KR20010017505A - Manufacture method of artificial wood - Google Patents

Abstract

PURPOSE: Provided is a process for producing artificial wood, which is excellent in tensile strength, impact strength and water resistance, and is applicable for in interior and exterior materials for building materials. CONSTITUTION: The process comprises the steps of: i) injecting 1-4wt% of one more coupling agent selected from maleic anhydride, phthalic anhydride and silane(3-methylacryloxypropyl trimethoxy silane), into wood meal and adding an initiator to the mixture, followed by treating the surface of the wood meal while stirring; ii) mixing 10-40wt% of one more resin selected from low-density-linear polyethylene, low-density polyethylene, high-density polyethylene, polypropylene and PVC, with the wood meal; and then iii) injecting the mixture into a mold and pressure-molding it to make a composite at 130-180deg.C for 5-30min under a pressure of 2.5-5.0MPa.

Description

Manufacture method of artificial wood}

The present invention relates to a method for manufacturing artificial wood through chemical treatment using wood powder obtained by crushing by-products, waste furniture, wood, etc. generated during wood processing.

Recently, due to the change in the perception of resources, many studies have been conducted in developing countries for the development of alternative resources and the recycling of resources in preparation for the depletion of resources. In recent years, the focus of attention on materials that meet the needs of the times is the development of building composite materials using waste.

The development of such waste recycling technology has the advantage of reducing costs by preventing environmental pollution and recycling resources.

In this situation, wood-reinforced plastic composites are stronger than conventional materials, have a beautiful aesthetics, are convenient and stable to manufacture, have excellent formability, and are particularly economical, which is sufficient to meet consumer needs compared to other materials. Do.

However, there has been a lot of problems in practical use due to the lack of a technology that can control the precise mixing control of the raw materials or the dimensional stability during manufacturing.

Therefore, there is an urgent need for the development of materials that can be recycled, but also provide additional functions such as good adhesion to materials and adhesion reliability as existing interior decoration materials.

Most of the upholstery furniture materials used so far are mostly MDF (Medium Density Fiberboard) and Particle Board (MDF) manufactured by recycling waste wood generated from processing of wood, and wood is partially used as a high-quality material.

However, MDF or PB has a problem in water resistance due to the limitation of interfacial bonding when it is used for a long time, and because wood is expensive due to lack of resources, there is a limit to use except for special fields.

Therefore, the development of new molding technology is urgently required to produce artificial wood having excellent physical properties.

On the other hand, looking at an example of the artificial wood manufacturing method so far; Korean Patent Application Publication No. 83-7283 describes the mixing of inorganic fibers such as asbestos hulls or glass fibers with main raw materials mixed with synthetic resin raw materials such as polyethylene, vinyl chloride, crests and shredded wood, or barley straw. Method of manufacturing artificial wood by mixing synthetic resin fibers such as PVC, mixing appropriate amount of foamed resin, or heating and pressing at 150 ~ 230 ℃ by inserting iron roll or wire mesh into core in the process of heat press molding Is disclosed.

In addition, Korean Patent Application Publication No. 84-362 uses wood fiber powder (wood powder obtained during the plywood manufacturing process and sawdust obtained during the manufacturing process), which is one of organic materials, as a filler. , PPG, MDI as a blowing agent, but the wood fiber powder as a filler in advance vacuum-dried at 200 ℃, and then mixed 1: 1 with the above polyurethane resin in a wooden mold so that the pattern of the natural wood can be expressed as it is The method of manufacturing a polyurethane resin board material by heat-processing shaping | molding at 80 degreeC is disclosed.

Also disclosed is a method of uniformly dispersing glass wool and pulp in water, mixing a binder and a deposition agent to form a mat in an agitator, and heating and pressing to cure and dry the binder to produce an artificial wood board. (Korean Patent Publication No. 89-17050).

In addition, Korean Patent No. 149476 discloses a first step of making paper porridge by mixing and pulverizing agricultural products and polyethylene resin containing waste paper and starch at 80 to 100 ° C, silicon resin 30 to 40 weight, and sodium silicate 6 to 12. 2nd step to make the first drug by mixing in the proportion of 45 to 60 weight by weight and emulsion vinyl acetate resin, 20 to 30 weight of castable refractory agent, 60 to 75 weight of first ammonium phosphate, 5 to 15 weight of silica gel 3rd process of mixing and grinding at 1,000 degreeC and obtaining a 2nd drug, 5-10 weight of sodium bicarbonate, 8-15 weight of ammonium chlorides, 40-50 weight of paraffin chlorides, 15-20 weight of 1st drugs, 2nd 15 drugs The agent which mixes and grind | pulverizes -20 weight at 800-1,000 degreeC, the paper porridge of a 1st process, and the powdered medicine of a 4th process in a ratio of 7-8.5: 1.5-3 by weight ratio, and heats it at 80-100 degreeC The artificial wood is prepared, including the sixth step of heating and pressing the mixture obtained in the fifth step and the fifth step. A method of preparation is also disclosed.

However, the artificial timbers developed so far have not been able to meet the above requirements.

It is an object of the present invention to provide a method for producing a composite material for artificial wood that can be secondary processed using waste wood, thinwood and other wood pulverized wood generated during processing of wood.

Another object of the present invention is to provide a technique for treating the surface of wood powder with a coupling agent in order to enhance the interfacial bonding force between wood powder and the binder and a method for producing a high strength composite material suitable for the purpose.

The present invention for achieving the above object is a process of treating the surface of the wood powder while adding 1 to 4 wt. Mixing the wood powder subjected to the surface treatment with 10 to 40 weight of resin; And putting the mixture into a mold and pressing to prepare a composite.

1 is a scanning electron micrograph (× 4000) of a composite obtained by press molding an untreated surface wood powder and resin mixture,

FIG. 2 is a scanning electron micrograph (× 4000) of a composite obtained by press molding a wood powder and a resin mixture surface-modified with 1 weight of a coupling agent,

3 is a scanning electron micrograph (× 4000) of a composite obtained by press molding a wood powder and a resin mixture surface-modified with 3 weights of a coupling agent.

Looking at each step of manufacturing the artificial wood according to the invention in detail,

(1) surface treatment process

The surface of the wood powder is modified to increase the bonding strength between the wood powder and the polymer resin. To this end, 1 to 4 weights of a coupling agent is added to the wood powder, followed by surface treatment with stirring by adding an initiator.

The wood powder that can be used can be used as long as it is obtained by crushing waste wood, thin lumber and other woods generated during wood processing, and the average particle size after crushing is 10 ~ 60㎛. It is preferable at the point of doing.

In this case, at least one selected from maleic anhydride, phthalic anhydride, and silane (3-methylacryloxypropyl trimethoxy silane) may be used as the coupling agent, and if the content is less than 1 weight, the coupling agent may be used. There is a quantitative problem to play a role as, there is a fear that the problem of weakening the bonding strength of the composite material itself 4 weight over surface coupling agent itself.

In addition, as an initiator, a common initiator can be used, and examples thereof include peroxide systems such as BPO and DCP.

(2) mixing process

The wood powder subjected to the surface treatment is mixed with 10 to 40 weight of the resin. At this time, the initiator is added to the resin at a constant ratio and mixed at a constant speed.

In this case, the resin serves as a binder with wood powder, and specific examples may include one or more selected from low density linear polyethylene, low density polyethylene, high density polyethylene, polypropylene, and PVC. There is a problem that it can not play a sufficient role as a binder in the composite, there may be a commercial problem when producing a prototype as a recycled product as the overweight 40 composite.

As described above, when the surface of wood flour is treated with a coupling agent through the step (1), the surface bonding strength between the resin and the wood flour may be improved, thereby ultimately improving water resistance when manufactured from wood.

(3) forming process

After mixing the wood powder and the resin as described above, to produce a mold for obtaining a composite material of a certain form, based on the pre-analyzed molding conditions, the mixed sample is put into the mold to produce a composite material by the press molding method.

Press molding is preferably performed at a temperature of 130 to 180 ° C. for 5 to 30 minutes at a pressure of 2.5 to 5.0 MPa. The most preferable conditions are a molding temperature of 150 ° C., a pressure of 3.3 MPa (478.62 psi), and a heating time of It is 5-30 minutes, and it cools for a predetermined time, maintaining pressure after shaping | molding.

The composite material prepared according to the above process can be obtained in various forms according to the shape of the mold, and has physical properties equivalent to those of the conventional products in flexural strength, tensile strength and impact strength.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Example 1

Couplings as shown in the following Tables 1 to 4 were added to the wood powder having a particle size of 55.85 μm obtained by pulverizing the mill, and then surface treated with stirring by adding BPO.

Subsequently, 10-40 wt% of low density linear polyethylene (LLDPE), a thermoplastic resin, was mixed with the surface-treated wood flour, and the mixed sample was put into a mold based on molding conditions pre-analyzed using a self-made mold. . Molding conditions were a temperature of 150 ℃, pressure was used as 3.3MPa (478.62psi), heating time was 20 minutes, and after the molding was cooled for a certain time while maintaining the pressure.

The content of wood flour in the composite material was up to 40 weight, and above that, the used matrix resin and filler were separated.

In order to measure the mechanical properties of the composite prepared as described above, using the Instron Model 5567 was measured according to ASTM D638M, ASTM 256, tensile strength, impact strength, the results are shown in Tables 1, 2 and 3, respectively.

Table 1 shows the results of measuring the tensile strength (MPa) of the composite prepared by mixing the respective coupling agent and wood powder, Table 2 is the impact strength (J / m) of the composite treated with maleic hydride, 3 is the impact strength (J / m) of the composite treated with phthalic unhydride, and Table 4 shows the impact strength (J / m) of the composite treated with silane.

The filling rate and the coupling agent treatment of the artificial wood prepared by using low density linear polyethylene as a matrix after the surface treatment of wood powder while varying the concentration of the coupling agent from Tables 1 to 4, and the mechanical properties of the composite As a result of observing the interfacial bonding phenomenon, the tensile strength increased as the reinforcement rate of wood powder increased, but when the reinforcement rate was more than 30 weight, the tensile strength decreased and the impact strength increased up to 30 weight. It showed a tendency to decrease.

When the reinforcement rate is excessively high, it was confirmed that the lack of matrix resin may reduce the adhesion between the reinforcement and the matrix resin, thereby deteriorating mechanical properties.

On the other hand, in order to observe the effect of the surface treatment of the wood powder with a coupling agent shown in the scanning electron microscope shown in Figures 1 to 3, as the treatment concentration of the coupling agent increases, the binding strength of the wood powder and resin and It was confirmed that the dispersibility was improved. In particular, in the case where resin and wood powder are combined without treatment with a coupling agent (FIG. 1), the bonding strength and dispersibility of the wood powder and the resin surface-treated with the coupling agent according to the present invention are mixed (FIGS. 2 and 3). You can see that this falls dramatically.

From these results, therefore, it can be confirmed that the present invention can be sufficiently utilized for the production of a composite material for artificial wood having excellent physical properties using wood powder.

As described in detail above, in the case of manufacturing a composite material by modifying the surface of the wood powder with a coupling agent according to the present invention and mixed with a resin, not only excellent physical properties such as tensile strength, impact strength, but also excellent water resistance, waste wood, furniture It is not only a molding technology that can recycle the back, but also it can prevent the environmental pollution caused by the disposal of all the waste wood, develop high value-added products, develop wood flour manufacturing technology that depends on the whole import of foreign currency In addition to savings, there is an advantage in that it can provide an opportunity to acquire foreign currency through export, and the manufactured composite material can be used for interior and exterior materials of building materials.

Claims (4)

After putting 1-4 weight of coupling agents into wood powder, The process of processing the surface of wood powder, adding and stirring an initiator; Mixing the wood powder subjected to the surface treatment with 10 to 40 weight of resin; And Method for producing interfacial-reinforced artificial wood comprising the step of putting the mixture into a mold and pressing to produce a composite. The interfacial-reinforced artificial wood according to claim 1, wherein at least one selected from maleic anhydride, phthalic anhydride and silane (3-methylacryloxypropyl trimethoxy silane) is used as the coupling agent. Manufacturing method. The method of claim 1, wherein the resin is one or more selected from among low density linear polyethylene, low density polyethylene, high density polyethylene, polypropylene, and PVC. The method for producing interfacial-reinforced artificial wood according to claim 1, wherein the molding is performed at a temperature of 130 to 180 DEG C for 5 to 30 minutes at a pressure of 2.5 to 5.0 MPa.