Fibres

Abstract

According to the present disclosure there is provided a high-quality fibre produced from potato haulm material, the fibre comprising one or more elementary fibres. There is also provided a method of producing such a fibre, an apparatus for performing the method, and a fabric comprising the fibre.

Description

[0001] Fibres

[0002] Technical field

[0003] This disclosure relates to fibres comprising one or more elementary fibres produced from the haulm of a potato plant, and to a method for producing the fibres.

[0004] Background

[0005] Cotton, polyester and other fibres such as wool, silk and viscose make up the majority of the world's textile production. These fibres are widely used due to their beneficial physical properties, however the manufacture of each of these fibre types has a significant environmental impact. Fashion is the second most polluting industry in the world (after oil), contributing to much of the world's fresh water and natural resource consumption. This is because natural plant-based fibres such as cotton must be grown, using significant agricultural resources including growing area and water. Animal based fibres such as wool also require agricultural resources in order to farm the animals from which they are harvested. Synthetic polyester fibres also have a significant environmental impact, as they are typically produced using petrochemical starting products, require large amounts of water for coolant during production, and can produce powerful greenhouse gases such as nitrous oxide as a by-product. As the world population continues to increase this problem is only set to worsen.

[0006] More sustainable approaches to producing fibres have been investigated. In recent times, there has been an increased drive for the use of recycled plastics in the manufacture of man-made fibres. However, concerns remain regarding the long-term disposal of such plastic fibres, since they are typically not bio-degradable. Furthermore, plastic fibres (including those made from recycled source material) are a major source of microplastic pollution due to fragmentation during wear and cleaning.

[0007] MMCF (Man Made Cellulosic Fibre), is a type of semi-synthetic fibre produced by pulping lignocellulosic material. In order to produce such fibres, cellulose in the feedstock is broken down into a cellulose solution and then reconstructed in a process called "wet spinning". The cellulose solution typically contains cellulose in the form of microfibrils and nanofibrils, which may be up to around lOOOnm in length (Dias et al., Journal of Molecular Liquids 312 (2020) 113450). In some examples, the cellulose may be so broken down that it comprises loose cellulose chains in suspension.

[0008] However, the production of MMCF often requires the use of toxic chemicals. Furthermore, the feedstock used to produce MMCF is primarily sourced from trees. The production of MMCF alone accounts for around 200 million trees cut down each year. Furthermore, MMCF are typically very absorbent to water, which can present significant problems when such fibres are used in clothing that may become wet, or even damp. Also, MMCF fibres can become fragile when wet.

[0009] Plants other than cotton have been considered as fibre sources that could potentially be grown and processed using less agricultural resources. However, issues remain with the quality and usefulness of fibres generated from such sources. For example, hemp fibres are significantly thicker and rougher than fibres such as cotton, leading to difficulties producing acceptable clothing materials, and the need for bespoke machinery for preparing fabric using such fibres. Fibres derived from jute, sisal and coir are also typically very rough and stiff making them unacceptable for use in most clothing. Furthermore, the production costs of these types of fibres are typically significantly higher than the production costs of more typically used fibres such as cotton.

[0010] There exists, therefore, a need to produce high-quality soft fibres from a sustainable and environmentally friendly source.

[0011] Summary of invention

[0012] According to a first aspect of the present disclosure, there is provided a fibre from a potato haulm, wherein the fibre comprises at least one elementary fibre. Such fibres are thin, strong, and durable. The fibres also have properties similar to existing textile fibres such as cotton, allowing for the fibres according to the first aspect to be easily processed using existing methods and equipment.

[0013] In an embodiment, at least one of the at least one elementary fibres is at least 40pm in length. Fibres comprising one or more elementary fibres of at least this length exhibit improved mechanical properties. In an embodiment, each of the one or more elementary fibres is at least 40pm in length. Fibres comprising elementary fibres that are each of at least this length exhibit improved mechanical properties.

[0014] In an embodiment, at least one of the one or more elementary fibres has a diameter of 350 micrometres or less. Such fibres exhibit good mechanical properties and are suitable for the production of high quality spun yarn.

[0015] In an embodiment, the fibre has a length of at least 10 millimetres. This is beneficial for use in the production of high quality spun yarn.

[0016] According to a second aspect, there is provided a material comprising a fibre according to any embodiment of the first aspect. Such materials will exhibit improved mechanical properties, due to the inclusion of fibres according to the first aspect. The inclusion of fibres according to the first aspect also provide ecological benefits, by reducing the use of alternate less sustainable fibres.

[0017] In an embodiment, the material is a textile. Fibres according to the first aspect are thin, strong, and durable, and thus well suited to the production of textiles for use in various applications, including in apparel.

[0018] In an embodiment, the material further comprises a non-potato fibre that is selected from a group comprising: natural fibres, plant-based fibres, synthetic fibres and semisynthetic fibres. A material comprising fibres according to the first aspect and other non-potato fibres allows for variation in the properties of material to be achieved, thereby broadening the applications for which the material can be used.

[0019] In an embodiment, the non-potato fibre is selected from a group comprising: cotton, hemp, nettle, manmade cellulosics (MMCF) and polyester. Each of these listed options offer particular properties, which can beneficially be added to a material comprising fibres according to the first aspect.

[0020] In an embodiment, there is provided a material, wherein: the material is a fibre reinforced composite comprising one or more reinforcing fibres; and at least one of the one or more reinforcing fibres comprise a fibre according to the first aspect. Fibres according to the first aspect are thin, strong, and durable. Thus, fibres incorporated into a composite material as part of the fibre reinforcement will improve the mechanical properties of the composite material. According to a third aspect, there is provided a method of producing a fibre according to the first aspect from a potato haulm.

[0021] In an embodiment, the method further comprises a step of subjecting the potato haulm to retting. Retting breaks down bonding material within the potato haulm, thereby aiding the extraction of fibres from the potato haulm material.

[0022] In an embodiment, the step of subjecting a potato haulm to retting involves one or more of: enzymatic retting, microbial retting, water retting, chemical retting, and dew retting. Each of these retting techniques offer particular benefits in the extraction of fibres from the potato haulm material.

[0023] In an embodiment, enzymatic retting is performed using an enzyme selected from a group comprising: pectinase, cellulase, laccase and hemicellulase. Each of these enzyme types act to break down bonding material within the potato haulm, thereby aiding the extraction of fibres from the potato haulm material.

[0024] In an embodiment, the enzymatic retting is performed using an enzyme selected from a group comprising: pectate lyase, pectinesterase (endo)polygalacturonase, protopectinase, exopolygalacturonase, polygalacturonase, laccase, xylanase, exocellulase, endocellulase, endogenous xylanase, exogenous xylanase, exoxylosidase, arabinfuranosidase, endogalactanase, exogalactosidase, exoglucanase, glucanase, lignin peroxidase, cellobiase, protease, mannanase, alpha-amylase, phytase, lysozyme, bromelain, keratinase, pectinase, mannanse, beta-glucosidase, trypsin, levansucrase and lipase. Each of these enzymes act to break down bonding material within the potato haulm, thereby aiding the extraction of fibres from the potato haulm material.

[0025] In an embodiment, the enzymatic retting is performed using an enzyme produced by a bacteria, the bacteria being selected from a group comprising: Bacillus subtilis, Bacillus Paralicheniformis, Dickeya chrysanthemi, Erwinia, Arthobacter, Pseodomonas, Streptomyces, Bacillus felsineus, Granulobacter pectinovorum, Bacillus asterosporous, Pythium ultimum, Bacillus macerans, Bacillus fiesineus, Bacillus polymyxa and Bacillus thuringiensis. Each of these bacteria types produce enzymes that act to break down bonding material within the potato haulm, thereby aiding the extraction of fibres from the potato haulm material. In an embodiment, the enzymatic retting is performed using an enzyme produced by a fungus, the fungus being selected from a group comprising: Penicillium glaucum, Penicillium italicum, Aspergillus niger and Aspergillus oryzae. Each of these fungi types produce enzymes that act to break down bonding material within the potato haulm, thereby aiding the extraction of fibres from the potato haulm material.

[0026] In an embodiment, the method further comprises a step of dehydrating the potato haulm after subjecting the potato haulm to retting. Dehydrating improves the extraction of fibres from the potato haulm material.

[0027] In an embodiment, the method further comprises a step of receiving pre-treated potato haulm. Pre-treating the potato haulm material helps to prepare the potato haulm for subsequent extraction and / or break down various parts of the haulm material, to aid in the extraction of the fibres.

[0028] In an embodiment, the method further comprises a step of pre-treating the potato haulm. Pre-treating the potato haulm material helps to prepare the potato haulm for subsequent extraction and / or break down various parts of the haulm material, to aid in the extraction of the fibres.

[0029] In an embodiment, pre-treating the potato haulm comprises at least one of: heat treatment, crimping, exposure to electrical discharge, steaming, blanching, steam explosion, chemical treatment, ultrasound, dehydrating, heating, microwaving, boiling and steaming. Each of these pre-treatment steps help to prepare the potato haulm for subsequent extraction and / or break down various parts of the haulm material, to aid in the extraction of the fibres.

[0030] In an embodiment, the method further comprises a step of mechanical separation. Mechanical separation improves the extraction of fibres, by physically separating the fibres and / or fibre bundles.

[0031] In an embodiment, the method further comprises a step of degumming. Degumming beneficially helps to release extracted fibres from one another, resulting in cleaner fibres.

[0032] In an embodiment, the method further comprising a step of refining, Refining beneficially helps to separate, clean and align the extracted fibres. Brief description of the drawings

[0033] One or more embodiments of the present disclosure will now be described by way of example only, with reference to the accompanying drawings, in which:

[0034] Figure 1 illustrates the composition of a typical Dicotyledon plant stem, with various components labelled;

[0035] Figure 2 illustrates example steps of a method for extracting a fibre comprising one or more elementary fibres from the haulm of a potato plant, according to the present disclosure;

[0036] Figure 3 illustrates example steps of an alternative method for extracting a fibre comprising one or more elementary fibres from the haulm of a potato plant, according to the present disclosure; and

[0037] Figure 4 illustrates example steps of a further alternative method for extracting a fibre comprising one or more elementary fibres from the haulm of a potato plant, according to the present disclosure.

[0038] Detailed description

[0039] According to the present disclosure, there is provided a fibre produced from a potato haulm, wherein the fibre comprises at least one elementary fibre. The term "elementary fibre" according to the present disclosure refers to a single phloem fibre. In some examples, the term "elementary fibre" may additionally or alternatively be referred to as one or more of a "phloem", "phloem fibre", "skin fibre", or "bast fibre". Elementary fibres are located within the phloem-containing bast region of a plant. In potato plants, elementary fibres are located within the phloem-containing region of the potato haulm, and are typically bonded together into bundles of elementary fibres. There is also provided a material comprising a fibre extracted from a potato haulm.

[0040] According to the present disclosure, there is also provided a method for extracting high quality fibres from the haulm of a potato plant. In some examples, the method may involve the use of retting, which in some examples may include a step of enzymatic retting. In other examples, a step of retting may not be involved, with a pre-treatment step being used as an alternative in order to allow for fibres comprising one or more elementary fibres to be extracted from the potato haulm. The term "haulm" according to the present disclosure refers to the above-ground portion of a plant, and more specifically to the above-ground portion of a potato plant. This may incorporate the stalk and / or the stem of the potato plant. In some examples, only the stalk or only the stem may be used in the fibre producing process.

[0041] As discussed in more detail below, by comprising one or more elementary fibres, the fibres according to the present disclosure are thin, strong and durable. The properties of the fibres produced according to the disclosed method make them suitable for processing into apparel textiles and, more specially, for woven and knit garments. The fibre properties may also allow for processing using the same equipment already widely used to process cotton fibres, without significant (or, indeed, any) modification of the equipment. The properties of the fibres produced according to the disclosed method also make them suitable for use in a wide range of further applications, such as fibre reinforcement in fibre reinforced composite materials.

[0042] According to the present disclosure, there is provided a method for producing a fibre, such as a spinnable fibre, comprising one or more elementary fibres, from a potato haulm. In some examples, this method may involve receiving pre-treated potato haulm material. In other examples, pre-treatment may be performed on potato haulm material. In some examples, the method may involve retting the material using an appropriate retting process. In some examples, the retting process may involve the use of an enzyme. In further examples, the method may include mechanical separation, degumming, and / or refining.

[0043] As explained in more detail below, the method discussed in the present disclosure allows fibres comprising one or more elementary fibres to be extracted from the potato haulm material, for use in the production of high quality fibres.

[0044] According to the present disclosure, fibres comprising one or more elementary fibres may be extracted from potato haulm material as individual elementary fibres or as bundles of elementary fibres. Extracted elementary fibres and / or elementary fibre bundles may be referred to as such, or may simply be referred to as "fibres". Thus, the term "fibre" used herein may refer to a single elementary fibre, to a bundle of fibres comprising one or more elementary fibres, and / or to a spinnable fibre comprising one or more elementary fibres. Figure 1 illustrates an example of a section of plant stem 100 from a Dicotyledon plant, such as a potato plant. The plant stem 100 has a stem 101 comprising a woody section 102 and a bast section 103. The woody section 102 comprises the pith and the xylem sections of the stem 101. The bast section 103 comprises bast fibre bundles 104. In some examples, the bast fibre bundles 104 may have a diameter of at least 20 pm. The bast fibre bundles 104 comprise bundles of individual elementary fibres 105. In some examples, the elementary fibres 105 may have a diameter of around 10-350 pm. An elementary fibre 105 comprises microfibrils 106. In some examples, microfibrils 106 may have a diameter of around 4-100 nm. Microfibrils comprise chains of cellulose 107.

[0045] Figure 2 illustrates an example of a process 200 incorporating a method that could be used to extract fibres from potato haulm material, suitable for use in various applications. This process involves a number of steps that should be considered merely optional features of an example process, and are not all necessary to implement the inventive method of the present disclosure.

[0046] The process may include a first step 201 of pre-treating the potato haulms. Pretreatment may help to prepare the potato haulm for subsequent extraction and / or break down various parts of the haulm material, to aid in the extraction of the fibres. Pre-treatment may, for example, reduce the amount of material bonding the fibres together in the haulm. In examples where retting is used, as described in more detail below, pre-treatment may thereby reduce the amount of retting needed to make the fibres extractable.

[0047] In some examples, pre-treatment may include one or more of: heat treatment, dehydration, crimping, exposure to electrical discharge, microwaving, steaming, boiling, blanching, steam explosion, chemical treatment, and ultrasound. Each of these different pre-treatment steps may help to break down different portions of the haulm material.

[0048] In some examples, pre-treatment may result in a decrease in the overall mass of the potato haulms. The mass loss may be, for example, due to the breakdown of non- cellulosic material in the potato haulms. This may reduce the bonding between the fibres in the haulm material. In some examples, the non-cellulosic material may comprise hemicellulose. In some examples, pre-treatment may alternatively, or additionally, break down the epidermis layer. This step may be beneficial in improving the extraction of fibres from the potato haulms. In some examples, pre-treatment may improve subsequent method steps.

[0049] In examples where retting is performed (including enzymatic retting), pre-treatment may allow for the retting agents (such as enzymes and / or chemicals) to more easily access the pectin-containing portions of the haulm material. This in turn may improve the speed and / or efficiency of the retting step.

[0050] In an example, heat treatment may involve heating the potato haulms in a dry atmosphere, in order to break down the hemicellulose material in the haulm material. In some examples, this may result in a mass loss of between 40% and 55% of the haulm material following pre-treatment. In some examples, the potato haulms may be heated to at least 260 degrees centigrade.

[0051] In another example, boiling may involve immersing the potato haulms in boiling water for a sufficient amount of time to cause breakdown of some of the non-cellulosic material. In an example, a boiling time of 225 minutes may result in a mass loss of approximately 40% of the haulm material following pre-treatment.

[0052] In another example, microwaving may involve subjecting the potato haulms to microwave radiation. In an example, the potato haulms may be soaked in water before being subjected to microwave radiation. Soaking the potato haulms may help the microwave radiation to be absorbed by the potato haulms, for example by increasing the water content of the potato haulms. In an example, subjecting soaked potato haulms to microwave radiation may result in a mass loss of between 20% and 40%.

[0053] In a further example, crimping may involve physically crushing and / or hammering the haulm material. This may result in the breakdown of some of the non-cellulosic material in the potato haulms.

[0054] In a second step 202, the potato haulm material is subjected to retting, in order to break down the bonding between the fibres and / or fibre bundles within the potato haulm, thereby to aid in the extraction of the fibres from the potato haulm material. In some examples, this step may involve enzymatic retting, although other retting methods may alternatively, or additionally, be employed. The fibres are typically bonded within the phloem-containing region of the potato haulm. In some examples, one or more fibres are extracted from the phloem. In some examples, the phloem comprises the fibres to be extracted from the haulm material. In some examples, each fibre may be a section of the phloem that has been extracted from the haulm material.

[0055] Retting may act to break down the middle lamella of the haulm material, which bond the fibres together within the potato haulm material. The middle lamella material comprises pectin, which may be broken down during the retting process.

[0056] In some examples, the retting step may involve enzymatic retting. This may be performed using a pectinolytic enzyme, which breaks down the pectin in order to allow the extraction of the fibres.

[0057] In some examples, enzymatic retting involves applying the retting enzymes directly to the potato haulm material. In some examples, the enzymes may be suspended in a liquid and the liquid may be applied to the haulm material; this may involve spraying the liquid on to the haulm material, or at least partially submerging / immersing the haulm material in the liquid.

[0058] In some examples, enzymes may additionally, or alternatively, be applied to the potato haulm material through the use of microorganisms. In some examples, the microorganisms may comprise bacteria and / or fungi. In such examples, enzyme generating bacteria and / or fungi may be applied to the potato haulm material; the bacteria and / or fungi then produce the retting enzymes in order for the enzymatic retting to take place. In such examples, the bacteria and / or fungi may be suspended in a liquid and the liquid may be applied to the potato haulm material; this may involve spraying the liquid on to the haulm material, or at least partially submerging the haulm material in the liquid.

[0059] In some examples, a combination of retting enzymes and bacteria that produce retting enzymes may be used in the retting process.

[0060] In some examples, the retting step may use an enzyme selected from a group comprising: pectinase, cellulase, laccase and hemicellulase. Each of these types of enzyme breaks down part of the bonding material that bonds the fibres within the haulm material. One or more of these enzymes may be used in order to help break down this bonding material. In some examples, one or more of these enzyme types may be used directly. In other examples, bacterial may be used to produce one or more of these enzyme types. In some examples, an enzyme used during the retting step may be selected from a group comprising: pectate lyase, pectinesterase (endo)polygalacturonase, protopectinase, exopolygalacturonase, polygalacturonase, laccase, xylanase, exocellulase, endocellulase, endogenous xylanase, exogenous xylanase, exoxylosidase, arabinfuranosidase, endogalactanase, exogalactosidase, exoglucanase, glucanase, lignin peroxidase, cellobiase, protease, mannanase, alpha-amylase, phytase, lysozyme, bromelain, keratinase, pectinase, mannanse, beta-glucosidase, trypsin, levansucrase and lipase. Each of these enzymes are known to be effective in breaking down part of the bonding material that bonds together fibres in the haulm material. In some examples, one of these enzymes may be used in isolation. In other examples, two or more enzymes may be used in combination.

[0061] In some examples, an enzyme used during the retting step may be produced using a bacteria selected from a group comprising: Bacillus subtilis, Bacillus Paralicheniformis, Dickeya chrysanthemi, Erwinia, Arthobacter, Pseodomonas, Streptomyces, Bacillus felsineus, Granulobacter pectinovorum, Bacillus asterosporous, Pythium ultimum, Bacillus macerans, Bacillus fiesineus, Bacillus polymyxa and Bacillus thuringiensis. Each of these bacteria have been shown to produce an enzyme known to be effective in breaking down part of the bonding material that bonds together fibres in the haulm material. In some examples, one of these bacteria may be used in isolation to produce enzymes for the enzymatic retting process. In other examples, two or more bacteria may be used in combination. In some examples, the bacteria may be applied directly to the haulm material. In other examples, the bacteria may first be used to produce enzymes and then subsequently the produced enzymes may be applied to the haulm material (without the presence of the bacteria).

[0062] In some examples, an enzyme used during the retting step may be produced using a fungus selected from a group comprising: Penicillium glaucum, Penicillium italicum, Aspergillus niger and Aspergillus oryzae. Each of these fungi have been shown to produce an enzyme known to be effective in breaking down part of the bonding material that bonds together fibres in the haulm material. In some examples, one of these fungi may be used in isolation to produce enzymes for the enzymatic retting process. In other examples, two or more fungi may be used in combination. In some examples, the fungi may be applied directly to the haulm material. In other examples, the fungi may first be used to produce enzymes and then subsequently the produced enzymes may be applied to the haulm material (without the presence of the bacteria). In some examples, the above-described enzymes, bacteria and fungi may be used in any combination in order to perform the enzymatic retting of the haulm material.

[0063] In some examples, alternative retting methods may alternatively, or additionally, be used. Examples include water retting, dew retting, microbial retting, and chemical retting.

[0064] Chemical retting involves the use of chemicals to assist with breaking down the bonding material within the haulm material, in order to allow the fibres to be extracted. In some examples, chemical retting may involve the use of one or more chemicals selected from a group comprising: hydrogen peroxide, sodium hydroxide, sodium chloride, ethylenediaminetetraacetic (EDTA), sodium bicarbonate, aminopolycarboxylic acids, glacial acetic acid, tartrine, chitosan, citric acid, alkylglucoside, potassium sulfate, sorbitol, glycerol, cysteine, sodium oxalate, bentonite, maleic anhydride, polyacrylic acid, polyhydroxyacrylic acid, sodium lauryl sulfate, sodium tripolyphosphate, tween 20, erythritol, hydroxypropionic acid, sodium citrate, potassium sorbate, attapulgite clay, magnesium sulfate, ethanol and calcium hydroxide. Each of these chemicals has been shown to assist in breaking down at least part of the bonding material of the haulm material.

[0065] Water retting may involve immersing potato haulm material in water for up to 2 weeks. In some examples, natural water sources such as a stream or a lake may be used.

[0066] Dew retting may involve exposing potato haulm material to naturally occurring dew for an extended period of time, for example for around a month.

[0067] Microbial retting may involve exposing potato haulm material to a liquid suspension that also contains microorganisms. This may be achieved, for example, by immersing potato haulm material in such a liquid suspension, or by spraying such a liquid suspension on to potato haulm material. The microorganisms produce retting agents, which may include, for example, enzymes. Examples of such enzyme-producing microorganisms are discussed above in relation to enzymatic retting.

[0068] In a third step 203, mechanical separation may be used to separate the fibres from the unwanted portion of the haulm material. In some examples, the fibres may be contained within fibrous bundles (which may also be referred to as "fibre bundles" or "elementary fibre bundles"), which are separated from the other portions of the haulm material. The other, unwanted, portion of the haulm material may comprise the shiv (the xylem-containing woody core of the haulm material, also referred to as the "shiv") and the epidermis. Typically, mechanical separation is performed using a decorticator, or is performed by hand.

[0069] In a fourth step 204, a first refining of the fibres may be performed. The first refining is a process in which fibre bundles are mechanically pulled into individual fibres and / or microbundles. The first refining step may involve the use of, for example, ultrasonication and / or carding. Ultrasonication is a process wherein ultrasonic waves (i.e., sound waves with a frequency of at least 20 kHz) are used to agitate the fibres and / or fibrous bundles in order to help separate and align them. Carding is a mechanical process that disentangles (and in some examples, cleans and / or intermixes) the fibres and / or fibrous bundles; this may be performed manually using hand tools or by a machine.

[0070] In a fifth step 205, degumming may be performed. In some examples, the fibres and / or microbundles produced by a refining step (or a mechanical separation step, if no refining step is performed) may retain some bonding material between fibres. Such bonding material may be, for example, pectin and / or lignin. In order to improve the quality of the fibres produced, a degumming step may be performed in order to break down at least some of this remaining bonding material. Degumming may involve, for example, enzymes, enzyme-producing bacteria, enzyme-producing fungi, chemicals, and / or mechanical force. The degumming step may involve any of the enzymes, enzyme-producing bacteria, an enzyme-producing fungi described above in relation to enzymatic retting (described in relation to the second step 202 illustrated in figure 2).

[0071] In some examples, degumming may additionally, or alternatively, involve the use of chemicals to break down at least some of the remaining bonding material. Chemicals for use in the degumming step may be selected from a group comprising: hydrogen peroxide, sodium hydroxide, sodium chloride, ethylenediaminetetraacetic (EDTA), sodium bicarbonate, aminopolycarboxylic acids, glacial acetic acid, tartrine, chitosan, citric acid, alkylglucoside, potassium sulfate, sorbitol, glycerol, cysteine, sodium oxalate, bentonite, maleic anhydride, polyacrylic acid, polyhydroxyacrylic acid, sodium lauryl sulfate, sodium tripolyphosphate, tween 20, erythritol, hydroxypropionic acid, sodium citrate, potassium sorbate, attapulgite clay, magnesium sulfate, ethanol and calcium hydroxide.

[0072] In some examples of degumming, fibrous bundles are hydrolysed enzymatically to break down the "gums" (pectins, lignins, hemicelluloses, etc...). The goal of degumming is to release fibres from each other and obtain cleaner fibres. In some examples, the degumming step may involve one or more of:

[0073] - using a pectinase solution to breakdown the gums; using mechanical pre-treatments; using mechanical pre-treatments with microwaves and / or ultrasound, optionally in the enzymatic solution; and using chemical chelators such as EDTA, oxalic acid and turmeric.

[0074] In some examples, the performance of the degumming step may be quantified by measuring the mass loss during the degumming step. In some examples, a degumming step involving an ultrasound pre-treatment step may give particularly advantageous results, with a measured mass loss of approximately 48%. A degumming step without pre-treatment may only achieve a mass loss of approximately 40%. In some examples, the addition of a chemical chelator may further improve the performance of the degumming step.

[0075] In some examples, any of the third 203, fourth 204 and fifth 205 steps may be repeated any number of times, in order to further separate and refine the fibres.

[0076] In some examples, pre-treatment may be performed before the degumming step 205. This pre-treatment may include one or more of: heat treatment, dehydration, crimping, exposure to electrical discharge, microwaving, steaming, boiling, blanching, steam explosion, chemical treatment, and ultrasound. Each of these different pre-treatment steps may help to break down different portions of bonding material between fibres and / or fibre bundles, thereby reducing the amount of material bonding the fibres and / or fibre bundles together. By performing pre-treatment, the efficiency of the degumming step 205 may be increased. Where enzymatic degumming is performed, for example, pre-treatment may reduce the amount of enzymes required in order to perform the degumming step 205.

[0077] In a sixth step 206, a second refining step may be performed. The second refining step may involve aligning the fibres in order to prepare them for processing into apparel textiles. As with the first refining step, in some examples the second refining step may be performed using ultrasonication and / or carding. Figure 3 illustrates an example of a process 300 incorporating a method that could be used to extract fibres from potato haulm material. The process 300 involves an example combination of method steps that do not involve a retting step.

[0078] In a first step 301, pre-treatment is performed on the potato haulm material. After pre-treatment, a second step 302 of mechanical separation is performed. In this example, the pre-treatment step allows for mechanical separation to be performed in order to extract fibres without the need for a retting step.

[0079] In a third step 303, degumming is then performed. In this example process, a step of retting is not performed. A degumming step 303 is therefore performed in order to help release the extracted fibres from one another, resulting in cleaner fibres. As described in more detail in relation to figure 2, in some examples a pre-treatment step may be performed before the degumming step.

[0080] A fourth step 304 of refining may then be performed. As discussed above in relation to the first illustrated process 200, the refining step may help to align the fibres to aid further processing.

[0081] Figure 4 illustrates an example of a process 400 incorporating a method that could be used to extract fibres from potato haulm material, suitable for use in the production of high quality fibres. The process 400 involves an example combination of method steps that do not involve a pre-treatment or degumming step.

[0082] In a first step 401, retting is performed on the potato haulm material. After retting, a second step 402 of mechanical separation is performed. In this example, the retting step allows for mechanical separation to be performed in order to extract fibres from the potato haulm material, without the need for pre-treatment.

[0083] A third step 403 of refining may then be performed. As discussed above in relation to the first 200 and second 300 illustrated processes, the refining step may help to align the fibres to aid further processing.

[0084] As illustrated in the processes shown figures 3 and 4, in some examples at least one of retting and degumming is performed. Each of these steps involves the use of enzymes, microbes, and / or chemicals in order to help break down pectin material from between the fibres. By performing at least one of these steps, cleaner and better separated fibres may be produced. Such fibres are typically more valuable, since they can be used to produce higher quality fibre based materials.

[0085] According to the present disclosure, there is provided an apparatus suitable for performing any of the previously discussed method steps. In some examples, one or more of the method steps may be performed by separate apparatuses.

[0086] In some examples, a fibre according to the present disclosure comprises one or more elementary fibres that are at least 40 pm in length. Elementary fibres of at least this length may be beneficial in the production of fibres for use in applications such as fibre reinforcement in composites.

[0087] In some examples, a fibre according to the present disclosure comprises one or more elementary fibres that are at least 3mm in length. In some examples, one or more elementary fibres are at least 5mm in length. In some examples, one or more elementary fibres are at least 10mm in length. Such elementary fibres may be easily spun into high quality fibres in order to produce yarn, for use in applications such as textiles. In some examples, elementary fibres of at least 3mm may be beneficial in the production of higher quality yarn. In some examples yarn incorporating a fibre produced according to the present disclosure may exhibit an increase in tensile strength with increasing fibre length.

[0088] In examples where yarn is produced by blending fibres produced according to the present disclosure with other materials such as cotton, increasing fibre length may allow for an increased blend percentage (i.e., a yarn with a higher proportion of the fibre produced according to the present disclosure). In some examples, increasing fibre length may allow for other materials such as cotton to be substituted completely.

[0089] In some examples, a fibre according to the present disclosure comprises elementary fibres that are no more than 50mm in length. In some examples, the elementary fibres are no more than 40mm in length. In some examples, the elementary fibres are no more than 35mm in length. This may beneficially result in the elementary fibres having a comparable length to typical cotton fibres, thereby improving the ease with which fibres produced according to the present disclosure can be blended with (or substituted for) cotton fibres. In some examples, fibres with a length close to that of cotton fibres can be blended at higher percentages with cotton fibres in a combined material (such as a combined spun yarn). Further beneficially, limiting the elementary fibres to the above described lengths may improve the ease of processing using spinning and weaving machinery. In some examples, elementary fibres that are longer than these lengths may be cut down such that they do not exceed the above described lengths, such a process may be referred to as "cottonisation".

[0090] Fibres according to the present disclosure that have a minimum length as discussed above can be processed in a similar way to cotton, and other widely used fibres. This is very beneficial, as it should allow for the fibres to be processed into apparel textiles using existing equipment designed for use with cotton and synthetic fibres such as polyester.

[0091] In some examples, a fibre according to the present disclosure comprising one or more elementary fibres has a diameter of 350 microns or less. In some examples, the fibre may have a diameter of 60 microns or less. In some examples, the fibre may have a diameter of 30 microns or less. In some examples, the fibre may have a diameter of 20 microns or less. A fibre according to the present disclosure will typically have a diameter of no less than 8 microns. The diameter of fibres according to the present disclosure are very similar to that of cotton. This may be beneficial in allowing for the fibres to be processed into apparel textiles using existing equipment designed for use with widely used fibres, such as cotton. Furthermore, the fibre properties should allow for the production of high-quality apparel textiles with similar visual and tactile properties to existing cotton and polyester based apparel fabrics. These properties of the fibres produced according to the present method are significant improvements over other plant-based fibres, which typically cannot be produced with a similarly low diameter, and are typically too stiff and rough to produce a high quality textile suitable for use in garments.

[0092] In some examples, a fibre according to the present disclosure that comprises one or more elementary fibres, has a length of at least 15 millimetres. This may allow for the fibres to be spun using standard machinery, designed for use with other materials such as cotton. In some examples, the fibres may be at least 70 millimetres long. In some examples, the fibres may be significantly longer than 70 millimetres, and may be substantially the same length as the potato haulm from which they are extracted.

[0093] In some examples, a fibre according to the present disclosure, that comprises one or more elementary fibres, may have a cellulose content of at least 30%, and in some examples at least 60%. Higher cellulose content may be beneficial in some applications. A cellulose content of 60% or higher may be beneficial for use in some applications, such as apparel textiles. In some examples, a fibre according to the present disclosure may be combined with fibres from one or more alternative sources, such as plant-based fibres, synthetic fibres or semi-synthetic fibres. By blending the fibre with fibres produced from other sources, a wider variety of material properties may be obtainable. Furthermore, the cost of production of a textile comprising the produced fibres may be reduced by incorporating a fibre from one or more other sources.

[0094] In some examples, a fibre according to the present disclosure that comprises one or more elementary fibres may be used in the production of products other than apparel textiles. In some examples, fibres according to the present disclosure that comprise one or more elementary fibres may be used in the production of any of the following: rigid materials, including sustainable composite materials for use in combination with, or as an alternative for, fibreglass and carbon fibre;

[0095] - automotive components, including interior rigid and semi-rigid panels;

[0096] - artificial leather, including in combination with polymer-based materials such as polyurethane;

[0097] - non-woven materials such as paper alternatives, personal protective equipment (PPE), thermal insulation.

[0098] A fibre according to the present disclosure (and the method according to the present disclosure used to produce such fibres) uses potato haulm as a source material. This is particularly advantageous from an environmental perspective as the potato haulm is presently considered a genuine waste material. This means that there is presently no known use for this portion of the plant; it cannot be used as animal feed as it contains toxins that may be harmful to animals, and cannot be composted to provide material for growing other plants due to the risk of proliferating potato-plant related diseases, such as potato blight.

[0099] In some examples, a fibre comprising one or more elementary fibres may be extracted from a potato haulm by retting the potato haulm using any suitable retting method. The retting method may involve any of: enzymatic retting, microbial retting, water retting, chemical retting and dew retting. Any of these retting methods may be used in isolation, in any combination and in any order.

[0100] Dew retting may be performed according to any suitable method. In some examples, the potato haulm may be propped up against a structure (a purpose-built structure, or an existing structure such as a fence), or may be formed into a self-supporting structure, for example by tying the ends of several potato haulms together to form a cone-like structure. In other examples, the potato haulms may be laid on a floor. In examples where the potato haulms are laid on the floor, it may be necessary to turn the haulms periodically to ensure even retting.

[0101] Once the potato haulms have been appropriately arranged for the chosen dew retting technique, the potato haulms are left outside to allow the retting process to take place. In such examples, naturally occurring microorganisms perform the retting process. In order for outdoor dew retting to take place, particular environmental conditions are needed.

[0102] Dew retting may be beneficial because the process requires minimal additional resources, such as energy and water. Furthermore, there is little consumable cost incurred since the process occurs naturally once the potato haulms have been prepared and arranged appropriately. Dew retting also allows for good scalability, and may be quicker and easier to perform at large volume than other techniques.

[0103] Table 1 - mechanical and physical properties of fibres produced according to the present disclosure and comparative known examples Table 1 illustrates the physical and mechanical properties of four example fibres produced according to the present disclosure (Examples 1-4 in Table 1). Table 1 also illustrates measured values for cotton and hemp fibres.

[0104] As illustrated in table 1, the physical and mechanical properties of fibres according to the present disclosure (Examples 1-4) have similar values to those of cotton. This is advantageous as it may allow for the fibres according to the present disclosure to more easily be blended with, and / or substituted for, cotton fibres in the production of textile materials.

[0105] For comparison, measured values for hemp fibres are also shown in Table 1. Hemp is a known plant-based fibre, which can be used in textiles.

[0106] Embodiments of the invention will now be described in the following numbered paragraphs:

[0107] 1. A method of producing fibres from potato haulm, the method including step of: subjecting a potato haulm to enzymatic retting.

[0108] 2. A method according to paragraph 1, wherein the enzymatic retting is performed using at least one pectinolytic enzyme.

[0109] 3. A method according to paragraphs 1 or 2, further comprising a step of mechanically separating fibres after enzymatic retting.

[0110] 4. A method according to any of paragraphs 1 to 3, wherein the enzymatic retting is performed using an enzyme selected from a group comprising: pectinase, cellulase, laccase and hemicellulase.

[0111] 5. A method according to any of paragraphs 1 to 4, wherein the enzymatic retting is performed using an enzyme selected from a group comprising: pectate lyase, pectinesterase (endo)polygalacturonase, protopectinase, exopolygalacturonase, polygalacturonase, laccase, xylanase, exo-cellulase, endocellulase, endogenous xylanase, exogenous xylanase, exoxylosidase, arabinfuranosidase, endogalactanase, exogalactosidase, exoglucanase, glucanase, lignin peroxidase, cellobiase, protease, mannanase, alpha-amylase, phytase, lysozyme, bromelain, keratinase, pectinase, mannanse, beta-glucosidase, trypsin, levansucrase and lipase. 6. A method according to any of paragraphs 1 to 5, wherein the enzymatic retting is performed using an enzyme produced by a bacteria, the bacteria being selected from a group comprising: Bacillus subtilis, Bacillus Paralicheniformis, Dickeya chrysanthemi, Erwinia, Arthobacter, Pseodomonas, Streptomyces, Bacillus felsineus, Granulobacter pectinovorum, Bacillus a steros porous, Pythium ultimum, Bacillus macerans, Bacillus fiesineus, Bacillus polymyxa and Bacillus thuringiensis.

[0112] 7. A method according to any of paragraphs 1 to 6, wherein the enzymatic retting is performed using an enzyme produced by a fungus, the fungus being selected from a group comprising: Penicillium glaucum, Penicillium italicum, Aspergillus niger and Aspergillus oryzae.

[0113] 8. A method according to any of paragraph 1 to 7, wherein the method further comprises a step of chemical retting.

[0114] 9. A method according to paragraph 8, wherein the chemical retting uses one or more chemicals selected from a group comprising: hydrogen peroxide, sodium hydroxide, sodium chloride, ethylenediaminetetraacetic (EDTA), sodium bicarbonate, aminopolycarboxylic acids, glacial acetic acid, tartrine, chitosan, citric acid, alkylglucoside, potassium sulfate, sorbitol, glycerol, cysteine, sodium oxalate, bentonite, maleic anhydride, polyacrylic acid, polyhydroxyacrylic acid, sodium lauryl sulfate, sodium tripolyphosphate, tween 20, erythritol, hydroxypropionic acid, sodium citrate, potassium sorbate, attapulgite clay, magnesium sulfate, ethanol and calcium hydroxide.

[0115] 10. A method according to any of paragraphs 1 to 9, wherein the method further comprises a step of receiving pre-treated potato haulm.

[0116] 11. A method according to any of paragraphs 1 to 10 wherein the method further comprises the step of pre-treating the potato haulm.

[0117] 12. A method according to paragraph 11, wherein pre-treating the potato haulm comprises at least one of: dehydrating, heating, microwaving, boiling and steaming.

[0118] 13. A method according to any of paragraphs 1 to 12, wherein the method further comprises a step of dehydrating the potato haulm after enzymatic retting.

[0119] 14. An apparatus for performing a method according to any of paragraphs 1 to 13. 15. A fibre from a potato haulm, the fibre having a thickness of 30 micrometres or less.

[0120] 16. A fibre according to paragraph 15, the fibre having a length of at least 15 millimetres.

[0121] 17. A fibre according to paragraphs 15 or 16, the fibre having a cellulose content of at least 60%.

[0122] 18. A material comprising a fibre according to any of paragraphs 15 to 17.

[0123] 19. A material according to paragraph 18, further comprising a non-potato fibre that is selected from a group comprising: plant-based fibres, synthetic fibres and semisynthetic fibres.

[0124] 20. A material according to paragraph 19, wherein the non-potato fibre is selected from a group comprising: cotton, hemp, nettle, manmade cellulosics (MMCF) and polyester.

Claims

Claims1. A fibre produced from a potato haulm, wherein the fibre comprises at least one elementary fibre.

2. A fibre according to claim 1, wherein at least one of the at least one elementary fibres is at least 40pm in length.

3. A fibre according to claim 2, wherein each of the one or more elementary fibres is at least 40pm in length.

4. A fibre according to any preceding claim, wherein at least one of the one or more elementary fibres has a diameter of 350 micrometres or less.

5. A fibre according to any preceding claim, the fibre having a length of at least 10 millimetres.

6. A material comprising a fibre according to any preceding claim.

7. A material according to claim 6, wherein the material is a textile.

8. A material according to claims 6 or 7, further comprising a non-potato fibre that is selected from a group comprising: natural fibres, plant-based fibres, synthetic fibres and semi-synthetic fibres.

9. A material according to claim 8, wherein the non-potato fibre is selected from a group comprising: cotton, hemp, nettle, manmade cellulosics (MMCF) and polyester.

10. A material according to claim 6, wherein: the material is a fibre reinforced composite comprising one or more reinforcing fibres; and at least one of the one or more reinforcing fibres comprise a fibre according to claims 1 to 6.

11. A method of producing a fibre according to any of claims 1 to 6 from a potato haulm.

12. The method of claim 11, further comprising a step of subjecting the potato haulm to retting.

13. The method of claim 12, wherein the step of subjecting a potato haulm to retting involves one or more of: enzymatic retting, microbial retting, water retting, chemical retting, and dew retting.

14. The method of claim 13, wherein enzymatic retting is performed using an enzyme selected from a group comprising: pectinase, cellulase, laccase and hemicellulase.

15. The method according to claim 14, wherein the enzymatic retting is performed using an enzyme selected from a group comprising: pectate lyase, pectinesterase (endo)polygalacturonase, protopectinase, exopolygalacturonase, polygalacturonase, laccase, xylanase, exo-cellulase, endocellulase, endogenous xylanase, exogenous xylanase, exoxylosidase, arabinfuranosidase, endogalactanase, exogalactosidase, exoglucanase, glucanase, lignin peroxidase, cellobiase, protease, mannanase, alphaamylase, phytase, lysozyme, bromelain, keratinase, pectinase, mannanse, betaglucosidase, trypsin, levansucrase and lipase.

16. The method according to claims 14 or 15, wherein the enzymatic retting is performed using an enzyme produced by a bacteria, the bacteria being selected from a group comprising: Bacillus subtilis, Bacillus Paralicheniformis, Dickeya chrysanthemi, Erwinia, Arthobacter, Pseodomonas, Streptomyces, Bacillus felsineus, Granulobacter pectinovorum, Bacillus a steros porous, Pythium ultimum, Bacillus macerans, Bacillus fiesineus, Bacillus polymyxa and Bacillus thuringiensis.

17. The method according to any of claims 14 to 16, wherein the enzymatic retting is performed using an enzyme produced by a fungus, the fungus being selected from a group comprising: Penicillium glaucum, Penicillium italicum, Aspergillus niger and Aspergillus oryzae.

18. The method according to any of claims 12 to 17, further comprising a step of dehydrating the potato haulm after subjecting the potato haulm to retting.

19. The method according to any of claims 11 to 18, further comprising a step of receiving pre-treated potato haulm material.

20. The method according to any of claims 11 to 19, further comprising one or more pre-treatment steps.

21. The method according to claim 20, wherein the one or more pre-treatment steps each comprise at least one of: heat treatment, crimping, exposure to electrical discharge, blanching, steam explosion, chemical treatment, ultrasound, dehydrating, heating, microwaving, boiling and steaming.

22. The method of any of claims 11 to 21, further comprising a step of mechanical separation.

23. The method according to any of claims 11 to 22, further comprising a step of degumming.

24. The method of any of claims 11 to 23, further comprising a step of refining.

Images