Transparent composite nano-fibre based multi-layer textile

Patent metadata

Field	Value
Publication number	US-12458915-B2
Application number	US-202117913354-A
Country	US
Kind code	B2
Filing date	Mar 18, 2021
Priority date	Mar 23, 2020
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A composite multi-layer textile, comprising at least one nanofibre layer with nanofibres with diameters below 100 nm and one support layer with microfibres with diameters below three microns, wherein the layers were produced by electrospinning. The multi-layer textile shows a general transmittance at #=550 nm greater than 60%, which shows improved properties concerning transparency, breathability and robustness. This is achieved in that the at least one nanofibre layer and the support layer are fused, forming solid domains in the multi-layer textile, at closed areas of a pattern used in the production process, wherein the solid domains are separated from each other or connected, showing defined shapes, with regular or irregular spatial distribution, while the fibre morphology of nanofibres of the nanofibre layer and microfibres of support layer is preserved on top of the open areas beside the solid domains, attaining a general transmittance greater than that given by the sum of the individual layers.

First claim

What is claimed is:

1 . A composite multi-layer textile, comprising at least one nanofibre layer with nanofibres with diameters below 100 nm and at least one support layer with microfibres with diameters below five microns,
wherein the layers were produced by an electrospinning process and the multi-layer textile shows an overall transmittance at λ=555 nm greater than 50%, wherein the at least one nanofibre layer and the at least one support layer are fused, forming solid domains in the multi-layer textile, at closed areas of a pattern used in the production process, wherein the solid domains are separated from each other or connected, showing defined shapes, with regular or irregular spatial distribution, while the fibre morphologies of the nanofibres of the at least one nanofibre layer and the microfibres of the at least one support layer are preserved beside the solid domains, attaining an overall transmittance of the entire multi-layer textile greater than the transmittance given by the sum of the individual layers' transmittances.

2 . The composite multi-layer textile according to claim 1 , wherein the multi-layer textile comprises a patterned layer with a pattern of closed and open areas, on a top or a bottom of an individual layer of the multi-layer textile, and the solid domains are formed at contact positions of the at least one nanofibre layer or the at least one support layer and the patterned layer.

3 . The composite multi-layer textile according to claim 1 , wherein the multi-layer textile comprises one nanofibre layer sandwiched between two outer support layers, showing solid domains at a fused position of all three layers.

4 . The composite multi-layer textile according to claim 2 , wherein the patterned layer is sandwiched between two nanofibre layers and two support layers, the patterned layer in direct contact with each of the two nanofibre layers.

5 . The composite multi-layer textile according to claim 2 , wherein the solid domains are formed as contact areas, connecting a layer of the at least one nanofibre layer, a layer of the at least one support layer, and the patterned layer, showing thicknesses between 1 μm and 100 μm.

6 . The composite multi-layer textile according to claim 5 , wherein the solid domains show maximal lateral widths between 10 μm and 100 μm at its widest points.

7 . The composite multi-layer textile according to claim 2 , wherein the solid domains on the multi-layer textile have a value between 30% and 70% of a total surface of the multi-layer textile.

8 . The composite multi-layer textile according to claim 2 , wherein the transverse thickness of the patterned layer varies between 1 μm and 100 μm and the patterned layer is a woven polymeric mesh.

9 . The composite multi-layer textile according to claim 2 , wherein the transverse thickness of the patterned layer varies between 1 μm and 100 μm and is formed by a thermoplastic material with a number of through holes as openings and a lattice-like structure as connection webs, while at least 30% of the total surface of the thermoplastic material is open.

10 . The composite multi-layer textile according to claim 1 , wherein the at least one nanofibre layer comprises chitosan/polycaprolactone nanofibres and the at least one support layer comprises polyester/polyurethane microfibres.

11 . A method for production of an optically transparent multi-layer textile, which shows an overall transmittance at λ=555 nm greater than 50% comprising the steps of:
electrospinning of at least one nanofibre layer and at least one support layer on a belt of a production setup on a patterned collector of an electrospinning apparatus or on a supplied patterned layer/porous substrate layer to form the at least one electrospun nanofibre layer and the at least one electrospun support layer, each of the patterned collector and the supplied patterned layer/porous substrate showing open and closed areas;
transport of the belt with the at least one electrospun nanofibre layer and the at least one electrospun support layer thereon to a hot press or calender;
implementation of a thermo-mechanical treatment step at an elevated temperature higher than room temperature and an elevated pressure of at least 1000N/cm2 for a minimum time interval, wherein the at least one electrospun nanofibre layer and the at least one electrospun support layer are fused at closed areas of the patterned collector or a pattern of the supplied patterned layer/porous substrate layer, forming a multiplicity of solid domains in the multi-layer textile, before
a cooling step is carried out at lowered temperatures and pressures.

12 . The method for production of a transparent multi-layer textile according to claim 11 , wherein the thermo-mechanical treatment step is carried out at temperatures of at least 70° C.

13 . The method according to claim 11 , wherein the minimum time interval is greater than or equal to 10 seconds.

14 . The method according to claim 11 , wherein the patterned collector of the electrospinning apparatus is formed by a metallic mesh or a perforated metal sheet and builds a part of or is integrated in the belt.

15 . The method according to claim 11 , wherein the patterned layer/porous substrate layer is a woven polymeric mesh or formed by a thermoplastic foil with a number of through holes as openings and a lattice-like structure as connection webs.

16 . The method according to claim 11 , wherein after the cooling step, the multi-layer textile is rolled onto a roll.

17 . A method of using a multi-layer textile as part of a facial mask as a medical device and/or as personal protective equipment, including the step of providing the composite multi-layer textile according to claim 1 .

Assignees

• Empa Eidgenoessische Mat & Forschungsanstalt
• Ecole Polytechnique Fed Lausanne Epfl

Inventors

• Barana Davide
• Fortunato Giuseppino
• Guex Anne Géraldine
• Rossi René
• Pelet Thierry
• Schönenberger Klaus
• Sidjanski Sacha
• Baatard Diane

Classifications

• B32B5/266

  next to one or more non-woven fabric layers · CPC title

• D04H1/728

  by electro-spinning {(electro-spinning methods and apparatus D01D5/0007)} · CPC title

• D04H1/558

  in combination with mechanical or physical treatments other than embossing · CPC title

• D04H1/4334

  Polyamides · CPC title

• D01D5/0084 Primary

  Coating by electro-spinning, i.e. the electro-spun fibres are not removed from the collecting device but remain integral with it, e.g. coating of prostheses · CPC title