JP5167520B2 - Method for producing porous ceramic using waste glass fiber reinforced plastic - Google Patents

Description

  The present invention relates to a method for producing a ceramic, and more particularly to a method for producing a lightweight, high-strength porous ceramic using recycled glass fiber reinforced plastic.

  Currently, various plastic products are used around us, and used plastics are called waste plastics, and their disposal is a big social problem. About 60% of this waste plastic is effectively utilized by recycling and other technologies, but the remaining 40% is disposed of by landfill or simple incineration, especially when glass fiber reinforced plastic is disposed of by landfill. In addition, glass fibers contained in plastics may contaminate the environment, and their effective use is strongly demanded.

  There are a thermal recycling method, a chemical recycling method, and a material recycling method as disposal methods of waste plastics, and the most suitable one is selected from these treatment methods for various types of waste plastics. However, since all of these treatment methods are intended for waste plastics made only of plastics, in the case of treating the above glass fiber reinforced plastics, there are cases where the glass fibers contained in the plastics cannot be treated.

  Then, the technique which presses the mixture of the crushed material of a waste glass fiber reinforced plastic and a thermosetting resin, and makes it a flooring and a paving material block is proposed (refer patent document 1). In addition, there is a technique for producing a porous ceramic in which a glass fiber reinforced plastic waste material is added to a base material in which limestone and clay are blended with copper smelting ore and then fired (see Patent Document 2).

JP 2002-294614 A Japanese Patent Laid-Open No. 6-116057

  However, the technique described in the above-mentioned Patent Document 1 is reused as a flooring material or a paving material block by mixing waste glass fiber reinforced plastic with a thermosetting resin and pressing it. The material of the floor material and the paving material block to be used is a plastic material (organic compound) containing the same fiber reinforcing material as before manufacture. When these are disposed of, the disposal method is expected to become a problem again, and thus the manufacturing method is not a fundamental disposal method for waste plastic. In addition, the manufacturing technology of the porous plastic of Patent Document 2 is similar in that the porous ceramic is manufactured using glass fiber reinforced plastic waste, but the porous material is formed by manufacturing at a firing temperature of less than 1000 ° C. The main purpose is to do so, and no technical disclosure has been made regarding the effective utilization of glass fibers. Furthermore, as shown in the examples described later, when glass fiber-containing waste plastic is mixed with clay to produce a porous glass fiber-containing ceramic at a firing temperature of less than 1000 ° C., The effect of glass fiber can hardly be expected, and the product does not have sufficient strength.

  In view of the above-mentioned problems, the present inventors, as a result of diligent research, mixed and molded waste plastic containing glass fiber with clay, and increased the temperature to a temperature at which the strength of the glass fiber increases as a ceramic strength increasing method. As a result, the technology for firing was established, and a lightweight, high-strength porous ceramic was provided. This technology provides fundamental waste plastic processing and reuse applications.

For this reason, the method for producing a porous ceramic of the present invention comprises a step of mixing waste glass fiber reinforced plastic and clay, a step of firing at a temperature at which the plastic component of the plastic is decomposed, and a glass fiber of the plastic. It is characterized by comprising a step of raising the temperature to a temperature at which the strength is increased by the component and firing.

The method for producing a porous ceramic according to the present invention includes a step of mixing and molding waste glass fiber reinforced plastic and clay, and a first firing step of raising the temperature to 700 to 1000 ° C. at which the plastic component of the plastic decomposes. The first feature is that the strength is increased by the unmelted glass fiber derived from the plastic, including a second firing step in which the glass fiber component of the plastic is further heated to 1100 ° C., a temperature at which the glass fiber component does not melt.

A second feature is that the method further includes a third baking step of maintaining a predetermined time at the baking temperature in the second baking step .

In the step of mixing and molding the waste glass fiber reinforced plastic and clay, a third feature is that the glass fiber components are mixed so as to contain 8% or more of the total mass ratio.

And it is the tile created by said manufacturing method, It is characterized by the above-mentioned.

Further characterized in that a paving absorbent blocks using the tile.

According to the porous ceramic of the manufacturing method according to the present invention, by forming a mixture of glass fiber reinforced plastic and clay to be discarded, and the temperature degrade plastic components, the temperature was raised to a temperature where the glass fiber component does not melt Because it is fired, it is possible to produce a porous ceramic that is lightweight and has high strength.

  The tiles and pavement water-absorbing blocks created by this manufacturing method can be obtained because they use cheap clay without using tile-specific clay, and can obtain strength equal to or higher than general tiles. Material costs are very low for tile quality.

  In addition, it has an excellent effect that it is possible to reuse waste plastic containing glass fiber, which has been difficult to effectively use.

  Hereafter, the manufacturing method of the porous ceramic using the waste glass fiber reinforced plastic of this invention is demonstrated in detail according to an Example. In the present embodiment, the manufacture of tiles will be described as an example, but the porous ceramic product that can be produced by the present technology is not limited to this.

  A commercial Kunitomi clay produced in Miyazaki Prefecture, which is not prepared for tiles, and a POM resin containing 40% glass fiber (manufactured by Polyplastics Co., Ltd.) as an additive material were prepared as the main raw material for tiles. This glass fiber-containing POM resin is used in automobile door mirrors and the like, and is considered to be discarded in large quantities at present and in the future.

(Tile molding)
1) Each of clay and POM resin is passed through a 500 μm sieve to obtain clay and POM resin powders of 500 μm or less.
2) The obtained clay and POM resin powder are mixed at a predetermined mixing ratio, 8% water of the raw material mass is added and kneaded, and 15 g is weighed and put into a mold.
3) The mold is put into an inverter hot press (manufactured by Motoyama Co., Ltd.), and molding is performed by holding at a pressure of 9.8 MPa for 1 minute.
The size of the test piece prepared with the mold is 20 mm in width and 70 mm in length at the time of molding, and the thickness is about 5 mm to 7 mm depending on the blending conditions. Table 1 shows the blending conditions of the POM resin. For comparison, a test piece containing POM resin (not including glass fiber) was also prepared.

(Tile firing)
The test piece prepared above was fired according to the following firing temperature conditions.
1) Temperature rise to 200 ° C. at 100 ° C./h 2) Hold for 1 hour at 200 ° C. 3) Temperature rise at 100 ° C./h to firing temperature T-200 ° C. 4) Temperature rise at 60 ° C./h to firing temperature T 5 ) Holding at firing temperature T for 1 hour 6) Furnace cooling to room temperature The firing temperature T was set to 900 ° C, 1000 ° C, 1100 ° C, 1200 ° C, and the test piece was fired. FIG. 1 shows the firing temperature condition (temperature rise curve).

(Shrinkage test)
The volume of the test piece of the fired tile before and after firing was measured to determine the volume, and the shrinkage was determined according to the following equation (1). The results are shown in FIG.

Ｖ_０：焼成前の試験片の体積、Ｖ：焼成後の試験片の体積

V ₀ : Volume of the test piece before firing, V: Volume of the test piece after firing

(result)
As shown in FIG. 1, when only clay and POM resin were mixed and fired, the shrinkage ratio of the test piece decreased as the mixing ratio of the POM resin increased. When clay and glass fiber-filled POM resin were mixed and fired, the glass fiber mixing rate increased as the glass fiber mixing rate increased, except for the firing temperature of 1100 ° C., even though the mixing rate increased. In particular, when fired at 1200 ° C., the glass fibers partially melt, so that the shrinkage rate of the test piece was remarkably increased as the glass fiber mixing rate increased. When the fired test piece was observed with a stereomicroscope, it was confirmed that the glass fiber component was not melted by firing up to 1100 ° C. and was partially melted by firing at 1200 ° C.

(Water absorption test)
The tile test piece was placed in a dryer and dried for 24 hours, and then its mass was measured. Next, this dried test piece was submerged at a position 10 cm below the surface of water in still water at about 20 ° C., allowed to stand for 24 hours, and then water droplets on the surface of the test piece were wiped off with a damp cloth, and the mass was measured again. From these measured values, the water absorption was determined according to the following formula 2. The results are shown in FIG.

ｍ_０：乾燥時の試験片の質量、ｍ：吸水後の試験片の質量

m ₀ : Mass of the test piece at the time of drying, m: Mass of the test piece after water absorption

(result)
Regardless of the presence or absence of glass fiber, the water absorption of the test piece increased as the mixing ratio of the POM resin increased. Moreover, when the test piece of the mixing rate of the same POM resin was baked at 900 degreeC-1100 degreeC, the water absorption rate of the test piece containing glass fiber was relatively high. And when baked at 1200 degreeC, the water absorption rate of the test piece without glass fiber was relatively high.

(Bending test)
Insert the tile test piece into a four-point bending jig and compress it with an autograph (AG500A manufactured by Shimadzu Corporation) at a cross speed of 0.5 mm / s. The maximum bending stress was determined. The results are shown in FIG.

Ｐ：最大荷重、Ｌ：下部支点間距離、ａ：上部荷重点間距離、ｂ：試験片の幅、ｈ：試験片の厚さ

P: maximum load, L: distance between lower fulcrums, a: distance between upper load points, b: width of test piece, h: thickness of test piece

(result)
The bending strength of the test piece decreased as the mixing ratio of the POM resin increased with or without glass fiber. However, the test piece with a glass fiber mixing rate of 8% (POM resin mixing rate 12%) or more at a firing temperature of 1100 ° C. and a test piece with glass fiber at a firing temperature of 1200 ° C. are both compared to the test piece without glass fiber, It was found that the bending strength was relatively high. In addition, since the bending strength of a general ceramic using clay in the ceramic industry has about 6 MPa, it was found that test pieces containing glass fibers at 1100 ° C. and 1200 ° C. are high-strength tiles. The reason for this high strength is that at 1100 ° C. before the glass fiber component partially melts, the glass fiber plays a role of reinforcing fiber in the composite material, and at 1200 ° C. where the glass fiber partially melts, the glass fiber melts to make clay. It is thought that there are two different high-strength generation mechanisms that act as a binder (binder) that hardens.

As described above, according to the method for producing a porous ceramic using the waste glass fiber reinforced plastic according to the present invention, the glass fiber reinforced plastic to be discarded and clay are mixed and molded, and the glass fiber component is decomposed. Since it is fired at a temperature at which it does not melt, it is possible to produce a porous ceramic that is lightweight and has high strength. The tiles and pavement water-absorbing blocks created by this manufacturing method use cheap clay instead of using tile-specific clay, and can be obtained with strength equal to or higher than general tiles. Material costs are very low for tile quality. In addition, if clay prepared exclusively for tiles is used, it is considered that even higher strength tiles can be produced.

  Tile made by porous ceramic manufacturing method using waste glass fiber reinforced plastic of the present invention makes use of high strength and porous characteristics, as a tile for river embankment using filtration function and heat island phenomenon countermeasure technology It can be used for water-retaining concrete.

It is a figure which shows baking temperature conditions (temperature rise curve). It is a figure which shows a shrinkage test result. It is a figure which shows a water absorption test result. It is a figure which shows a bending test result.

Claims (3)

A step of mixing waste glass fiber reinforced plastic and clay, a first firing step of raising the temperature to 700 to 1000 ° C. at which the plastic component of the plastic decomposes, and a temperature at which the glass fiber component of the plastic does not melt The manufacturing method of the porous ceramic which increased the intensity | strength by the glass fiber which is not melted from the said plastics including the 2nd baking step which heats up further to 1100 degreeC.   The method for producing a porous ceramic according to claim 1, further comprising a third firing step in which the firing temperature in the second firing step is maintained for a predetermined time. The waste glass fiber reinforced plastic and clay are mixed and molded, and the glass fiber component is mixed so as to contain 8% or more of the total mass ratio. A method for producing a porous ceramic.

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