JP2006150819A - Bamboo fiber reinforced plastic and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bamboo fiber reinforced plastic excellent in mechanical characteristics such as flexural strength. <P>SOLUTION: Rope-like bamboo fibers obtained by intertwisting fibers of bamboo culms into a shape of rope and/or fibers of bamboo culms are placed into a mold in the state that they are trued up to the lengthwise direction, a thermosetting resin is charged into the mold, and compression hot molding or the like is performed to produce a bamboo reinforced plastic. In the bamboo fiber reinforced plastic manufactured, the fibers of bamboo culms or rope-like bamboo fibers are aligned to the direction of their length, and, because of this, mechanical characteristics such as flexural strength and the like become excellent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plastic reinforced with bamboo cocoon fibers and a method for producing the same.

There is a product in which bamboo cocoon fibers are mixed into a thermoplastic resin to produce a pellet, and then this pellet is used for injection molding to produce a product.
Bamboo grows quickly, and even if it is cut down, it will be in a state of only a few years. Bamboo cocoon fibers are 1.5 times stronger than steel bars. Therefore, by mixing bamboo cocoon fibers, the strength of the plastic can be improved, and it can be manufactured at a lower cost than plastics mixed with glass fiber, carbon fiber, or the like. Further, mixing bamboo fiber in a large amount has an advantage that disposal becomes easier than plastic reinforced with glass fiber or carbon fiber.
However, in the injection molding using pellets, only bamboo short fibers can be used, and the process of refining bamboo fibers is complicated. In addition, the bending strength is insufficient as compared with plastics reinforced with glass fiber or carbon fiber.

  An object of the present invention is to provide a bamboo fiber reinforced plastic that eliminates the above-mentioned drawbacks and is excellent in mechanical properties such as bending strength.

  In order to achieve the above object, the present inventor has conducted intensive research, and as a result, when the bamboo cocoon fiber is molded and cured with a thermosetting resin in a state where the length direction is aligned, the bending strength of the resulting bamboo fiber reinforced plastic, etc. As a result, the present inventors have found that the mechanical properties of these are significantly improved.

That is, the bamboo fiber reinforced plastic according to claim 1 is obtained by molding and curing bamboo cocoon fibers with a thermosetting resin in a state where they are aligned in the length direction.
The bamboo fiber reinforced plastic according to claim 2 is formed and cured with a thermosetting resin in a state in which bamboo cocoon fibers are aligned in the length direction and bundled.
The bamboo fiber reinforced plastic according to claim 3 is obtained by molding and curing a rope-like bamboo fiber obtained by twisting bamboo cocoon fibers into a rope shape with a thermosetting resin in a state where the fibers are aligned in the length direction.
The bamboo fiber reinforced plastic according to claim 4 is prepared by aligning the bamboo-like bamboo fibers and / or the bamboo cocoon fibers obtained by twisting bamboo cocoon fibers into a rope shape in the length direction.
Further, at least one member of the group consisting of bamboo cocoon fiber, glass fiber, and carbon fiber is molded and cured with a thermosetting resin in a state where the directions are not aligned.
The manufacturing method according to claim 5, the rope-like bamboo fibers obtained by twisting bamboo cocoon fibers and / or the bamboo cocoon fibers are put in a mold in a state of being aligned in the length direction,
Next, after the thermosetting resin is put into the mold, compression heating molding is performed.
The manufacturing method of Claim 6 impregnated the thermosetting resin in the state which aligned the rope-like bamboo fiber which twisted the bamboo cocoon fiber and / or the bamboo cocoon fiber in the length direction. After that, it is put into a mold and subjected to compression heating molding.
In the manufacturing method according to claim 7, the thermosetting resin is applied in a state in which the bamboo-like bamboo fibers obtained by twisting bamboo cocoon fibers and / or the bamboo cocoon fibers are aligned in the length direction. After that, it is put into a mold and subjected to compression heating molding.
In the manufacturing method according to claims 6 and 7, after impregnating or applying the thermosetting resin into the mold, the thermosetting resin may be further introduced into the mold.
In addition, the bamboo cocoon fiber of each of the above production methods is preferably formed by boiling the bamboo cocoon in a high-pressure kettle to decompose bamboo hemicellulose and lignin, and then defibrating to make a fiber.

  The thermosetting resin may be any of phenol resin, epoxy resin, unsaturated polyester resin, urethane resin, melamine resin, urea resin, and the like.

Bamboo fiber reinforced plastic improves the bending strength by about 2 to 5 times compared to the one not containing bamboo cocoon fiber.
In addition, the bamboo cocoon fibers used are cheaper than glass fibers and carbon fibers, and fiber reinforced plastics can be manufactured at low cost. In addition, there are advantages that glass fiber and carbon fiber do not have, such as easy disposal.
Furthermore, if the bamboo cocoon fibers are twisted in a rope shape as in the inventions of claims 3 to 7, they can be placed side by side in a mold, and can be used after being cut to a desired length.
Further, as in the invention of claim 4, when at least one of bamboo cocoon fiber, glass fiber and carbon fiber is further added without aligning the direction, the bending strength in all directions is improved.
When the bamboo cocoon fiber is manufactured as in the ninth aspect of the invention, the decomposition of hemicellulose and lignin is better than when steam is used, and the bamboo cocoon fiber is easily taken out without being cut halfway. Further, the steam generator and the pipe for introducing the steam can be omitted, and the equipment is simple.

  Embodiments of the present invention will be described below.

First, the bamboo cocoon fiber used in the present invention is manufactured as follows. Cut bamboo such as bamboo and bamboo shoots, and cut the leaves after dropping the leaves into several centimeters to 2 meters to make bamboo.
Next, the bamboo material is put into a high-pressure kettle together with water or hot water, and the temperature of the water or hot water is raised and the pressure in the kettle is raised to boil the bamboo material under high temperature and high pressure. At this time, water or hot water may be added under reduced pressure.
Thereafter, the bamboo material is taken out from the high-pressure kettle, and is defibrated using a defibrating machine to form fibers.

Next, the produced bamboo cocoon fiber is cut into a desired length and aligned in a mold. Alternatively, the produced bamboo cocoon fibers are cut into a desired length and bundled into a mold.
Thereafter, a thermosetting resin is put into the mold.
The thermosetting resin may be any of powder, granule, and liquid, and the charging includes both adding powder or granule and pouring liquid.
The thermosetting resin may be any known one such as a phenol resin, an epoxy resin, an unsaturated polyester resin, a urethane resin, a melamine resin, or a urea resin.
And the bamboo fiber reinforced plastics of desired shapes, such as a board | plate material, are obtained by compression thermoforming.
Bamboo cocoon fibers are preferably placed in bamboo fiber reinforced plastic in a weight ratio of 10 to 75%, but if the weight ratio is 1 to 90%, the weight ratio is 10 to 75%. Although it is somewhat inferior, the effect that mechanical characteristics, such as bending strength, improve is acquired.

The obtained bamboo fiber reinforced plastic has a bending strength in the direction orthogonal to the length direction of the mixed bamboo fiber of about 2 to 5, although it varies depending on the mixing ratio of the bamboo fiber as compared with the plastic not mixed with the bamboo fiber. Double the improvement.
It is recommended to use it for those that place great importance on bending strength, such as beam-shaped parts.

  Next, another embodiment will be described.

The method of manufacturing the bamboo cocoon fiber is the same as that of the above embodiment, and the subsequent manufacturing method is different.
That is, a plurality of bamboo bamboo fibers produced are twisted into a rope shape, the rope-like bamboo fiber is cut into an appropriate length, and the directions are aligned and placed in a mold. At the same time, bamboo cocoon fibers (not rope-shaped) are put in the mold without aligning the direction, and a thermosetting resin is put into the mold.
And the bamboo fiber reinforced plastic of a desired shape is obtained by compression thermoforming.
Bending strength in all directions is improved as compared with the above embodiment.

Next, another embodiment will be described.
The method of manufacturing the bamboo cocoon fiber is the same as that of the above embodiment. The bamboo cocoon fibers are twisted as they are or twisted into a rope shape, impregnated or coated with a thermosetting resin in a state of being aligned in the length direction, and then placed in a mold. Thereafter, a thermosetting resin is appropriately put into the mold, and a bamboo fiber reinforced plastic having a desired shape is obtained by compression thermoforming.
Compared with each of the above embodiments, the direction of the bamboo cocoon fiber or the rope-like bamboo fiber caused by introducing the thermosetting resin into the mold is less likely to be produced, and the manufacture is facilitated.

In each of the above embodiments, when producing bamboo cocoon fiber, it is boiled in a high-pressure kettle. Instead, it is placed in a blasting device to make the inside of the blasting device high pressure and high temperature ( (165 to 200 ° C.) may be introduced into the apparatus, and then the pressure may be reduced at once, and this may be repeated about 5 times, followed by defibration.
However, it is much better to decompose hemicellulose or lignin that joins the bamboo cocoon fibers when boiled in a high-pressure kettle than to produce bamboo cocoon fibers by using a blasting device. The work is simplified and it is easy to produce bamboo cocoon fibers.
Bamboo fiber reinforced plastics using bamboo cocoon fibers with a length of several millimeters or more have better mechanical properties such as bending strength than bamboo fiber reinforced plastics using bamboo cocoon fibers less than several mm in length. Therefore, boiling in a high-pressure kettle makes it easier to obtain long bamboo fibers and is optimal for the production of bamboo fibers according to the present invention.
In each of the above embodiments, bamboo fiber reinforced plastic is used as it is, but it is a composite material that is further coated with a resin that has good bondability with the used thermosetting resin and improves sliding characteristics and wear characteristics. May be.
Furthermore, although it is somewhat inferior in terms of disposal, for the purpose of improving friction (sliding) characteristics, wear characteristics, etc., the bamboo fence fibers include glass fibers, carbon fibers, or other various inorganic materials, and It may be molded and cured with a thermosetting resin after appropriately adding an organic material.

Claims (9)

Bamboo fiber reinforced plastic made by molding and curing bamboo cocoon fibers with thermosetting resin in the state of length. Bamboo fiber reinforced plastic, which is formed and cured by thermosetting resin with bamboo cocoon fibers aligned in the length direction and bundled. Bamboo fiber reinforced plastic obtained by molding and curing a rope-like bamboo fiber made by twisting bamboo cocoon fibers into a rope shape with a thermosetting resin aligned in the length direction. Align the bamboo cocoon fiber and / or bamboo cocoon fiber in the length direction, twisting bamboo cocoon fiber into a rope shape,
Furthermore, bamboo fiber reinforced plastic obtained by molding and curing at least one of the fibers of the group consisting of bamboo cocoon fiber, glass fiber and carbon fiber with thermosetting resin in a state where the directions are not aligned. Put the bamboo cocoon fibers twisted in a rope shape and / or bamboo cocoon fibers into the mold in the state of being aligned in the length direction,
Next, a method for producing a bamboo fiber reinforced plastic is characterized in that a thermosetting resin is put into the mold and then compression-heating is performed. After impregnating the thermosetting resin with the rope-like bamboo fibers and / or the bamboo fence fibers twisted in the shape of a rope in the form of a rope, put them in the mold, A method for producing bamboo fiber reinforced plastic, characterized by performing compression heating molding. After applying a thermosetting resin in a state where the bamboo cocoon fibers and / or bamboo cocoon fibers obtained by twisting bamboo cocoon fibers into a rope shape are aligned in the length direction, they are put in a mold, A method for producing bamboo fiber reinforced plastic, characterized by performing compression heating molding. The method for producing bamboo fiber reinforced plastic according to claim 6 or 7, wherein after being put in the mold, a thermosetting resin is further put into the mold, and then compression heating molding is performed. 9. The bamboo cocoon fiber according to any one of claims 5 to 8, wherein the bamboo cocoon is boiled in a high-pressure kettle to decompose bamboo hemicellulose and lignin, and then fibrillated and fiberized. The manufacturing method of the bamboo fiber reinforced plastic of description.