JP2008260238A - Manufacturing method for vegetable fiber molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a vegetable fiber molding which can obtain a molding using a lignin contained in the vegetable fiber. <P>SOLUTION: This manufacturing method for a vegetable fiber molding comprises the matting process of forming a mat 20 containing the vegetable fiber, the vapor treatment process of exposing the mat 20 to a steam at 150°C or higher within a pressure oven 16 to which the steam is supplied from a boiler 15, and the molding process of obtaining the molding 21 by shaping the vapor treated mat 20, under pressure using a heat press 17. Further, after the vapor treatment process and before the molding process, it is possible to add the moisture removal process of reducing the moisture content of the mat 20 to not more than 30%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a plant fiber molded body. More specifically, the present invention relates to a method for producing a plant fiber molded body that is molded using lignin contained in plant fibers.

In recent years, plant resources that absorb a large amount of carbon dioxide have attracted attention from environmental viewpoints such as reduction of carbon dioxide emissions and fixation of carbon dioxide, and are expected especially for alternative uses such as resin moldings using fossil fuels. Yes. However, among plant bodies, plant fibers mainly used are difficult to maintain a sufficient shape only by entanglement between plant fibers, and it is also difficult to perform free shaping. Therefore, the binder component is normally mix | blended with the plant fiber, and it is utilized as the composite material to which sufficient shaping property which can maintain the entanglement state of fibers was provided.
However, a synthetic resin binder using fossil fuel is not preferable from the above environmental viewpoint. On the other hand, there is a problem that a binder component such as polylactic acid that can be biosynthesized and biodegradable is expensive. In addition, a technique using a lignin-based material collected or collected from plant resources as a binder component is disclosed in Patent Document 1 below.

JP 2006-7534 A

However, the technique disclosed in Patent Document 1 extracts lignin contained in a plant body by various methods, and adds the lignin to the cellulosic material again to obtain a molded body. In addition, in order to improve the processability and handleability, usually, there is a complexity that a processing operation for converting this lignin into lignophenol or the like is required.
This invention is made | formed in view of the said prior art, and aims at providing the manufacturing method of the plant fiber molded object which can obtain a molded object using the lignin contained in plant fiber. .

That is, the present invention is as follows.
(1) matting step for forming a mat containing plant fibers;
A steam treatment step of exposing the mat to water vapor at a temperature of 150 ° C. or higher;
And a molding step of forming a molded body by pressurizing the steam-treated mat, and producing the plant fiber molded body.
(2) The manufacturing method of the vegetable fiber molded object as described in said (1) whose vapor pressure of the said steam treatment process is 1.7-2 Mpa.
(3) The plant fiber molded body according to (1) or (2), further including a water removal step for reducing the moisture content of the mat to 30% or less after the steam treatment step and before the molding step. Manufacturing method.
(4) The said formation process is a manufacturing method of the vegetable fiber molded object in any one of said (1) thru | or (3) which is a process of heating in addition to the said pressurization.
(5) The molding step is any one of the above (1) to (4), which is performed using a hot press die provided with a release agent on the die surface or a hot press die having a die surface made of a fluororesin. The manufacturing method of the vegetable fiber molded object of description.
(6) The manufacturing method of the vegetable fiber molded object in any one of said (1) thru | or (5) whose fiber which comprises the said mat is only the said vegetable fiber.

  According to the method for producing a plant fiber molded body of the present invention, a molded body can be obtained using lignin contained in the plant fiber. In particular, lignin contained in plant fibers can be used without being collected and separated, and a molded product can be obtained using only plant fibers without adding a binder component to the plant fibers. it can. In this case, no harmful substances are generated by incineration and high environmental performance is obtained. Moreover, since it is not necessary to add a binder component, a molded product can be obtained at low cost. Further, when wood is used, since the wood itself is not flexible, a foaming (lamination) step is required after performing the steam treatment in the previous step, but this method does not require a subsequent step. In addition, a steam-treated mat can be obtained in a simple manner, and the work efficiency and workability at the time of transport for performing the subsequent process {for example, boarding (hot press molding) and the like} are excellent. Furthermore, plant fibers generally have a smaller specific gravity than the binder component, and it is difficult to uniformly disperse and mix them. However, in the production method of the present invention, a molded product can be obtained without using the binder component. Does not occur.

When the vapor pressure in the vapor treatment step is 1.7 to 2 MPa, a molded article having excellent lignin exudation effect and excellent strength and formability can be obtained.
When a moisture removal step is performed after the steam treatment step and before the molding step to reduce the moisture content of the mat to 30% or less, the safety in the molding step is improved, and further higher strength and shapeability are achieved. A molded body provided is obtained.
When the molding step is a step of heating in addition to pressurization, a molded body having higher strength and formability can be obtained.
If the molding process is performed using a hot press mold with a mold release agent applied to the mold surface, or a hot press mold with a mold surface made of a fluororesin, even if lignin is exuded to the surface of the plant fiber, it is smooth. Demolding can be performed, and a more precise desired shape can be easily obtained, and particularly excellent moldability can be obtained.
When the fibers constituting the mat are only plant fibers, no harmful substances are generated by incineration and high environmental performance is obtained. In addition, a large amount of lignin that can be used can be secured, and the strength and shapeability of the resulting molded body are excellent.

Hereinafter, the present invention will be described in detail.
The method for producing a plant fiber molded body of the present invention comprises a matting step for forming a mat containing plant fibers,
A steam treatment step of exposing the mat to water vapor at a temperature of 150 ° C. or higher;
A molding step of shaping the steam-treated mat while pressurizing it to obtain a molded body.

The “matting step” is a step of forming a mat containing plant fibers.
The “plant fiber” is a fiber obtained from a plant. The type of plant fiber is not particularly limited. Examples thereof include plant fibers obtained from various plant bodies such as wheat, rice, bamboo, various conifers (such as cedar and cypress), broad-leaved trees, and cotton. These may use only 1 type and may use 2 or more types together.

Moreover, the collection site | part of the plant fiber in a plant body is not specifically limited, You may use the plant fiber collected from any site | part which comprises plant bodies, such as a wood part, a non-wood part, a leaf part, a stem part, and a root part. Furthermore, only plant fibers obtained from a specific part may be used, or plant fibers obtained from two or more different parts may be used in combination.
In addition, the kenaf in this invention is an early-growing annual grass which has a wooden stem, and is a plant classified into the mallow family. Hibiscus cannabinus and hibiscus sabdariffa etc. under the scientific name are included, and further, red corn, cucumber kenaf, western hemp, taykenaf, mesta, bimli, umbari and bombay hemp, etc. under the common names are included.
The jute in the present invention is a fiber obtained from jute hemp. This jute hemp shall include hemp and linden plants including jute (Chorus corpus capsularis L.), and hemp (Tunaso), Shimatsunaso and Morohaya.

  Although the shape of a vegetable fiber is not specifically limited, Usually, fiber length is 10 mm or more. If the fiber length is 10 mm or more, it is easy to obtain higher strength (bending strength, bending elastic modulus, etc.) in the obtained plant fiber molded body. The fiber length is preferably 10 to 150 mm, more preferably 20 to 100 mm, and particularly preferably 30 to 80 mm. Furthermore, the fiber diameter is usually 1 mm or less. When the fiber diameter is 1 mm or less, particularly high strength is obtained in the obtained plant fiber molded body. The fiber diameter is preferably 0.01 to 1 mm, more preferably 0.05 to 0.7 mm, and particularly preferably 0.07 to 0.5 mm. Furthermore, it is preferable that it is 1-10 dtex. Moreover, it is preferable to suppress the fiber of the form which remove | deviates from the said range to 10 mass% or less of the whole plant fiber. Thereby, the strength of the molded body obtained can be maintained high.

The “mat” is a non-woven fabric formed of fibers containing the plant fibers. The density of the mat is not particularly limited, but is preferably 0.5 g / cm ³ or less (usually 0.1 g / cm ³ or more, more preferably 0.13 to 0.2 g / cm ³ ). In this range, in the steam treatment step, the steam sufficiently acts between the constituent fibers, and it becomes possible to exude lignin from the plant fibers more evenly, and the strength of the obtained molded body can be improved. In addition, the basis weight is preferably 3000 g / m ² or less (usually 1200 g / m ² or more). In this range, in the steam treatment step, the steam sufficiently acts between the constituent fibers, and it becomes possible to exude lignin from the plant fibers more evenly, and the strength of the obtained molded body can be improved.
Furthermore, the thickness of the mat is not particularly limited, but is usually 5 mm or more (further 5 to 70 mm, particularly 7 to 50 mm, usually 100 mm or less).
The weight per unit area (g / m ² ) referred to in the present invention is a value obtained by measuring the mass per 1 m ² with an electronic scale or the like with a moisture content of 10%. The density (g / cm ³ ) is a value calculated by converting the weight per unit area (g / m ² ) to g / cm ³ and dividing by the mat thickness (cm) measured with calipers. .

  Matting in the matting step may be performed by any method, but usually a dry method or a wet blending method is used. Among these, examples of the dry method include an airlay method and a card method. Moreover, a papermaking method is mentioned as a wet method. Among these, it is preferable to use a dry method. This is because the dry method has higher production efficiency than the wet method, particularly when plant fibers having a length in the preferred range as described above are used.

  In the matting step, the mat obtained through the airlay method, the card method, or the like can be post-processed. As post-processing, for example, the entanglement between the plant fibers in the mat is strengthened, the mat is multilayered (especially when the card method is used, the mat before cutting can be folded and multilayered), The thickness of the mat can be reduced by pressing or the like. Among the methods described above, methods for performing the step of entanglement (entanglement step) include a needle punch method, a stitch bond method, a water punch method, and the like. Of these, the needle punch method is preferred because of its high efficiency.

The mat used in the present invention may contain fibers other than the plant fibers. Examples of other fibers include synthetic fibers (biodegradable polymer fibers such as polylactic acid fibers and thermoplastic resin fibers such as polyolefin resin fibers). These other fibers may use only 1 type and may use 2 or more types together. When these other fibers are contained, the content of the other fibers is 90% by mass or less (more than 100% by mass of the entire mat when the moisture content of the mat is maintained at 10% (equilibrium moisture content)). It is preferable to set it as 30-70 mass%).
The mat used in the present invention may contain other fibers, but may be composed only of plant fibers. When it consists only of plant fiber, the mixing process with a resin fiber etc. is not required, a manufacturing process becomes simple and manufacturing efficiency can be raised significantly.

  Furthermore, the mat used in the present invention can contain other components in addition to the above fibers. Examples of other components include hydrolysis inhibitors, antistatic agents, flame retardants, antibacterial agents, and coloring agents. These may use only 1 type and may use 2 or more types together. When these other components are contained, the content of the other components is 5% by mass or less based on 100% by mass of the entire mat when the moisture content of the mat is maintained at 10% (equilibrium water content). More preferably, it is preferable to set it as 0.1-1 mass%. Within this range, the biodegradability of the resulting molded article is particularly difficult to inhibit.

  The “steam treatment step” is a step of exposing the mat to water vapor having a temperature of 150 ° C. or higher. The lignin component contained in the plant fiber is considered to be leached from the inside of the fiber toward the fiber surface through this steam treatment process. However, the present inventors have found that the plant fiber exuded with the lignin component has a reduced flexibility and becomes brittle, and it is difficult to form a mat from the embrittled plant fiber. This is because the fragile plant fibers cannot be normally formed due to clogging in a machine for matting. For this reason, in this invention, after performing the said matting process, a steam processing process is performed. By carrying out like this, it can shape | mold smoothly using the lignin exuded from the matted plant fiber.

  In the steam treatment process, the mat is usually exposed to water vapor in a closed system. Therefore, it is preferable to perform exposure to water vapor in a pressure vessel. Moreover, the temperature of the water vapor | steam in a steam processing process should just be 150 degreeC or more. This is because by setting the water vapor temperature to 150 ° C. or higher, the bending elastic modulus of the molded body can be greatly improved as compared with the case of using water vapor at a temperature lower than that. The upper limit of the water vapor temperature is not particularly limited, but is preferably 250 ° C. or lower. This is because the strength of the molded body can be maintained high by suppressing the water vapor temperature to 250 ° C. or lower.

  The steam temperature in this steam treatment step is preferably 165 ° C. or higher. This is because by setting the temperature to 165 ° C. or higher, the bending strength of the molded body can be greatly improved as compared with the case of using steam at a temperature lower than that. Furthermore, the water vapor temperature is preferably set to 220 ° C. or lower. Thereby, the characteristics of both the bending strength and the bending elastic modulus can be maintained high with a good balance. Moreover, as for this water vapor temperature, 170-205 degreeC is more preferable, 170-195 degreeC is still more preferable, 170-190 degreeC is especially preferable. This is because, in this range, particularly high bending strength and bending elastic modulus can be obtained at the same time.

In addition, the vapor pressure in the steam treatment step is not particularly limited as long as it can be the above-described steam temperature. For example, it is preferably 1.5 to 2.5 MPa, and 1.7 to 2.0 MPa. Is more preferable. In this range, the burden on the mat to be steamed is small and the lignin exudation effect can be maintained high.
Further, the steam treatment time (time for exposure to steam in the above temperature range) is not particularly limited, but is usually 5 minutes or more. By performing the treatment for 5 minutes or more, it is easier to obtain the effect of performing the steam treatment, and it is particularly preferable to carry out the treatment for 7 minutes or more. Further, this steam treatment time may be applied as much as possible, but is preferably 60 minutes or less from the viewpoint of production efficiency, and more preferably 35 minutes or less.

Moreover, after performing this steam treatment process, the moisture removal process which reduces the moisture content of the mat which performed the steam treatment can be provided.
By providing the “moisture removal step”, pressurization can be performed more safely even when pressurization is performed in the subsequent molding step. The amount of water to be removed in this water removal step is not particularly limited, but it is preferable to reduce the moisture content of the mat to 30% or less. By making this moisture content 30% or less, in addition to being able to perform a shaping | molding process more safely, the intensity | strength of the obtained molded object can be maintained higher. Furthermore, more accurate molding can be performed. In this step, the moisture content of the mat is usually required to be 10 to 30%, and may be lowered to 10% or less, but it is not usually necessary.

The “molding step” is a step of obtaining a molded body by shaping a steam-treated mat while applying pressure. By providing this step, the plant fibers can be maintained and shaped in a strongly bonded state using the lignin leached from the plant fibers in the steam treatment step.
Although the pressurization pressure in this shaping | molding process is not specifically limited, It is preferable to set it as 1-10 Mpa, and it is more preferable to set it as 1-5 Mpa.

  Further, in this molding step, it is possible to perform the molding without heating if there is residual heat remaining from other steps performed before the molding step, but it is preferable to perform the heating. This heating may be performed simultaneously with the pressurization, or may be performed in advance prior to the pressurization, but it is more preferable from the viewpoint of production efficiency to perform the heating at the same time (that is, performing hot pressing).

  The heating temperature in this molding step is not particularly limited, but it is preferable that the temperature in the mat to be molded is 180 ° C. or higher. Since lignin has thermosetting properties, it can be considered that plant fibers can be more reliably bonded to each other by setting the temperature to 180 ° C. or more, and this bonding force can be easily maintained. The heating temperature is preferably 195 to 255 ° C, and more preferably 200 to 250 ° C. In this range, higher moldability can be obtained, and higher strength can be obtained in the molded body. When performing this heating, in order to obtain the effect of pressurization more reliably, pressurization for 30 seconds or more is preferable, and pressurization is more preferably performed for 1 to 5 minutes.

  In the molding step, any mold may be used, but preferably a hot press mold in which a mold release agent is applied to the mold surface or a hot press mold in which the mold surface is made of a fluororesin is used. Is preferred. This makes it easier to obtain a desired shape. That is, the lignin exuded from the plant fiber adheres to the mold surface, and the mold can be smoothly demolded without hindering the mold demolding. Thereby, it is easy to obtain a more precise desired shape, and particularly excellent moldability is obtained.

[2] Plant fiber molded body The shape, size, thickness and the like of the plant fiber molded body obtained by the production method of the present invention are not particularly limited. Further, its use is not particularly limited. Examples of the plant fiber molded body include interior materials, exterior materials, and structural materials such as automobiles, railway vehicles, ships, and airplanes. Among these, examples of the automobile article include an automobile interior material, an automotive instrument panel, and an automotive exterior material. Specifically, door base material, package tray, pillar garnish, switch base, quarter panel, armrest core material, automobile door trim, seat structure material, console box, automobile dashboard, various instrument panels, deck trim, bumper, Examples include spoilers and cowlings. Furthermore, for example, interior materials such as buildings and furniture, exterior materials, and structural materials may be mentioned. That is, a door cover material, a door structure material, a cover material of various furniture (desk, chair, shelf, bag, etc.), a structural material, etc. are mentioned. In addition, a package, a container (such as a tray), a protective member, a partition member, and the like can be given.

Hereinafter, the present invention will be specifically described with reference to Examples and FIGS.
[1] Production Example 1 of Plant Fiber Molded Body
The jute (plant fiber) cut to about 65 mm was supplied from the plant fiber supply unit (11 in FIG. 1) to the card machine (12 in FIG. 1) to obtain a laminate composed only of plant fibers. Further, this laminate is punched using a needle punch (13 in FIG. 1) to give three-dimensional entanglement strength between plant fibers, and then cut into a predetermined size by a cutting machine (14 in FIG. 1). Thus, a mat (20 in FIG. 1) was obtained (mat forming step). The obtained mat had a thickness of 10 to 15 mm, a density of 0.13 to 0.2 g / cm ³ , and a basis weight of 2 kg / m ² .
The resulting mat (20 in FIG. 2) is carried into a pressure vessel (16 in FIG. 2), steam with a steam temperature of 200 ° C. is sent from the boiler (15 in FIG. 2), and the vapor pressure in the pressure vessel is maintained at 2 MPa. However, the mat was exposed to water vapor for 10 minutes (steam treatment step).
Next, the supply of steam into the pressure vessel was stopped, and the inside of the pressure vessel was evacuated using a vacuum device (not shown) to reduce the moisture content of the mat to 10% (moisture removal step).
Thereafter, a mat subjected to steam treatment and moisture removal processing is taken out from the pressure vessel, and a heat press machine having a mold (171 in FIG. 2) whose surface is processed with fluororesin (Teflon (registered trademark)) (FIG. 2). 2) and sandwiched between the above molds heated to 230 ° C. together with a spacer having a thickness of 2.3 mm, and subjected to hot pressing at a pressure of 1.18 MPa (12 kgf / cm ² ) for 3 minutes (molding step) . Then, it removed from the metal mold | die and obtained the plant fiber molded object (21 of FIG. 2) which consists only of plant fiber. The obtained plant fiber molded body had a thickness of 2.3 mm and a density of 0.8 g / cm ³ .

Example 2
Except for the treatment conditions in the steam treatment step being a steam temperature of 180 ° C., a plant fiber molded body (thickness 2.3 mm, density 0.8 g / cm ³ plate made only of plant fibers) is the same as in Example 1. A shaped molding) was obtained.

Example 3
Except for the treatment conditions in the steam treatment step being a steam temperature of 180 ° C. and a treatment time of 30 minutes, a plant fiber molded body consisting of only plant fibers (thickness 2.3 mm, density 0.8 g) as in Example 1. / Cm ³ plate-like molded product).

Example 4
Except for the treatment conditions in the steam treatment step being a steam temperature of 160 ° C. and a treatment time of 30 minutes, a plant fiber molded body consisting of only plant fibers (thickness 2.3 mm, density 0.8 g) as in Example 1. / Cm ³ plate-like molded product).

Comparative Example 1
After performing the matting process, the steam treatment process and the water removal process are not performed, and the molding process is performed to produce a plant fiber molded body made of only plant fibers (thickness 2.3 mm, density 0.8 g / cm ³ plate) A shaped molding) was obtained. Various conditions in the matting process and the molding process are the same as in Example 1.

[2] Evaluation of plant fiber molded body (1) Characteristic evaluation before wet aging For each of the plant fiber molded bodies obtained in Examples 1 to 4 and Comparative Example 1, the bending strength and the flexural modulus were measured. In this measurement, a plate-shaped test piece made of each plant fiber shaped body having a thickness of 2.3 mm, a width of 50 mm, and a length of 150 mm in a density of 0.8 g / cm ³ and a water content of about 10% is used. It was. Each test piece is supported at two fulcrums (curvature radius 3.2 mm) with a fulcrum distance (L) of 100 mm, and a speed of 50 mm / min from an action point (curvature radius 3.2 mm) arranged at the center between the fulcrums. The maximum load (P) immediately before the fracture of each test piece was measured. The bending strength of each specimen was calculated using the obtained maximum load (P) and the following formula (1) (based on JIS K7171). Further, using this result, the flexural modulus (MPa) was calculated according to JIS K7171. The results are shown in Table 1.
Bending strength (MPa) = 3PL / 2Wt ² (1)
However, P in Formula (1) is the maximum load, L is the distance between fulcrums, W is the width of the test piece, and t is the thickness of the test piece.

(2) Characteristic evaluation after wet aging and wet aging Each test piece of Examples 1 to 4 and Comparative Example 1 was taken out after placing in an environment of temperature 50 ° C. and humidity 95% RH for 400 hours, and at room temperature and normal humidity The bending strength and bending elastic modulus of each test piece, which was allowed to stand at (23 ° C., 65% RH) for 1 day and the water content became about 10%, were measured before wet aging in the above [2] (1). The measurement was performed in the same manner, and the results are shown in Table 1.

(3) Effects of Examples From the results in Table 1 above, the bending strength before and after wet aging of the molded body of Example 4 subjected to the steam treatment exposed to steam at 160 ° C. for 30 minutes is a comparison in which the steam treatment is not performed. Although there is no significant difference from the molded body of Example 1, the flexural modulus is found to be a significant increase of 2.2 times in Example 4 with respect to the flexural modulus of Comparative Example 1 before wet aging. This is considered to be because lignin exudes from the plant fiber by steam treatment, and a high elastic modulus is obtained by the action of this lignin.

  In addition, the molded body of Example 3 subjected to the steam treatment by being exposed to water vapor at 180 ° C. for 30 minutes has a bending strength of 2.7 times that of Comparative Example 1 before wet aging and 3.6 after wet aging. Doubled, a significant improvement is observed. Further, the bending elastic modulus is 2.7 times before moisture aging and 4.5 times after moisture aging, and a further significant improvement is recognized. Moreover, in this Example 3, both the bending strength before and after wet aging and the bending elastic modulus after wet aging are excellent as compared with Example 4.

Furthermore, although the molded article of Example 2 subjected to the steam treatment by being exposed to water vapor at 180 ° C. for 10 minutes has excellent strength, compared with Example 4, both of the characteristics are deteriorated after aging. From this, it can be seen that it is effective to perform the treatment for a longer time even at the same water vapor temperature in order to improve the durability of moisture.
Further, the molded body of Example 1 subjected to the steam treatment exposed to water vapor at 200 ° C. for 10 minutes has excellent strength, but the strength characteristics before wet aging are small as compared with Examples 2 and 3. However, the change before and after wet aging is minimized in the examples. This shows that a higher water vapor temperature in the water vapor treatment is effective for the purpose of improving the moisture aging characteristics.

  The method for producing a plant fiber molded body of the present invention is widely used in the fields related to automobiles and fields related to architecture. It is particularly suitable for interior materials, exterior materials, and structural materials for automobiles, railway vehicles, ships, airplanes, etc., and among them, it is suitable for automobile interior materials, automotive instrument panels, automotive exterior materials, etc. is there. Specifically, door base material, package tray, pillar garnish, switch base, quarter panel, armrest core material, automobile door trim, seat structure material, console box, automobile dashboard, various instrument panels, deck trim, bumper, Examples include spoilers and cowlings. Furthermore, it is also suitable for interior materials, exterior materials and structural materials such as buildings and furniture. Specifically, door cover materials, door structure materials, cover materials for various furniture (desks, chairs, shelves, bags, etc.), structural materials, and the like can be given. In addition, it is also suitable as a package, a container (such as a tray), a protective member, and a partition member.

It is typical explanatory drawing explaining a matting process. It is typical explanatory drawing explaining a water vapor treatment process and a formation process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11; Plant fiber supply part (hopper), 12; Card machine, 13; Needle punch, 14: Cutting machine, 15; Boiler, 16; Pressure pot, 17; Molding machine, 171; Plant fiber molded body.

Claims (6)

Matting step for forming a mat containing plant fibers;
A steam treatment step of exposing the mat to water vapor at a temperature of 150 ° C. or higher;
And a molding step of forming a molded body by pressurizing the steam-treated mat, and producing the plant fiber molded body.   The method for producing a plant fiber molded body according to claim 1, wherein the steam pressure in the steam treatment step is 1.7 to 2 MPa.   The manufacturing method of the vegetable fiber molded object of Claim 1 or 2 provided with the water | moisture-content removal process which reduces the moisture content of the said mat to 30% or less after the said steam treatment process and before the said shaping | molding process.   The said shaping | molding process is a process of heating in addition to the said pressurization, The manufacturing method of the vegetable fiber molded object in any one of Claims 1 thru | or 3.   The vegetable fiber shaping | molding in any one of the Claims 1 thru | or 4 which perform the said shaping | molding process using the hot press type | mold which gave the mold release agent to the type | mold surface, or the hot press type | mold which the type | mold surface consists of a fluororesin. Body manufacturing method.   The method for producing a plant fiber molded body according to any one of claims 1 to 5, wherein the fibers constituting the mat are only the plant fibers.

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