WO2012074230A2 - Method for preparing artificial wood using natural vegetable fibroid material - Google Patents

Abstract

The present invention relates to a method for preparing artificial wood using a natural vegetable fibroid material, and more specifically, to a preparation method of artificial wood comprising: the binder coating step of mixing a synthetic resin comprising polypropylene or high density polyethylene, and ethylene-vinyl acetate or linear low density polyethylene with a binder selected from maleated polypropylene (MAPP), a titanate-based binder and a zirconia-based binder and a silicone oil; the drying step of drying one or more natural vegetable fibroid powders selected from the group consisting of waste paper, rice straw, corn stalks, African millet stalks, hemp, coffee husks, coconut leaves, sugarcane dregs and green tea dregs; the first mixing step of mixing the binder-coated synthetic resin and the natural vegetable fibroid powders dried at the drying step; the second mixing step of adding one or more additives selected from the group consisting of a lubricant, an antioxidizing agent, a UV stabilizer, a nucleating agent, a filler and an inorganic pigment to the natural vegetable fibroid powders from the first mixing step to mix the mixture; and the molding step of adding a swelling agent and molding the mixture into synthetic wood using an extrusion molding machine. Artificial wood which is light and can maintain a strength (physical property) similar to that of natural wood by remarkably reducing the content of a synthetic resin which is heavy and has a high toxic gas production rate in case of a fire is provided, by employing the method for preparing artificial wood using a natural vegetable fibroid material of the present invention.

Description

Manufacturing method of artificial wood using natural vegetable fiber

The present invention relates to a method for manufacturing artificial wood using natural vegetable fiber, and more particularly, by reducing the amount of synthetic resin, the gas generation rate is reduced in the event of a fire, and natural vegetable fiber contains a large amount of natural wood, but light weight natural wood It relates to a method for manufacturing artificial wood using natural vegetable fiber having the same texture.

 Generally, natural wood is economical, has a relatively small specific gravity, and is easy to process, and is used for various purposes throughout the industry. However, natural wood has the disadvantages of poor moisture resistance, pollution resistance and corrosion resistance.

 In order to solve this problem, it was intended to manufacture artificial wood mixed with sawdust or wood chips and synthetic resin. However, artificial wood containing the sawdust or wood chips should include more than 60% by weight of synthetic resin to maintain the same properties as natural wood. However, synthetic wood containing more than 60% by weight of synthetic resin is heavy weight, high resin content, and also disadvantageous price competitiveness, there is a risk that can release a large amount of harmful gas in the event of fire.

 The present invention for solving the above problems is to provide a method for manufacturing artificial wood using natural vegetable fiber that can maintain the strength (physical properties) similar to natural wood even significantly reducing the content of synthetic resin.

 Accordingly, the present invention provides a preferred embodiment, selected from polypropylene (MAPP), titanate and zirconate based on maleate treated synthetic resin mixed with polypropylene or high density polyethylene, ethylene vinyl acetate or linear low density polyethylene. A binder coating step of coating the synthetic resin by mixing a species of binder and silicon oil; A drying step of drying one or more natural vegetable fiber powders selected from the group consisting of waste paper, rice straw, corn stalks, sorghum, hemp, coffee bark, palm fronds, sugarcane grounds and green tea grounds; A first kneading step of kneading the binder-coated synthetic resin and the natural vegetable fiber powder dried in the drying step together; A second kneading step of kneading by adding one or more additives selected from the group consisting of a lubricant, an antioxidant, a UV stabilizer, a nucleating agent, a filler, and an inorganic pigment to the mixture that has passed through the first kneading step; It provides an artificial wood manufacturing method using natural vegetable fibers, including; forming step of adding an expanding agent and molding into an artificial wood product using an extrusion molding machine.

 In the artificial wood manufacturing method according to the embodiment, the drying step is the first drying step of drying so that the moisture content of the natural vegetable fiber powder at 80 ~ 100 ℃ less than 5% by weight; It provides a method for producing artificial wood using natural vegetable fiber comprising; and a second drying step of drying so that the water content of the natural vegetable fiber powder is less than 1% by weight at 100 ~ 130 ℃.

 In the artificial wood manufacturing method according to the embodiment, the synthetic resin in the binder coating step comprises 13 to 29 parts by weight of polypropylene or high density polyethylene and 3 to 11 parts by weight of ethylene vinyl acetate or linear low density polyethylene based on a total of 100 parts by weight of artificial wood It provides a method for producing artificial wood using natural vegetable fiber.

 In the method of manufacturing artificial wood according to the above embodiment, the polypropylene in the binder coating step provides a method of manufacturing artificial wood using natural vegetable fibers of homopoly or impact polypropylene having a melt index of 7 to 15.

 In the artificial wood manufacturing method according to the embodiment, the high-density polyethylene in the binder coating step provides an artificial wood manufacturing method using natural vegetable fibers having a melt index of 2 ~ 10.

 In the artificial wood manufacturing method according to the embodiment, the linear low-density polyethylene in the binder coating step provides an artificial wood manufacturing method using natural vegetable fibers having a melt index of 1-4.

 In the artificial wood manufacturing method according to the embodiment, the binder coating step is to mix 16 to 40 parts by weight of synthetic resin, 0.8 to 3 parts by weight of binder and 0.2 to 0.5 parts by weight of silicone oil based on 100 parts by weight of artificial wood Provided is a method for preparing artificial wood using vegetable fiber.

 In the method of manufacturing artificial wood according to the embodiment, in the first kneading step, 16 to 40 parts by weight of the synthetic resin coated with a binder and 50 to 75 parts by weight of the natural vegetable fiber powder dried in the drying step are added to 100 parts by weight of the artificial wood. It provides a method for producing artificial wood using natural vegetable fiber.

 In the artificial wood manufacturing method according to the embodiment, the first kneading step provides a method for manufacturing artificial wood using natural vegetable fiber that is kneaded at 80 ~ 110 ℃ for 7 to 15 minutes.

 In the artificial wood manufacturing method according to the embodiment, the content of the additive added in the second kneading step provides an artificial wood manufacturing method using natural vegetable fiber which is 2 to 6 parts by weight based on 100 parts by weight of the total artificial wood.

 In the artificial wood manufacturing method according to the embodiment, the additive added in the second kneading step is 0.2 to 1 parts by weight of lubricant, 0.1 to 0.3 parts by weight of antioxidant, 0.2 to 0.6 parts by weight of UV based on 100 parts by weight of artificial wood It may include a stabilizer, 0.3 to 0.7 parts by weight of nucleating agent, 1 to 3 parts by weight of filler, 0.2 to 0.4 parts by weight of inorganic pigment.

 In the method of manufacturing artificial wood according to the embodiment, the second kneading step provides a method of manufacturing artificial wood using natural vegetable fiber, which is kneaded at 110 to 140 ° C. for 10 to 20 minutes.

 In the artificial wood manufacturing method according to the embodiment, the molding step provides an artificial wood manufacturing method using natural vegetable fibers that are molded by an extrusion molding machine heated to 180 ~ 230 ℃.

 In the artificial wood manufacturing method according to the embodiment, between the second kneading step and the molding step using a pellet molding machine with a vacuum device heated to 170 ~ 200 ℃ gelled raw material through the second kneading step It provides a method for producing artificial wood using natural vegetable fiber, characterized in that it further comprises a; pelletizing step of producing a pellet of 2 ~ 3mm size.

 According to the production method of the present invention, it is possible to provide a synthetic wood using natural vegetable fiber that can maintain the strength (physical properties) similar to natural wood, while lightly reducing the content of synthetic resin, which is heavy in weight and has a high rate of harmful gases during fire. .

 1 is a flow chart showing a method for manufacturing artificial wood using natural vegetable fiber according to an embodiment of the present invention.

 Method for producing a synthetic wood made from natural vegetable fibers according to the present invention,

 1. A mixture of polypropylene (MAPP), titanate-based and zirconate-based silicone oil and silicone oil is mixed with a synthetic resin mixed with polypropylene or high-density polyethylene, ethylene vinyl acetate or linear low density polyethylene. A binder coating step of coating the synthetic resin;

 2. Drying step of drying at least one natural vegetable fibrous powder selected from the group consisting of waste paper, rice straw, corn stalks, sorghum, hemp, coffee skin, palm fronds, sugar cane grounds and green tea grounds;

 3. a first kneading step of kneading the binder-coated synthetic resin and the natural vegetable fiber powder dried in the drying step together;

 4. a second kneading step of kneading by adding one or more additives selected from the group consisting of a lubricant, an antioxidant, a UV stabilizer, a nucleating agent, a filler, and a pigment to the natural vegetable fiber powder which has undergone the first kneading step; And

 5. The step of adding an expanding agent and molding into an artificial wood product using an extrusion machine; characterized in that it comprises a.

 Hereinafter, the present invention will be described in detail.

1. Binder Coating Step

 First, silicone oil is mixed with a binder selected from polypropylene (MAPP), titanate-based and zirconate-based maleates, in a synthetic resin containing polypropylene or high-density polyethylene, ethylene vinyl acetate or linear low density polyethylene. A binder coating step of coating the synthetic resin. In this case, the silicone oil not only makes the binder evenly coated on the synthetic resin, but also facilitates the kneading by improving the flow of the resin in the pelletization step or the molding step, thereby improving moldability and physical properties.

 In addition, the content of the synthetic resin is less than the amount of natural vegetable fibrous powder in the above, when using the ethylene vinyl acetate or linear low-density polyethylene when processing in the pelletizing step or molding step to improve the flow of the mixture and facilitate uniform dispersion It is desirable to reduce the defective rate as well as to increase the physical properties (impact strength).

 In the above, the synthetic resin is preferably 13 to 29 parts by weight of polypropylene or high density polyethylene and 3 to 11 parts by weight of ethylene vinyl acetate or linear low density polyethylene based on 100 parts by weight of artificial wood. More specifically, the synthetic resin is preferably a mixture of 20 to 70 parts by weight of ethylene vinyl acetate or linear low density polyethylene with respect to 100 parts by weight of polypropylene or high density polyethylene. In this case, it is preferable to use homo or impact polypropylene having a melt index of 7 to 15, and high density polyethylene preferably has a melt index of 2 to 10. In addition, the ethylene vinyl acetate preferably has an acetic acid content of 3 to 21% (w / w), and the linear low density polyethylene preferably has a melt index of 1 to 4.

 The synthetic resin is coated by mixing with a silicone oil and a binder selected from maleated polypropylene, titanate-based or zirconate-based. At this time, it is preferable to mix 16 to 40 parts by weight of synthetic resin, 0.8 to 3 parts by weight of binder and 0.2 to 0.5 parts by weight of silicone oil based on 100 parts by weight of artificial wood.

 The binder is used to increase the binding force between the synthetic resin and the natural vegetable fiber powder. In principle, the natural vegetable fibrous powder has a hydrophilic polarity and the synthetic resin has a hydrophobic nonpolarity, so the binding strength of the two materials is weak. The interaction of these natural vegetable fiber powders with the synthetic resin is greatly improved by the addition of a binder, resulting in a new chemical bond at the interface between the two materials. In addition, the binder of the present invention can be evenly dispersed in a large amount of natural vegetable fiber powder and a medium amount of synthetic resin even in a very small amount, and first mixed with a synthetic resin and then mixed with a large amount of natural vegetable fiber powder to increase dispersibility to the maximum. Can be. The binder may also increase the bending strength, modulus of elasticity, and the like as well as improve the bonding strength between the natural vegetable fiber powder and the synthetic resin, and may improve dimensional stability, impact strength, and the like.

2. Drying Step

 Prepare at least one natural plant fiber powder selected from the group consisting of waste paper, rice straw, corn stalks, sorghum, hemp, coffee skin, palm fronds, sugar cane waste and green tea dregs. The size of the natural plant fiber powder is preferably 80 ~ 150mesh. In the case of using the natural vegetable fiber powder, the use of sawdust has the advantage that can be used to obtain an artificial wood with excellent physical properties because it can utilize a uniform amount of fiber with the same ingredients, unlike the fiber content is not constant depending on the species. In addition, natural vegetable fiber powder has an advantage that can be more light weight because the specific gravity is about 0.85 but the wood powder is 1.37. At this time, the ratio of the diameter to the particle length of the natural vegetable fiber powder is preferably 3: 1 to 5: 1.

 Then, the prepared natural vegetable fiber powder is dried. At this time, the fiber powder is preferably dried so that the moisture content is less than 1% by weight. If the moisture content of the natural vegetable fiber powder is high, there is a possibility that the problem of not evenly kneading with the synthetic resin to be described later. More specifically, since a large amount of natural vegetable fiber powder is mixed compared to synthetic resins, the volume of the natural vegetable fiber powder is large. However, when the water content of the powder is high, the volume of the powder becomes larger, which may prevent uniform mixing. In addition, when the moisture content is high, it may be difficult to continuously proceed the process due to the static electricity generated in the natural vegetable fiber powder in the first kneading step, the second kneading step or the pelletizing step. In this case, not only the physical properties of the manufactured synthetic wood are lowered, but also a problem that the defective rate is increased in the pelletizing step or the molding step occurs. More specifically, when the water content of the natural vegetable fiber powder is high, carbonization may occur in the pelletizing or forming step, resulting in deterioration of physical properties or inability to flow in the mold, resulting in unmolding. Depression or smoothness may occur.

 Specific examples of the method for drying the content of the prepared natural vegetable fiber powder to be less than 1% by weight include the first drying step of drying the natural vegetable fiber powder to a water content of less than 5% by weight at a temperature of 80 ~ 100 ℃ and There is a method of going through a secondary drying step of drying so that the water content is less than 1% by weight at a temperature of 100 ~ 130 ℃. Here, although not particularly limited, the first drying step is preferably performed on the tunnel-type closed conveyor belt of 80 ~ 100 ℃, the second drying step is preferably carried out for 7 to 15 minutes in a blender of 100 ~ 130 ℃. Do. The reason for this two-step drying step is that the initial moisture content of the natural vegetable fiber powder is 12 to 15%. In a tunnel-type closed conveyor belt dryer, it is not only possible to lower the moisture content to 1% at a time, but even if it is well sealed Because it penetrates. Desirable drying equipment to be used in the secondary drying step is preferably a structure that can automatically control the heat from the outside as a blender having a heating function therein. This drying facility can be completely mixed with the impeller can uniformly dry the natural vegetable fiber powder on the outside and inside.

3. First kneading stage

 The binder is coated with the synthetic resin and the natural vegetable fiber powder dried in the drying step. At this time, it is preferable to combine 16 to 40 parts by weight of the synthetic resin coated with a binder and 50 to 75 parts by weight of the natural vegetable fiber powder dried in the drying step based on 100 parts by weight of the artificial wood. More specifically, 16 to 40 parts by weight of the synthetic resin in which the binder is mixed with respect to 100 parts by weight of artificial wood, together with 50 to 75 parts by weight of the natural vegetable fiber powder dried in the drying step, 7 ~ 7 ~ in a super blender at 80 ~ 110 ℃ It is preferable to knead | mix and pressurize and heat for 15 minutes.

 The binder-coated synthetic resin is 13 to 29 parts by weight of polypropylene or high density polyethylene, 3 to 11 parts by weight of ethylene vinyl acetate or linear low density ethylene, 0.8 to 2.5 parts by weight of maleated polypropylene based on 100 parts by weight of artificial wood It is preferable that a binder selected from titanate-based and zirconate-based and 0.2-0.5 parts by weight of silicone oil are mixed.

 Synthetic resin coated with the binder is evenly mixed with the dried natural vegetable fiber powder while being flexible in a blender at 80-110 ° C., resulting in a gel with evenly distributed natural vegetable fiber powder.

4. The second kneading stage

 It is a step of kneading by adding one or more additives selected from the group consisting of a lubricant, an antioxidant, a UV stabilizer, a nucleating agent, a filler, and a pigment to the natural vegetable fiber powder which has undergone the first kneading step. At this time, the additive is preferably added in an amount of 2 to 6 parts by weight based on 100 parts by weight of artificial wood. More specifically, after adding at least one additive selected from the group consisting of 2-6 parts by weight of lubricant, antioxidant, UV stabilizer, nucleating agent, filler, pigment based on 100 parts by weight of artificial wood, the blender at 110 ~ 140 ℃ It is preferable to make a gel-like synthetic raw material by kneading by pressing and heating for 10 to 20 minutes in the mixture.

 The additive is an important factor for the performance and processability (mixing, extrusion) of the natural vegetable fiber powder. Natural vegetable fibrous powder often causes problems such as warping, cracking, discoloration and coloring, and is used as a structural material, so the role of additives to increase mechanical strength is very important. It is also essential for smoothing the surface of the composite and increasing yield while reducing product defects in the extrusion process. In the present invention, the additive increases stability, serves as a preservative, enables weight reduction, and improves mechanical properties.

 As a specific specific example of the present invention, the natural vegetable fiber powder subjected to the first kneading step includes 0.2 to 1 parts by weight of lubricant, 0.1 to 0.3 parts by weight of antioxidant, 0.2 to 0.6 parts by weight of UV stabilizer, based on 100 parts by weight of artificial wood, It is preferable to add an additive including 0.3 to 0.7 parts by weight of a nucleating agent, 1 to 3 parts by weight of a filler, and 0.2 to 0.4 parts by weight of an inorganic pigment.

 Specifically, the lubricant may be added to improve the surface properties of the product by increasing the dispersibility of the natural vegetable fiber powder during kneading and molding because the high viscosity of the synthetic resin at high temperatures. As the lubricant, one selected from the group consisting of fatty acids, acid amides, fluoropolymers, and hydrocarbons may be used.

 The antioxidant may be added to prevent the natural vegetable fiber powder from receiving oxygen from the air, phenolic antioxidants are mainly used.

 In the above UV stabilizers may be added to block ultraviolet rays, one selected from the group consisting of benzotrizole-based, benzophenone-based, triamine-based may be used.

 In addition, the nucleating agent may be added to shorten the molding cycle by improving the crystallization temperature at the same time to improve the physical properties such as the stiffness, heat deformation temperature of the synthetic resin (PP or PE) to refine the crystals One is selected from the group consisting of acid metal salts, sorbitol-based and phosphate ester metal salts.

 The filler may be added to improve the long-term deformation due to impact strength, bending strength, heat deformation temperature and load, it may be selected from the group consisting of calcium carbonate, talc, mica.

 In the above, inorganic pigments are added to impart color to the present invention, and are mainly colored and colored on synthetic resins.

 The reason why the kneading step is separated into two stages of the first kneading step and the second kneading step is that the binder mixed with the synthetic resin in the binder mixing step is an additive for increasing the binding force between the synthetic resin and the natural vegetable fiber powder, without separating the kneading step. In the case of mixing and kneading at the same time, when the binder is combined with the synthetic resin or the natural vegetable fiber powder before the other various additives (additives in the second kneading step) are first combined with the synthetic resin or the natural vegetable fiber powder, the bonding strength is lowered and the physical properties are reduced and uniform. This is because the dispersion is not dispersed so that the extrusion amount change in the pelletizing step or the forming step is severe and may cause mass defects.

5. Pelletizing Step

 Pelletizing the gelled material through a second kneading step into pellets of 2 to 3 mm by means of a pellet molding machine with a vacuum apparatus heated to 170 to 200 ° C., and drying through the vacuum apparatus (pellet molding machine). During the step, kneading step, etc., it is possible to remove the remaining water impregnated again.

 This makes the gelled raw material into pellets prior to molding of the present invention, which allows for easy storage prior to manufacture of the finished product and allows the components of the raw material to be more evenly distributed through the pelletization step. Pelletizing step in the artificial wood manufacturing method of the present invention can be omitted in some cases.

 More specifically, the reason for the pelletization step as described above is that the amount of natural vegetable fiber powder is higher than that of the compounded synthetic resin. This is because it is difficult to uniformly disperse the powders and additives, which may cause not only physical properties but also deterioration of product quality (surface state, depression, color, etc.).

 In addition, when the pelletization step is not carried out, the moisture content of the natural vegetable fiber powder is lowered to less than 1% during the drying step, so that when the kneaded raw material is brought back into the stock, a problem of having to go through the previous step again due to moisture impregnation may occur. have. On the other hand, since the synthetic resin is coated on the natural vegetable fiber powder after the pelletization step, even if brought to inventory can be minimized moisture impregnation.

6. Molding Step

 After mixing the expansion agent in the gelled raw material or pelletized raw material through the second kneading step, and heat-melting at 180 ~ 230 ℃ and molding into an artificial wood product containing a natural vegetable fiber powder using an extruder. More specifically, in the forming step, the expansion agent 0.86phr (Parts perhundred parts of Rubber) ~ 2.04phr based on the gelled raw material or pelletized raw material is mixed, and the mixed raw material is extruded with a heated vacuum apparatus There is a method of putting into a molding machine. Then, the heating conditions of the extruder is set to 180 ~ 230 ℃ and heated and melted, passed through a die to convert into a continuum having a cross-section of the desired shape (plate, mold release, etc.), cooled, solidified, wound or cut can be have.

 In the above, the swelling agent is to reduce the weight of the artificial wood product is to use a thermally expandable microspheres based on the acrylonitrile copolymer and containing a low boiling hydrocarbon. At this time, it is preferable to inflate the expansion agent and the gelled or pelletized raw material by heat-melting, and then expand it by 30 to 70% by adding about 1 to 4 minutes of heat in an atmosphere of 180 to 230 ° C. This is a mechanical expansion method, not a chemical foaming agent or a gas foaming method that expands only to synthetic resins, and is an expansion method that has little relationship with the content of synthetic resins and is less affected by external conditions such as temperature and humidity. Since chemical foaming or gas foaming is intended to expand synthetic resins, it is difficult to expand medium weight synthetic resins and reacts sensitively to external conditions (moisture, temperature, etc.). . In particular, the gas foaming method requires a lot of risk or facility investment because the gas must be injected from the outside.

 Synthetic wood of the present invention according to the manufacturing method can be extruded according to the site in the form of a plate or a release shape, despite the synthetic resin contained 16 to 40% by weight, such as the strength (physical properties) and touch like natural wood Have

 Optimal embodiments have been disclosed in the specification. Herein, specific terms have been used, but they are used only for the purpose of illustrating the present invention and are not intended to limit the scope of the present invention as defined in the claims or the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (14)

1. The synthetic resin is mixed with a silicone oil of at least one binder selected from polypropylene (MAPP), titanate-based and zirconate-based polypropylene (MAPP), titanate-based and zirconate-based synthetic resins mixed with polypropylene or high-density polyethylene, ethylene vinyl acetate or linear low-density polyethylene Binder coating step of coating;

   A drying step of drying one or more natural vegetable fiber powders selected from the group consisting of waste paper, rice straw, corn stalks, sorghum, hemp, coffee bark, palm fronds, sugar cane grounds and green tea grounds;

   A first kneading step of kneading the synthetic resin mixed with the binder and the natural vegetable fiber powder dried in the drying step together;

   A second kneading step of kneading by adding one or more additives selected from the group consisting of a lubricant, an antioxidant, a UV stabilizer, a nucleating agent, a filler, and an inorganic pigment to the mixture that has passed through the first kneading step; And

   Adding a swelling agent and the molding step of molding into an artificial wood product using an extrusion molding machine; artificial wood manufacturing method using natural vegetable fiber comprising a.
2. The method of claim 1, wherein the drying step

   A primary drying step of drying at 80 to 100 ° C. such that the water content of the natural vegetable fiber powder is less than 5 wt%; And

   A method of manufacturing artificial wood using natural vegetable fiber, comprising; a second drying step of drying so that the water content of the natural vegetable fiber powder is less than 1% by weight at 100 ~ 130 ℃.
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