Natural nonwoven materials

Abstract

There is described a nonwoven material comprising a multilayered stack, the multilayered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre of from about 80 to 100% w/w leaf or stem fibre and from about 1 to 20% w/w of a polymer, wherein the polymer is fusible at a temperature of about 180° C. or less. There is also described a novel method of enzyme degumming leaf and/or stem fibres.

Claims

1. A nonwoven material comprising: a finishing resin layer; and a multilayered stack, the multi-layered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre that is a mixture of; (i) more than 50% w/w of air-laid enzymatically degummed leaf fibre or enzymatically degummed stem fibre or mixtures thereof which are derived from one or more plants of the Bromeliaceae family wherein said leaf or stem fibres or mixtures thereof being degummed at a temperature of about 40° C.; (ii) from about 15 to 20% w/w of a fusible polymer, wherein the polymer is fusible at a temperature of less than 180° C.; wherein one or more of the discrete interconnected layers is associated with the fusible polymer for use in the manufacture of a material; (iii) wherein the multilayered stack is coated with the finishing resin layer and wherein the finishing resin layer and the fusible polymer are different; (iv) calendering the material; and (v) curing the curable material, wherein the cured material is the cured nonwoven material.

2. A nonwoven material according to claim 1 wherein the leaf fibres or stem fibres have a length of from about 2 to 12 cm.

3. A nonwoven material according to claim 1 wherein the fusible material is a resin.

4. A nonwoven material comprising: a finishing resin layer; and a multilayered stack, the multi-layered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre that is a mixture of; (i) from about 80 to 95% w/w of air-laid enzymatically degummed leaf fibre or enzymatically degummed stem fibre or mixtures thereof said leaf or stem fibres or mixtures thereof being degummed at a temperature of about 40° C.; (ii) from about 15 to 20% w/w of a fusible polymer, wherein the polymer is fusible at a temperature of less than 180° C.; wherein one or more of the discrete interconnected layers is associated with the fusible polymer; (iii) wherein the multilayered stack is coated with the finishing resin layer and wherein the finishing resin layer and the fusible polymer are different; and (iv) calendering the material.

5. The material according to claim 4 wherein the material is an artificial leather.

6. The material according to claim 4 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase, hemicellulase, pectinase and cellulase, and mixtures thereof.

7. The material according to claim 4 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof.

8. The material according to claim 4 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase (Biopectinase) or a mixture of polygalacturonase and hemicellulase.

9. The material according to claim 4 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase and hemicellulase.

10. A nonwoven material comprising a finishing resin layer; and a multilayered stack, the multilayered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre which is a mixture of: (i) from about 80 to 95% w/w of air-laid enzymatically degummed leaf fibre or enzymatically degummed stem fibre or mixtures thereof; said leaf or stem fibres or mixtures thereof being degummed at an acidic pH; (ii) from about 5 to 20% w/w of a polymer, wherein the polymer is fusible at a temperature of less than 180° C.; (iii) wherein one or more of the discrete interconnected layers is associated with the fusible polymer; (iv) wherein the multilayered stack is coated with the finishing resin layer and wherein the finishing resin layer and the fusible polymer are different; (v) calendering the material; (vi) curing the curable material; and (vii) wherein the treated material is subjected to tumbling, so that the treated material resembles leather.

11. A nonwoven material comprising: a finishing resin layer; and a multilayered stack, the multilayered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre which is a mixture of: from about 80 to 95% w/w of air-laid enzymatically degummed leaf fibre or enzymatically degummed stem fibre or mixtures thereof; said leaf or stem fibres or mixtures thereof being degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof; (ii) from about 5 to 20% w/w of a fusible polymer, wherein the polymer is fusible at a temperature of less than 180° C.; (iii) wherein one or more of the discrete interconnected layers is associated with the fusible polymer; (iv) wherein the multilayered stack is coated with the finishing resin layer and wherein the finishing resin layer and the fusible polymer are different.

12. A nonwoven material comprising: a finishing resin layer; and a multilayered stack, the multilayered stack comprising discrete interconnected layers, each of the layers, which may be the same or different, comprising a composite fibre which is a mixture of: from about 80 to 95% w/w of air-laid enzymatically degummed leaf fibre or enzymatically degummed stem fibre or mixtures thereof said leaf or stem fibres or mixtures thereof being degummed at a temperature of about 40° C.; (ii) from about 5 to 20% w/w of a fusible polymer, wherein the polymer is fusible at a temperature of less than 180° C.; (iii) wherein one or more of the discrete interconnected layers is associated with the fusible polymer; (iv) wherein the multilayered stack is coated with the finishing resin layer and wherein the finishing resin layer and the fusible polymer are different: (v) calendering and curing the material; and (vi) wherein the treated material is subjected to tumbling, so that the treated material resembles leather.

13. The material according to claim 12 wherein the leaf fibre comprises leaves of one or more plants of the Bromeliaceae family.

14. The material according to claim 12 wherein the leaf fibre comprises a relatively high content of the leaves of Ananas Comosus (Linn), pineapple.

15. The material according to claim 12 wherein the material comprises fibres having a linear mass density of from about 10 to 20 tex.

16. A nonwoven material according to claim 12 wherein the leaf fibres or stem fibres have a length of from about 2 to 12 cm.

17. A nonwoven material according to claim 12 wherein the fusible material is a resin.

18. The material according to claim 12 wherein the material is an artificial leather.

19. The material according to claim 12 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase, hemicellulase, pectinase and cellulase, and mixtures thereof.

20. The material according to claim 12 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof.

21. The material according to claim 12 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase (Biopectinase) or a mixture of polygalacturonase and hemicellulase.

22. The material according to claim 12 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase and hemicellulase.

23. The material according to claim 1 wherein the material is an artificial leather.

24. The material according to claim 1 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase, hemicellulase, pectinase and cellulase, and mixtures thereof.

25. The material according to claim 1 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof.

26. The material according to claim 1 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase (Biopectinase) or a mixture of polygalacturonase and hemicellulase.

27. The material according to claim 1 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase and hemicellulase.

28. The material according to claim 4 wherein the leaf fibre comprises leaves of one or more plants of the Bromeliaceae family.

29. The material according to claim 4 wherein the leaf fibre comprises a relatively high content of the leaves of Ananas Comosus (Linn), pineapple.

30. The material according to claim 4 wherein the material comprises fibres having a linear mass density of from about 10 to 20 tex.

31. A nonwoven material according to claim 4 wherein the leaf fibres or stem fibres have a length of from about 2 to 12 cm.

32. A nonwoven material according to claim 4 wherein the fusible material is a resin.

33. The material according to claim 10 wherein the leaf fibre comprises leaves of one or more plants of the Bromeliaceae family.

34. The material according to claim 10 wherein the leaf fibre comprises a relatively high content of the leaves of Ananas Comosus (Linn), pineapple.

35. The material according to claim 10 wherein the material comprises fibres having a linear mass density of from about 10 to 20 tex.

36. A nonwoven material according to claim 10 wherein the leaf fibres or stem fibres have a length of from about 2 to 12 cm.

37. A nonwoven material according to claim 10 wherein the fusible material is a resin.

38. The material according to claim 10 wherein the material is an artificial leather.

39. The material according to claim 10 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase, hemicellulase, pectinase and cellulase, and mixtures thereof.

40. The material according to claim 10 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof.

41. The material according to claim 10 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase (Biopectinase) or a mixture of polygalacturonase and hemicellulase.

42. The material according to claim 10 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase and hemicellulase.

43. A nonwoven material according to claim 11 wherein the leaf fibres or stem fibres have a length of from about 2 to 12 cm.

44. A nonwoven material according to claim 11 wherein the fusible material is a resin.

45. The material according to claim 11 wherein the material is an artificial leather.

46. The material according to claim 11 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase, hemicellulase, pectinase and cellulase, and mixtures thereof.

47. The material according to claim 11 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with one or more enzymes selected from the group consisting of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase, and mixtures thereof.

48. The material according to claim 11 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase, pectinesterase, pectinic lyase and hemicellulase (Biopectinase) or a mixture of polygalacturonase and hemicellulase.

49. The material according to claim 11 wherein the degummed leaf fibre or degummed stem fibre or mixtures thereof are enzymatically degummed with a mixture of polygalacturonase and hemicellulase.

50. The material according to claim 1 wherein the leaf fibre comprises leaves of one or more plants of the Bromeliaceae family.

51. The material according to claim 1 wherein the leaf fibre comprises a relatively high content of the leaves of Ananas Comosus (Linn), pineapple.

52. The material according to claim 1 wherein the material comprises fibres having a linear mass density of from about 10 to 20 tex.

Description

(1) The invention will now be described by way of example only and with reference to the accompanying figures in which FIG. 1 is a schematic representation of plasma treatment;

(2) FIG. 1 is a representation of Ugolini equipment and solution containers;

(3) FIGS. 3a to e are photographs of the dried fibres; and

(4) FIGS. 4 to 9 are microimages of the fibres after degumming.

(5) All percentages are given by weight, unless stated otherwise.

DETAILED DISCLOSURE

(6) The main component of the material is leaf or stem fibres, especially pineapple leaf fibre (PALF). PALF is a vegetable based fibre extracted from the leaves of the plant Ananas Comosus (Linn) from the Bromeliaceae family by decorticating either manually or using mechanical methods. The main chemical constituents of pineapple leaf fibres are cellulose (75-90%), lignin (2-5%) and ash (1.1%).

(7) The physical and mechanical properties of certain leaf fibres, e.g. pineapple, abaca and banana are shown below in Tables II, III and IV.

(8) TABLE-US-00002 TABLE II PINEAPPLE ABACA BANANA PROPERTIES RAW TREATED RAW TREATED RAW TREATED 1. Tensile strength, kg/gm/m 24.97 16.33 40.80 31.58 20.90 25.71 2. Fineness (Denier) 21.54 17.45 98.50 22.70 48.80 43.05 3. Residual Gum, % 35.04 7.69 28.70 6.40 41.90 10.29 4. Moisture Content, % 9.31 7.86 10.80 8.24 9.70 9.79 5. Hot Water Extractives 5.52 3.64 2.86 1.02 16.45 11.49 6. Cold Water Extractives 5.36 0.65 1.45 0.47 14.21 8.27 7. Alcol-Ben Extractives, % 1.95 1.33 1.70 0.35 1.70 1.40 8. Total cellulose, % 75.44 95.97 68.50 86.11 56.44 89.98 9. Alpha Cellulose, % 56.09 87.33 54.50 63.27 49.53 54.23 10. Lignin, % 4.31 2.50 8.70 3.23 13.22 3.86 11. Ultimate Cell Length(mm) 5.00 — 3.00 — 3.50 — 12. Ultimate Cell Diameter(mm-3) 8.00 — 20.00 — 25.00 —

(9) TABLE-US-00003 TABLE III Physical and Mechanical Properties of Pineapple Leaf Fibre (PALF) PROPERTIES VALUE Density (g/cm3) 1526 Softening Point (C.) 104 Tensile Strength (MPa) 170 Young's Modulus (MPa) 6260 Specific Modulus (MPa) 4070 Elongation at Break (%) 3 Moisture Regain (%) 12

(10) TABLE-US-00004 TABLE IV Chemical Constituents % Composition Total cellulose 87.56 Alpha-Cellulose 78.11 Hemicellulose 9.45 Lignin 4.78 (From SITRA-University Technology Malaysia) American Standard Testing & Materials International (ASTM) 2003

(11) The superior mechanical properties of pineapple leaf fibres are associated with their high cellulose content. They are relatively inexpensive, and abundantly available. PALF is a strong fibre with silky appearance. The outer, long leaves are preferred. PALF are usually left on the ground after the pineapple fruit is harvested. Other leaf or stem fibres that can be used are sisal, banana leaf fibre, hemp and flax fibre.

(12) PALF is extracted from pineapple leaves, once the pineapple fruit has been cut from the plant. The leaves are decorticated where leaves are crushed and beaten by a rotating wheel set with blunt knives, so that only fibres remain. The fibre is then dried, brushed and collected in hunks. The length of PALF at this stage has an average of 70/100 cm long.

(13) The fibres are ‘cleaned’ by removing unwanted gum/tissue to form separate fibres. For chemical degumming the conventional process consisted in an aqueous solution of sodium hydroxide. More precisely, 2% o.w.f has been dissolved in distilled water. A liquor ratio 1:25 has been used. PALF samples have been treated in the chemical formulation during 10 to 40 minutes, e.g. 30 minutes, at 60° C. to 90° C., e.g. 80° C. Then, treated samples have been rinsed in distilled water and have been dried at room temperature.

(14) The fibres are washed and rinsed and then loaded into a vertical vacuum tank, with chemicals dissolved in water and added to the tank. This degumming liquor is aqueous solution of sodium hydroxide and ammonia. Soaking takes from 2 to 6 hours depending on how much gum should be retained by the fibres. Softening agents are then added, then the fibres are rinsed in water and sun dried.

(15) The above procedure is a standard chemical process for degumming fibres. Alternatively, the degumming procedure may comprise enzyme degumming as described herein.

(16) In the present invention, for the purpose of forming a nonwoven material, the optimum length of the fibres was found to be about 2-12 cm, e.g. 4-10 cm, especially about 6 cm to provide good overall mechanical properties in the finished material while allowing easy handling and processing. Fibres are cut to the desired length by a standard cutting machine.

(17) From about 80 to 100% w/w of the nonwoven mesh is made up of PALF. The rest, from about 0 to 20% w/w, is made up of a fusible polymer, e.g. a polyester, fibres, approximately 5 cm in length. This is used as the melting fibre or binder in the nonwoven mesh. A mixture of the above cut fibres are air laid with an “Air-Laying Machine” suitable for the production of air laid nonwovens. A mat is made by stacking two or more air laid layers, total weight of from about 100 to about 2000 gpsm, e.g. 400 gpsm. This is achieved on a standard air laying machine in which fibres are fed into the machine and carded; this is followed by air laying. The layers are mechanically bonded, e.g. by needle punching.

(18) Needle punched nonwovens are created by mechanically orienting and interlocking the fibres of a spun bonded or carded web. This mechanical interlocking is achieved with thousands of barbed felting needles repeatedly passing into and out of the web.

(19) As mentioned above, about 80 to 100% w/w of the nonwoven mesh is made up of PALF, with the any balance being a fusible polymer, e.g. a polyester, which is used as a melting fibre or binder in the nonwoven mesh. The resulting nonwoven has a density of from about 100 to about 2000 gpsm, e.g. from about 200 to 400 g/m.sup.2 and is from about 0.5 mm to about 15 mm thick, e.g. from about 2.5 mm to about 3 mm thick. It is, for example, wound into rolls 2.15 m wide by 50 m long.

(20) The nonwoven mesh or mat having a weight of for example, from about 100 to about 400 g/m.sup.2, was finished to form an artificial material using one or more of the following process steps:

(21) The nonwoven materials are advantageous because, inter alia, they take colour very well and are compatible with the resins and finishings used. In addition it is biodegradable and does not use toxic and polluting tanning chemicals and so is more socially responsible than leather. It can be used as a substitute material in making, for example, fashion accessories, furnishings, clothing, home interiors panels, bags, luggage, the car industry, shoes, etc.

(22) 1. Heat Set of Nonwoven Mat:

(23) The compaction is useful in obtaining grater basis weight or GPSM (grams per square meter) and density, more bulk, higher strength and improves the adhesive properties.

(24) The mat was pressed at a temperature of 90° C. to 200° C. for 1 to 30 seconds, e.g. 120° C. for 30 seconds, at a pressure of 1 to 4 kg/cm.sup.2. At this temperature, the fusible polymer, e.g. a polyester, melted and fused the PALF fibres together.

(25) 2. Laminated with Mesh:

(26) A co-polymer, polymer and/or bio-polymer mesh is applied on one or two sides of nonwoven PALF by the application of temperature, e.g. from about 90° C. to about 200° C., and pressure, e.g. from about 1 to about 4 kg/cm.sup.2. The mesh is designed not to peel away from the nonwoven fabric.

(27) This process is optional according to the properties that are desired to give to the material. The properties that it provides not are essential to obtain the final material/fabric.

(28) 3. Chemical Treatments

(29) PALF nonwovens are finished with various chemicals in order to obtain the specific property depending on end-use. Different chemical finishes are discussed below.

(30) Four methods or treatments are described and valid to obtain different finishing in the PALF non woven

(31) 3.1 First Way. by Transfer Paper

(32) A transfer paper coated with a finishing resin composition:

(33) Was used to transfer the resin onto the surface of the non woven mat using a calendaring machine, with a thick blade to apply the composition. The paper was not removed at this stage. The composition penetrated into the nonwoven mat.

Composition 3.1.1

(34) TABLE-US-00005 100% water based acrylic, soft (standard), e.g. 90% to 97% polyurethane PKA Antifoaming agent, e.g. BG-Print ASF - BGH 0.1% to 0.3% Thickener e.g. Cresaclear TE 1.2% to 1.8% Isocyanate Bayhydur XP 2655 - Bayer 1.6% to 2.3% Other auxiliary chemicals, e.g. extra finishes, thickener, 0% to 4% pigment, metallic powder, etc.

(35) The resulting coated mat was then dried and cured in a press under heat and pressure (with the transfer paper in situ) at a temperature of 90° C. to 150° C., and a pressure: of 1 kg/cm.sup.2 to 4 kg/cm.sup.2, for 1 to 30 seconds, e.g. 120° C. at 1.5 kg/cm.sup.2 to 2 kg/cm.sup.2 for 10 seconds or 150° C. for 60 seconds.

Composition 3.1.2

(36) TABLE-US-00006 100% water based acrylic, soft (standard) 96.43% antifoaming agent (BG-Print ASF″ - 0.19% BGH Spain) Thickener (″Cresaclear TE″ - Cresa) 1.45% Isocyanate (Bayhydur XP 2655 - Bayer) 1.93%
3.2 Second Way, by Immersion or Wet Processes

(37) Dyeing of PALF nonwoven; dyes and pigments can be added as a concentrate. These processes are referred to as producer colouration or melt dyeing.

(38) 3.2.1 Resin and Dyeing by Foulard Machine

(39) Resin was applied to the mat on a Foulard (2 horizontal rollers with pressure: laboratory foulard). The composition penetrated into the mat.

(40) A composition with Formulation A

(41) TABLE-US-00007 Water 50% to 90% Antifoaming agent, e.g. BG-Print ASF - BGH 0.1% to 0.4% 100% water based soft acrylic, polyurethane, latex,  9% to 30% silicone or bio-reins (standard) Antimigrating agent, e.g. Migravit TCP 2.5% to 4.0%

(42) The mat was dried and polymerised at a temperature of 120 to 160° C. for 1 to 5 minutes, e.g. 120° C. for 2 minutes, depending upon the resin morphology.

(43) 3.2.2 Resin and Dyeing Machine

(44) This process will be carried out with only one step in the same bath of dyeing. This method has it as purpose to use the resin in the process of dyeing in one step.

(45) The prepared solution will add colour to the PALF nonwoven and besides will provide with the finished resin.

(46) TABLE-US-00008 Water 50% to 90% Antifoaming agent, e.g. BG-Print ASF - BGH 0.1% to 0.4% 100% water based soft acrylic, polyurethane, latex,  9% to 30% silicone or bio-reins (standard), e.g. polyurethane PKA Antimigrating agent, e.g. Migravit TPC 2.5% to 4.0% Synthetic or organic pigment, e.g. blue S-RRR  1% to 10% Sodium sulphate and carbonate sodium 0% to 8%

(47) The mat was dried and polymerized at a temperature of 120 to 160° C. for 1-5 minutes. The temperature will depend upon the resin morphology, and the need to eliminate water.

(48) 3.3 Third Way, Surface Coating Treatment

(49) This methodology is based on the accomplishment of a cover or coating that provides resin and colour to the PALF nonwoven mat. After this treatment the nonwoven mat remains compacted and is coloured.

(50) This treatment is carried out using a coating process. This coating can be obtained through adequate equipment or machinery, e.g. screen printing, calendaring, etc., to cover the PALF nonwoven and the viscosity of the formulation employed. The used formulation 3.3.1:

(51) TABLE-US-00009 100% water based soft acrylic, polyurethane, latex, 85% to 95% silicone or bio-reins (standard) Antifoaming agent, e.g. BG-Print ASF-BGH 0.1% to 0.4% Thickener, e.g. Cresaclear TE  1% to 10% Isocyanate, e.g. Bayhydur XP 2655-Bayer   1% to 2.5% Synthetic or organic colour pigment  0% to 10%

(52) The mat was then dried at a temperature of 150 to 160° C. for 1 to 5 minutes, e.g. 150° C. for 1 minute.

(53) This process of coating and polymerising can be repeated several times until the correct consistency is achieved for the present application.

(54) 3.4 Fourth Way, Spraying Method

(55) This process will be carried out if it is necessary as a continuation of the processes described previously. 3.2.1 and 3.2

(56) The treatment provides colour, the surface/side is treated by spraying. The purpose is to obtain two colours differentiated on both sides of the nonwoven. More than one coating may be applied. The treatment is carried out applying a liquid formulation that provides the colour.

(57) TABLE-US-00010 Water 60% to 80% 100% water based soft acrylic, polyurethane, latex, 10% to 30% silicone or bio-reins (standard) Isocyanate 0 to 5%, e.g. 1% to 2.5% Synthetic or organic colour pigment  1% to 10%

(58) The nonwoven mat was then dried at a temperature of 120 to 160° C. for 1 to 5 minute, e.g. 150° C. for 1 minute.

4. Finishing Processes

(59) Different finishes may be applied to the nonwoven mat. Some methods are used to improve the surface characteristics of the PALF nonwoven mat. Nonwovens are finished with various chemicals in order to obtain the specific property depending on end-use. Different chemical finishes are discussed below.

(60) 4.1 Water Repellents

(61) Water repellent finishes are a type of barrier, which function to lower the critical surface tension of the fibre surface. To be most effective it is important that the fibres are treated evenly on all surfaces to give the lowest critical surface tension possible. Water repellence can be achieved with a variety of chemical finishes such as waxes, wax dispersions, melamine wax extenders, chrome complexes, silicones, and fluorochemicals. The finishes require curing to develop the best repellence.

(62) 4.2 Plasma Treatment

(63) Also a Plasma treatment may be used to confer several properties, e.g. extra strength, surface finishing, etc. on the surface of nonwoven mat.

(64) Plasma treatment will be used to confer several properties of finished on the surface of nonwoven mat. Plasma treatment comprises treatment with an ionised gas (e.g. from a glow-discharge) with an essentially equal density of positive and negative charges. The ionised gas can exist over an extremely wide range of temperatures and pressures. According to requirements the materials to be processed (PALF nonwoven), will be treated for seconds or some minutes with plasma. Essentially four main effects can be obtained depending on the treatment conditions. The cleaning effect is mostly combined with charges in the wettability and the surface texture. This leads for example to increase of quality printing, painting, dye-uptake, adhesion and so forth. Generation of radicals. The presence of free radicals induces secondary reactions like cross linking. Furthermore, graft polymerization can be carried out as well as reaction with oxygen to generate hydrophilic surface. Plasma polymerization. It enables to deposition of solid polymeric materials with desired properties onto the substrates. Increase of microroughness. This effects, for example, an anti-pilling finishing of wool.

(65) The advantage of such a treatment is that the modification is restricted to the uppermost layers of the substrate, thus not affecting the overall desirable bulk properties of the substrate adherent

(66) 4.3 Leather Finish

(67) The methods used are continuous and usually involve one or several pairs of rollers operating under pressure.

(68) The calenders are common in nonwoven finishing. The embossing effect is used to obtain special effects such as leather graining or texturised leather like.

(69) A calendaring machine, with a thick blade was used to apply a commercially available leather finishing, e.g. a standard formulation. The nonwoven mat was then dried by a mechanical tumbling at a temperature of 150° C. to 160° C. for 1 to 5 minutes.

(70) A calendaring machine, with a thick blade was used to apply a commercially available leather finishing formulation Astacin Finish PFM TF from BASF

(71) The mat was then dried at a temperature of 160° C. for 1 minute.

(72) 4.4 Thermoplastic Binders, Resins and Emulsion Polymers

(73) Binders and resins are widely used in the finishing of nonwovens to add strength, control stiffness, add moldability or pleatability, provide durable flame retardants, colour, reduce linting and control shrinkage. They soften when exposed to heat and return to their original state when cooled and, hence, can be set. Emulsion polymers are also called latexes. The common binders, resins and polymers include acrylics, PVC, polyacrylic acid, urethanes, starch, vinyl acetate etc.

(74) 4.5. Tumbling (Mechanical Finishes)

(75) This process provides softness and handling into the nonwoven fabric after finishing

(76) The process reduces the rigidity of the PALF nonwoven as a result the previous treatments.

(77) This finish mainly provides smoothness and a tactile feel.

(78) These are mechanical processes that can be carried out with different methodologies and equipment: Vacuum tumbling machine, cylinder or calender tumbling machine and/or hand tumbling, to provide the desired tactile feel and softness.

(79) 5. Degumming

(80) 5.1. Exhaust Process Description

(81) Samples were processed in Ugolini exhaustion equipment. During treatment, the fibres are exhausted in the solution at a velocity of 40 rpm and determined temperature and time (according to supplier information). The fibres are placed inside a small container of 300 ml capacity. The container is completely filled with the enzymatic solution so the fibres can be well impregnated into the bath. The Ugolini equipment is described in FIG. 2.

(82) 5.2. Enzymatic Processes Description

(83) Various processes have been realized in order to determine the best enzymatic formulation. Temperature and pH parameters have been kept constant according to the technical information of the supplier. Enzyme formulation, enzyme concentration, and process time parameters have been varied.

(84) Five enzymes formulations have been developed. Biopectinase and polygalacturonase enzymes will be used alone. Then, polygalacturonase will be associated to hemicellulase and cellulase enzymes to observe their effect on the degumming of the fibre. Biopectinase M01 will be associated to cellulase for the same reasons. However, Biopectinase will not be associated to hemicellulase as it is already composed of this material. The following table 1 presents the different materials used in this study and table 2 presents different combination of enzymes made:

(85) TABLE-US-00011 TABLE 1 Materials description Activity Product Composition (U/ml) Supplier Biopectinase M01 Polygalacturonase, 60 000 Biocon Española pectinesterase, pectinic lyase and hemicellulase. Polygalacturonase Pectinase 11 000 +/− Biocon Española 5% Xylanase Hemicellulase 36 000 − Biocon Española 5% + 10% Biosoft L Cellulase 50 000 Biocon Española

(86) TABLE-US-00012 TABLE 2 Enzymes combination description Reference Enzyme combination Description E1 Biopectinase M01 Enzyme complex E2 Biopectinase M01 + Biosoft L Enzyme complex + cellulase E3 Polygalacturonase Pectinase E4 Polygalacturonase + Xylanase Pectinase + hemicellulase E5 Polyglacturonase + Xylanase + Pectinase + hemicellulase + Biosoft L cellulase

(87) Temperature and pH values of each bath have been determined according to the optimum temperature and pH of each enzyme. For example, best activity of polygalacturonase, xylanase and Biosoft L is located at pH 3-5.5, pH 4-7 and acidic pH, respectively. So, optimum pH formulation has been fixed to 5. So, Biopectinase M01 temperature and pH applied values were 40° C. and 4.25, respectively, when Polygalacturonase temperature and pH applied values were 50° C. and 5, respectively.

(88) The following table 3 present the formulation of the enzymatic baths. Liquor ratio has been kept constant to 1:40.

(89) TABLE-US-00013 TABLE 3 Baths formulation Process Activity Bath Enzyme temperature Process time Sample reference Polygalacturonase number reference Enzyme concentration o.w.f. (*) pH (° C.) (hours) (**) (U/ml) Bath no 1 E1 14.6% biopectinase 4.25 40 2, 4 and 6 B1 2, B1 4, B1 6 5.5 Bath no 2 E1 36.7% biopectinase 4.25 40 2, 4 and 6 B2 2, B2 4, B2 6 13.8 Bath no 3 E2 14.6% biopectinase + 1% cellulase 4.25 40 2, 4 and 6 B3 2, B3 4, B3 6 5.5 Bath no 4 E2 36.7% biopectinase + 1% cellulase 4.25 40 2, 4 and 6 B4 2, B4 4, B4 6 13.8 Bath no 5 E3 2% polygalacturonase 5 50 2, 4 and 6 B5 2, B5 4, B5 6 5.5 Bath no 6 E3 5% polygalacturonase 5 50 2, 4 and 6 B6 2, B6 4, B6 6 13.8 Bath no 7 E4 2% polygalacturonase + 1% xylanase 5 50 2, 4 and 6 B7 2, B7 4, B7 6 5.5 Bath no 8 E4 5% polygalacturonase + 1% xylanase 5 50 2, 4 and 6 B8 2, B8 4, B8 6 13.8 Bath no 9 E5 2% polygalacturonase + 1% xylanase + 5 50 2, 4 and 6 B9 2, B9 4, B9 6 5.5 1% cellulase Bath no 10 E5 5% polygalacturonase + 1% xylanase + 5 50 2, 4 and 6 B10 2, B104, B10 6 13.8 1% cellulase

(90) It was observed that the enzymatic bath was transparent before treatment and yellowish after treatment. This means that the fibre has been cleaned from its pectic material which is present in the bath. In the case of the conventional process, the colour of the bath was more intense (it turned to orange) but the fibres were less cleaned, rougher and have yellow colour. Also, we observe short (4 mm) parts of chemically treated fibres in the bath after rinsing. This last observation shows that fibres have been damaged by the chemical process.

(91) 5.3. Enzymatic Process Optimization

(92) As we observed in the visual analysis, most of best results have been obtained at the longest time process, i.e. at 6 hours. So, the process time will be increased in the optimisation of the processes. Also, best results have been obtained at 5% o.w.f of enzyme. Enzyme concentration hasn't been increased as these products have an optimum activity at a determined concentration and this activity could decrease after 5%.

(93) Process optimization consisted of increasing the process time from 6 hours to 8 hours. Moreover, all enzymes have been used at 5% o.w.f. Process temperature has been adjusted to 45° C. which is optimum temperature for most enzyme activity. The following table 4 presents the optimised baths formulation.

(94) TABLE-US-00014 TABLE 4 Optimised baths formulation Activity Enzyme Solution Process Process Sample Polygalacturonase Bath number reference Enzyme concentration (o.w.f) pH temperature time reference (U/ml) Bath no 11 E1 36.7% biopectinase 4.25 45° C. 8 hours B11 8 16.5 Bath no 12 E2 36.7% biopectinase + 1% 4.25 45° C. 8 hours B12 8 16.5 cellulase Bath no 13 E4 5% polygalacturonase + 1% 5 45° C. 8 hours B13 8 16.5 hemicellulase Bath no 14 E5 5% polygalacturonase + 1% 5 45° C. 8 hours B14 8 16.5 hemicellulase + 1% cellulase
Process Observations:

(95) It was observed that bath n°12 and bath n°14 present short broken fibres inside. Bath n°14 present more quantities of broken fibres than bath n°12. So, after analysing the composition of baths n°12 and 14, we can conclude that cellulase enzyme is responsible for the breaking of fibres. Moreover, the presence of hemicellulase increases the degradation of the fibres.

(96) Samples Presentation:

(97) After drying of the samples, they have been separated manually for their characterization. Indeed, the fibres have rough appearance after drying but once they are opened they become softer than before. At industrial stage, the manual opening should be done by means of an opener (conventional textile equipment). The optimised samples are represented in FIGS. 3 a to e.

(98) As can be seen in the figures, non treated and conventional samples have yellowish colour. Enzymatic treatment improved the aspect of the fibres giving them a white colour. It was observed on last figure that polygalacturonase, hemicellulase and cellulase treated fibres (B14 8) was more damaged than the others. All fibres (conventional and enzymatic process) present a rough touch after treatment. Indeed, the treatments eliminate the waxes and other components on the surface of the fibres which provide them a soft touch. After opening process, fibres are softer than before. No softening agent has been used for environment issues.

(99) No-treated, conventionally treated and enzymatic treated fibres have been characterized by measuring their length, their tensile strength and by observing them in a microscope. The obtained results are resented in this part.

(100) 5.4. Fibre Length

(101) Length of the fibres has been determined using standard UNE 40152:1984. Samples have been conditioned 24 hours at 20° C.±2° C. and 65%±5% h.r. (relative humidity). The conditions of the measurements are presented in the following table 5:

(102) TABLE-US-00015 TABLE 5 Conditions of the essay Essay atmosphere: 22° C. (20° C. ± 2° C.)-60% (65% ± 5% h.r.) Number of measurements between 100-300 (for each sample): Previous treatment: Not applicable

(103) The following table 6 present the results obtained for the each sample:

(104) TABLE-US-00016 TABLE 6 Length measurements results Average Coefficient of Maximum length Sample length (cm) variation (%) (cm) Not treated 75 6.7 85 B11 8 62 22.2 80 B12 8 52 20.0 70 B13 8 69 15.2 90 B14 8 41 15.0 55 Conventional 41 32.2 70
Observations:

(105) No treated sample has the highest fibres' length. After treatment fibres' length of all samples has been reduced. We observed that sample B14 8 and conventionally treated fibres present the highest decrease of length. This result could be due to the aggressive action of chemicals (NaOH) and cellulase enzyme combined with hemicellulase. Sample B12 8, also treated with cellulase, present short fibres' length. After no treated sample, sample which has higher fibre length is sample B13 8, corresponding to fibres treated with polygalacturonase and hemicellulase.

(106) 5.5. Fibre Fineness

(107) Fibres' fineness and title have been determined using the microscope ZEISS Axioplan, a camera and the programme of analysis DeltaPix 300. The test consists of extracting the shortest fibres from the sample, observe them with the microscope with transmitted light and take a picture of them at ×25. Then, the program measures the fineness and the title of about 150 fibres.

(108) The following table 7 present the obtained fineness and title of the fibres.

(109) TABLE-US-00017 TABLE 7 Fineness measurements results Average Minimum Maximum fineness fineness fineness Average fibre Sample (μm) (μm) (μm) CV (%) title (dTex) Not treated 75 21 393 59.8 68 B11 8 80 29 597 84.6 78 B12 8 63 25 165 38.9 48 B13 8 71 30 176 41.1 60 B14 8 71 18 224 44.8 61 Conventional 60 28 150 33.3 43
Observation:

(110) Table 7 shows that results present a high coefficient of variation value. This is due to irregularities in the fineness of the fibres. For example, sample B11 8 has a higher diameter than not treated sample. This could be due to the union produced between the fibres after drying. As mentioned before, in part 0, the pectic material which links the fibres together has been hydrolysed but fibres keep being united. This physical union could be eliminated by means of an opening machine.

(111) Conventional sample present the best results and the lowest coefficient of variation. These results show that conventional process is more efficient in for separating the fibres although it could damage them. After conventional sample, best results have been obtained with sample B12 8 treated with biopectinase and cellulase enzymes.

(112) 5.6. Microscopic Inspection

(113) Microscopic inspection has been determined using Microscope ZEISS Axioplan and the program DeltaPix 300. Longitudinal sections of each sample have been made and they have been observed through a microscope with an image magnification of ×12.5. Samples have been observed with transmitted light. The following images have been taken of each sample:

(114) Not Treated Sample

(115) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres depicted in FIG. 4.

(116) Conventional Sample

(117) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres. In this case, we observed highest quantity of detached fibrils depicted in FIG. 5.

(118) Sample B11 8

(119) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres depicted in FIG. 6.

(120) Sample B12 8

(121) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres. In this case, we observed less quantity of detached fibrils than in the previous cases. We also observed that the fineness and the shape of those fibres were more regular than other fibres depicted in FIG. 7.

(122) Sample B13 8

(123) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres depicted in FIG. 8.

(124) Sample B14 8

(125) Micro images of more significant zones of the sample. We observe the presence of fibrils detached from the fibres. In this case, we observed less quantity of detached fibrils than in the previous cases depicted in FIG. 9.

(126) Observation:

(127) During the microscopic observation, we observed that the main difference between the samples is the damage represented by the presence of filament detached from the fibres. The formation of these fibrils can be due to phenomena of abrasion or chemical action. Not treated sample also present fibrils, but conventional sample present more quantity of fibrils than before treatment. So, conventional treatment increases the degradation of the fibres and the formation of fibrils.

(128) The degradation of samples B13 8, B11 8 and not treated is similar.

(129) Samples B12 8 and B14 8 present less quantity of fibrils than other samples. Indeed, we observe high quantity of fibrils in the bath after treatment. So, we can conclude that cellulose is responsible for the elimination of the fibrils on the surface of the fibres. More precisely, cellulase polish the fibre. Moreover, cellulase is commonly used for the elimination of fibrils on the surface of cotton fabrics.

(130) 5.7. Fibre Tensile Strength

(131) Tensile strength of the samples has been measured by means of INSTRON 5544 equipment, according to standard UNE EN ISO 5079:1996. The temperature and the humidity conditions during the test were 20.9° C. and 63%, respectively.

(132) The results are presented in the following table 8:

(133) TABLE-US-00018 TABLE 8 Samples tensile strength and elongation at break CV of CV of Tensile Strength strength Extension at extension at strength (cN) (%) break (%) break (%) (cN/Tex) Not treated 111.56 44.72 3.62 51.44 16.41 Conventional 154.76 21.82 4.21 36.09 35.99 B11 8 127.39 32.24 3.45 21.52 16.33 B12 8 47.93 50.61 1.42 87.42 9.99 B13 8 82.85 32.62 3.88 69.08 13.81 B14 8 34.39 27.35 1.98 22.60 5.64
Observation:

(134) Conventional sample presents best results, followed by not treated and B11 8 samples. Not treated sample should have the highest tensile strength as any additive products likely to weaken the fibre have been applied. However, conventional sample obtained better results than not treated sample. We suppose that the high tensile strength of conventional sample is due to the presence of fibrils which may adhere to the fibre increasing the coefficient of friction and thus adding more strength to the fibre (as we saw in microscopic inspection, fibrils are more present in this sample). Also, tensile strength of conventional fibre could have been increased by the presence of NaOH. Indeed, during the mercerisation process of cotton, the addition of more than 23% of NaOH can increase the tensile strength of the fibre.

(135) As we can see in the table, samples which obtain lowest tensile strength are samples B12 8 and B14 8 due to the presence of cellulase enzyme in their treatment bath. Also, we can make a correlation between results obtain in microscopic inspection and obtained in tensile strength measurement. Indeed, samples with lower quantity of filaments are samples which showed lower tensile strength, i.e. Samples treated with cellulase enzyme.

(136) After conventional sample best results are obtained with B11 8 and B13 8 samples, treated with biopectinase and polygalacturonase+hemicellulase, respectively.

CONCLUSION

(137) Length measurements showed that chemical treatment and cellulase enzymes damage the fibres. Sample B13 8 (polygalacturonase & hemicellulase) have the longest fibres, right after no treated sample. Third best sample is B11 8 with a length of 62 cm.

(138) Fineness measurements showed that best results have been obtained with conventional process. Fineness of conventional sample could be due to the defibrillation of the fibre. More precisely, the diameter of the fibre is lower when the fibrils are taken out. Right after conventional process, best results have been obtained with samples B12 8 (48 dTex) and B13 8 (60 dTex).

(139) Microscopic inspection showed that conventional process damages the fibres increasing the number of superficial fibrils. On the other part, cellulase enzyme is responsible for the elimination of the fibrils of the fibres.

(140) Tensile strength values show that best results have been obtained with conventional process. However, best enzymatic process has been obtained with samples B11 8 and B13 8. Results also showed that cellulase enzyme have an influence on the tensile strength of the fibre.