KR101042694B1 - Artificial wood using natural vegetable fiber - Google Patents

Abstract

The present invention relates to artificial wood using natural vegetable fiber, specifically, one or more natural vegetable fiber selected from the group consisting of waste paper, rice straw, corn stalk, sorghum, hemp, coffee bark, palm fronds, sugar cane dregs and green tea dregs. powder; Synthetic resins comprising polypropylene or high density polyethylene and ethylene vinyl acetate or linear low density polyethylene; At least one binder selected from maleated polypropylene (MAPP), titanate and zirconate; And one or more additives selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers, and inorganic pigments.
Artificial wood using the natural vegetable fiber of the present invention as described above can significantly maintain the strength (physical properties) similar to natural wood, while lightly reducing the content of synthetic resin with a heavy weight and high harmful gas generation rate in the event of fire.

Description

Synthetic Wood Using Natural Fiber Plastics

The present invention relates to artificial wood using natural vegetable fiber, and more particularly, by reducing the amount of synthetic resin significantly, harmful gas generation rate is reduced in the event of a fire, and natural vegetable fiber contains a large amount of light weight such as natural wood It is about artificial wood using natural vegetable fiber that not only has texture but also has better physical performance, processability and workability than natural wood.

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 is to provide an artificial wood using natural vegetable fiber having a superior strength (physical properties), processability, workability, etc. than natural wood, even significantly reducing the amount of synthetic resin.

Accordingly, the present invention is a preferred first embodiment, one or more natural vegetable fiber powder selected from the group consisting of waste paper, rice straw, corn sorghum, sorghum, hemp, coffee bark, palm fronds, sugar cane waste and green tea dregs; Synthetic resins comprising polypropylene or high density polyethylene and ethylene vinyl acetate or linear low density polyethylene; At least one binder selected from maleated polypropylene (MAPP), titanate and zirconate; Silicone oil; Swelling agent; And at least one additive selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers, and inorganic pigments.

In the artificial wood according to the embodiment, there is provided an artificial wood comprising a natural vegetable fiber powder, characterized in that the water content is less than 1% by weight.

In the artificial wood according to the embodiment, the synthetic resin may include 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.

In the artificial wood according to the embodiment, the polypropylene may include a natural vegetable fibrous powder that is a homo or impact polypropylene having a melt index of 7 to 15.

In the artificial wood according to the embodiment, the high density polyethylene may include a natural vegetable fiber powder having a melt index of 2 to 10.

In the artificial wood according to the embodiment, the linear low density polyethylene may include a natural vegetable fiber powder having a melt index of 1 to 4.

In the artificial wood according to the embodiment, it provides an artificial wood comprising natural vegetable fiber powder, characterized in that it further comprises 0.2 to 0.5 parts by weight of silicone oil with respect to 100 parts by weight of artificial wood.

In the artificial wood according to the embodiment, 60 to 75% by weight of one or more natural plant fiber powder selected from the group consisting of waste paper, rice straw, corn sorghum, sorghum, hemp, coffee bark, palm fronds, sugar cane dregs and green tea dregs; 13-29 weight% of polypropylene or high density polyethylene, and 3-11 weight% of ethylene vinyl acetate or linear low density polyethylene; 0.5 to 2.5% by weight of one binder selected from maleated polypropylene (MAPP), titanate and zirconate; And 2-6% by weight of one or more additives selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers and inorganic pigments.

In the artificial wood according to the embodiment, the additive 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 stabilizer, 0.3 to 0.7 parts by weight of nucleating agent, based on 100 parts by weight of artificial wood, It provides artificial wood comprising natural vegetable fiber powder containing 1 to 3 parts by weight of filler, 0.2 to 0.4 parts by weight of inorganic pigment.

In the artificial wood according to the embodiment, it provides an artificial wood comprising natural vegetable fiber powder, characterized in that it further comprises 0.7 to 2.5 parts by weight expansion agent based on 100 parts by weight of the artificial wood.

According to the present invention, it is possible to provide a synthetic wood using natural vegetable fiber that can maintain the strength (physical properties), processability, workability, etc., which is lighter than natural wood, while reducing the content of synthetic resin, which is heavy in weight and has a high rate of harmful gases during fire. Can be.

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

Synthetic wood made from natural vegetable fibers according to the present invention,

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;

Synthetic resins comprising polypropylene or high density polyethylene and ethylene vinyl acetate or linear low density polyethylene;

At least one binder selected from maleated polypropylene (MAPP), titanate and zirconate; Silicone oil; Swelling agent; And

And at least one additive selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers and inorganic pigments.

Hereinafter, the present invention will be described in detail.

1. Natural vegetable fiber powder

First, the natural vegetable fiber powder of the present invention is preferably at least one selected from the group consisting of waste paper, rice straw, corn stalk, sorghum, hemp, coffee bark, palm fronds, sugarcane dregs, green tea dregs and the like. The size of the natural plant fiber powder is preferably 80 ~ 150mesh. The reason for using the above-mentioned natural vegetable fiber powder in the present invention is that when using the sawdust or wood flour in the manufacture of artificial wood, unlike the content of the fiber is not constant depending on the species, it is possible to utilize the same components and uniform content of the fiber This is because this excellent artificial wood can be obtained. 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.

In addition, the prepared natural vegetable fiber powder is preferably dried so that the moisture content is less than 1% by weight.

Specific examples of the method for drying the prepared natural vegetable fiber powder to less than 1% by weight, the first drying step and 100 ~ to dry the natural vegetable fiber powder to a water content less than 5% by weight at a temperature of 80 ~ 100 ℃ 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 130 ℃. Here, although not particularly limited, the first drying step is preferably performed on a 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 ℃. . The reason for this two-step drying step is that the initial moisture content of the natural vegetable fiber powder is 12-15%. In a tunnel-type closed conveyor belt dryer, it is not only possible to lower the moisture content by 1% at a time, but even if it is well sealed Because it penetrates. Preferred drying equipment to be used in the secondary drying step is a facility in which only the heating blender is modified in the general blender, but the inside is the same as the general blender, but the outside is preferably a structure that can automatically control the heat. This drying facility can be completely mixed with a number of impellers, it is possible to uniformly dry the natural vegetable fiber powder on the outside and inside.

If the moisture content of the natural vegetable fiber powder is high, there is a fear 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 from the natural vegetable fiber powder in the artificial wood manufacturing process.

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.

2. Synthetic resin

The synthetic resin is preferably mixed with polypropylene or high density polyethylene, and ethylene vinyl acetate or linear low density ethylene.

The content of synthetic resin is less than the amount of natural vegetable fibrous powder. However, when ethylene vinyl acetate or linear low density polyethylene is used during processing in artificial wood molding, the mixture flows well and the uniform dispersion facilitates the defect rate. It is desirable to not only reduce, but also to increase 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 10 to 85 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. At this time, it is preferable to use homo or impact polypropylene having a melt index of 7 to 15, and the 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.

3. Binder

The synthetic resin is preferably mixed with a binder selected from maleated polypropylene, titanate and zirconate salts. At this time, the silicone oil may be further mixed. 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 pelletizing step or the molding step, thereby improving the moldability and physical properties.

In addition, the content of the synthetic resin to be mixed in comparison with the large amount of natural vegetable fibrous powder in the above, when using the ethylene vinyl acetate or linear low-density polyethylene during 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).

The synthetic resin is preferably mixed with a binder selected from maleated polypropylene, titanic acid salt and zirconate salt. 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 with respect to 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 bending strength, modulus of elasticity, and the like, as well as improve bonding strength between natural vegetable fiber powder and synthetic resin, and improve dimensional stability, impact strength, and the like.

After mixing the synthetic resin and the binder (and silicone oil), it is preferable to knead with the pre-dried natural vegetable fibrous powder. 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.

3. Additive

In addition, the gel is preferably kneaded by adding at least one additive selected from the group consisting of a lubricant, an antioxidant, a UV stabilizer, a nucleating agent, a filler, and an inorganic pigment. 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 long-term deformation due to impact strength, bending strength, heat deformation temperature and load, and may be selected and used from the group consisting of calcium carbonate, talc and 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 gelling raw material containing the additive may be pelletized into pellets of 2-3 mm by a molding machine for pellets with a vacuum apparatus heated to 170 to 200 ° C. In addition, the residual water impregnated again may be removed through a drying step, a kneading step, and the like through the vacuum apparatus (pellet molding machine).

This makes the gelled raw material into pellets prior to (artificial wood) molding of the present invention, thereby facilitating storage prior to production of the finished product and allowing the components of the raw material to be more evenly distributed through pelletization. In the artificial wood of the present invention, pelletization may be omitted in some cases.

The reason for pelletizing as described above is that the amount of natural vegetable fiber powder is higher than that of the compounded synthetic resin, so that the molding and mixing immediately after kneading maximize the function of the synthetic resin or the natural vegetable fiber powder and the additive evenly. This is because it is difficult to cause not only physical properties but also deterioration of product quality (surface state, depression, color, etc.).

In addition, when the pelletization is not performed, since the water content of the natural vegetable fiber powder is lowered to less than 1%, a problem of having to go through the previous step again due to water impregnation may be caused by bringing the kneaded raw material back to the stock. 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.

Next, the gelled raw material or the pelletized raw material is heated and melted at 180 to 230 ° C. with an additive, and then molded into an artificial wood product including natural vegetable fiber powder using an extrusion molding machine. More specifically, in the molding step, the expansion agent 0.86phr (Parts perhundred parts of Rubber) ~ 2.04phr based on the gelled raw material or pelletized raw material, 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 inflate heavy 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.

Artificial wood according to the present invention as described above is 60 to 75% by weight of at least one natural plant fiber powder selected from the group consisting of waste paper, rice straw, corn, sorghum, hemp, coffee bark, palm leaves, sugar cane residue and green tea residues; 13-29 weight% of polypropylene or high density polyethylene, and 3-11 weight% of ethylene vinyl acetate or linear low density polyethylene; 0.5 to 2.5% by weight of one binder selected from maleated polypropylene (MAPP), titanate and zirconate; And 2 to 6% by weight of one or more additives selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers and inorganic pigments. The artificial wood may be extruded according to the site in the shape of a plate or a release, and has a strength (physical property) and feel similar to that of natural wood even though the synthetic resin is contained in a small amount of 16 to 40% by weight.

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 (10)

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;
Synthetic resins comprising polypropylene or high density polyethylene and ethylene vinyl acetate or linear low density polyethylene;
At least one binder selected from maleated polypropylene (MAPP), titanate and zirconate; Silicone oil; Swelling agent; And
Artificial wood comprising a natural vegetable fiber powder comprising; at least one additive selected from the group consisting of lubricants, antioxidants, UV stabilizers, nucleating agents, fillers and inorganic pigments.
The method of claim 1,
Artificial wood comprising natural vegetable fiber powder, characterized in that the water content is less than 1% by weight.
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