Method for producing silk pieces from bagworm larvae

Abstract

Methods are developed and provided for producing silk pieces with high silk recovery efficiency without causing mechanical damage to the cocoon silk of bagworm larvae on the substrate. Bagworm larvae are disposed together with a solvent-soluble substrate, and after the bagworm larvae are caused to spin cocoon silk on the surface of the substrate, the substrate is dissolved with a solvent, and the cocoon silk is separated.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for producing a silk block formed of a cocoon filament derived from a larva of a moth belonging to the family of bagworm moths, i.e., a bagworm larva. BACKGROUND

[0002] Silk constituting a cocoon of an insect, and hair of a mammal have been utilized as animal fibers since ancient times in clothing and the like. In particular, mulberry silk (often expressed as "silk of the silkworm" in this specification) derived from a silkworm, which is a larva of Bombyx mori, is now also valued as a high-grade natural raw material because of excellent hygroscopicity, moisture retention, and heat retention, and in addition, has a unique luster and a smooth skin touch.

[0003] However, in nature, there are animal fibers having properties rivaling or superior to those of mulberry silk. In recent years, in order to effectively use animal fibers having such excellent properties as new natural raw materials, exploration and research and development thereof have been advanced.

[0004] Among them, silk derived from spiders (often expressed as "spider silk" in this specification) has been attracting attention. Spider silk has softness, stretchability, and a high elastic force of 5 to 6 times that of polystyrene, and is expected as a medical raw material such as a surgical suture, and a special raw material such as a disaster prevention rope / protective clothing (Non-Patent Literatures 1 and 2). However, spider silk has problems that it cannot be mass-produced because it is difficult to collect a large amount of silk from spiders due to mass rearing of spiders, and in addition, the production cost is high. This problem has been attempted to be solved by producing spider silk using a host such as a silkworm, Escherichia coli, and the like using a genetic recombination technique (Patent Literatures 1 and 2). However, the silkworm, Escherichia coli, which produces spider silk, is a genetic recombinant, and thus can only be reared and cultured in a facility equipped with a prescribed device, with a problem of a large burden of maintenance management. In addition, there is a problem that a liquid spider silk protein expressed in Escherichia coli needs to be converted into a fiber, and the number of processes also increases accordingly. Further, the spider silk discharged from the genetic recombinant silkworm also has a problem that it is only a few percent (a few %) mixed in mulberry silk at the present stage, and cannot be obtained as 100% spider silk that can effectively utilize the properties of spider silk by 100%.

[0005] In addition, there is an insect called a bagworm larva (alias "bag worm"). The bagworm larva is a general term for larvae of moths belonging to the family of Psychidae of the order of Lepidoptera, and is known to usually hide in a spindle-shaped or cylindrical nest made by wrapping leaves, branches, and the like with silk, to move together with the nest at the time of feeding, and the like, and to live together with the nest during the entire larval period. Figure 1

[0006] ​The cocoon silk spun by the bagworm larvae (in this specification, often expressed as "bagworm larvae silk") has recently been attracting attention as a new natural raw material of animal fibrous nature having superior properties compared to silkworm silk and spider silk. For example, with respect to the elastic modulus, the bagworm larvae silk of Eumeta minuscula also reaches 3.5 times that of silkworm silk, and furthermore, 2.5 times that of the spider silk of Nephila clavata, boasting a very strong strength (Non-Patent Documents 1 and 2). Furthermore, since it not only has a gloss and brilliance equal to or greater than that of silkworm silk, but also has a cross-sectional area of a single fiber that is about 1 / 7 that of a single fiber of silkworm silk, a cloth that is finer and smoother in texture, and thin and light in feel to the touch compared to silkworm silk can be produced.

[0007] In terms of rearing, the bagworm larvae also have advantages compared to silkworms and spiders. The bagworm larvae, like silkworms, are phytophagous, and thus, unlike carnivorous spiders, the supply of food is easy, and can be stably supplied. Furthermore, even though they are the same phytophagous, they have advantages compared to silkworms. For example, silkworms in principle take only fresh leaves of species belonging to the genus Morus (for example, M. bombycis, M. alba, and M. ilhou, etc.) as food, and thus the rearing region and rearing period are around the supply site of mulberry leaves and the leafing period of mulberry. On the other hand, the bagworm larvae are euryphagous, and have low specificity to the bait leaves, and many species can take leaves of various tree species as food. Thus, the acquisition of bait leaves is easy, and the rearing region is not selected. Furthermore, depending on the species, leaves of evergreen trees can also be bait leaves, and thus, unlike mulberry, which is a deciduous tree, bait leaves can be supplied throughout the year. Also, the bagworm larvae are smaller in size compared to silkworms, and thus the rearing space is sufficient at or below the same as silkworms, and mass rearing is also easy. Thus, the rearing cost can be suppressed.

[0008] Further, in terms of production, the bagworm larvae are also superior compared to silkworms. For example, silkworms only spin silk in large amounts when cocooning, and cocooning is performed at the same period in all larvae. Thus, the period for silk harvesting overlaps, and the labor period is concentrated. However, the bagworm larvae repeatedly spin silk when nesting and moving throughout the larval period. Thus, by artificially adjusting the period for silk harvesting, the labor period can be dispersed.

[0009] As described above, the bagworm larvae silk has properties exceeding those of silkworm silk and spider silk, and furthermore, has many advantages in production, and thus is expected as a very promising new natural raw material.

[0010] However, the bagworm larva silk also has several problems in its practical use. One of the problems is related to the characteristics of the bagworm larva nest. The surface of the bagworm larva nest must have impurities such as leaves and branch pieces attached thereto. This is due to the habit of the bagworm larva to introduce small branch pieces and leaves around the nest into the nest for protection of color during the construction and expansion of the nest. In the production of bagworm larva silk, these impurities need to be completely removed. In the past, the impurities were removed by hand work from the nest in which the nest was constructed, or the nest was softened by long-time immersion in warm water to cause the impurities to be detached. However, the removal of these impurities requires a large amount of labor and time. In addition, in the prior art, there are problems that the impurities cannot be completely removed, and that the bagworm larva silk is finally mixed with a very small amount of leaves and the like in the product, or the bagworm larva silk is dyed to light brown by pigments derived from the impurities, and only a low-quality product can be obtained. Although decoloring treatment using alkali and acid can be performed for the purpose of removing the pigments, the strength of the bagworm larva silk is damaged, and the quality is significantly reduced.

[0011] In addition, in the bagworm larva silk, in addition to the nest silk that constitutes the nest, there is such a silk as a support silk. As shown in FIG. 1B, Figure 1 The support silk is the bagworm larva silk that is discharged as a silk for a hook foot for preventing falling from a branch and the like when the bagworm larva moves. It has been clarified from the research results of the present inventors and the like that the support silk is stronger and has excellent mechanical properties compared to the nest silk. In addition, if it is a support silk, unlike the nest silk, impurities such as leaves and branch pieces do not exist mixedly. Therefore, if the use of the support silk can be adopted, it can also be practical as the bagworm larva silk.

[0012] However, since the movement of the bagworm larva is difficult to control and depends on the insect, the bagworm larva moves back and forth in the same place, and as a result, several layers of the discharged silk are overlapped, and only a state in which the silk is complicatedly entangled can be obtained. Figure 1 C) In addition, the bagworm larva silk is discharged in a state in which the fiber component and the paste-like component that covers the surface thereof are mixed, but in the case of the support silk, the paste-like component is attached to the surface of the base material of the branch and the leaf, and thus the support silk is fixed to the base material. The fixation by the paste-like component is relatively strong, and thus there is also a problem that the support silk that is layered on the base material is damaged and fragmented by mechanical peeling when it is recovered.

[0013] Prior art documents

[0014] Patent documents

[0015] Patent Document 1: WO2012 / 165477

[0016] Patent Document 2: WO2013 / 065651

[0017] Non-patent documents

[0018] Non-patent literature 1: Osako, Shigeru, 2002, Sen'i Kikakai (Fiber and Industry), 58: 74-78

[0019] Non-patent literature 2: Gosline J.M. et al., 1999, 202, 3295-3303 SUMMARY

[0020] PROBLEMS TO BE SOLVED BY THE INVENTION

[0021] An object of the present application is to develop and provide a method of recovering a large portion of the cocoon silk of the bagworm larvae without damaging the cocoon silk of the bagworm larvae on the base material. Furthermore, using the method, the cocoon silk of the bagworm larvae is put to practical use as a new natural raw material.

[0022] METHOD FOR SOLVING THE PROBLEMS

[0023] In order to solve the above problems, the present inventors and others have conducted intensive research repeatedly, as a result of which, by the reverse idea of recovering the cocoon silk that has been spun without peeling the cocoon silk from the base material, and dissolving the base material itself, the cocoon silk that has been spun is recovered as a silk block in a substantially complete state without causing physical damage caused by peeling at all. The silk block formed from the cocoon silk that has been recovered can also be utilized as a nonwoven fabric, and furthermore, by spinning on a base material in a desired three-dimensional shape and recovering, a nonwoven fabric in a three-dimensional shape that is difficult to process from a plane can also be produced. The present application provides the following solutions based on the above method.

[0024] (1) A method of producing a silk block of bagworm larvae silk, comprising the steps of: a disposing step of disposing a bagworm larvae together with a solvent-soluble base material; a spinning step of causing the bagworm larvae to spin on the solvent-soluble base material; a dissolving step of dissolving the solvent-soluble base material with a solvent; and a separating step of separating the solvent-soluble base material from the bagworm larvae silk spun on the base material, the solvent being a solvent that does not damage, modify, or dissolve the bagworm larvae silk.

[0025] (2) The method according to (1), further comprising a recovering step of recovering the bagworm larvae together with the nest after the spinning step and before the dissolving step.

[0026] (3) The method according to (1) or (2), the solvent being water.

[0027] (4) The method according to (1) or (2), the solvent being a low-polarity solvent.

[0028] (5) A method for producing a block of bagworm larvae silk, comprising the following steps: a preparation step, in which bagworm larvae are prepared together with a heat-fusible substrate; a silk-spinning step, in which bagworm larvae spin silk on the heat-fusible substrate; a melting step, in which the heat-fusible substrate is heated and melted at a temperature at which the bagworm larvae silk is not damaged, not thermally modified and not melted; and a separation step, in which the heat-fusible substrate is separated from the bagworm larvae silk spun on the substrate.

[0029] (6) According to the method described in (5), before the above-mentioned spinning process and the above-mentioned melting process, the following recycling process is further included: recycling the bagworm larvae together with the nest.

[0030] (7) The method according to any one of (1) to (6) further comprises the following washing step: washing the separated bagworm larvae silk.

[0031] (8) The method according to any one of (1) to (7) further comprises the following drying step: drying the separated bagworm larvae silk.

[0032] (9) The substrate is disposed on the support body according to any one of (1) to (8).

[0033] (10) The substrate has a planar shape or a three-dimensional shape according to any one of (1) to (9).

[0034] (11) A nonwoven fabric made from burrowing moth larvae silk obtained by any one of the burrowing methods described in (1) to (10).

[0035] This specification contains the disclosure of Japanese Patent Application No. 2018-078522, which forms the basis of the priority of this application.

[0036] The effects of the invention

[0037] According to the silk block production method of the present invention, the scaffold silk of bagworm larvae spinning silk on a substrate can be collected as silk blocks with a high recovery rate without causing mechanical damage. Attached Figure Description

[0038] Figure 1 Image A: External view of the nest of the bagworm larva (Bagworm larva). Image B: Image showing the silk-spinning behavior of the bagworm larva. It shows the larva moving while spinning support silk (arrow), and hooking its claws onto the spun support silk (thin arrow). Image C: Image showing the state of the support silk larva on a plastic board. It shows the larva's complex entanglement with the spun support silk in a zigzag pattern.

[0039] Figure 2A A diagram showing the procedure flow of the production method of bagworm larva silk of the present application. In this flow, the case where the substrate used is a solvent-soluble substance is shown.

[0040] Figure 2B A diagram showing the procedure flow of the production method of bagworm larva silk of the present application. In this flow, the case where the substrate used is a thermally fusible substance is shown.

[0041] Figure 3 A diagram for explaining the embodiment of the present application. The white circle observed in the dotted circle in the diagram of c is the scaffold silk of bagworm larva discharged from the bagworm larva. DETAILED DESCRIPTION

[0042] 1. Silk block production method

[0043] 1-1. Summary

[0044] The first aspect of the present application is a silk block production method of bagworm larva silk. The production method of the present application is a method of producing a silk block by disposing a bagworm larva on a solvent-soluble substrate or a thermally fusible substrate, discharging scaffold silk after that, dissolving or fusing the substrate, separating the scaffold silk discharged by the bagworm larva from the substrate, and thereby collecting the scaffold silk of the bagworm larva as a target, and obtaining a silk block. According to the method of the present application, a silk block can be produced efficiently with the scaffold silk discharged on the substrate being recovered without causing physical damage to the scaffold silk by mechanical operations such as peeling, and without the scaffold silk on the substrate being wasted.

[0045] 1-2. Definition of terms

[0046] The following terms frequently used in the present specification are defined as follows.

[0047] The term "bagworm larvae" refers to the general term for the larvae of moths belonging to the family Psychidae within the order Lepidoptera, as described above. Psychidae moths are distributed worldwide, but all larvae (bagworm larvae) live their entire larval stage by piecing together natural materials such as leaves and twigs using their own spun silk, creating nests from these materials. Furthermore, all species share the following habit: when removed from their nests, they will, in principle, use surrounding substrates to build their own nests. Therefore, the bagworm larvae used in this specification are those belonging to the family Psychidae and exhibiting the aforementioned habits, regardless of species, age, or sex. For example, the family Lymphadenidae includes genera such as *Acanthopsyche*, *Anatolopsyche*, *Bacotia*, *Bambalina*, *Canephora*, *Chalioides*, *Dahlica*, *Diplodoma*, *Eumeta*, *Eumasia*, *Kozhantshikovia*, *Mahasena*, *Nipponopsyche*, *Paranarychia*, *Proutia*, *Psyche*, *Pteroma*, *Siederia*, *Striglocyrbasia*, *Taleporia*, *Theriodopteryx*, and *Trigonodoma*. The larvae used in this specification can belong to any of these genera. Furthermore, the larvae can be any instar from the first to the last instar. However, to obtain a higher quality amount of silk from the larvae, larger larvae are preferred. For example, if of the same species, later instar larvae are preferred; if both are male and female, larger females are preferred. Moreover, larger species within the Lymphadenidae family are preferred. For example, large species such as the large bagworm (Eumeta japonica) and the tea bagworm (Eumeta minuscula) are suitable as species for use in this invention.

[0048] Furthermore, the bagworm larvae used in the production method of this invention are not limited, but are bagworm larvae that have maintained their nest. "Maintaining the nest" means that the bagworm larvae carry the nest with them. As described above, the bagworm larvae live with their nest, and this continues when feeding and moving. Figure 1 As shown in Figure B, only a portion of the larvae are exposed outside the nest; in principle, the entire larvae should not be exposed throughout the larval stage. When the bagworm larvae are artificially separated from the nest, exposing their entire bodies to the outside world, the naked bagworm larvae prioritize nest reconstruction to protect their bodies and maintain warmth, thus producing nest silk. Therefore, in order for the support silk, which is the objective of this invention, to be produced, it is preferable to pre-exist in a nest-like state for the bagworm larvae.

[0049] In the present specification, the term "silk" refers to silk derived from insects, and refers to silk made of protein discharged by larvae and adult insects of insects for the purpose of nest building, movement, fixation, cocoon making, prey capture, and the like. In the present specification, in the case of a simple expression of "silk", it refers to a general silk of a wide range of insects without specifying the name of the insects, and in the case of indicating silk derived from a specific insect, the name of the organism from which the silk is derived is attached to the silk, such as "silk of the silkworm (Bombyx mori)" and "silk of the bagworm (Tineola bisselliella)".

[0050] In the present specification, the term "silk of the bagworm" refers to silk discharged by the bagworm larvae. The silk of the bagworm larvae of the present specification includes single fibers, discharged fibers, and aggregate fibers. The term "single fiber" refers to a filament that is the smallest unit of a fiber component, and is also referred to as a monofilament. The single fiber has a silk fibroin protein as a main component. The silk of the bagworm larvae and the silk of the silkworm are discharged in the state of a difilament in which two single fibers are combined by a sericin protein as an adhesive substance in a natural state. This difilament is referred to as a "discharged fiber". The nest of the bagworm larvae and the cocoon of the silkworm are made of the discharged fiber. In addition, a substance in which a plurality of discharged fibers are bundled to become a fiber bundle is referred to as an "aggregate fiber (filament)". Raw silk obtained by a reeling process corresponds to the aggregate fiber. Further, the raw silk is treated with soap, lye, and alkaline reagents such as sodium carbonate, urea, and enzymes, and the sericin protein is removed, and the obtained silk is referred to as "washed silk".

[0051] There are two types of scaffold silk and nest silk in the silk of the bagworm larvae. The term "scaffold silk" refers to silk discharged by the bagworm larvae for movement as described above, and has a function as a scaffold for preventing falling from branches, leaves, and the like. The bagworm larvae discharge scaffold silk in a zigzag shape toward the direction of travel when moving, and move while hooking the claws of both feet to the silk. On the other hand, the term "nest silk" refers to silk discharged for a nest, and is discharged in order to splice leaves and branch pieces and make the inner wall of the nest, which is a living area, a comfortable environment. In the present specification, the silk of the bagworm larvae refers to scaffold silk unless otherwise specified.

[0052] In the present specification, the term "silk block" refers to an aggregate of silk composed only of the silk of the bagworm larvae. The nest of the bagworm larvae is an aggregate of the silk of the bagworm larvae, but generally, impurities such as small branch pieces, leaves, and the like are mixed, and thus does not correspond to the silk block of the present application. Therefore, the silk block in the present specification can generally be produced by a certain artificial process. The state of the silk block is not limited. Even in the case of a complicatedly entangled state of the silk of the bagworm larvae, it can be in the state of a bundle in which one or a plurality of filaments are wound.

[0053] In the present specification, the "base material" means a base for reeling of the reeling silk. The reeling silk is attached while the bagworm larvae move on the surface of the base material, and the reeling is performed. The raw material constituting the base material, the appearance of the base material, and the like are described below.

[0054] The "solvent" used in the present application is a solvent which does not damage, does not modify, and does not dissolve the bagworm larvae silk, particularly the fibroin protein as a fiber component thereof. For example, a strong acidic solvent and a strong basic solvent which denature the protein are not suitable as the solvent used in the present application. The solvent can be classified into a high polarity solvent (hydrophilic solvent) and a low polarity solvent (hydrophobic solvent) based on the level of polarity, but either one of the solvents is included in the present specification. In the high polarity solvent, a part of organic solvents, for example, lower alcohols (methanol, ethanol, and the like), and acetic acid are included in addition to water. Further, in the low polarity solvent, other large amount of organic solvents (low polarity organic solvents), for example, hexane, toluene, chloroform, dichloromethane, dichloroethane, trichloroethylene, acetone, diethyl ether, xylene, carbon tetrachloride, methyl acetate, ethyl acetate, tetrahydrofuran, and acetonitrile, and the like are included. In view of the easiness of the operation (including the waste liquid treatment and the like), the safety, and the purchase cost, water (including warm water and hot water) is particularly preferable as the solvent of the present application.

[0055] In the present specification, the "solvent solubility" means a property capable of being dissolved in the above solvent. Therefore, the "solvent soluble base material" means a base material capable of being dissolved in a specific solvent.

[0056] In the present specification, the "thermal fusibility (or thermal fusibility)" means a property capable of being easily fused by heat. The "thermal fusible base material" means a base material which is in a solid state at normal temperature (15°C to 25°C) under the atmospheric pressure, and can be changed to a liquid state by being fused by heating. The melting point of the thermal fusible base material is only required to be lower than the temperature at which the bagworm larvae silk is damaged, is modified by heat, or is fused. The bagworm larvae silk starts to be thermally decomposed if it exceeds 260°C, and therefore the melting point is only required to be at least 260°C or lower. It is preferable that the melting point be 200°C or lower, more preferable that it be 150°C or lower, 140°C or lower, 130°C or lower, or 120°C or lower. In order to reduce the heating cost, not to expose the bagworm larvae silk to an excessively high temperature, it is preferable that the melting point be a temperature higher than the normal temperature, and be 100°C or lower. For example, a range of 40°C to 100°C, 45°C to 98°C, 50°C to 95°C, 55°C to 90°C, 60°C to 85°C, 65°C to 80°C, or 70°C to 75°C is appropriate.

[0057] 2. Production method

[0058] The procedure flow of the present aspect is shown in Figure 2A and Figure 2BIn the middle. As shown in the figure, the production method of this scheme consists of the first process ( Figure 2A ) and the second process ( Figure 2B It consists of two independent processes.

[0059] 2-1. Pretreatment

[0060] The pretreatment of bagworm larvae used in the method of the present invention will be described.

[0061] In this method, live bagworm larvae are used in both the first and second processes during the preparation and silk-spinning steps. However, the bagworm larvae are not fed in principle during these processes. In this invention, the longer the distance the bagworm larvae travel per unit time, the more support silk can be obtained. However, this is because if feeding occurs during silk collection, the bagworm larvae may become engrossed in feeding and hardly move. However, silk-spinning is essentially the release of proteins (bagworm larvae silk) synthesized and accumulated in the body, thus the bagworm larvae consume a large amount of energy and protein during movement. Therefore, it is desirable that the bagworm larvae supplied to the production method of this invention be adequately fed beforehand as a pretreatment. There are no limitations on the feeding method or feeding time. As long as a sufficient amount of food is provided until the bagworm larvae stop feeding, it is acceptable.

[0062] Furthermore, it is preferable to allow the larvae to defecate after feeding. This is to prevent the feces from contaminating the silken supports expelled by the bagworm larvae. Defecation only requires leaving the larvae at normal rearing temperatures for a sufficient period of time after feeding. For example, it is sufficient to leave the larvae at a temperature of 10–30°C, preferably 15–25°C, for at least 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 8 hours, or less than 24 hours, 20 hours, 18 hours, 15 hours, 12 hours, or 10 hours.

[0063] 2-2. First Process

[0064] In the first process ( Figure 2A In this process, the substrate is characterized by using a solvent-soluble substance. The process includes the following essential steps: preparation (S0101), spinning (S0102), dissolving (S0104), and separation (S0106); and the following optional steps: recovery (S0103), washing (S0107), and drying (S0108). Each step will be described below.

[0065] 2-2-1. Configuration Process

[0066] The “configuration process” (S0101) is the process of configuring bagworm larvae together with a solvent-soluble substrate, and is an essential process in this invention.

[0067] The solvent-soluble base material used in the present process is not particularly limited as long as it is soluble in the above solvent, but is classified here into a water-soluble base material (water-soluble raw material) and a low-polarity solvent-soluble base material, which are described below in detail.

[0068] The "water-soluble base material" in the present specification means a base material composed of a substance soluble in water, which is in a solid state in a dry environment. The "dry environment" means an environment under standard conditions (at 15°C to 25°C under atmospheric pressure) and having a humidity of 50% or less, preferably 40% or less, 30% or less, 20% or less, or 10% or less. Specific examples of the water-soluble base material include gelatin, starch, and pullulan. The water-soluble base material used in the present process is not limited, and can be one or a combination of two or more base materials selected from the above group. The water-soluble base material can be not only soluble in water (pure water) but also soluble in an aqueous solution containing one or two or more solutes.

[0069] The "low-polarity solvent-soluble base material" in the present specification means a base material composed of a substance soluble in a low-polarity solvent, which is in a solid state under the above standard conditions. The "low-polarity solvent" herein mainly means a low-polarity organic solvent. Specifically, examples include hexane, toluene, chloroform, dichloromethane, dichloroethane, trichloroethylene, benzene, acetone, diethyl ether, dimethylbenzene, methyl acetate, ethyl acetate, carbon tetrachloride, and acetonitrile. Examples of the low-polarity solvent-soluble base material are not limited, and include polystyrene, vinyl acetate, cellulose acetate, an acrylic resin, and polycarbonate. As long as it is soluble in the same solvent, it can be a combination of two or more low-polarity solvent-soluble base materials.

[0070] The thickness of the solvent-soluble substrate used in this process is not limited. In the case of making the substrate too thick, the substrate itself can have rigidity, but on the other hand, the manufacturing cost of the substrate becomes high, and the substrate is difficult to dissolve in the dissolving process, or the separation of the substrate from the support silk in the separation process is difficult. On the other hand, in the case of making the substrate too thin, the manufacturing cost of the substrate is suppressed, and in addition, the dissolution of the substrate in the dissolving process, the separation of the substrate from the support silk in the separation process become easy, but on the other hand, the rigidity of the substrate itself is lost and thus cannot maintain a certain shape, and cannot function as a base. Therefore, it is only necessary to appropriately determine considering the manufacturing cost of the substrate, the rigidity, the ease of processing in the subsequent processes, and the like. In general, in the case of a water-soluble substrate, there is no limitation, but the average thickness of the substrate is preferably 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, 1.0 mm or more, 1.2 mm or more, or 1.5 mm or more, and further preferably 3.0 mm or less, 2.8 mm or less, 2.5 mm or less, 2.2 mm or less, or 2.0 mm or less. In addition, in the case of being composed of a thin film in which the average thickness of the water-soluble substrate is 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, or less than 0.5 mm, the substrate itself does not have rigidity to maintain a certain shape, and thus the substrate can be disposed on an appropriate support having a desired shape.

[0071] In the present specification, the "support" is a member that can impart rigidity and / or shape to the solvent-soluble substrate by disposing the solvent-soluble substrate on the surface thereof. The support is a selective constituent element used in the production method of the present application, and can be used as needed.

[0072] The material of the support is not particularly limited as long as it has rigidity to a degree that can maintain a certain shape. Examples include glass, metal, plastic, synthetic rubber, ceramic, or paper, plant pieces (for example, containing wood pieces), and animal pieces (for example, containing bone pieces, shells, sponges). The heat-fusible substrate described later can also be used as a support. In addition, a solvent-soluble substrate having a different property from the solvent-soluble substrate used as a spinning base can also be used as a support. For example, a case in which a thin film of a water-soluble substrate is used as a solvent-soluble substrate for spinning, and a low-polarity solvent-soluble substrate having a surface to which the water-soluble substrate is adhered is used as a support.

[0073] The shape and size of the substrate used in this process are not limited. For example, the shape can be a planar shape, such as a sheet or plate, or a three-dimensional shape. When it is desired to obtain a planar nonwoven fabric formed from the scaffold silk of a bagworm larva, this can be achieved by using a planar substrate and spinning silk across its entire planar surface. Furthermore, when it is desired to obtain a nonwoven fabric formed from scaffold silk having a desired three-dimensional shape, this can be achieved by using a substrate having that desired three-dimensional shape and spinning silk across the entire surface of the substrate. Nonwoven fabrics with such three-dimensional shapes can, for example, serve as scaffold materials in regenerative medicine.

[0074] The size of the substrate can be whatever size is required. However, if the support silk is the silk of a bagworm larva that is spun out as it moves, then while there is no limitation, the lower limit is preferably the same as or greater than the body length of the bagworm larva. For example, the long axis and long diameter can be 1 cm or more, 2 cm or more, 3 cm or more, 4 cm or more, or 5 cm or more. On the other hand, regardless of the upper limit of the substrate size, if the long axis and long diameter are 10 cm or more, 15 cm or more, 20 cm or more, 25 cm or more, or 30 cm or more, it is preferable to have multiple bagworm larvae spin silk.

[0075] The phrase "combining bagworm larvae with a solvent-soluble substrate" refers to positioning the bagworm larvae and the substrate in a manner that allows them to contact the surface of the solvent-soluble substrate. For example, the bagworm larvae can be placed directly on the substrate, or they can be positioned so that they can move to reach the substrate. A specific example of the latter is placing bagworm larvae on the bottom of an open-mouthed plastic container and then covering the container with a solvent-soluble substrate. Since bagworm larvae prefer higher positions, they move along the side of the container, reaching the lower surface of the substrate, which corresponds to the top of the container, where they expel support silk threads as they move.

[0076] Furthermore, the species and number of bagworm larvae used are not considered. For example, one bagworm larva can be used at a time, or multiple larvae can be used for each substrate that produces support silk. Also, the species and age of the bagworm larvae are not considered. When using multiple larvae, each individual can be of the same species and age, or different species and ages of bagworm larvae can be mixed.

[0077] 2-2-2. Silk-spinning process

[0078] The “silk-spinning process” (S0102) is an essential process in this invention, in order to enable bagworm larvae to move and spin support silk threads on the surface of the substrate.

[0079] The duration of this process varies depending on the species, age, and number of bagworm larvae used, and is therefore not limited. It can continue until the necessary amount of support silk is spun onto the substrate. For example, when using one final-instar bagworm larva from the large bagworm moth, and spinning silk on a circular substrate with a diameter of 9 cm, it can be spun for 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, or 7 days or more. The support silk is spun as the bagworm larva moves, as described above, so the amount of support silk obtained is proportional to the distance the bagworm larva moves on the substrate. Therefore, the spinning process is shorter when using multiple larvae compared to spinning silk with a single larva. Furthermore, since the larvae spin silk continuously without feeding, they may frequently stop spinning silk during this process. In such cases, they can be replaced with new bagworm larvae, and the spinning process can continue.

[0080] To maximize the amount of silk spun by bagworm larvae per unit time, it is preferable that the temperature and humidity remain constant or change minimally during this process. Preferably, the temperature is around 20°C, for example, within the range of 15°C–25°C or 18°C–22°C, and the humidity is around 50%, for example, within the range of 40%–65% or 45%–60%. There are no particular restrictions on the light-dark period in this process; it can be a light-only period, or a periodic light-dark period can be applied. For example, within a 24-hour cycle, the light period can be 6–18 hours, 7–17 hours, 8–16 hours, 9–15 hours, 10–14 hours, 11–13 hours, or 12 hours, leaving the remainder as the dark period.

[0081] 2-2-3. Recycling Process

[0082] The "recycling process" (S0103) is an optional process in this invention that involves recycling bagworm larvae used in the silk-spinning process along with their nests. The purpose of this process is to separate and recycle unwanted bagworm larvae from the substrate.

[0083] On the substrate after the silk-spinning process, bagworm larvae are present, mixed with the spinned support silk. However, bagworm larvae are not needed in the subsequent dissolution process. Furthermore, bagworm larvae that have stopped spinning silk need not be present even during the silk-spinning process. Furthermore, if bagworm larvae are treated with solvent along with the substrate and support silk in the dissolution process, undesirable staining of the bagworm larvae silk may occur due to body fluids of the bagworm larvae, extracts from dead leaves used for the nest, etc.; the possibility of mixing with nest silk may exist; and the substrate dissolution efficiency may be reduced due to the bagworm larvae and the nest. Therefore, although this process is optional, it is preferable to recover them before the dissolution process.

[0084] There is no limitation to the method for recovering bagworm larvae from the substrate. Any method for separating bagworm larvae from the substrate can be used. For example, the bagworm larvae in contact with the substrate can be peeled off along with their nests. However, for the purposes of the invention, a method that minimizes damage to the support silk is preferred. For example, the support silk can be induced to detach spontaneously from the substrate. As a specific example of this method, one can utilize the aforementioned property of bagworm larvae to move upwards, causing the substrate, previously positioned at the top of the container, to become the bottom surface by inverting it. The substrate can be recovered simply after the bagworm larvae have moved to the side of the container. Alternatively, heating the substrate can be used. The bagworm larvae detach spontaneously from the substrate to avoid the high temperature, so the substrate can be recovered simply after they have moved. The heating temperature only needs to be above room temperature, at a temperature that does not damage the bagworm larvae's silk and does not melt the substrate. For example, temperatures above 30°C, 33°C, 35°C, 38°C, 40°C, 42°C, 45°C, 48°C, or 50°C, and below 80°C, 75°C, 70°C, 65°C, 60°C, or 55°C are acceptable.

[0085] In addition, the recovered bagworm larvae can be reused in the production method of the present invention after being fed.

[0086] 2-2-4. Dissolving process

[0087] The "dissolving process" (S0104) is a process of dissolving the solvent-soluble substrate with a solvent, and is an essential process in this invention. In this process, the solid solvent-soluble substrate is dissolved and becomes liquid.

[0088] The solvent used in this process is a solvent capable of dissolving the solvent-soluble substrate used in the spinning process. For example, if a water-soluble substrate is used in the spinning process, the solvent is water (pure water) or an aqueous solution containing one or more solutes. Furthermore, if a low-polarity solvent-soluble substrate is used in the spinning process, the solvent is a low-polarity solvent capable of dissolving that substrate. As a specific example, if the low-polarity solvent-soluble substrate is polystyrene or an acrylic resin, various low-polarity solvents such as hexane, xylene, chloroform, and carbon tetrachloride can be used as the solvent.

[0089] The temperature of the solvent used in this process is not particularly limited, as long as it does not damage, modify, or dissolve the silk of the bagworm larvae, and is below the boiling point of the solvent. Generally, a room temperature range is sufficient, such as 1℃~35℃, 5℃~32℃, 10℃~30℃, 12℃~27℃, 15℃~25℃, or 18℃~20℃. However, generally speaking, the higher the solvent temperature of the solute, the more readily it dissolves. Especially in the case of water-soluble substrates, the higher the water temperature, the shorter the dissolution time of the substrate. Therefore, a higher solvent temperature is preferred for rapid dissolution of the substrate. For example, when the solvent is water, the water temperature at atmospheric pressure is preferably 35°C or higher, 38°C or higher, 40°C or higher, 42°C or higher, 45°C or higher, 48°C or higher, 50°C or higher, 52°C or higher, 55°C or higher, 58°C or higher, 60°C or higher, 62°C or higher, 65°C or higher, 68°C or higher, 70°C or higher, 72°C or higher, 75°C or higher, 78°C or higher, 80°C or higher, 82°C or higher, 85°C or higher, 88°C or higher, 90°C or higher, 92°C or higher, 95°C or higher, and 98°C or higher. Furthermore, the solvent may be preheated before this step and / or heated during this step.

[0090] The method of dissolving the substrate is not particularly limited as long as it allows the solvent-soluble substrate to come into contact with the solvent. Examples include immersing the solvent-soluble substrate in a solvent, and spraying or jetting the solvent onto the solvent-soluble substrate. The ejected support filaments can come into contact with the solvent. When immersing the solvent-soluble substrate in a solvent, the solvent can be stirred using, for example, a stir bar or stirring rod, to improve dissolution efficiency.

[0091] The dissolution time is the time until the solvent-soluble substrate is completely dissolved by the solvent. The specific time can be appropriately determined based on the substrate material, as well as the type, temperature, and amount of solvent. For example, when the substrate is polystyrene and has been treated by impregnation in xylene or carbon tetrachloride, the lower limit at room temperature is 5 seconds or more, 10 seconds or more, 15 seconds or more, 20 seconds or more, 25 seconds or more, 30 seconds or more, or 45 seconds or more, 50 seconds or more, or 60 seconds or more. Furthermore, the upper limit is 10 minutes or less, 8 minutes or less, 5 minutes or less, 3 minutes or less, or 2 minutes or less.

[0092] 2-2-5. Separation Process

[0093] The "separation step" (S0106) is a necessary step in this invention to separate the dissolved solvent-soluble substrate from the scaffold silk. After the dissolution step, the method for separating the solvent containing the substrate from the bagworm larva silk is not limited. Since the scaffold silk is a fibrous solid, and the solvent containing the substrate is a liquid, existing solid-liquid separation methods can be used. For example, separation can be performed using centrifugation with a dehydration device or similar method. Furthermore, without the aforementioned recovery step, the bagworm larvae, nest, and occasionally their excrement may also remain as solids. In this case, there are no limitations; for example, the scaffold silk can be wound around a rod or similar object and separated from the solvent, thereby simultaneously separating the scaffold silk from the bagworm larvae.

[0094] After this process, the scaffold silk for the target bagworm larvae can be obtained.

[0095] 2-2-6. Washing process

[0096] The "washing process" (S0107) is a process of washing the separated scaffold filaments. This process is optional and can be performed only as needed. This process is preferred when obtaining pure scaffold filaments that are not contaminated with solvent-soluble substrates.

[0097] In the scaffold filaments obtained after the separation process, solvent residues may sometimes remain from the solvent-soluble substrate. In this case, the solvent vaporizes, thus creating the possibility of repolymerization of the dissolved solvent-soluble substrate; therefore, it is preferable to completely remove the solvent by washing. Furthermore, during this process, a portion of feces or other contaminants adhering to the scaffold filaments can also be removed simultaneously.

[0098] In this process, the washing liquid used for washing can be the same solvent used in the dissolution process. If a low-polarity solvent is used in the dissolution process, other solvents with high affinity for that low-polarity solvent can also be used as the washing liquid. A highly volatile washing liquid is preferred. For example, if xylene is used as the solvent in the dissolution process, toluene, benzene (as other low-polarity solvents), or ethanol (as a polar solvent) can be used as the washing liquid. However, it is preferable to use a solvent that does not contain other components as the washing liquid. For example, if a water-soluble substrate is used, pure water (including warm water) is preferred over an aqueous solution containing other solutes.

[0099] There are no limitations on the washing method, as long as it removes the solvent used in the dissolution process from the scaffold silk. The washing solution can be sprayed onto the scaffold silk, or it can be immersed in the washing solution. Alternatively, the washing solution adhering to the scaffold silk can be removed after washing using the same method as in the separation process.

[0100] There is no limit to the number of washes. It can be performed once or multiple times. In this instruction manual, "multiple times" means, for example, 2–20 times, 2–15 times, 2–10 times, 2–7 times, 2–5 times, 2–4 times, or 2–3 times. Generally, multiple washes are preferred. When performing multiple washes, the washing solution used in each wash can be the same or different. Furthermore, the washing methods can be the same or different.

[0101] 2-2-7. Drying process

[0102] The "drying process" (S0108) is a process of drying the collected scaffold filaments, and is an optional process performed as needed in this invention. Solvent or washing liquid remains in the scaffold filaments obtained after the above separation process or the above washing process. In this process, the solvent or washing liquid remaining in the scaffold filaments after the separation process or the washing process is removed by drying. The desired scaffold filaments can be obtained after this process.

[0103] There are no particular limitations on the drying method as long as it does not modify or deteriorate the silk of the support and reduces the amount of residual solvent or washing liquid. Examples include natural drying methods (including sun drying) that expose the solvent or washing liquid to outside air to vaporize it, air drying methods that use a blower or other means to expose the solvent or washing liquid to warm or cold air, dehumidification drying methods that place the solvent or washing liquid in a closed space for a certain period of time with a desiccant, heating drying methods that evaporate the solvent or washing liquid by heating, depressurization drying methods that use a vacuum pump or other means to degas the container and cause it to evaporate, or combinations thereof.

[0104] The drying time can be appropriately determined based on the solvent or washing liquid used and the drying method. For example, when using easily vaporized solvents or washing liquids such as xylene or ethanol, and when drying by air drying, a drying time of 5 seconds to 10 minutes, 10 seconds to 5 minutes, or 20 seconds to 3 minutes is sufficient.

[0105] 2-3. Step 2

[0106] In the second process ( Figure 2B The process is characterized by using a thermally fusible material as the substrate. This process includes the following essential steps: a preparation step (S0101), a spinning step (S0102), a melting step (S0105), and a separation step (S0106); and the following selective steps: a recycling step (S0103), a washing step (S0107), and a drying step (S0108). Each step will be described below.

[0107] 2-3-1. Configuration Process

[0108] The configuration step (S0101) in the second process is a required step and is basically the same as the configuration step in the first process. Therefore, only the differences between the configuration step and the first process will be explained here.

[0109] This process differs from the preparation process in step 1 in that it uses a heat-fusible substrate instead of a solvent-soluble substrate.

[0110] There is no limitation on the type of heat-fusible substrate. All raw materials possessing the characteristics of heat-fusible substrates as defined above can be used. As a specific example of a heat-fusible substrate that can be used in the second process, wax can be cited. Waxes include plant-based waxes such as wood wax and animal-based waxes such as beeswax. Furthermore, regarding the shape and size of the heat-fusible substrate, it follows the shape and size of the solvent-soluble substrate used in the first process.

[0111] 2-3-2. Silk-spinning process

[0112] The "coating process" (S0102) in the second process is a necessary process. Except for the difference in using a heat-fusible substrate as the substrate, it is the same as the coating process in the first process. Therefore, this process can be performed simply by following the coating process in the first process.

[0113] 2-3-3. Recycling Process

[0114] The "recycling process" (S0103) in the second process is a necessary process and is basically the same as the recycling process in the first process. Therefore, this process can be carried out simply by following the recycling process in the first process.

[0115] 2-3-4. Melting process

[0116] The "melting process" (S0105) is a necessary characteristic process of the second process, which is a process of heating and melting a heat-fusible substrate. In this process, the solid substrate is dissolved and becomes liquid.

[0117] In this process, the heating temperature used to melt the heat-fusible substrate is higher than the melting point of the heat-fusible substrate, and there is no particular limitation as long as it does not damage, thermally modify, or dissolve the silk of the bagworm larvae. The lower limit of the heating temperature is the melting point, which varies depending on the heat-fusible substrate, so it can be appropriately determined according to the heat-fusible substrate used. Furthermore, if the temperature is below 260°C as described above, the silk of the bagworm larvae will not undergo thermal decomposition, so the upper limit of the heating temperature only needs to be below 260°C. However, if the silk of bagworm larvae is exposed to temperatures exceeding 200°C for an extended period, the possibility of damage or modification due to heat cannot be ruled out. Therefore, the upper limit of the heating temperature is preferably below the melting point of the heat-fusible substrate used, which is below +50°C, +45°C, +40°C, +35°C, +30°C, +25°C, +20°C, +15°C, +10°C, or +5°C.

[0118] There are no particular limitations on the method of melting the substrate, as long as it can heat the heat-fusible substrate. Examples include heating the heat-fusible substrate by placing it on a heater or hot plate, heating it in a microwave oven, exposing it to hot air, and melting it by immersing it in boiling water if the melting point of the heat-fusible substrate is less than 100°C.

[0119] The melting time is the time until the heat-fusible substrate is completely melted. The specific time can be appropriately determined based on the material of the heat-fusible substrate and the heating temperature. For example, if the substrate is beeswax with a melting point of 62°C, and the heating temperature is 80°C, the melting time can be 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, or 90 minutes.

[0120] 2-3-5. Separation process

[0121] The "separation process" (S0106) is a necessary step, which separates the scaffold filaments from the liquid fusible substrate. The separation process in the second step is essentially the same as that in the first step. In the first step, the solvent dissolved in the solvent-soluble substrate is separated from the scaffold filaments; however, in this step of the second step, the liquid fusible substrate is different. The scaffold filaments are fibrous solids, while the fusible substrate in this step is liquid during the melting process. Therefore, existing solid-liquid separation methods can be used, following the separation process of the first step. However, if the temperature in this step is lower than the melting point of the fusible substrate, the substrate begins to solidify through repolymerization. Therefore, the fusible substrate is prevented from repolymerizing before and during this step. For example, separation can be achieved by continuing heating at the same temperature as the melting process, applying a polymerization inhibitor or polymerization suppressant, or adding a diluent used in the washing process described below, thereby forming a mixture of the thermally fusible substrate and the diluent.

[0122] 2-3-6. Washing process

[0123] The "washing process" (S0107) is a selection process, which involves washing the separated scaffold filaments. The washing process in the second process is essentially the same as that in the first process. However, unlike the first process, the second process differs in how the molten, hot-melt substrate adheres to the separated scaffold filaments. Therefore, this difference will be specifically explained here.

[0124] In this process, if the temperature is below the melting point of the hot-melt substrate, the adhered substrate will repolymerize and solidify. Therefore, it is desirable that the hot-melt substrate be completely removed by washing.

[0125] The washing solution used is not particularly limited as long as it is a solvent that does not damage, modify, or dissolve the scaffold silk and has a temperature higher than the melting point of the heat-fusible substrate used. For example, in the case where the heat-fusible substrate is beeswax with a melting point of 62°C, the beeswax adhering to the scaffold silk can be melted and removed by using water at a temperature of 70°C or higher as the washing solution. A more preferred washing solution is a diluent with high affinity for the heat-fusible substrate. In this case, the temperature of the diluent does not necessarily need to be higher than the melting point of the heat-fusible substrate. Here, "diluent" refers to a solvent that can easily dissolve the molten heat-fusible substrate. For example, if the heat-fusible substrate is beeswax, solvents such as chloroform, carbon tetrachloride, and xylene can be used as diluents.

[0126] 2-3-7. Drying process

[0127] The "drying process" (S0108) in the second process is a selection process and is the same as the drying process in the first process. Therefore, this process can be carried out simply by following the drying process in the first process.

[0128] 2-4. Effects

[0129] Harvesting the scaffold silk of bagworm larvae spinning silk on a substrate without causing mechanical damage has been difficult in previous techniques.

[0130] According to the silk harvesting method and silk block production method of the present invention, instead of peeling off the support silk filaments spun by the bagworm larvae on the substrate, the silk is harvested by dissolving or melting the substrate itself, thus separating the liquid substrate from the fibrous bagworm larvae silk filaments. This solves the above-mentioned problem and stably obtains silk blocks formed solely from the support silk filaments of the bagworm larvae, which possess excellent mechanical properties.

[0131] 3. Nonwoven fabric made of support silk threads

[0132] 3-1. Overview

[0133] The second aspect of the present invention is a nonwoven fabric made from the support silk of the bagworm larvae. The nonwoven fabric of the present invention is made from filament blocks obtained using the production method of the first aspect.

[0134] 3-2. Composition

[0135] The filaments obtained by the production method of the first embodiment have the property of being spun on a substrate by the movement of the bagworm larvae, resulting in a mesh-like structure. Furthermore, when spun in several layers, a nonwoven fabric is formed on the substrate. Therefore, the filaments formed from the support silk of the bagworm larvae obtained by the production method of the first embodiment can be used as a nonwoven fabric in themselves.

[0136] Furthermore, in the production method of the first embodiment, by making the substrate three-dimensional and stacking scaffold filaments on its entire surface, the resulting filament block can become a nonwoven fabric that traces the three-dimensional shape of the substrate. By making the substrate into a desired three-dimensional shape, it can be used, for example, as a scaffold material for culturing cells in regenerative medicine, and as a natural nonwoven fabric without any impact on the human body.

[0137] Furthermore, the filaments obtained through the production method of Scheme 1 can also be further processed into nonwoven fabrics using existing nonwoven fabric manufacturing methods. There are no limitations on existing nonwoven fabric manufacturing methods; hydroentangling and needle punching can be used.

[0138] Example

[0139] <Method for producing filament blocks of bagworm larvae silk using water-soluble substrate>

[0140] (Purpose)

[0141] Using the method of the present invention, a filament block composed of the support silk of bagworm larvae is produced.

[0142] (Methods and Results)

[0143] The bagworm larvae used were the final instar larvae of the large bagworm moth (large bagworm larvae). The substrate used was a water-soluble substrate with gelatin as a solvent.

[0144] (1) Production of gelatin casting film

[0145] Gelatin used in medical capsules readily dissolves in water above 40°C. Therefore, gelatin capsules were used to create gelatin casting films as a substrate for the scaffold to spin silk. An appropriate amount of tap water was prepared in a beaker and heated to boiling using a hot stirrer. After boiling, gelatin capsules (manufactured by Capsules Japan Co., Ltd.) were dissolved at a concentration of 1 wt%. After dissolution, 10 mL of the solution was poured into a 9 cm plastic petri dish and allowed to dry at room temperature. Thus, a gelatin casting film with a diameter of 9 cm and a thickness of approximately 0.1 mm was obtained as a water-soluble substrate. Figure 3 a) Plastic petri dishes are used directly as supports for the substrate.

[0146] (2) Preparation and silk spinning of bagworm larvae

[0147] An ice cup (manufactured by Mineron Chemical Industry Co., Ltd.) was used as the container for spinning silk. One large bagworm larva was placed into each ice cup, and a gelatin casting film, prepared as a water-soluble substrate as described in (1), along with a plastic culture dish serving as a support, was used as the top cover of the ice cup, with the gelatin casting film forming the bottom surface. Then, the plastic culture dish was fixed to the ice cup using a protective strap. Figure 3 (b) Next, the bagworm larvae were allowed to spin silk for 5 days without being fed, at a temperature of 25°C and a light-to-dark ratio of 16:8. However, the initially introduced bagworm larvae stopped spinning silk on the second day and were therefore retrieved and replaced with new final-instar bagworm larvae of the larger bagworm moth.

[0148] (3) Recovery and dissolution of gelatin casting film

[0149] After the silk threads emerge, the gelatin-cast membrane and plastic culture dish are separated from the ice cup. At this moment, numerous support silk threads are extruded onto the surface of the gelatin-cast membrane. Figure 3 c). Next, the gelatin casting film was peeled off from the plastic petri dish. Figure 3 d) Immerse in boiling water with stirring for 5 minutes. Figure 3e). After the gelatin-cast film was completely dissolved in boiling water, the scaffold filaments suspended in the boiling water were taken. The taken scaffold filaments were then washed with fresh boiling water and dried at room temperature. As a result, [the desired product was obtained]. Figure 3 The scaffold silk shown in f. The surface of the harvested scaffold silk was examined using a stereomicroscope, and no gelatin residue was detected. It is clear from the above that the method for producing silk blocks from bagworm larvae of the present invention can yield silk blocks composed solely of pure scaffold silk.

[0150] All publications, patents and patent applications referenced in this specification are incorporated herein by direct reference.

Claims

1. A method for producing silk clumps from bagworm larvae, comprising the following steps: The preparation process involves combining bagworm larvae with a solvent-soluble substrate. The silk-spinning process allows bagworm larvae to spin silk on a solvent-soluble substrate; The dissolution process involves dissolving a solvent-soluble substrate using a solvent; and The separation process separates the solvent-soluble substrate from the silk filaments spun by bagworm larvae on the substrate. The solvent is one that does not damage, modify, or dissolve the silk of bagworm larvae.

2. The method according to claim 1, further comprising a recycling step after the silk-spinning step and before the dissolving step: recycling the bagworm larvae together with the nest.

3. The method according to claim 1 or 2, wherein the solvent is water.

4. The method according to claim 1 or 2, wherein the solvent is a low-polarity solvent.

5. A method for producing silk clumps from bagworm larvae, comprising the following steps: The preparation process involves combining bagworm larvae with a heat-fusible substrate. The silk-spinning process enables bagworm larvae to spin silk on a heat-fusible substrate; The melting process involves heating a heat-fusible substrate to a temperature at which the silk of the bagworm larvae is not damaged, not thermally modified, and not melted. as well as The separation process separates the heat-fusible substrate from the silk filaments of the bagworm larvae that have been spun onto the substrate.

6. The method according to claim 5, further comprising a recycling step after the silk-spinning step and before the melting step: recycling the bagworm larvae together with the nest.

7. The method according to any one of claims 1, 2, 5 and 6, further comprising the washing step of washing the separated bagworm larvae silk.

8. The method according to any one of claims 1, 2, 5 and 6, further comprising the following drying step: drying the separated bagworm larvae silk.

9. The method according to any one of claims 1, 2, 5 and 6, wherein the substrate is disposed on the support.

10. The method according to any one of claims 1, 2, 5 and 6, wherein the substrate has a planar shape or a three-dimensional shape.

11. A nonwoven fabric made from bagworm larvae silk obtained by the method for producing filaments according to any one of claims 1 to 10.

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