process according to the present invention, comprising a mechanical compaction step by needling, allows to obtain the compact multilayer material, leaving the chemical composition of the starting layers unchanged, but varying their physical-chemical and mechanical characteristics, so as to obtain a multilayer material with good mechanical resistance, high density, reduced thickness, good structural homogeneity and breathability.

Note that by needle-punching the layer of mixed textile fibre veil, the following different layers can be obtained: a medium needle-punched veil 6 of mixed textile fibre or a hard needle-punched veil 4 of mixed textile fibre. It is worth noting that the hard needle-punched veil 4 of mixed textile fibre and the medium needle-punched veil 6 of mixed textile fibre differ substantially from each other in their respective density values.

Preferably, the hard needled web 4 of mixed textile fibre has a higher density than the medium needled web 6 of mixed textile fibre.

Preferably, the hard needled veil 4 of mixed textile fibre has a thickness of between 0.3 and 1.0 cm, preferably equal to 0.8 cm.

Preferably, the medium needled veil 6 of mixed textile fibre has a thickness of between 0.5 and 1.5 cm, preferably equal to 1.0 cm.

Note that the density of the individual layers depends essentially on the type of needle table used, in particular, it depends on the number of punches per unit area. These parameters of the needle punching machine therefore determine the density of the needled web of mixed textile fiber. In fact, by appropriately choosing the number of punches per unit area, it is possible to control the density and mechanical resistance values, which are inversely proportional parameters, obtaining multilayer materials with greater density and lower thermal resistance or, vice versa, with lower density and density? thermal resistance.

Advantageously, the needling compaction process modifies the chemical-physical and mechanical characteristics of each layer and, consequently, also of the multilayer, ensuring greater mechanical resistance, greater density, reduction of thickness, and better homogeneity. Always advantageously, these improved properties are even more marked for the layers comprising the mixed textile fiber.

Preferably, phase C of the preparation process according to the present invention comprises the following sub-phases which are alternative to each other:

C1. carry out the needling using a standard configuration needling machine, preferably using a 9 needle table;

C2. carry out the needling using a standard configuration needling machine, preferably using a needle table 11;

C3. conduct the needling using a non-standard configuration needling machine, preferably using a double needle table 9; or C4. conduct the needling using a non-standard configuration needling machine, preferably using a double needle table 11.

Compact multilayer material

The object of the present invention is a compact multilayer material 1 comprising at least three layers, of which at least one layer is the mattress 2 comprising a mixed textile fibre comprising at least two natural fibres, and the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, are independently selected from: the polylactic acid (PLA) layer 3, the hard needled layer 4 of mixed textile fibre, the medium needled layer 6 of mixed textile fibre, the mattress 2 comprising the mixed textile fibre, the hemp layer 5.

Preferably, at least two natural fibers are chosen from: Asclepias fiber, kapok fiber, balsa fiber, cattail fiber.

Preferably, the mixed textile fibre comprises a carded fibre of polylactic acid (PLA) in a quantity between 60 and 90%, preferably equal to 80% by weight with respect to the total weight of the mixed textile fibre (w/w).

Optionally, the remaining at least two layers, in addition to the at least one layer which is the mattress 2 comprising the mixed textile fibre, are a layer of fermented protein fibres and/or a layer of fermented cellulose fibres.

Preferably, the multilayer material 1 comprises three layers, of which an internal layer which is the mattress 2 comprising the mixed textile fibre, and two external layers independently selected from: the polylactic acid (PLA) layer 3, the hard needled layer 4 of mixed textile fibre, the medium needled layer 6 of mixed textile fibre, the hemp layer 5, or of which an internal layer which is the hard needled layer 4 of mixed textile fibre and two equal external layers which are the mattress 2 comprising the mixed textile fibre.

Preferably, the compact multilayer material 1 comprises five layers, of which a central layer which is the mattress 2 comprising the mixed textile fibre, two equal intermediate layers selected from the hard needled web 4 of mixed textile fibre, the medium needled web 6 of mixed textile fibre, the hemp web 5, and two peripheral layers independently selected from the PLA web 3, the hard needled web 4 of mixed textile fibre, the medium needled web 6 of mixed textile fibre, the hemp web 5.

Preferably, the compact multilayer material 1 is obtained by the preparation process according to the present invention.

Preferably, the compact multilayer material 1 comprises three layers, including an inner layer and two outer layers, adjacent to the inner layer.

Preferably, the inner layer is the mattress 2 comprising the mixed textile fibre.

Preferably, the outer layers are the same or different from each other.

It is worth noting that the compact multilayer material 1 comprising three layers, of which two external layers are equal to each other, has a symmetrical three-layer configuration in the distribution of the layers.

In accordance with a first preferred embodiment of the compact multilayer material 1, the internal layer is the mattress comprising the mixed textile fibre and the external layers are equal to each other and are selected from: the PLA layer 3, the hard needled layer 4 of mixed textile fibre, the hemp layer 5, the medium needled layer 6 of mixed textile fibre.

Preferably, the compact multilayer material 1 according to the first preferred embodiment is obtained by the preparation process according to the present invention, wherein the phase C comprises the subphase C1 or C2.

Advantageously, the compact multilayer material 1 in accordance with the first preferred embodiment is particularly suitable for the production of mattress padding, since the external layers promote better durability and washability of the mattress itself, ensuring better consistency and greater resistance over time.

By way of example, in Figures 3-a, 3-b, and 3-c three embodiments of the compact multilayer material 1 of the invention are schematized, in which the internal layer is the mattress 2 comprising the mixed textile fiber, and the external layers are equal and are respectively selected from the PLA layer 3, the hard needled layer 4 of mixed textile fiber, and the hemp layer 5. Each of these three embodiments, represented in Figures 3-a, 3-b, and 3-c, is obtained by means of the preparation process according to the present invention, in which phase C comprises sub-phase C1 or C2.

In accordance with a second preferred embodiment of the compact multilayer material 1, the internal layer is the mattress 2 comprising the mixed textile fibre and the external layers are equal to each other and are the medium needled veil 6 of mixed textile fibre.

Preferably, the compact multilayer material 1 according to the second preferred embodiment is obtained by the process according to the present invention, wherein the step C comprises the substep C4.

Advantageously, the compact multilayer material 1 in accordance with the second preferred embodiment has excellent thermal quality, in terms of insulation, as well as good homogeneity.

According to a third preferred embodiment, the inner layer is the hard needled web 4 of mixed textile fibre and the outer layers are the same and are the mattress 2 comprising the mixed textile fibre.

Preferably, the compact multilayer material 1 according to the third preferred embodiment is obtained by the process according to the present invention, wherein the step C comprises the substep C4.

Advantageously, the compact multilayer material 1 according to the third preferred embodiment has a high mechanical resistance along the external layers, which makes it particularly suitable for the production of mattress padding with high external mechanical resistance.

By way of example, in figure 5-a there is a schematic representation of an embodiment of the compact multilayer material 1 according to the present invention, wherein the internal layer is the mattress 2 comprising the mixed textile fibre and the external layers are the same and are the medium needled web 6 of mixed textile fibre; in figure 5-b there is a schematic representation of an embodiment of the compact multilayer material 1, wherein the internal layer is the hard needled web 4 of mixed textile fibre and the external layers are the same and are the mattress 2 comprising the mixed textile fibre. Each of the embodiments, represented in figures 5-a and 5-b, is obtained by means of the process according to the present invention, wherein the phase C comprises the sub-phase C4.

Preferably, the two outer layers are different from each other and are an upper outer layer and a lower outer layer.

It is worth noting that the compact multilayer material 1 according to the present invention comprising three layers, of which two external layers are different from each other, has an asymmetric three-layer configuration in the distribution of the layers.

Preferably, the upper outer layer is chosen from the PLA veil 3, the hard needled veil 4 of mixed textile fibre, or the hemp veil 5.

Preferably, the lower outer layer is the medium needled veil 6 of mixed textile fibre.

In accordance with a fourth preferred embodiment of the compact multilayer material 1, the upper outer layer is selected from the PLA veil 3, the hard needled veil 4 of mixed textile fiber, or the hemp veil 5, the lower outer layer is the medium needled veil 6 of mixed textile fiber, and the inner layer is the mattress 2 comprising the mixed textile fiber.

Preferably, the compact multilayer material 1 according to the fourth embodiment is obtained by the process according to the present invention, wherein the step C comprises the substep C1, preferably with a needle table 9 which, in use, acts on the side of the upper outer layer.

Advantageously, the compact multilayer material 1 according to the fourth preferred embodiment has different thermal properties along the thickness.

Therefore, advantageously the upper outer layer and the lower outer layer can be chosen with the aim of obtaining one outer layer more efficient than the other from the point of view of thermal performance.

By way of example, in figures 4-a, 4-b, and 4-c three different embodiments of the compact multilayer material 1 according to the present invention are shown, in a 3-layer asymmetric configuration, wherein the internal layer is the mattress 2 comprising the mixed textile fiber, the lower external layer is the medium needled web 6 of mixed textile fiber, and the upper external layer is respectively the PLA web 3, the hard needled web 4 of mixed textile fiber, the hemp web 5. Each of these three embodiments, shown in figures 4-a, 4-b, and 4-c, is obtained by means of the preparation process according to the present invention, wherein the phase C comprises the sub-phase C1, preferably with a needle table 9 which, in use, acts on the side of the upper external layer.

Preferably, the compact multilayer material 1 according to the present invention comprises five layers, of which a central layer, which is the mattress 2 comprising the mixed textile fibre, two intermediate layers, adjacent to the central layer, and two peripheral layers, each adjacent to one of the intermediate layers.

Preferably, the peripheral layers are the same or different from each other.

Preferably, the middle layers are equal to each other.

It is worth noting that the compact multilayer material 1 comprising five layers, of which two peripheral layers are equal to each other and two intermediate layers are equal to each other, has a symmetrical five-layer configuration in the distribution of the layers.

Preferably, the intermediate layers are equal to each other and are chosen from: medium needled veil 6 of mixed textile fibre, hard needled veil 4 of mixed textile fibre, hemp veil 5.

Preferably, the peripheral layers are equal to each other and are chosen from: the PLA veil 3, the hard needled veil 4 of mixed textile fibre, the hemp veil 5, the medium needled veil 6 of mixed textile fibre.

In accordance with a fifth preferred embodiment of the compact multilayer material 1, the central layer is the mattress 2 comprising the mixed textile fiber, the peripheral layers are equal to each other and are selected from the PLA veil 3, the hard needled veil 4 of mixed textile fiber, the hemp veil 5, and the intermediate layers are equal to each other and are the medium needled veil 6 of mixed textile fiber.

Preferably, the compact multilayer material 1 according to the fifth preferred embodiment is obtained by the preparation process according to the present invention, wherein the phase C comprises the subphase C1 or C4.

Advantageously, the compact multilayer material 1 according to the fifth preferred embodiment has a high resistance over time.

Advantageously, the compact multilayer material 1 according to the fifth preferred embodiment, wherein the peripheral layers are equal and are the hard needled web 4 of mixed textile fiber, has a high chemical homogeneity, since all the layers comprise the mixed textile fiber.

Advantageously, the compact multilayer material 1 according to the fifth preferred embodiment, wherein the peripheral layers are equal and are the hemp veil 5, is particularly environmentally friendly.

By way of example, in figures 6-a, 6-b and 6-c three different embodiments of the compact multilayer material 1 of the invention are schematized, in a symmetrical five-layer configuration, in which the central layer is the mattress 2 comprising the mixed textile fibre, the intermediate layers are equal and are both the medium needled layer 6 of mixed textile fibre, and the peripheral layers are equal and are selected respectively from the PLA layer 3, the hard needled layer 4 of mixed textile fibre, the hemp layer 5. Each of these three embodiments, represented in figures 6-a, 6-b and 6-c, is obtained through the preparation process in accordance with the present invention, in which phase C comprises sub-phase C1 or C4.

In accordance with a sixth preferred embodiment of the compact multilayer material 1, the peripheral layers are equal to each other and are the medium needled web 6 of mixed textile fibre, the intermediate layers are equal to each other and are selected from the hard needled web 4 of mixed textile fibre, the hemp web 5, and the central layer is the mattress 2 comprising the mixed textile fibre.

Preferably, the compact multilayer material 1 according to the sixth preferred embodiment is obtained by the preparation process according to the present invention, wherein the phase C comprises the subphase C4.

Advantageously, the compact multilayer material 1 according to the sixth preferred embodiment has excellent thermal insulation, an excellent progression of density and resistance along the thickness, and is particularly suitable for the production of mattresses that are soft and fluffy on the outside and particularly resistant on the inside.

By way of example, figures 8-a and 8-b show schematically two embodiments of the compact multilayer material 1 of the invention, in a symmetrical five-layer configuration, in which the central layer is the mattress 2 comprising the mixed textile fibre, the peripheral layers are equal and are the medium needled layer 6 of mixed textile fibre, and the intermediate layers are equal and are respectively the hard needled layer 4 of mixed textile fibre and the hemp layer 5. Each of these two embodiments, represented in figures 8-a and 8-b, is obtained by means of the preparation process in accordance with the present invention, in which phase C comprises sub-phase C4.

Preferably, the peripheral layers are different from each other and are an upper peripheral layer and a lower peripheral layer.

It is worth noting that the compact multilayer material 1, comprising an upper peripheral layer and a lower peripheral layer, has an asymmetric five-layer configuration in the distribution of the layers.

Preferably, the upper peripheral layer is chosen from the PLA veil 3, the hard needled veil 4 of mixed textile fibre, or the hemp veil 5.

Preferably, the lower peripheral layer is the medium needled veil 6 of mixed textile fibre.

According to a seventh preferred embodiment of the compact multilayer material 1, the upper peripheral layer is selected from the PLA layer 3, the hard needled layer 4 of mixed textile fiber, the hemp layer 5, the lower peripheral layer is the medium needled layer 6 of mixed textile fiber, the intermediate layers are the same and are the medium needled layer 6 of mixed textile fiber, and the central layer is the mattress 2 comprising the mixed textile fiber.

Preferably, the compact multilayer material 1 according to the seventh preferred embodiment is obtained by the process according to the present invention, wherein the step C comprises the substep C4.

By way of example, in figures 7-a, 7-b, and 7-c, three different embodiments of the compact multilayer material of the invention are shown, in an asymmetric five-layer configuration, wherein the central layer is the mattress 2 comprising the mixed textile fibre, the intermediate layers are the medium needled web 6 of mixed textile fibre, the lower peripheral layer is the medium needled web 6 of mixed textile fibre, and the upper peripheral layer is chosen respectively from the PLA web 3, the hard needled web 4 of mixed textile fibre, and the hemp web 5. Each of these three embodiments, shown in figures 7-a, 7-b, and 7-c, is obtained through the preparation process according to the present invention, wherein phase C comprises sub-phase C4.

Thermally insulating padding

A further object of the present invention is a thermally insulating padding 7 comprising the compact multilayer material 1 in accordance with the present invention.

For the purposes of this invention, the term "padding" generally refers to anything used for padding.

By way of example and not limitation, the thermally insulating padding 7 can be used:

- in the clothing field, as padding for jackets, in particular down jackets, coats, gloves and/or hats;

- in the domestic and furnishing sector, as padding for sofas, cushions, mattresses and/or quilts;

- in the construction sector, as insulating padding for walls, roofs and/or floors, improving the energy efficiency of buildings;

- for camping products, such as sleeping bag fillings, mattresses and other camping products useful for warming the body;

- in the packaging industry, as padding to insulate products sensitive to cold during transport, thus promoting their conservation.

Advantageously, given the property of the mixed textile fibre to vary its volume as a function of temperature, the compact multilayer material 1 and, consequently, the thermally insulating padding 7 comprising the compact multilayer material 1 in accordance with the present invention, also present, among others, this same property and the same advantages related to it.

In this regard, by way of example, to better characterize the aforementioned property of the mixed textile fiber to expand its volume as a function of temperature, in figures 9-a and 9-b a thermally insulating padding 7 comprising the compact multilayer material 1 in accordance with the present invention is schematically shown, respectively at a temperature lower than 5°C, in which the thermally insulating padding 7 is in an expanded condition, and at a temperature higher than 10°C, in which the thermally insulating padding 7 is in a resting condition.

In the preferred embodiment, illustrated in figures 9-a and 9-b, the padding 7 comprises a lining 14, preferably made of textile material, which encloses the compact multilayer material 1.

Item of clothing

A further object of the present invention is a garment 8 comprising thermally insulating padding 7 comprising the compact multilayer material 1 according to the present invention.

For the purposes of the present invention, an item of clothing is generically understood to be a garment, or generally what is part of a person's clothing.

Preferably, item of clothing 8 is a jacket, a down jacket, a coat, a glove, a hat, a scarf, a mitten, a bag. Preferably, item of clothing 8 is a down jacket.

Advantageously, given the property of the thermally insulating padding 7 according to the present invention to vary its volume as a function of the temperature, the item of clothing 8 comprising the thermally insulating padding 7 also presents this same property and the same advantages related to it.

By way of example, in figures 10-a and 10-b, a garment 8 comprising the thermally insulating padding 7 comprising the compact multilayer material 1 in accordance with the present invention is schematically shown, respectively at a temperature lower than 5°C, in which the garment 8 is in an expanded condition, and at a temperature higher than 10°C, in which the garment 8 is in a resting condition.

EXAMPLES

By way of example and not limitation, the compositions of some embodiments of the compact multilayer material in accordance with the present invention, in a symmetrical three-layer configuration, are reported below in Table 1.

Table 1: Composition of different samples of compact multilayer material according to the present invention, in a symmetrical three-layer configuration.

Again by way of example and not limitation, the compositions of some embodiments of the compact multilayer material in accordance with the present invention, in an asymmetric three-layer configuration, are reported below in Table 2.

Table 2: Composition of different samples of compact multilayer material according to the present invention, in asymmetric three-layer configuration

Again by way of example and not limitation, the compositions of some embodiments of the compact multilayer material in accordance with the present invention, in a symmetrical five-layer configuration, are reported below in Table 3.

Table 3: ?Composition of different samples of compact multilayer material according to the present invention, in a symmetric five-layer configuration.?

Again by way of example and not limitation, the compositions of some embodiments of the compact multilayer material in accordance with the present invention, in an asymmetric five-layer configuration, are reported below in Table 4.

Table 4: ?Composition of different samples of compact multilayer material according to the present invention, in asymmetric five-layer configuration.?

Claims (9)

1. Compact multilayer material (1) comprising at least three layers, of which at least one layer is a mattress (2) comprising a mixed textile fibre comprising at least two natural fibres, and the remaining at least two layers, in addition to said at least one layer which is the mattress (2) comprising the mixed textile fibre, are independently selected from: a polylactic acid (PLA) layer (3), a hard needled layer (4) of mixed textile fibre, a medium needled layer (6) of mixed textile fibre, the mattress (2) comprising the mixed textile fibre, a hemp layer (5). 2. Compact multilayer material (1) according to claim 1, comprising three layers, of which an internal layer which is the mattress (2) comprising the mixed textile fibre, and two external layers independently selected from the polylactic acid (PLA) veil (3), the hard needled veil (4) of mixed textile fibre, the medium needled veil (6) of mixed textile fibre, the hemp veil (5), or of which an internal layer which is the hard needled veil (4) of mixed textile fibre and two equal external layers which are the mattress (2) comprising the mixed textile fibre. 3. Compact multilayer material (1) according to claim 1, comprising five layers, of which a central layer which is the mattress (2) comprising the mixed textile fibre, two equal intermediate layers selected from the hard needled veil (4) of mixed textile fibre, the medium needled veil (6) of mixed textile fibre, the hemp veil (5), and two peripheral layers independently selected from the PLA veil (3), the hard needled veil (4) of mixed textile fibre, the medium needled veil (6) of mixed textile fibre, the hemp veil (5). 4. Compact multilayer material (1) according to any of claims 1 to 3, wherein the at least two natural fibres are selected from: Asclepias fibre, kapok fibre, balsa fibre, cattail fibre. 5. Compact multilayer material (1) according to any of claims 1 to 4, wherein the mixed textile fibre comprises a carded fibre of polylactic acid (PLA) in an amount between 60 and 90%, preferably equal to 80% by weight with respect to the total weight of the mixed textile fibre (w/w). 6. Process for preparing the compact multilayer material (1) according to any of claims 1 to 5, comprising the following steps: A. prepare at least three layers, of which at least one layer is the mattress (2) comprising the mixed textile fibre; B. overlapping said at least three layers, forming a non-compact multilayer; C. compact the non-compact plywood by needle punching, obtaining the compact multilayer material (1). 7. Process according to claim 6, wherein the remaining at least two layers, in addition to the at least one layer which is the mattress (2) comprising the mixed textile fibre, are independently selected from: the polylactic acid (PLA) veil (3), a mixed textile fibre veil, the mattress (2) comprising the mixed textile fibre, the hemp veil (5). 8. Thermally insulating padding (7) comprising the compact multilayer material (1) according to any of claims 1 to 5. 9. Item of clothing (8) comprising the thermally insulating padding according to claim 8.