METHOD FOR MANUFACTURING A SILK NONWOVEN FABRIC AND PLANT FOR MANUFACTURING A SILK NONWOVEN FABRIC

Abstract

The present invention relates to a method for manufacturing a non-woven silk textile comprising the steps: a) Providing a support (S) on which the textile will be manufactured, b) Selecting silkworms in a given stage of biological development of the silkworm, c) Placing the silkworms on the support (S), d) Waiting for the silkworms to secrete silk until the end of the given stage of biological development, e) Removing said silkworms. (Fig.1]

Description

Title of the invention: METHOD FOR MANUFACTURING A SILK NON-WOVEN TEXTILE AND INSTALLATION FOR MANUFACTURING A SILK NON-WOVEN TEXTILE TECHNICAL FIELD AND PRIOR ART

[0001] The present invention relates to a method for manufacturing non-woven silk textile and to an installation for manufacturing a non-woven silk textile.

[0002] Silk is a textile of animal origin that is used to make silk fabrics. In industry, it is generally produced by the caterpillars of certain butterflies, such as the silkworm moth (Bombyx Mori). Sericulture consists of all the operations of growing the mulberry tree, raising the silkworm to obtain the cocoon, reeling the cocoon, and spinning the silk. The silkworm produces silk proteins that are secreted in the form of a single thread ("slime") essentially comprising two proteins, fibroin and sericin. The fibroin forms a filament around which the sericin will act as a natural adhesive, fixing and protecting the filaments. This slime is used by the silkworm to suspend and then make a cocoon in which it can complete its development and transformation into a butterfly.

[0003] Traditional methods of obtaining silk consist of killing the caterpillar and destroying the cocoon. Conventionally, the cocoons are placed in ovens at 70 to 80°C, then soaked in boiling water so that the sericin dissolves and softens, which allows the fibroin filament to be released. During this stage, most of the sericin present in the natural silk of the cocoon is eliminated, either by being destroyed by the heat or by being dissolved and carried away by the rinsing water. Next comes a spinning stage, during which several fibroin filaments, conventionally around ten, are joined and glued together due to the cooling of the remaining sericin. Consequently, the silk thread obtained from a conventional manufacturing method contains a small proportion of sericin, which is slightly water-soluble.This thread is also made up of a plurality of fibroin filaments, not a single filament as in the original slime. Fabrics made from this thread will therefore have completely different properties than natural silk. In addition, this process of producing silk involves killing the animal used to make the cocoon.

[0004] A method for manufacturing a non-woven silk textile has been developed by the inventors and is described in document WO2017 / 198969. This method consists of placing silkworms at the time when they secrete the silk on a support not having no roughness or hollows to prevent silkworms from attaching to the surface. The silkworms then move over the surface and deposit the silk threads, creating a non-woven textile. At the end of the silk production cycle, the silkworms are stored in a place where they transform into a chrysalis, then into a butterfly. This manufacturing process offers the great advantage of no longer requiring the death of the silkworms. In addition, it allows the sericin to be preserved in the textile and thus the natural properties of the silk.

[0005] The inventors seek to further control the quality of the non-woven silk textile, i.e. for example to control the texture of the textile and its weight. Statement of the invention

[0006] It is therefore one of the aims of the present application to provide a method for manufacturing a non-woven silk textile by which the quality of the textile is better controlled.

[0007] The aim stated above is achieved by a method of manufacturing a non-woven silk textile comprising the steps: - Supply of a group of silkworms in the process of secreting natural silk, - Selection of silkworms according to a given stage of biological development of the silkworm, - Placement of selected silkworms on a support without roughness or substantial hollows, - Wait as long as the silkworms are in the given silkworm biological development stage.

[0008] Thanks to the invention, it is possible to obtain non-woven textiles in which the texture and density are controlled.

[0009] Indeed, the inventor discovered that, depending on the stage of silk secretion reached by the silkworm, i.e. for example the start of the secretion sequence and the end of the secretion sequence, the quality of the non-woven silk textile was different.

[0010] For example, the more advanced the stage reached, the denser the silk produced will be and the higher its weight. Conversely, the earlier the stage, the fluffier the texture of the silk and the lower its weight.

[0011] In other words, the silkworms do not remain on the support from the moment they secrete silk until they have finished secreting it but only over a period of secretion which corresponds to a quality of deposit.

[0012] The invention also relates to a method for manufacturing a non-woven silk textile comprising a step of tilting the support and to a device for producing a non-woven silk textile comprising a support for the silkworms and means for tilting the support.

[0013] Thanks to the invention, it is possible to improve the control of the production of the textile obtained.

[0014] Indeed, by tilting the support, it was possible to control the movement of the silkworms which tend to climb along the support. Thus by tilting the support, it is possible to force the silkworms to move in certain directions and control the deposition of the silk.

[0015] For example, a regular change of the inclination in the different directions makes it possible to obtain a relatively homogeneous non-woven silk textile over a large part of the support.

[0016] The support can have any shape, it can define a two-dimensional silk deposition surface or a three-dimensional surface.

[0017] The present invention then relates to a method for manufacturing a non-woven silk textile comprising the steps: a. Provision of a support on which the textile will be manufactured, b. Selection of silkworms in a given stage of biological development of the silkworm, c. Placing the silkworms selected in step b) on the support, d. Waiting for silkworms to secrete silk until the end of the de-seeding stage given biological development, e. Removal of said silkworms.

[0018] In one embodiment, after step e), steps c) and d) are repeated with silkworms in the given biological development stage or in another biological development stage.

[0019] Preferably, the given biological development stages belong to a phase, called the production phase, after the silkworms have finished excreting excrement.

[0020] For example, during the production phase, silkworms may exhibit a first, second, and third stage of given biological development, occurring chronologically in that order, the later the stage occurring, the denser the silk produced.

[0021] In an exemplary embodiment, one or more steps c), d) and e) are carried out with silkworms at the first given stage of biological development and then one or more steps c), d) and e) with silkworms at the third given stage of biological development.

[0022] Advantageously, during step d), the support is inclined relative to the horizontal.

[0023] Preferably, the angle of inclination and / or the direction of inclination is or are modified during step d).

[0024] The present invention also relates to an installation for the production of non-woven silk textile comprising a frame, at least one arm fixed to the frame by a first end, and a support mounted on a second end of the arm by means of a ball joint.

[0025] The support is advantageously mounted removably on the second end of the arm.

[0026] For example, the frame extends vertically and has several arms so as to allow several supports to be arranged one above the other. BRIEF DESCRIPTION OF THE FIGURES

[0027] The following description will be better understood with the aid of the attached drawings in which: - [Fig.l] is a representation of an example of an installation for the production of non-woven silk textiles according to the invention, - [Fig.2] is a representation of the installation of [Fig.l] from another point of view and at a different production phase, - [Fig.3] is a photo of an example of a non-woven silk textile obtained using the process according to the invention, - [Fig.4] is a photograph of another example of a non-woven silk textile obtained using the process according to the invention, - [Fig.5] is a photograph of another example of a non-woven silk textile obtained using the process according to the invention, - [Fig.6] is a detail view of another example of a silk production facility. DETAILED DESCRIPTION OF EMBODIMENTS

[0028] In the following description, the term "support" means an element comprising a surface on which the silk will be deposited. In an exemplary embodiment, the surface extends in two dimensions, the support is then for example a plate, one of the faces of which forms the surface for depositing the silk. In another exemplary embodiment, the surface extends in three dimensions, the support is for example a sphere or a half-sphere.

[0029] Furthermore, preferably the surface on which the silk is deposited does not have any asperities whose dimension is greater than 3 mm, preferably greater than 1 mm, more preferably greater than 0.5 mm, even more preferably greater than 0.1 mm; the surface of the support also does not have any recesses whose width is greater than 15 mm, preferably greater than 10 mm, more preferably greater than 5 mm, even more preferably greater than 1 mm.

[0030] Further, the surface and / or support is configured to limit the progression of the silkworm. For example, the support is suspended so that when the silkworm is at the edge of the surface, it encounters the void and turns around or runs along the edge.

[0031] Furthermore, in the case where the textile is not intended to remain on the support, its surface is made of a material which allows the silk textile to be removed without damaging it, for this the material is impermeable to sericin. At least the surface of the support is made of glass, metal, inorganic polymer such as polysiloxanes (silicones), or organic polymer such as polystyrene (PS), poly(methyl methacrylate) (PMMA), for example Plexiglas® or Altuglas® or polycarbonate, for example of the Prolians® brand.

[0032] According to another exemplary embodiment, the support comprises a coated textile. A coated textile comprises a woven textile covered with a layer of synthetic material, for example a layer of polyvinyl chloride (PVC). The use of a coated textile has the advantage of providing a support with a slight roughness, which is sufficient for the silkworms to cling but insufficient for them to form a cocoon. This roughness makes it possible to reduce the falling of the silkworms from the support. In addition, by choosing the color of the coated textile, it is possible to reveal the defects as will be described below. Preferably, the coated textile is stretched over a frame, such supports then have a reduced mass compared to the supports described above, for example made of plexiglass.

[0033] A support comprising a solid plate covered with a coated textile does not depart from the scope of the present invention.

[0034] In another example, when the support and the silk are intended to remain assembled, a surface permeable to sericin is chosen.

[0035] Furthermore, it may be envisaged to have supports which give a certain texture to the textile.

[0036] The surface of the support is suitable for the silkworm, in other words it is not toxic to it.

[0037] Alternatively, only the surface is made of a material having the required qualities and produced on an element made of another material.

[0038] Preferably, the support is transparent to facilitate observation of the textile.

[0039] The silkworm is an eruciform larva ("caterpillar") of a butterfly that produces natural silk. The silkworm is chosen from, for example, the mulberry silkworm (Bombyx mori), the Tussah silkworm (Antheraea pernyi), the Japanese oak saturnine (Antheraea yamamai), the tree-of-the-valley silkworm, also called Bombyx eri (Samia cynthia), the Tasar species, the tree-of-the-valley silkworm -Samia ricini, the Philosamia species, the Muga silkworm, the Hyalophora euryalus silkworm, the Rothschildia hesperis silkworm, the Eupackardia calleta silkworm, the Rothschildia lebeau silkworm, the Anaphe silkworm, the Fagara silkworm, the Pachypasa otus D silkworm, the Coan silkworm, Mussel silkworm, a species of spider, Coscinocera Hercules species, Hyalophora gloveri species, Copaxa multifenestrata species, Samrong species, Nangtui species, Nanglai species, Huafai species, Nangnoi species, Nanglaung species, Nangseiw species, Surin 4 species, Nongkh species.

[0040] The appropriate rearing conditions for causing the silkworm to secrete natural silk are part of conventional sericulture and are well known to those skilled in the art. According to one embodiment, rearing the silkworm comprises feeding it with white mulberry leaves (Morus alba) for approximately 30 days.

[0041] In the following description, the terms “non-woven textile”, “textile”, “non-woven silk” and “silk” are synonymous.

[0042] Figures 1 and 2 schematically represent an example of installation II for the manufacture of non-woven silk textile.

[0043] The installation II comprises a frame 2 comprising four vertical uprights 4.1, 4.2, 4.3, 4.4 connected by horizontal crosspieces 6 at their longitudinal ends delimiting a rectangular parallelogram.

[0044] Furthermore, the frame comprises intermediate horizontal crosspieces 8 between two vertical uprights 4.1, 4.2 and 4.3, 4.4, so that the crosspieces are located on two parallel faces of the rectangular parallelogram. On each face, the horizontal crosspieces are superimposed one above the other.

[0045] This installation allows production to be verticalized.

[0046] Furthermore, the chassis comprises bent arms fixed 10 by one end to the intermediate crosspieces and provided at the other end with a plate 12 so as to form saddles.

[0047] The arms and supports are sized to ensure that the edges of the support are sufficiently far from the uprights 4.1 to 4.4 and the crosspieces 8, thereby preventing silkworms from attaching to the uprights or crosspieces and forming cocoons.

[0048] Furthermore, the distance between two supports is chosen to prevent the silkworms from finding an attachment point to form the cocoon and also preferably to allow easy access to the support and to have a good view of them.

[0049] In the example shown, the arms are arranged on either side of each intermediate cross member 8, some of the arms are therefore located inside the chassis and others outside the chassis. Alternatively, only arms inside the chassis or outside the chassis are provided.

[0050] In the example shown, two arms extend from one side of each intermediate crosspiece.

[0051] The saddles form suspension means for the supports S, so that their edges are suspended, thereby limiting the movement of the worms to the support.

[0052] In the example shown, the four saddles inside the chassis ensure the suspension of a large support and the four saddles outside the chassis provide two by two the suspension of smaller supports.

[0053] In this example, the arms located outside the chassis have a larger horizontal dimension than the arms inside the chassis to provide sufficient space between the chassis and the fifth wheels. This embodiment is in no way limiting.

[0054] By arranging two frames 2 next to each other, the external saddles facing the two frames can be used to suspend large-sized supports.

[0055] The frames and the support are placed in an atmosphere controlled in temperature and humidity, for example the temperature is maintained at 23°C and the humidity level is maintained at a few tens of %.

[0056] Silkworms V can be seen on the supports.

[0057] The manufacturing method according to the invention comprises the following steps: - Supply of at least one support provided with a surface for the manufacture of the textile, - Supply of silkworms in the process of secreting silk, - Placing silkworms on the surface of the support, - Waiting for the silkworms to deposit the silk, - Removal of silkworms, - Recovery of the silk, the support may or may not be preserved.

[0058] Advantageously, the manufacturing method also includes a step of checking the silk.

[0059] According to the invention, the manufacturing method also comprises a step of selecting the silkworms according to the stage of silk secretion.

[0060] At a certain stage of its growth, the silkworm begins to secrete silk. This silk normally serves to enable it to make a cocoon for its transformation into a butterfly.

[0061] The silkworm secretes silk for about 3 to 6 days. This period will be referred to as the secretion sequence.

[0062] During the secretion sequence, several phases are observed: - A purging phase that can last about 24 hours, during which the silkworms produce silk and also excrete excrement. This silk is not usable. - A so-called pre-production phase, which can also last around 24 hours, during which the silkworms still release some excrement but the silk can be used, for example, if it is dyed. - A production phase which lasts approximately 48 hours during which the silkworms produce silk of a uniform color, white in the example shown.

[0063] the inventor discovered that the production phase included several stages of production, mainly three.

[0064] During the secretion sequence, the silkworm moves its head so as to form a figure eight. The silk thread is then arranged on the surface substantially in the shape of an eight.

[0065] the inventor discovered that the amplitude of the head of the silkworm and therefore the size of the figure eight thus formed evolved during the secretion sequence, more particularly she observed that the size of the figure eight decreased as the secretion sequence progressed, the inventor identified for example three stages. It will be understood that more than three stages can be defined.

[0066] The larger the figure eight, the fluffier the silk formed and the textile has a low density. The smaller the figure eight, the denser the silk. In addition, the more advanced the production phase, the more limited the worms' movements.

[0067] The first stage corresponds to the period when the eight are the largest and the worms are mobile. This first stage lasts a few hours, for example around 5 hours. The textile is then fluffy / fibrous and has a low weight, for example around 15 g / m2.

[0068] The second stage corresponds to the following period during which the eight are smaller and the worms remain quite mobile. The textile is denser and finer. This stage lasts between 24h and 48h. The weight of the textile obtained is a few tens of g / m2, for example 40 g / m2.

[0069] The third stage corresponds to the period during which the silkworms are very little mobile and produce silk that is even finer and more compact than in the second stage. This stage lasts approximately 24 hours.

[0070] Thus the inventor determined that by choosing to use silkworms in one of the secretion stages to manufacture silk, it was possible to predict the quality and visual appearance of the textile that would be obtained.

[0071] Thus, by using only silkworms in the first stage of secretion, the textile obtained had a fluffy appearance compared to a textile obtained by using only silkworms in the second stage of secretion.

[0072] The manufacturing method according to the invention then further comprises the steps: - Selection of silkworms in a given stage of biological development of the silkworm to obtain a given textile quality, - Placing the said silkworms on the support, - Removal of said silkworms at the end of said given secretion stage.

[0073] For the sake of simplicity, the “given silkworm biological development stage” will be referred to as the “given secretion stage”.

[0074] In one embodiment, during the manufacturing process, it may be provided to replace the silkworms with other silkworms in the same given secretion stage. For example, by using silkworms only in the first stage of secretion, we obtain a thicker textile while retaining the fluffy appearance.

[0075] Very advantageously the first silkworms which are in another stage of secretion are used to manufacture a textile having the quality associated with this new stage of secretion.

[0076] In another embodiment, the silkworms that are completing their secretion stage are replaced by silkworms of another secretion stage. For example, silkworms in the third secretion stage can be placed on a textile obtained with silkworms in the first secretion stage in order to homogenize the textile or possibly make patterns at given locations by placing the silkworms in these locations which are very little mobile.

[0077] The method according to the invention offers great control in the quality of the non-woven silk textile which is obtained.

[0078] The secretion stage and the end of a secretion stage can be determined based on the time elapsed from the start of the secretion sequence. It can also be determined by observing the silkworms whose size decreases as the production phase progresses, and / or by observing the color of the silkworms and / or by observing the work of the silkworms. The silkworm is initially white and the further the secretion stage progresses and the closer it gets to the end of its spinning period, the more yellow it becomes.

[0079] In [Fig.3], we can see a non-woven silk textile obtained with silkworms in the first stage of secretion.

[0080] In [Fig.4], we can see a non-woven silk textile obtained by first using silkworms in the first secretion stage, then silkworms in the third secretion stage.

[0081] The greater the number of silkworms on a given surface, the more homogeneous the textile obtained will be. The number of silkworms is of the order of several hundred per m2.

[0082] Nevertheless, it is possible to consider using a reduced number of silkworms, particularly to create patterns.

[0083] In [Fig.5] we can see an example of a textile obtained with a reduced number of silkworms in the first stage of secretion. The worms tend to form comma-shaped patterns.

[0084] In an advantageous example, the manufacturing method comprises a step of verifying the manufactured textile sheets. This verification can take place when the textile sheets are removed from their support.

[0085] The verification may include a step of verifying the presence of a coloring defect. For this, the sheet is placed on a plate of a homogeneous color close to that of the silk threads. In the present example in which the silk is white, the verification plate is chosen to be white.

[0086] The verification can also include a step of verifying the homogeneity and density of the silk produced. For this, a plate of a darker color than that of the silk threads is chosen. In the case of white silk, a black plate can be chosen.

[0087] In another embodiment, it is desired to secure two sheets of textile together, for example to form a three-dimensional shape. The sheets are for example secured by their edges. To achieve this securing, the edges of the sheets are placed in contact with each other, and silkworms are preferably placed at the third stage. The very fine and dense silk produced at this stage secures the two sheets.

[0088] In [Fig.6], we can see an example of installation 12 according to another example of embodiment of the invention.

[0089] The installation 12 comprises at least one support and means for suspending the support offering the possibility of tilting the support.

[0090] Silkworms tend to seek the highest point to make their cocoon. By tilting the support, the worms are encouraged to move up to the highest point.

[0091] The installation comprises at least one tilting support, which makes it possible to control the movement of the silkworms and thus to control the distribution of the silk thread on the surface of the support.

[0092] Very advantageously, the support is orientable so as to allow the surface to be inclined in all directions and thus to offer greater possibilities for controlling the movement of the silkworms.

[0093] Preferably, the tilting of the support is carried out in several stages.

[0094] The support is horizontal, the angle of inclination is equal to 0°, and the worms are arranged on the support. The support remains in this position for example between 40 min and 60 min.

[0095] Then the support is inclined at a certain angle, for example 30° around a first horizontal axis, for a certain time, for example 40 min to 60 min.

[0096] The support is then tilted by an additional angle of 30°. The support is then tilted by 60°, and remains in this position for a certain time, for example 40 min to 60 min.

[0097] The support is then inclined around a second horizontal axis, for example oriented at a right angle to the first axis, for example at an angle of 30° for a certain time, for example 40 min to 60 min.

[0098] The support is then inclined by an additional angle of 30°. The support is then inclined by 60° in the horizontal axis, and remains in this position for a certain time, for example 40 min to 60 min.

[0099] It is then possible to manage the homogeneity of the silk thus produced. Indeed, one can obtain either a gradient of thickness, the part of the textile located highest will be the thickest. In another example, one can obtain a relatively homogeneous thickness by tilting the support in all directions.

[0100] In [Fig.6], the installation comprises a chassis comprising a vertical mast 14 and angled arms 16 extending laterally from the mast 14 and distributed along the mast in the vertical direction. The arms are distributed relative to each other to allow easy access to and viewing of the support.

[0101] In addition, this installation makes it possible to verticalize production and reduce the space required for production.

[0102] The installation also comprises a suspension structure 18 for a support, said structure 18 being articulated by a ball joint 20 on the free end 16.1 of an arm 16.

[0103] The suspension structure has in the example represented an H shape. For example, the support has on its lower face anti-slip means which make it possible to maintain the support on the structure while facilitating the installation and removal of the support from the structure. Any other means of securing the support to the structure falls within the scope of the present invention.

[0104] In this example, the tilting of the support is carried out manually.

[0105] Advantageously, means 22 for locking the position of the suspension structure relative to the arm are provided. In the example shown, this is a threaded rod moved by a wheel which passes through the housing of the ball head and tightens the ball joint in its housing.

[0106] The ball joint allows the support to be tilted in all directions and therefore to be able to control the movement of the silkworms and therefore the deposition of the silk in all directions on the support.

[0107] Advantageously, the inclination of the support is automated. For this, one or more electric motors are mounted at the level of the ball joint and are capable of pivoting the support around the three axes of space. Very advantageously, a control unit controlling the electric motor(s) is implemented, allowing a modification of the inclination according to programmed sequences.

[0108] Tilting the support also makes it possible to reduce the number of silkworms required to obtain a homogeneous surface.

[0109] In the example shown, a ball joint is provided in an intermediate zone of the arm to allow another support to be suspended, for example of smaller dimensions.

[0110] Preferably, the suspension structure is removable and allows other types of structure to be attached.

[0111] It will be understood that the shape of the arms and the shape of the suspension structure is in no way limiting. Furthermore, the arms may be carried by a chassis of the type shown in [Fig.l].

[0112] The manufacturing method implementing the tilting support comprises the steps: - Provision of at least one tilting support provided with a surface for textile manufacturing, - Supply of silkworms in the process of secreting silk, - Placing silkworms on the surface of the support, - Modification of the inclination of the support, - Waiting for the silkworms to deposit the silk, - Removal of silkworms, - Recovery of the silk, the support may or may not be preserved.

[0113] The step of modifying the inclination of the support can advantageously comprise several sub-steps of modifying the inclination according to different angles as described above and very advantageously in different directions so as to control the movement of the silkworms in different directions and to best control the distribution of the deposition of the silk on the support.

[0114] Furthermore, being able to modify the direction of inclination of the support can make it possible to create variable thicknesses of materials on the same sheet of silk. It is then, for example, possible to obtain a gradient of silk thickness with more thickness on one side of the sheet and less thickness on the opposite side.

Claims

Claims

1. A method of manufacturing a non-woven silk textile comprising the steps of: a) Providing a support on which the textile will be manufactured, b) Selecting silkworms in a given stage of biological development of the silkworm, c) Placing the silkworms selected in step b) on the support, d) Waiting for the silkworms to secrete silk until the end of the given stage of biological development, e) Removing said silkworms.

2. A manufacturing method according to claim 1, wherein after step e), steps c) and d) are repeated with silkworms in the given biological development stage or in another given biological development stage.

3. A manufacturing method according to claim 1 or 2, wherein the given biological development stages belong to a phase, called the production phase, after the silkworms have finished excreting excrement.

4. A manufacturing method according to claim 3, wherein during the production phase the silkworms may exhibit a first, a second and a third given biological development stage, occurring chronologically in this order, the later the stage occurring the denser the silk produced.

5. Manufacturing method according to claim 4, in which one or more steps c), d) and e) are carried out with silkworms at the first given biological development stage and then one or more steps c), d) and e) with silkworms at the third given biological development stage.

6. Manufacturing method according to one of claims 1 to 5, in which, during step d), the support is inclined relative to the horizontal.

7. A manufacturing method according to claim 6, wherein the tilt angle and / or the tilt direction is or are changed during step d).

8. Installation for the production of non-woven silk textile according to the manufacturing method of any one of claims 1 to 7, comprising a frame (2), at least one arm (10) fixed to the frame (2) by a first end, and a support (S) mounted on a second

9. end of the arm (10) by means of a ball joint. Installation according to claim 8 in which the support (S) is removably mounted on the second end of the arm (10).

10. Installation according to claim 8 or 9, in which the frame (2) extends vertically and comprises several arms (10) so as to allow several supports (S) to be arranged one above the other.

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