KR20170003228A

KR20170003228A - Wood plastic composite and its manufacture method and wooden floor materials prepared by wood plastic composite

Info

Publication number: KR20170003228A
Application number: KR1020150093620A
Authority: KR
Inventors: 손달호
Original assignee: (주)경동월드와이드
Priority date: 2015-06-30
Filing date: 2015-06-30
Publication date: 2017-01-09

Abstract

The present invention relates to a wood-plastic composite material that is made up of wood flour, a plastic resin, and a cross-linking agent. In the wood-plastic composite material, the wood flour and the plastic resin are contained at a weight ratio of 70 to 80:20 to 30, the plastic resin is at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), and polystyrene (PS), and 1 to 5 parts by weight of the cross-linking agent is contained with respect to 100 parts by weight of the wood flour-plastic resin mixture. With the wood-plastic composite material according to the present invention, flexure attributable to bond stress and bond strength between the stacked materials are improved, deterioration attributable to moisture permeation into a floor subjected to construction is prevented, a bonding force can be improved between the wood flour and the plastic resin in the composite material, and stability can be maximized regarding a change in dimensions attributable to temperature and humidity. Accordingly, the present invention can be effectively used as a flooring material in various places such as mountain paths, gyms, and cafes.

Description

TECHNICAL FIELD [0001] The present invention relates to a wood-plastic composite material, a method of manufacturing the same, and a flooring material produced therefrom. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a wood-plastic composite material, a method for manufacturing the same and a flooring material produced therefrom, and more particularly to a wood-plastic composite material having a wood powder content of 70% or more and a wood- A wood-core layer, a melamine sheet layer, or both of these wood core layers and a melamine sheet layer are laminated on a wood-plastic composite material, and a flooring material produced therefrom.

Wood Plastic Composite is a composite material made by mixing natural materials such as wood powder or wood fiber with thermoplastic synthetic resin. It is made by combining fine wood powder or wood fiber of micron unit with synthetic resin. It has all the advantages. Such a wood-plastic composite material has much better durability than natural wood such as moisture resistance, heat resistance, tensile strength, and bending strength, compared with wood having a severe deformation due to external environment such as moisture.

The above-mentioned wood-plastic composite material has no deformation, it can be manufactured as a standardized product without the need of a preservative treatment such as wood, and has a high workability. It does not require any painting or management as compared with a general wood or wood material, It has excellent natural texture and is widely used as interior materials and exterior materials for construction. In addition, it has attracted attention as an environment-friendly material because it has advantages of being reusable and reworkable.

Due to these characteristics, wood-plastic composites have more than 20% annual growth rate for use in interior and exterior materials such as decks, fences and siding in North America and Japan, and the use of wood-plastic composites is increasing in Korea.

For example, Korean Utility Model Registration No. 20-0399316 discloses a composite panel made of wood fiber and plastic fiber as a base material, and is used as a base material for a wood- An ondol flooring laminated with a natural veneer is disclosed. In the case of the above design, it is a main purpose to provide the surface texture of the surface design and the appearance effect freely while strengthening the surface physical property which is a disadvantage of the plywood floor. The dimensional stability is similar to that of the plywood floor, but when the composite panel and the natural veneer are attached with the adhesive So that it is not free from the warping phenomenon of the product due to the stress generated in the product.

On the other hand, Korean Patent Registration No. 10-0679815 discloses an invention in which a high density fiberboard is used as a center layer and a veneer is laminated on a surface veneer and a veneer on the bottom, thereby solving the structural problem of stability and variation of temperature and humidity. Density layer is laminated on top of the high-density fiberboard as a center layer, and a balance layer having a density of 100 +/- 30% of the surface laminated layer is laminated on the bottom. The durability problem can be overcome to a certain extent by the high- When the wood of each layer stacked on the upper and lower portions of the fiberboard is formed in the same direction, there is a possibility of being deformed by bending or twisting. In order to solve the dimensional stabilization problem with respect to temperature and humidity, The process becomes complicated.

Therefore, there is no need to apply the backside waterproofing layer separately, and studies on a flooring material in which a wooden core layer or a laminated wood is laminated on a wood-plastic composite material having excellent dimensional stability and bending strength have been continuously carried out. , When an adhesive is attached to the wood-plastic composite material to form an adhesive layer, the wood-plastic composite material needs to have a high wood powder content in order to provide a better adhesive force. However, when wood flour is mixed with wood flour in an amount of 70% or more in the conventional wood-plastic composite material, the bonding strength with the plastic resin is lowered, and due to the frictional resistance in the extruded mold due to the increase of the wood flour content The outer appearance of the product is not homogeneous, and the resin content required for bonding with the wood and the resin is lowered, causing a phenomenon of breakage or cracking due to a decrease in bonding strength at the corner portion.

Therefore, a wood-plastic composite material which can increase the adhesion between the wood-plastic composite material constituting the flooring material and the other woody material while also increasing the bonding force between wood and the plastic resin in the wood-plastic composite material itself, It is necessary to study the method of manufacturing composites.

Korean Registered Utility Model No. 20-0399316 Korean Patent No. 10-0679815

Accordingly, it is an object of the present invention to provide a wood-plastic composite material for solving the above problems, a method for manufacturing such a wood-plastic composite material, and a flooring material produced using the wood-plastic composite material as a base layer.

In order to achieve the above object, the present invention provides a wood-plastic composite material comprising wood powder, a plastic resin and a crosslinking agent, wherein the wood powder and the plastic resin are contained in a weight ratio of 70 to 80:20 to 30, Is one or more selected from the group consisting of polyethylene (PE), polypropylene (PP) and polystyrene (PS), and the cross-linking agent is 1 to 5 parts by weight based on 100 parts by weight of the mixture of the wood- Plastic composite material.

According to a preferred embodiment of the present invention, the wood-plastic composite material comprises wood powder, a plastic resin and a crosslinking agent; Compounding said mixture at a temperature between 110 and 175 캜; Pre-pressing the compounded particles; And feeding the pre-pressed particles to a belt tip at a temperature of 110 to 180 캜 to perform press-molding.

According to a preferred embodiment of the present invention, the crosslinking agent is preferably a coupling agent having a maleic anhydride content of 3% or more.

According to another preferred embodiment of the present invention, there is provided a flooring material in which a wood core layer or a surface pattern layer is further laminated on the wood-plastic composite material, and a wood core layer and a surface layer on the wood- Wherein the wood-plastic composite material has a thickness of 2 to 11 mm, and the thickness of the wood-plastic composite material is preferably 2 to 11 mm More preferably 3 to 5 mm.

According to another preferred embodiment of the present invention, the wood core layer is preferably at least one selected from the group consisting of veneer, veneer laminate and hard fiber board, and the surface layer is not limited thereto But it is preferably at least one selected from the group consisting of wood veneer, high pressure melamine (HPM) layer and low pressure melamine (LPM) layer.

Also, the wood core layer or the surface pattern layer constituting the flooring material of the present invention is laminated through an adhesive layer, and the adhesive layer may be an epoxy or polyurethane type, a phenol type, a polyisocyanate Based resin and an ethylene-vinyl acetate resin, and further, a surface coating layer is further laminated on the surface pattern layer constituting the flooring material of the present invention.

According to a preferred embodiment of the present invention, the flooring material has a connection structure by T & G (Tongue and Groove), a click system, or a connector.

According to another preferred embodiment of the present invention, there is provided a method of manufacturing a wood-plastic composite material, comprising: preparing a wood-plastic composite material, a wood core layer and a surface pattern layer; And laminating and laminating a wood core layer or a surface pattern layer on the wood-plastic composite material with an adhesive layer interposed therebetween, and integrating the laminated wood core layer or the surface pattern layer by thermocompression bonding. The obtained flooring material is subjected to side and end processing to form a T & The present invention also provides a method of manufacturing a flooring material having a connection structure of a flooring material. In the case where the wood core layer is laminated on the wood-plastic composite material with the adhesive layer interposed therebetween, a surface pattern layer is laminated on the wood core layer with a second adhesive layer interposed therebetween, The first adhesive layer, the woody core layer, the second adhesive layer, the surface pattern layer and the surface coating layer are integrated.

According to the wood-plastic composite material of the present invention, the warpage phenomenon due to the adhesion strength and the adhesion stress between laminated materials is improved, the deterioration due to penetration of moisture at the bottom of the construction is prevented, the bonding force between the wood- It can be widely used as a flooring material used in various places such as a hiking trail, a gymnasium, and a cafe because it can maximize the stability of dimensional change according to temperature and humidity.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical cross-sectional view showing respective laminated materials constituting a flooring material of the present invention. Fig.
2 (A) is a surface of a wood-plastic composite produced according to the manufacturing process of the present invention (wood particle: 0.1 to 3.0 mm, wood powder content: 70 to 80% by weight, press molding) Is a surface of a wood-plastic composite material manufactured according to a conventional manufacturing process (wood particle: 0.1 to 0.7 mm, wood powder content: 70 to 80% by weight, extrusion molding).
3 is a view showing a high-speed mixer used in a high-speed mixing stage in the process of manufacturing the wood-plastic composite material of the present invention.
4 is a view showing a twin-screw type extruder used in the compounding step in the process of manufacturing the wood-plastic composite material of the present invention.
5 is a view showing a belt press used for press forming in the B / P molding step in the process of manufacturing the wood-plastic composite material of the present invention.
6 is a schematic process flow diagram of a manufacturing process of a wood-plastic composite material of the present invention and a whole process of manufacturing a flooring material.
7 is a view showing the mechanism of the manufacturing process of the wood-plastic composite material of the present invention.
8 is a view showing a test apparatus used for bending strength test.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

The "Wood Plastic Composite" of the present invention is a mixture of wood and a plastic resin, and may be called a synthetic wood or simply a WPC. Hereinafter, a method of manufacturing such a wood-plastic composite material and a method of using the wood- A manufacturing method of the flooring material will be described.

[Production of wood-plastic composite material]

1. Preparation of raw materials :

Wherein the wood powder and the plastic resin are contained in a weight ratio of 70 to 80:20 to 30, and the wood powder and the plastic resin are contained in a ratio of 73 to 77: 23 to 27 By weight. The crosslinking agent is preferably added in an amount of 1 to 5 parts by weight based on 100 parts by weight of a mixture of wood and a plastic resin.

The wood powder preferably has a moisture content of 7% or less, and the wood powder particles have an average size of 0.1 mm to 3.0 mm, preferably 0.1 mm or less and 10% or less, and 1.0 mm or more and 10% Do. The plastic resin is not limited thereto, but is preferably polyethylene, polypropylene or polystyrene resin. In addition, the crosslinking agent is not limited thereto, but is preferably a coupling agent having a maleic anhydride content of about 3% or more.

The reason why the particle size of the wood powder constituting the wood-plastic composite material of the present invention is preferably 0.1 to 3.0 mm is that the content of the plastic resin to be added is relatively lowered by reducing the surface area compared to conventionally used wood powder particles of 0.1 to 0.7 mm So that the content of wood flour is increased, thereby maximizing the adhesive force between the laminated materials of the flooring material to be produced later.

In addition, since the wood powder content accounts for more than 70% of the entire wood-plastic composite material, the problem of lowering the bonding strength between the wood and the plastic resin and the problem of lowering the bonding strength of the edge portions is not caused by the conventional extrusion process, It is possible to overcome the limit of physical properties due to the increase of the content.

2. High-speed mixing stage :

As shown in FIG. 3, the raw materials are mixed in a high-speed mixer having two or more stirring blades at the bottom and then mixed for 30 minutes at a temperature of about 750 rpm or more. do. Inside the high-speed mixer, the temperature rises to 110 ° C due to the friction of the raw materials, and the residual moisture of the wood flour drops from about 7% to less than about 1%. The purpose of the high-speed mixing step is to homogeneously mix the raw materials of different sizes and specific gravity, and additionally adjust the moisture content to give optimal conditions for the following compounding process.

3. Compiling step :

And compounding each raw material in a twin screw type extruder set at a temperature range of 110 to 175 DEG C, wherein the plastic resin is melted to bind the wood particle. The compounding step is carried out for the purpose of dissolving the plastic resin and the cross-linking agent in each of the uniformly mixed raw materials so as to coat and bond the wood powder particles. The compounding extruder has two screw barrels horizontally Along side by side, it rotates in the same direction and feeds the mixed material between two screws.

In this case, heat is externally applied to melt the plastic resin. The suitable temperature is operated at a temperature of 90-190 ° C. More specifically, the inlet portion is 90-120 ° C, the portion in which the plastic resin is melted and bonded to the wood Is set at 150 to 175 DEG C, and the discharge section is set at 120 to 140 DEG C. The two screw barrels are sequentially combined with the screw shapes for conveying, pressurizing, agitating, pressurizing, and conveying the raw materials, which are determined by the angle, spacing and blade thickness of the screw blades.

The intermediate raw material discharged through the compounding extruder exhibits a temperature of 160 to 180 ° C. and is conveyed to the next stage in a form suitable for molding by manifesting viscosity and fluidity. At this time, the temperature of the melt section of the compounding equipment is higher than 190 ° C. The wood is overheated in the feedstock and burning or color change is a problem. In case of wood burning, it may cause problems in molding due to the occurrence of bonding water or the release of lignin. Also, when the temperature of the melting zone is operated below 150 ° C, Can cause.

4. Prepressing step :

A step of forming a shape by applying a constant pressure to compound particles in a hot state at 160 to 180 ° C, wherein the step of primary molding the compound with a roller press or a low-pressure hydraulic press is referred to as a pre- The purpose of this pre-pressing step (also referred to as pseudomorphic step) is to fill the density of the intermediate material (also referred to as compound) from the extruder to maximize the flexural strength in the final molding and to minimize the variation in physical properties of the molded part . In the case of the conventional wood-plastic composite material process, the intermediate raw material from the compound is cooled to a predetermined temperature level, and then the product is extruded in the final extrusion molding machine, cooled, and then commercialized. This extrusion molding method has a disadvantage in that it can not but produce a small-sized wood-plastic composite material. Therefore, this pre-pressing step for molding large size wood-plastic composites is a process to compensate for the disadvantages of physical property deviations (porosity, absorptivity, flexural strength, etc.) The filling specific gravity of compound raw material is 0.4 ~ 0.5, while the specific gravity of filling is increased to 0.9 ~ 1.0 at pre-pressing, where the flexural strength is 150 ~ 200kgf / cm ² .

The apparatus used in the pre-pressing step is not limited to the type and the method but may be an apparatus capable of applying a load of 5 to 15 kgf per unit area (cm ² ). More specifically, And a homogeneous size (1 to 4 mm) compound filled with a raw material, a hydraulic press capable of press-molding an upper mold or an upper or lower drum having a gap at which the compound can be pressed to a certain thickness A roller press capable of pressing the raw material through the rollers is preferred. In particular, the width of the false foam to be formed by filling the raw material of the compound at an appropriate temperature at the time of pre-pressing is set to 1,000 mm or more.

5. B / P molding step :

At the temperature of 110 ~ 200 ℃, the raw material with the first pseudomorphic shape is put into the end of the belt to final shape with the desired thickness (3 ~ 25T) and size, and the molding pressure is about 40 bar.

As shown in FIG. 5, the board having a modulus of the raw material of the proper temperature is put into a belt press which presses the upper and lower sides with a roller drum, and finally pressurizes to the optimum molding pressure. The belt press is sequentially divided into a heating zone and a cooling zone. The heating zone is pressurized at a unit pressure of 40 bar in an atmosphere maintained at a temperature of 110 to 200 ° C. More specifically, a heating zone set at a temperature of 140 to 170 占 폚 is pressed and passed at a line speed of 1 to 2.0 M / min (7T thickness forming standard). If the set temperature is lower than 140 캜, the plastic resin of the false-type sheet hardens, causing the fluidity of the raw material to drop significantly, resulting in defective molded products. When the temperature is higher than 170 캜, the false- . The final thickness of the formed product is determined by the spacing of the upper and lower rollers and the final formed thickness is formed to a thickness of 5 to 7 mm. The press-molded plate discharged from the belt press discharging portion is discharged through the cooling section. During the cooling section, a certain load is applied to the molded plate, and cooling is performed. This is because the stress and the loosening of the plastic nature of the temperature change repeat this case it is possible to cause deformation of the product load is cooled, and applied under the load until the final cooling time (less than 35 ℃) is a five or a 10kgf / cm ² .

6. Cutting Sanding steps :

The step of cutting the cold-rolled plate to the standard dimensions and cutting the upper and lower surfaces to reduce the dimensional deviation to within ± 0.1 mm and smoothen the mounting surface. The final molded plate of 5 to 7 mm thickness is required to attach the product Surface is processed to thickness 3 ~ 4mm.

The wood-plastic composite material of the present invention can be obtained by the above-mentioned 6-step manufacturing process. The mechanism for the core compounding step, pre-pressing step and B / P molding step is summarized in FIG. 2 (A) shows the surface of the wood-plastic composite material produced according to the production process of the present invention (wood powder particle: 0.1 to 3.0 mm, wood powder content: 70 to 80 weight%, press molding) 2 (B) shows the surface of the wood-plastic composite material produced according to the method of the present invention, which is produced by the following method.

[Production of flooring material]

1. Attachment step :

A wood core layer made of veneers, veneer plywood or fiberboard of the same size (3 to 4 T in thickness) prepared by applying 60 to 80 g / m ^{2 of the} adhesive onto the polished wood-plastic composite material with a thickness of 3 to 4 mm is attached. The surface layer is composed of a high pressure melamine (HPM) layer, a low pressure melamine (LPM) layer and a low pressure melamine layer. The surface layer layer is formed by laminating the wood core layer and a surface pattern layer thereon. low pressure melamine) layer or veneer (0.4 to 3 T). The adhesive to be used is an aqueous or non-aqueous adhesive, and at least one selected from the group consisting of epoxy, polyurethane, phenol, polyisocyanate and ethylene-vinyl acetate is used.

The wood-plastic composite material of the present invention may be used by attaching only a wood core layer using an adhesive on the wood-plastic composite material, or by attaching only the surface pattern layer using an adhesive on the wood-plastic composite material. However, when the wood-plastic composite material, the wood core layer, and the surface pattern layer are all laminated, as described above, the wood-plastic composite material is used as the base layer, and the wood core layer is laminated thereon, .

2. Pressing step :

The composite sheet laminated with the adhesive is a step of pressing and holding the adhesive sheet for the necessary time for manifesting the strength of the adhesive. Pressure needed for the pressing is pressurized with 5 ~ 10kgf / cm ² and a hydraulic or pneumatic cylinder type.

3. Product specification Cutting and end side machining steps :

The completed composite sheet is cut to the size of product standard and made into a flooring material and then subjected to side and end processing. Side and end machining has a tongue and groove (T & G) joint structure with a protruding portion on one side of the flooring product and the other side having a groove for fitting the protruding portion, and the lateral side is also the same. In addition, it is possible to have a connection structure by a click system or a connector.

As described above, the wood-plastic composite material and the method of manufacturing the flooring material using the same have been described. The press-type wood-plastic composite material molded according to the process of the present invention is superior to the conventional wood- And a high content of wood powder, the adhesion between the wood-plastic composite material and the wood core layer at the time of manufacturing the flooring material is increased, and the adhesion of the wood-plastic composite material to the wood- And the problem of adhesive force generated in the plastic composite material is improved.

In the case of non-polar PE or PP resin, the adhesive strength of the adhesive used is significantly lower than that of conventional wood-based flooring. This is a basic property of a non-polar plastic resin, In order to maintain the physical properties and to maximize the wood powder content and to increase the particle size of the wood powder to be used, the wood particles of the large particles are used for strengthening the floor or steel It is one of the characteristics of the present invention that a wood-plastic composite material having adhesion close to woody flooring such as a floor was developed.

The basic principle of adhesion is classified into the case where the adhesive is applied with the adhesive agent (the case where the adhesive agent is absorbed into the pores of the woody material in the case of a steel floor) and the case where the adhesive agent is cured by the chemical reaction between the adhesive agent and the adhesive agent, The surface of the adhered wood-plastic composite material is characterized by maximizing the adhesive force on the same principle as the surface of the wood.

As shown in FIG. 1, the flooring material of the present invention has a multi-layer laminated structure composed of a wood-plastic composite material as a substrate layer and has a structure that maximizes the balance effect, For this purpose, the middle layer is composed of a woody layer and the uppermost layer is composed of a surface pattern layer.

The wood-plastic composite sheet produced in the present invention is a structure in which wood powder is molded from a raw material and has physical properties such as tensile force and flexural strength symmetrical in each direction. Since the balance between the upper and lower portions is maintained, When a laminated wood or HPM sheet is adhered using an adhesive, it may cause deformation of the final product due to stress or tensile force generated due to stress or an elasticity of the adhesive or shrinkage expansion due to moisture of the HPM sheet. However, the deformation of this end product has been solved through the case of the present invention in which the adhesive layer to be adhered is composed of a multi-layer adhesive layer capable of offsetting such stress or tension. The multi-layered adhesive layer is a layer composed of a middle layer and an uppermost layer on a wood-plastic composite substrate layer. The stress or tensile force generated in the base layer and the intermediate core layer is a stress or tension , The balance of the product is maximized and the warping phenomenon is improved. However, in the case where no stress or tensile force is generated between the stress of the adhesive or between the wood-plastic composite material and the sheet laminated thereon, the flooring material laminated with the vignetting material or the HPM sheet may be manufactured on the wood-plastic composite material , A flooring material obtained by directly laminating a wood core layer on the wood-plastic composite material may be produced.

In the present invention, the wood core layer (intermediate layer) may be a fiber board, a veneer or a veneer laminate. The fiber board is composed of a high density fiber board and has a specific gravity of 0.8 g / cm ² or more, And the veneer can be used in a hardwood or a wild material native to the Southeast Asian region, which is naturally grown in the Russian region. The veneer is cut in a rotary race method, and is used for a balance effect of a wood-plastic composite material of 3 to 4 mm And the water content of 7 ~ 10% is used, and the specific gravity of 0.4 ~ 1.0 g / cm ² is used according to the species.

In addition, the veneer plywood may be a plywood of the inner plywood obtained by laminating the veneer in an odd number of layers, and a water content of 7 to 10% is used.

The top surface layer of the laminated material constituting the flooring material of the present invention is adhered with a melamine sheet (HPM or LPM) composed of a printing layer having a thickness of 0.4 to 0.7 mm and a melamine-impregnated overlay sheet, It is possible to provide a flooring material having high abrasion resistance, scratch resistance and impact resistance.

The uppermost layer may be applied with a veneer (including a sliced cut wood or veneer having a thickness of 0.4 to 4 mm) coated with a surface (UV coating) for the purpose of improving discoloration and increasing abrasion resistance.

The veneer is used to express the natural texture and design of the log. All kinds of logs can be applied. In general, the logs are cut by slicing and used in a range of 0.3 to 0.7 mm.

FIG. 6 is a schematic view showing the entire process flow of the wood-plastic composite material of the present invention and the flooring material using the same.

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

< Example >

Examples 1 to 3, Comparative Examples 1 to 7 :

The flexural strength, porosity and water absorption of the wood-plastic composite material produced according to the manufacturing process of the wood-plastic composite material of the present invention were examined by the following methods.

For the bending strength test, a load of an average strain rate of about 50 mm / min is applied to the surface of the test piece using the test apparatus shown in Fig. 8, and the maximum load (P) is measured according to the following equation. .

Where P is the maximum load (N), L is the span (mm), B is the width of the test piece (mm), and T is the thickness of the test piece)

The porosity test is performed by drying the test specimen at a temperature of 110 ± 5 ° C until it becomes constant and then cooling it from the desiccator to room temperature. Let the mass at this time be m1. Next, the cooled and dried test specimens are placed in an airtight container, and the container is sealed and held in vacuum for 25 minutes until it reaches 2500 Pa. Thereafter, the vacuum is shut off and the solution for impregnation is gradually put into the airtight container to cover about 20 mm. Next, the vessel is closed again and maintained under reduced pressure for 30 minutes. After the pressure reduction process is further performed, the mass is measured in a state in which the test piece is contained in the impregnation solution, and the mass at this time is defined as m2. After that, a cotton fabric immersed in the impregnation solution is prepared, lightly squeezed once, the test specimen in the impregnation liquid is quickly removed, the impregnated surface is wiped with the prepared cotton fabric cloth, and the mass is measured. And the mass ratio at this time is m3, and the porosity is calculated according to the following porosity equation.

(Where m1 is the dry mass of the test specimen, m2 is the apparent mass of the liquid when immersed in a liquid in a vacuum, and m3 is the mass in air when wetted with liquid)

The water absorption test was carried out after measuring the weight of the test specimen before immersion, and after horizontally laying it horizontally at a depth of about 3 cm from the water surface in water of 20 ± 1 ° C for 24 hours to remove excess water remaining on the surface, The weight is placed in the center of 10 absorbing sheets of each angle, and about 3 kg of plate-like weight of the same size is superimposed thereon. After about 30 seconds, the mass is measured within 10 minutes.

(In the above formula, w1 is the mass (g) before the soaking and w2 is the mass (g) after the soaking)

In the case of wood-plastic composites (Examples 1 and 2) produced according to the manufacturing process of the present invention as shown in the following Table 1, and grain size and molding method of wood powder were different (Comparative Examples 1 and 2) (Comparative Examples 3 and 4), and when the wood powder content exceeded 80% (Comparative Example 5), the properties were analyzed and compared. The results are shown in Table 2 below.

division Particle size of wood powder
(mm) Of wood and plastic resin
Mixing ratio Molding method Example 1 0.1 to 3.0 7: 3 Press molding Example 2 0.1 to 3.0 8: 2 Press molding Comparative Example 1 0.1 to 0.7 7: 3 Extrusion molding Comparative Example 2 0.1 to 0.7 8: 2 Extrusion molding Comparative Example 3 0.1 to 0.7 7: 3 Press molding Comparative Example 4 0.1 to 0.7 8: 2 Press molding Comparative Example 5 0.1 to 0.7 8.5: 1.5 Press molding

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5
Molding
size width 1220 mm
More than 1220 mm
More than 150mm 150mm 1220 mm
More than 1220 mm
More than 1220 mm
More than Length No limit No limit No limit No limit No limit No limit No limit thickness 7mm 7mm 25mm 25mm 7mm 7mm 7mm Flexural strength
(kgf / cm ² ) 457 405 414 255 429 387 274 Porosity (%) 7.37 7.44 0.84 1.97 6.52 7.10 10.86 Absorption Rate (%) 6.35 6.67 0.16 1.63 4.95 5.27 9.52

As can be seen from Table 2, it was found that the flexural strength, the porosity and the water absorption were the greatest in Examples 1 and 2 produced according to the manufacturing process of the wood-plastic composite material of the present invention. It was found that the wood particle content was in the range of 0.1 to 3.0 mm, the wood particle content in the wood-plastic composite material was 70 to 80 wt%, and the wood-plastic composite material molding method exhibited the most excellent physical properties in the case of press molding. (Comparative Examples 1 and 2), it was found that not only the size of the molded plate was small but also the physical properties thereof were small. When the size of the wood powder particles was as small as 0.1 to 0.7 mm (Comparative Examples 3 and 4) It was found that all of the physical properties were slightly lower than those of the wood-plastic composite material of the present invention. In addition, when the content of wood flour exceeded 80% (Comparative Example 5), it was found that the bending strength was significantly lowered.

On the other hand, the inventors of the present invention investigated how the physical properties of the wood-plastic composite material changes when the wood-plastic composite material of the present invention is produced by adjusting the wood powder content in the state of using the grain size of 0.1 to 3.0 mm. The results are shown in Table 3 below.

division Comparative Example 6 Example 1 Example 3 Example 2 Comparative Example 7
Molding
size width 1220 mm
More than 1220 mm
More than 1220 mm
More than 1220 mm
More than 1220 mm
More than Length No limit No limit No limit No limit No limit thickness 7mm 7mm 7mm 7mm 7mm Wood powder: percentage of resin 6.5: 3.5 7.0: 3.0 7.5: 2.5 8.0: 2.0 8.5: 1.5 Flexural strength
(kgf / cm ² ) 460 457 455 405 208 Porosity (%) 0.84 7.37 7.38 7.44 15.86 Absorption Rate (%) 0.16 6.35 6.32 6.67 13.52

Example 3 was carried out between Example 1 (70% by weight of wood powder) and Example 2 (80% by weight of wood powder), which was already examined, and the physical properties when the wood powder content was 75% by weight were examined. (Comparative Example 6) and the case where the wood powder content was 85% by weight (Comparative Example 7).

As expected, when the wood powder content was less than 70% by weight, the porosity and the water absorption were low, and when the wood powder content was more than 80% by weight, the bending strength remarkably decreased.

Examples 1-1 to 3-1 and Comparative Examples 6-1 to 7-1 :

As shown in Table 3, an experiment was conducted to examine how the adhesive strength was changed by increasing the wood powder content from 65 wt% to 85 wt%.

The surfaces of the wood-plastic composites of Examples 1 to 3 and Comparative Examples 6 to 7 of Table 3 were polished and then the surface of the melamine impregnated surface was treated with ethylene-acetic acid Vinyl-based adhesive was adhered with the same weight of 120 g / m < ² > to measure the adhesive strength.

According to the adhesive strength test method of KS F3101, the specimens were boiled in boiling water for 4 hours, dried at 60 ± 3 ° C for 20 hours, boiled in boiling water for 4 hours, immersed in normal water, cooled, The maximum load at the time of fracture is measured by pulling the both ends at a load speed of 2 mm / min in the direction of both ends and calculating according to the following formula.

(Where P is the maximum load, b is the length (mm) of the bonded section, and h is the width (mm) of the test piece)

The adhesive strength of the wood plastic composite material of Example 1 was tested in Example 1-1, and the remaining examples were similarly shown.

division Comparative Example 6-1 Example 1-1 Example 3-1 Example 2-1 Comparative Example 7-1
Molding
size width 1220 mm
More than 1220 mm
More than 1220 mm
More than 1220 mm
More than 1220 mm
More than Length No limit No limit No limit No limit No limit thickness 7mm 7mm 7mm 7mm 7mm Wood powder: percentage of resin 6.5: 3.5 7.0: 3.0 7.5: 2.5 8.0: 2.0 8.5: 1.5 Adhesion
(N / mm ² ) 0.66 1.11 1.13 1.18 Substrate breakage

As expected, the adhesion of wood-plastic composites and melamine impregnated resins increased with increasing wood flour content. As can be seen from the bending strength data in Table 3, the conventional problem that the bond between the wood and the plastic resin is lowered in the wood-plastic composite material when the wood powder content is increased, And it can be overcome by the increase of the particle size of molding and wood grain.

Further, it was found through the data of the bending strength (400 or more) of Table 3 and the adhesive strength (1.0 or more) of Table 4 that the desirable wood powder content was 70 to 80% by weight.

Examples 4 to 6, Comparative Examples 8 to 10 :

(N / mm ² ), thermal dimensional change rate-width (%), thermal dimensional change rate-length (%), thermal conductivity (w / (m (Mm), flexural stability - high temperature (mm), etc. were evaluated.

The rate of dimensional change is measured by using a 0.01 mm scale dial gauge when the specimen reaches the constant weight at a temperature of 20 ± 1 ° C and a relative humidity of 65 ± 5% Then, the test piece is allowed to stand at 80 ± 1 ° C and relative humidity of 65 ± 1% for 24 hours, and then the length is measured.

L1 is a length under the condition of a temperature of 20 ± 1 ° C and a relative humidity of 65 ± 5% and L2 is a length under a condition of a temperature of 80 ± 1 ° C and a relative humidity of 65 ± 5%

The test specimens were dried at 105 ± 1 ℃ until they reached constant weight, and then the heat flux through the test specimens was directly measured electrically at 25 ± 1 ℃ according to the thermal conductivity test method of KS L9015, Calculate the thermal conductivity by measuring the temperature difference of the specimen at that time.

Absorption Thickness The rate of expansion was measured by using a 0.01 mm scale dial gauge when the specimen reached a constant mass at a temperature of 20 ± 1 ° C and a relative humidity of 65 ± 5% Measure and calculate the rate of change in thickness before and after immersion.

(Where T1 is the thickness of the test piece before immersion and T2 is the thickness of the test piece after immersion)

For the bending stability, each specimen was prepared in the same size of 85 mm × 800 mm × 7 T, then left at a temperature of 20 ± 1 ° C for 24 hours, curl (curled) The height is the value measured with a clearance gauge. The measured value at high temperature is the value obtained by measuring the height of the curl placed on the stone column after being left at 80 ± 1 ℃ for 24 hours.

The above properties were measured by changing the production conditions of the wood-plastic composite material little by little, and the production conditions were changed as shown in Table 5 based on Example 1.

division Wood flour
Particle size
(mm) Throat Division
Of plastic resin
Mixing ratio Molding method Stacking order
(Based on wood-plastic composites) Example 1 0.1 to 3.0 7: 3 Press molding Melamine impregnation sheet attachment Example 4 0.1 to 3.0 7: 3 Press molding Fiberboard core layer / HPM layer Example 5 0.1 to 3.0 7: 3 Press molding Veneer core layer / HPM layer Example 6 0.1 to 3.0 7: 3 Press molding Veneer plywood core layer /
HPM layer Comparative Example 8 0.1 to 0.7 7: 3 Extrusion molding Attach HPM layer Comparative Example 9 With melamine-impregnated sheet on the top layer of the inner plywood Comparative Example 10 High density fiberboard is used as base material and melamine impregnated sheet is attached to the top layer

The physical properties of the flooring prepared under the same conditions as those in Table 5 were evaluated, and the results are shown in Table 6 below.

Example 1 Example 4 Example 5 Example 6 Comparative Example 8 Comparative Example 9 Comparative Example 10 Hot dimensions
Rate of Change - Width (%)
0.04
-0.03
-0.02
-0.02
0.05
-0.11
-0.12 Hot dimensions
Rate of change -
Length(%)
0.04
-0.03
0.02
0.02
0.05
-0.01
-0.11 Thermal conductivity
(w / (m · k)) 0.319 0.317 0.315 0.314 0.320 0.107 0.112 Adhesion
(N / mm ² ) 1.11 - 1.15 1.18 0.13 1.21 - Absorption thickness
Expansion ratio (%) 0.9 1.5 1.1 1.2 1.0 - 5.3 Flexural Stability -
Low temperature (mm) 1.2 0.5 1.2 0.5 4.5 0.4 0.3 Flexural Stability -
High temperature (mm) 5.1 3.4 4.2 4.7 9.2 5.1 2.2

As compared with Comparative Example 8 in which a melamine-impregnated sheet was attached to a conventional wood-plastic composite material at the longitudinal direction thermal dimensional change ratio, the flooring materials of Examples 1 and 4 to 6 exhibited a lower change rate than the equivalent level. This is considered to be a great advantage in the embodiment in that the advantage of the wood property having a relatively low rate of change of the dimensional dimension is shown.

The thermal conductivity of the wood-plastic composites was lower than that of Comparative Example 8, but the characteristics of the wood-plastic composites having high thermal conductivity were also shown in the examples and they were superior to the wood flooring.

Adhesion Comparison In conventional wood-plastic composite material of low adhesion: show the adhesive strength (1.15 ~ 1.2N / mm ²⁾ close to the conventional wood-based flooring in Examples 5 and 6 compared to (Comparative Example 8 0.13N / mm ²⁾ As a result of the improvement of the absorbency of the adhesive according to the manufacturing process of the wood-plastic composite material of the present invention and the strengthening of the adhesive strength by the application of the wood core layer.

It was found that the flexural stability was lowered in the case of Comparative Example 8 in which the cross-section was adhered at the bending stability (low temperature and high temperature), but it was found that the stability was improved when the wood core layer in the wood-plastic composite material of the present invention was provided . (Comparative Example 10), which is higher than that of the conventional flooring material (Comparative Example 10). However, as compared with the steel flooring (Comparative Example 9), the wood-plastic composite material and the melamine- It is judged that the core layer provided improved bending stability.

Examples 7 to 10, Comparative Examples 11 to 12 :

For the purpose of improving the discoloration and increasing the abrasion resistance, various physical properties of the flooring material on which the veneer (0.7 mm in thickness) having the surface coated (UV coated) on each substrate were analyzed.

The products were prepared according to the production conditions shown in Table 7 below.

division Wood flour
Particle size
(mm) Throat Division
Of plastic resin
Mixing ratio Molding method Stacking order
(Based on wood-plastic composites) Example 7 0.1 to 3.0 7: 3 Press molding Vignetted Example 8 0.1 to 3.0 7: 3 Press molding Fiberboard core layer / veneer Example 9 0.1 to 3.0 7: 3 Press molding Veneer core layer / veneer Example 10 0.1 to 3.0 7: 3 Press molding Veneer plywood core layer /
Veneer Comparative Example 11 0.1 to 0.7 7: 3 Extrusion molding Vignetted Comparative Example 12 With the veneer of domestic plywood and the veneer on the surface

The properties of the flooring prepared according to these conditions were evaluated, and the results are shown in Table 8 below.

Example 7 Example 8 Example 9 Example 10 Comparative Example 11 Comparative Example 12 Hot dimensions
Rate of Change - Width (%)
0.04
-0.02
-0.02
-0.02
0.05
-0.12 Hot dimensions
Rate of change -
Length(%)
0.05
0.02
0.04
-0.02
0.06
-0.02 Thermal conductivity
(w / (m · k)) 0.311 0.310 0.308 0.309 0.312 0.103 Adhesion
(N / mm ² ) 1.07 - 1.10 1.18 0.07 1.12 Absorption thickness
Expansion ratio (%) 1.3 1.6 1.3 1.3 1.3 - Flexural Stability -
Low temperature (mm) 0.7 1.1 0.5 0.3 4.4 0.4 Flexural Stability -
High temperature (mm) 3.4 4.0 4.9 2.6 9.2 5.1

As can be seen from Table 8, it was found that the results are almost the same as those of the case of the flooring obtained by laminating the melamine sheet layer or the wood core layer and the melamine sheet layer on the wood-plastic composite material of the present invention. The adhesive strength between the laminated materials was much smaller than that of Comparative Example 11 obtained by extrusion molding and the particle size of the wood powder was small. there was.

10 ... ... Paint layer
20 ... ... Surface pattern layer
30 ... ... The second adhesive layer
40 ... ... Wood core layer
50 ... ... The first adhesive layer
60 ... ... Wood-plastic composites

Claims

A wood-plastic composite material comprising wood flour, a plastic resin and a crosslinking agent,
The wood and the plastic resin are contained in a weight ratio of 70 to 80:20 to 30,
The plastic resin is at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), and polystyrene (PS)
Wherein the cross-linking agent is included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the mixture of the wood and the plastic resin.

The method according to claim 1,
The wood-plastic composite material,
Mixing wood flour, a plastic resin and a crosslinking agent;
Compounding said mixture at a temperature between 110 and 175 캜;
Pre-pressing the compounded particles; And
Pressing the pre-pressed particles to a belt tip at a temperature of 110 to 180 占 폚 to press-mold the preformed particles.

The method according to claim 1 or 2,
Wherein the crosslinking agent is a coupling agent having a maleic anhydride content of 3% or more.

A flooring material characterized in that a wood core layer or a surface pattern layer is further laminated on the wood-plastic composite material according to claim 1 or 2.

The method of claim 4,
Wherein the wood core layer and the surface pattern layer are sequentially laminated on the wood-plastic composite material when the wood core layer and the surface pattern layer are all laminated on the wood-plastic composite material.

The method according to claim 4 or 5,
Wherein the wood-plastic composite material has a thickness of 3 to 5 mm.

The method according to claim 4 or 5,
Wherein the wood core layer is at least one selected from the group consisting of a veneer, a veneer laminate, and a hard fiber board.

The method according to claim 4 or 5,
Wherein the surface pattern layer is at least one selected from the group consisting of a laminated wood, a high-pressure melamine (HPM) layer, and a low-pressure melamine (LPM) layer.

The method according to claim 4 or 5,
Wherein the wood core layer or the surface pattern layer is laminated through an adhesive layer.

The method of claim 9,
Wherein the adhesive layer is at least one selected from the group consisting of an epoxy-based, polyurethane-based, phenol-based, polyisocyanate-based, and ethylene-vinyl acetate based resin as an aqueous or non-aqueous adhesive.

The method according to claim 4 or 5,
Wherein a surface coating layer is further laminated on the surface pattern layer.

The method according to claim 4 or 5,
Wherein the flooring material has a connection structure by a Tongue and Groove (T & G), a click system, or a connector.

Preparing a wood-plastic composite, a wood core layer and a surface pattern layer;
And laminating and laminating a wood core layer or a surface pattern layer on an upper part of the wood-plastic composite material with an adhesive layer interposed therebetween,
Wherein the obtained flooring material is subjected to side and end processing to have a connection structure by a T & G, click system, or connector.

14. The method of claim 13,
And laminating the surface layer layer on the wood core layer with a second adhesive layer interposed therebetween and thermally compressing and integrating the lacquer core layer on the wood-plastic composite material with the adhesive layer interposed therebetween. (Method for manufacturing flooring material).