WO2012019364A1

WO2012019364A1 - Modified wood fiber-reinforced cement external wall panel and producing method therefor

Info

Publication number: WO2012019364A1
Application number: PCT/CN2010/075985
Authority: WO
Inventors: 赵金平; 刘素梅; 王莹; 易松林; 周梦文; 丁艳玲; 王霞
Original assignee: 北新集团建材股份有限公司
Priority date: 2010-08-13
Filing date: 2010-08-13
Publication date: 2012-02-16
Also published as: KR101408022B1; KR20130038866A

Abstract

A modified wood fiber-reinforced cement external wall panel is provided, which comprises the following ingredients: 60 to 100 parts of cement, 10 to 20 parts of calcium powder, 10 to 30 parts of silica powder, 2 to 10 parts of expanded perlite, 0.2 to 4 parts of modified wood fiber, 0 to 1.5 parts of polypropylene fiber, 20 to 40 parts of secondary pulverized coal ash, 0.2 to 0.4 parts of methyl cellulose, 0 to 8 parts of pulp, 0 to 6 parts of initial setting agent, 2 to 10 parts of gypsum whisker and 0.2 to 8 parts of mica sheet. The producing method for the modified wood fiber-reinforced cement external wall panel includes the following steps: blending the materials according to the proportions of the various raw materials firstly, and mixing the materials in a mixer secondly, and then kneading the mixed materials in a kneader while spraying water evenly, and extruding the kneaded materials by a extruder to form the product, and curing the product after pressure-steaming.

Description

Wood modified fiber reinforced cement outer wall board and manufacturing process thereof

Technical field

The invention relates to a fiber cement outer wall panel and a production process thereof.

Background technique

With the booming construction industry and the modernization of buildings, the use of exterior wall panels in construction projects is increasing. At present, among the raw materials for the existing exterior wall panels, especially the cement exterior wall panels, polypropylene fiber (PP), asbestos, etc. are often used for the cement reinforcing fiber materials. Although the PP is well dispersed with the cement matrix, the price is high, and Asbestos is a harmful substance and cannot reflect environmental protection requirements. The plasticizer material is mostly made of expensive sulfhydryl cellulose (MC), and the amount of MC is more than 2.0 parts based on 100 parts of cement. Therefore, the existing cement siding is manufactured. The raw materials cause high cost of the finished product and a bulk density of up to 1.6 g/cm ³ , which brings certain difficulties to the construction. Moreover, there are process problems such as wet work and high labor intensity in the operation of the existing external wall form. In addition, too few exterior wall base forms and monotonous decorations are not regrettable for today's pursuit of individualized architecture.

In addition, in the production of fiber cement siding, in order to reduce product density, it is necessary to increase the water consumption of the formula. As the amount of water used in the formulation increases, the wet expansion rate of the product also increases. When the formula uses more than 50% water, the product's wet expansion rate will reach or exceed 0.25%, which will significantly reduce the product's volume stability and service life.

In addition, the fiber cement siding is subjected to atmospheric steam curing during the production process, so that the product has a certain initial strength to ensure the completion of the subsequent production process. When the water content of the fiber cement siding is more than 40%, the existing curing method will easily lead to problems such as no strength and easy bubbles.

In addition, fiber cement siding needs to be colored during the production process. The current treatment is usually treated by coloring the paint. Since the paint is organic, its durability is poor, and the outer wall panel is prone to surface coating for a long time. Layer aging, fading and peeling problems. Moreover, the service life of fiber cement siding is 50 years, while the life of ordinary coatings is only 8-10 years, and the service life of high-grade coatings is more than 20 years. In the service life of fiber cement siding, at least 3 -5 repair coatings Loading, resulting in excessive maintenance costs. Summary of the invention

The technical problem to be solved by the present invention is to provide a manufacturing process of a wood-modified fiber reinforced cement siding, which can make the amount of MC less than 0.5%, and the production cost can be greatly reduced.

In order to solve the above problems, the present invention provides a wood modified fiber reinforced cement outer wall panel comprising the following components: 60 to 100 parts of cement, 10 to 20 parts of calcium powder, 10 to 30 parts of silicon powder, and expanded perlite 2 ~ 10 parts, modified wood fiber 0.2 ~ 4 parts, polypropylene fiber 0 ~ 1.5 parts, secondary fly ash 20 ~ 40 parts, thiol cellulose 0.1 ~ 0.4 parts, pulp 0 ~ 8 parts, initial setting agent is 0 ~ 6 parts, gypsum whiskers 2 ~ 10 parts, tablets ^ mica 0.2 ~ 8 parts.

Preferably, the modified wood fiber is obtained by the following method: the wood fiber is treated by low pressure steam explosion, that is, the wood fiber is placed in a water vapor pressure vessel of 150 ~ 170 ° C, l ~ 2.5 MPa, and then in 3-4 The pressure drops to normal pressure within seconds.

Preferably, a layer of silane coupling agent is sprayed on the surface of the modified lignocellulosic fiber subjected to low pressure steam explosion treatment.

Preferably, the component further comprises 0.2 to 8 parts of a sheet-like mineral material, and the sheet-like mineral material is mica.

Preferably, the mica has a particle size of 40 to 80 mesh.

Preferably, the component further comprises 2 to 10 parts of gypsum whiskers.

The invention also provides a manufacturing process of a wood modified fiber reinforced cement outer wall panel, wherein the process comprises: mixing various raw materials according to the ratio, and then stirring the batch material in a mixer; and then stirring the material Kneading in a kneading machine, and simultaneously spraying water; the kneaded material is extruded through an extruder, and is subjected to steaming treatment for curing.

Preferably, the curing comprises the following steps:

1) After the fiber cement siding is extruded, the fiber cement siding is carried out at 20-30 °C.

10-20 hours of low temperature steam curing, curing humidity is controlled at 60-80%, after the cement is finally set in the fiber cement siding, then enter the next curing stage;

2) 5 to 15 hours of high temperature steam curing at 60 ~ 90 °C, curing humidity control 70-90%, to avoid the excessive humidity caused by the strength of the fiber cement siding water absorption saturation.

Preferably, the method further comprises coloring the whole body, that is, mixing the prepared inorganic pigment in the raw material powder for producing the fiber cement siding, and adsorbing it on the surface of the other particles by high-speed stirring, thereby achieving the purpose of sufficiently dispersing, and then Add water and stir.

The invention has the following advantages:

1) By adding modified wood fiber to the component, not only can the amount of mercapto cellulose (MC) be greatly reduced, but also the advantages of greatly reducing cost, improving tensile strength, and enhancing sheet dimensional stability.

2) According to the invention, in the process of producing the fiber cement siding, when the formula water consumption is more than 50%, the flaky mineral material (the mica is preferably used in the present invention) is added to the raw material, so that the wet expansion of the product can be made. Reduced to less than 0.17%, while the wet expansion rate of conventional products is usually above 0.25%;

3) By adding gypsum whiskers to the components instead of the traditional glass fibers, not only the bending damage load of the outer wallboard is increased by more than 50%, but also the impact resistance, shear resistance and crack resistance are improved by at least 10%;

4) The invention adopts a combination of low temperature steam curing and high temperature steam curing to steam-maintain the fiber cement siding, so that the product has high initial strength, and the product is not easy to generate bubbles, thereby improving product quality and production efficiency. ;

5) The invention adds the inorganic pigment to the fiber cement outer wall board, and uses the targeted production and maintenance process to make the fiber cement outer wall board have a color, bright color, beautiful appearance, and can withstand high temperature without fading. Because it is colored throughout the body and is an inorganic material, its color can sustain the entire life of the product. It solves the problems of short life, aging, fading, peeling and multiple repairs of coatings on traditional siding surface coatings. Preferred embodiment of the invention

Example 1

(1) Mixing of ingredients: ordinary Portland cement, silicon powder, calcium powder, dispersed waste newspaper, pulp, expanded perlite, modified lignocellulosic, sulfhydryl cellulose (MC) ), the initial setting agent, gypsum whiskers and mica are mixed in a mixer for 10 minutes, and the temperature inside the mixer is controlled. Below 50 °C, the size of mica is controlled at 40 ~ 80 mesh;

The ingredients of the raw materials (by weight) are:

Cement: 100 parts, silicon powder: 20 parts, calcium powder: 15 parts, expanded perlite: 5 parts, modified wood fiber: 4 parts, MC: 0.4 parts, pulp: 4 parts, initial setting: 3 parts, plaster Whiskers: 10 parts, mica: 8 parts.

(2) Kneading: The mixed materials were kneaded in a kneading machine for 15 minutes, and the water was sprayed at the same time, and the water consumption was 46 parts.

(3) Extrusion molding: The kneaded material is extruded through an extruder, (maximum section size 340mm l6mm, length can be cut freely), extrusion pressure is not less than 2Mpa, extrusion extrusion speed is not more than 6 m /min.

(4) Maintenance:

Firstly, after the fiber cement siding is extruded, the fiber cement siding is subjected to low temperature steam curing at 20-30 ° C for 10-20 hours, and the curing humidity is controlled at 60-80%. After the cement in the board is finally set, it will enter the next curing stage;

2) Perform high-temperature steam curing at 60-90 °C for 5-15 hours, and maintain the humidity control at 70-90% to avoid the excessive humidity caused by the water-saturated effect of the fiber cement siding.

The fiber cement siding is steam-cured by the combination of the above-mentioned low-temperature steam curing and high-temperature steam curing, so that the product has a high initial strength, and the product is not easy to generate bubbles, thereby improving product quality and production efficiency.

If the existing curing process is used, when the water consumption of the fiber cement siding is more than 40%, the product has no strength within 24 hours, and it usually takes 48-72 hours to have a certain strength. After using this curing process, the product has good strength within 24 hours, which greatly improves production efficiency. At the same time, the existing curing is likely to cause water saturation on the surface of the product, and in the subsequent steam curing, the surface water vaporizes, thereby generating bubbles. Generally, the incidence of bubbles is more than 50%. After using this curing process, the incidence of surface bubbles is less than 0.5%.

In addition, the whole body coloring process specifically includes the following process steps:

Firstly, the prepared inorganic pigment is blended in the raw material powder for producing the fiber cement siding, and is adsorbed on the surface of the powder granule by high-speed stirring, thereby achieving the full dispersion of the inorganic pigment. Purpose, then add water and stir. In this embodiment, the inorganic pigment may be selected from iron oxide red.

In addition, the specific preparation process of the above modified wood fiber is as follows:

After the wood fiber slag is blasted by low-pressure steam, it is treated by spraying with a silane coupling agent to obtain a modified wood fiber which is excellent in performance and can be well combined with inorganic non-metal materials such as cement.

Low pressure steam explosion:

Wood fiber can be treated with low pressure steam explosion to achieve improved fiber properties. Wood fiber is a natural polymer material composed of cellulose, hemicellulose, lignin and extracts. It is an anisotropic material with unevenness and complex interface properties.

In the steam explosion process, the plant fiber raw material is in a water vapor pressure vessel of 150 ~ 170 ° C, l ~ 2.5 MPa, the fiber is swollen by the liquid, the pore is filled with steam, when the pressure steam is suddenly decompressed, in the pore The gas expands rapidly, causing some of the lignin to be stripped and dissociating the material into fine fibers. At the same time, hemicellulose and cellulose are partially hydrolyzed into soluble sugars, the lignin is softened, the transverse strength is weakened, and the plasticity is soft and plastic. The fiber separation caused by the blasting mainly occurs in the intercellular layer, and the fiber itself is hardly damaged. Since the low pressure steam explosion removes most of the amorphous material hemicellulose, the resulting fiber has good stability and can be used as a reinforcing fiber for cement-based materials.

The low-pressure steam blasting process is based on the premise that the wood fiber raw material softens at high temperature and weakens the cellulose. Under the sudden decompression, the rapid expansion of water vapor causes the instantaneous conversion of lignocellulose, and the steam explosion pressure has a steam explosion effect. Larger impact. With the increase of steam explosion pressure, the degree of hemicellulose conversion is relatively large; cellulose also undergoes a certain degree of conversion with increasing pressure, but the conversion rate is not very high; and the polymer of lignin is solved. It is difficult to gather.

Spraying of silane coupling agent:

The silane coupling agent is an organosilicon compound having a special structure. In its molecule, it has both a reactive group capable of bonding with an inorganic material such as glass, cement, metal, etc., and a reactive group bonded to an organic material such as a synthetic resin or the like. Usually, only one of the three silanol groups formed by hydrolysis of the silane coupling agent at the interface is bonded to the surface of the substrate; the remaining two si—OH, or condensed with si—OH in other silanes, or in a free state . Therefore, two kinds of material interfaces with widely different properties can be coupled by a silane coupling agent, thereby improving the performance of the composite material and increasing the bonding strength, and obtaining a novel composite material with excellent performance and reliability. By atomizing the silane coupling agent and spraying it onto the surface of the modified wood fiber, the modified wood fiber can be physically coated, so that the organic wood fiber can be tightly combined with the inorganic polymer to make the strength and adhesion of the material. Significant improvement in force, electrical properties, hydrophobicity, anti-aging properties, etc.

The silane coupling agent has two groups of different properties, and the hydrophilic group can react with chemical groups on the surface of the inorganic material (such as glass, fly ash, etc.) to form a strong chemical bond; the organophilic group The group can react with the organic molecules or physically entangle, so that the interface between the organic and inorganic materials is chemically bonded, and the bonding strength is greatly improved.

Example 2

The ingredients of the raw materials (by weight) are:

Cement: 60 parts, silicon powder: 10 parts, calcium powder: 10 parts, expanded perlite: 5 parts, modified wood fiber: 0.2 parts, MC: 0.2 parts, pulp: 4 parts, initial setting: 3 parts, gypsum Whiskers: 2 parts, mica: 0.2 parts.

The other preparation process is the same as in Example 1.

Example 3

The ingredients of the raw materials (by weight) are:

Cement: 80 parts, silicon powder: 30 parts, calcium powder: 20 parts, expanded perlite: 5 parts, modified wood fiber: 2 parts, MC: 0.3 parts, pulp: 4 parts, initial setting: 3 parts, plaster Whiskers: 6 parts, mica: 4 parts.

The other preparation process is the same as in Example 1.

Table 1 Effect of adding mica

Add modified wood fiber effect

Table 3 Effect of adding gypsum whiskers

In the above, the above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, any modifications, equivalents, improvements, etc. made within the spirit and principles of the present invention, All should be included in the scope of protection of the present invention.

Claims

Claim

1. A wood modified fiber reinforced cement outer wall panel, which comprises the following components: 60 to 100 parts of cement, 10 to 20 parts of calcium powder, 10 to 30 parts of silicon powder, and 2 to 10 parts of expanded perlite. 0.2 ~ 4 parts of modified wood fiber, 0 ~ 1.5 parts of polypropylene fiber, 20 ~ 40 parts of secondary fly ash, 0.2 ~ 0.4 parts of sulfhydryl cellulose, 0 ~ 8 parts of pulp, 0 ~ 6 of initial setting agent Parts, gypsum whiskers 2 ~ 10 parts, flaky mica 0.2 ~ 8 parts.

2. The siding according to claim 1, wherein the modified wood fiber is obtained by a method of blasting wood fibers by low-pressure steam blasting, that is, placing the wood fibers at 150-170 ° C, 1 ~. In a 2.5 MPa water vapor pressure vessel, the pressure is then reduced to atmospheric pressure within 3-4 seconds.

The siding panel according to claim 2, wherein a surface of the modified lignocellulosic fiber subjected to the low-pressure steam explosion treatment is sprayed with a silane coupling agent.

4. The siding panel according to claim 1, wherein the mica has a particle size of 40 to 80 mesh.

A process for producing a wood-modified fiber reinforced cement outer wall panel according to any one of claims 1 to 4, wherein: the various raw materials are compounded in the above ratio, and then the batch is stirred in a mixer; Then, the stirred material is kneaded in a kneading machine, and the water is sprayed at the same time; the kneaded material is extruded through an extruder, and is subjected to steaming treatment for curing.

6. The process of claim 5 wherein said curing comprises the steps of:

1) After the fiber cement siding is extruded, the fiber cement siding is subjected to low temperature steam curing at 20-30 ° C for 10-20 hours, and the curing humidity is controlled at 60-80%. After the cement in the board is finally set, it will enter the next curing stage;

2) Perform high temperature steam curing at 60 ~ 90 °C for 5 ~ 15 hours, and maintain humidity at 70-90% to avoid the influence of excessive humidity on the water-saturated impact of fiber cement siding.

7. The process according to claim 6, further comprising: coloring the entire body, that is, mixing the prepared inorganic pigment into the raw material powder for producing the fiber cement siding, and adsorbing it by high-speed stirring. The other particles are surfaced for the purpose of full dispersion and then stirred with water.