CN104526791B - Durable wood-plastic laminated plate for wood building in high-humidity environment and preparation method thereof - Google Patents

Abstract

The invention discloses a durable structural wood-plastic laminate for wooden buildings in a high-humidity environment and a preparation method thereof. The laminate includes a wood single-layer board and a high-molecular plastic alloy, and the high-molecular plastic alloy is arranged on the wood single-layer. In the laminate and between a plurality of wood single-layer boards; the wood single-layer board is a low-density fast-growing wood veneer with a thickness in the range of 1-3mm; the polymer plastic alloy has a melting temperature of 130-140°C It is composed of polyethylene in the range of 160-170°C and polypropylene in the range of 160-170 ° C. The mass ratio of polyethylene and polypropylene is in the range of 80:20 to 50:50. The mass ratio of the wood single-layer board to the polymer plastic alloy is The range is 70:30～30:70. The invention can be used for wall boards and roof boards for wooden buildings in high-humidity environments, or as laminates for dimension timber and glued wood structural parts.

Description

Durable structural wood-plastic laminate for wood buildings in high-humidity environment and preparation method thereof

technical field

The invention relates to the technical field of building structure engineering, in particular to a durable structural wood-plastic laminate for wood buildings in high-humidity environments and a preparation method thereof.

Background technique

With the advancement of industrial technology and the improvement of people's living standards, the demand for public buildings and outdoor garden landscape projects in construction continues to increase. In recent years, my country has introduced advanced manufacturing technology and equipment for modern wood structure buildings from developed countries such as Europe, America and Japan, which has further promoted the development of wood structure buildings in China. However, since wood is a natural biomass composite material, more than 70% of its chemical components are composed of glucose unit polymerization. In addition, wood often contains a certain amount of water, most of which show weak acidity, and wood The porous structure makes it contain a lot of oxygen, etc., which provide living conditions for organisms that infect wood. Therefore, materials that are directly used without rational design and pretreatment are vulnerable to insects, fungi and other organisms. Rotting reduces quality and even scraps, especially in warm and humid coastal outdoor environmental conditions such as East China and South China.

Correspondingly, the stock of forest resources in my country and the supply of timber cannot meet the demand for materials used in the timber industry. Especially after the recovery of timber structures in my country in recent years, the contradiction between supply and demand of timber will increase day by day. However, the common fast-growing forests such as poplar, fir, and eucalyptus in my country have a short growth cycle, large variability, loose material, large voids, low density, low mechanical properties, and poor anti-corrosion performance. It is used for wood-based panels, papermaking, packaging materials, building templates, etc., but is rarely used in furniture and building structural components, and its application range is greatly limited. At present, my country's timber industry is faced with a large amount of fast-growing forest timber that cannot be efficiently utilized, and on the other hand, it spends a lot of foreign exchange to import foreign timber. Therefore, it is an effective way to solve the contradiction between wood supply and demand by modifying domestic fast-growing forest wood through wood physics, chemistry or both methods to improve the mechanical properties of materials and anti-corrosion and insect-proof properties, and to meet the functional needs of the market for materials. measure.

Conventional wood preservative treatment is achieved by adding preservatives to the interior of the wood, but wood preservatives contain toxic chemical components, so they are "double-edged swords". cause potential harm. Due to the inherent shortcomings of traditional wood preservatives and people's irrational use of them, as human beings pay more and more attention to environmental issues, wood preservatives have produced a series of public hazards in use, such as environmental pollution, potential toxicity to organisms, etc. Some adverse effects have caused widespread concern.

In addition, wood-plastic composite materials are prepared in the form of wood and polymer plastics, so that the materials have good dimensional stability, anti-corrosion and insect-proof performance, which also prolongs the service life of wood, improves the service quality of products, and reflects the ecological nature of wood buildings. Effective measures for safety and security.

Wood-plastic composites (WPC for short) are materials or products that are compounded or further processed by one or more cellulose materials and one or more thermoplastics through plastic processing technology. , partial degradability, low environmental pollution, low cost, low water absorption, excellent mechanical properties, anti-aging, good dimensional stability, no cracking, etc., and has similar processability to wood.

However, the vast majority of wood-plastic composite materials use extrusion processing. Although the product can be formed at one time, its width is limited (usually below 150cm, and a few products are below 40cm), which is not suitable for places that need to use large-scale panels; The wood grain or printing method simulates the wood grain, and the wood feeling is not strong; the wood raw material of the wood-plastic composite material is mechanically crushed wood, and then mixed with polymer plastics to form granules. With "a production method of wood-plastic composite material (patent number 201210324577.9)", "a wood-plastic composite material and its production method (patent number 201110437199.0)", "a flame-retardant tobacco stem powder-based wood plastic Composite materials and their preparation methods (Patent No. 201110355179.9)", "Manufacturing method of wood-plastic composite profiles (Patent No. 201210056055.5)" and many other patented product preparation methods, all cause a large number of wood fibers to be cut off, excessive damage to the wood Fiber structure, even if the product density is increased, its mechanical properties are still low, which cannot meet the needs of wood construction materials in terms of structural performance. The surface loses wood texture and color, and cannot meet the needs of wood structure materials in terms of appearance decoration. It can only be used in fields that do not require high mechanical properties and decorative effects. The patent "A Formaldehyde-free Plywood and Its Preparation Method (Application No. 201310080167.9)" uses plastic film and wood single-layer laminated composite hot pressing method, the product has wood texture and other appearance effects, but the product has anti-corrosion and insect-proof properties and mechanical properties. insufficient.

However, the existing structural panels used for wood structure roof or floor and wall materials, mainly include oriented strand board OSB, plywood, laminated veneer lumber, etc. Thinner single-layer boards can be achieved by pre-spraying or impregnating preservatives, but the use of heavy metal preservatives for this kind of plywood has a greater load on the environment and has adverse effects on people's health. It uses adhesives containing formaldehyde. In the process of production and use, a large amount of free formaldehyde will be released and cause environmental pollution. In the World Health Report 2002 released by the World Health Organization, indoor air pollution is clearly listed as one of the top ten factors threatening human health, and formaldehyde has been identified as a strong carcinogen.

Contents of the invention

The purpose of the present invention is to provide a wood-plastic laminate for durable structures and its preparation method for wooden buildings in high-humidity environments, which solves the problem that traditional wood composite materials contain toxic components, and the preservatives contained in conventional anticorrosive wood are harmful to the environment and humans. Negative impact, the preparation process of traditional wood-plastic composite materials makes the product unable to achieve both appearance decoration effect, anti-corrosion and insect-proof performance, and mechanical properties.

The technical solution adopted in the present invention is: a durable structural wood-plastic laminate for wooden buildings in high-humidity environments, the laminate includes wood single-layer boards and polymer plastic alloys, and the polymer plastic alloys are arranged on wood single-layer panels. Within laminates and between multiple timber single-ply panels;

The wood single-layer board is a low-density fast-growing wood veneer with a thickness in the range of 1-3 mm;

The polymer plastic alloy is composed of polyethylene whose melting temperature is in the range of 130-140°C and polypropylene in the range of 160-170°C, and the mass ratio of polyethylene to polypropylene is in the range of 80:20-50:50 , the mass ratio of the wood single-layer board to the polymer plastic alloy ranges from 70:30 to 30:70.

Preferably, the wood single-layer board is domestic fast-growing poplar, fir, masson pine or eucalyptus.

A method for preparing the above-mentioned durable wood-plastic laminate for wood buildings in a high-humidity environment, comprising the following steps:

(1) Raw material preparation

① Control the moisture content of the wood single-layer board within the range of 10-25%;

②The thermoplastic polymer plastic alloy is granulated according to a predetermined mass ratio to make a plastic alloy sheet with a thickness of 0.2-0.6mm;

③ Configure an aqueous solution of larch tannin and lignosulfonate mixture, wherein the mass percentages of calcium lignosulfonate, larch tannin and water are 5%, 10% and 85% respectively;

④ The number of layers of wood single-layer boards and polymer plastic sheets is determined according to the thickness and density of wood and plastic, as well as the target thickness and density of laminated boards;

(2) Wood single-layer board pretreatment

impregnating the wood single-layer board in an aqueous solution of a mixture of larch tannin and calcium lignosulfonate, and then drying the impregnated wood single-layer board until the moisture content is in the range of 10% to 15%;

(3) Preparation of wood-plastic laminates

①Use volatile non-toxic organic solvents to clean and remove dust and other negatively-affected accumulations on the surface of polymer plastic sheets;

②The wood single-layer board and the polymer plastic sheet are laminated alternately to form a single-layer board and plastic composite configuration; when focusing on the mechanical properties of a certain main direction in the board surface, the wood texture is arranged along the grain direction; When emphasizing on the use of the mechanical properties of the primary and secondary vertical directions in the plane of the board, the texture of the wood is arranged vertically for the adjacent wood single-layer boards;

③ Place the laminated board composed of wood single-layer board and polymer plastic sheet in the gap of the hot-pressing plate of the hot-pressing machine for hot-pressing.

The durable structural wood-plastic laminate facing wooden buildings in high-humidity environment involved in the present invention is composed of a single-layer wooden board and a polymer plastic alloy, and the melting point of the polymer plastic alloy is lower by controlling the hot-pressing temperature Part of the melt penetrates into the interior of the wood, and the part with a higher melting point softens and flows to form a continuous film between the adjacent wood single-layer boards. The polymer plastic melted into the wood laminate and between the wood laminates is mechanically connected. This connection and the polymer plastic melted into the wood strengthen the wood, the polymer plastic between the single-layer boards plays a role in bonding and molding the laminate, and all the polymer plastics also improve the product. Anti-insect, anti-corrosion, dimensional stability.

The laminated board of the present invention has the characteristics of solid wood appearance visibility, environmental friendliness, moisture-proof and not easily deformed, controllable anti-corrosion and insect-proof performance, does not contain heavy metal preservatives and adhesives that are burdensome to the environment and people, can be partially degraded and recycled, and has excellent mechanical properties. , can be used for wall panels and roof panels for wooden buildings in high-humidity environments, or as laminates for dimension lumber and glued wood structural parts.

Beneficial effect:

1. Since the laminated board of the present invention has adopted the entire wood single-layer board, the board has the visibility of the appearance of solid wood from the appearance, and the polymer plastic alloys adopted are all odorless, tasteless, non-toxic white translucent Solid material that does not alter the grain and tone of the wood;

2. The polymer plastic alloy contained in the single-layer board in the laminated board of the present invention has good water resistance, and the water absorption rate of the plastic is less than 0.01%, so the laminated board formed especially has moisture resistance and is not easily deformed;

3. The polymer plastic contained in the laminated board of the present invention has good insect-proof and anti-corrosion properties, and there is no need to add conventional heavy metal anti-corrosion agents that are burdensome to the environment and people, and the anti-corrosion properties of the board can be controlled by the use ratio of plastics. Therefore, the product High environmental friendliness and good anti-corrosion performance;

4. The laminated board of the present invention spreads, partially melts and infiltrates and forms chemical bonds through the polymer plastic between the wood single-layer boards to bond and form, without adding conventional polymer adhesives that are burdensome to the environment and people, so The product is environmentally friendly,

5. The laminated board of the present invention is composed of naturally grown wood and polymer plastics, wherein the wood part can be naturally degraded, and the polymer plastic part can be recycled;

6. The polymer plastic contained in the surface wood single-layer board of the laminated board of the present invention has no polarity, the pollutants are not easy to stick, and the product has good self-cleaning property;

7. The wood single-layer board in the laminated board of the present invention is filled with polymer plastics, and the plastic can play a role of fascination and reinforcement for wood, and the mechanical properties of the board are excellent, and can be used as a structure requiring high mechanical properties in wooden buildings member.

Description of drawings

Figure 1 is a schematic diagram of a wood-plastic laminate for durable structures facing high-humidity environment wood buildings.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1

A durable wood-plastic laminated board for wooden buildings in high-humidity environments, the laminated board includes a wood single-layer board and a polymer plastic alloy, and the polymer plastic alloy is arranged in the wood single-layer board and a plurality of wood single-layer boards between the laminates;

As shown in Figure 1, the laminated board includes odd-numbered wood single-layer boards 1, even-numbered wood single-layer boards 2, polymer plastics 3 inside wood single-layer boards and polymer plastics 4 between wood single-layer boards.

The wood single-layer board is a low-density fast-growing wood veneer with a thickness of 1mm; the wood single-layer board is domestic fast-growing poplar; the polymer plastic alloy is made of polyethylene and 160 The composition of polypropylene at -170°C, the mass ratio of polyethylene and polypropylene is 80:20, and the mass ratio of the wood single-layer board to polymer plastic alloy is 70:30.

A method for preparing the above-mentioned durable wood-plastic laminate for wood buildings in a high-humidity environment, comprising the following steps:

(1) Raw material preparation

① Control the moisture content of the wood single-layer board at 10%;

②The thermoplastic polymer plastic alloy is granulated according to a predetermined mass ratio to make a plastic alloy sheet with a thickness of 0.3mm;

③ Configure an aqueous solution of larch tannin and lignosulfonate mixture, wherein the mass percentages of calcium lignosulfonate, larch tannin and water are 5%, 10% and 85% respectively;

④ The number of layers of wood single-layer boards and polymer plastic sheets is determined according to the thickness and density of wood and plastic, as well as the target thickness and density of laminated boards;

(2) Wood single-layer board pretreatment

impregnating the wood single-layer board in an aqueous solution of a mixture of larch tannin and calcium lignosulfonate, and then drying the impregnated wood single-layer board until the moisture content is 10%;

(3) Preparation of wood-plastic laminates

①Use volatile non-toxic organic solvents to clean and remove dust and other negatively-affected accumulations on the surface of polymer plastic sheets;

②The wood single-layer board and the polymer plastic sheet are laminated alternately to form a composite configuration of single-layer board and plastic, in which the grain of the wood is arranged along the grain direction;

③ Place the laminated board composed of wood single-layer board and polymer plastic sheet in the gap of the hot pressing plate of the hot press for hot pressing. The hot pressing temperature is 160°C and the hot pressing time is 1.5min/mm.

Example 2

A durable wood-plastic laminated board for wooden buildings in high-humidity environments, the laminated board includes a wood single-layer board and a polymer plastic alloy, and the polymer plastic alloy is arranged in the wood single-layer board and a plurality of wood single-layer boards between the laminates;

The wood single-layer board is a low-density fast-growing wood veneer with a thickness of 2mm; the wood single-layer board is domestic fast-growing Chinese fir; the polymer plastic alloy is composed of polyethylene and 160-170 The composition of polypropylene at ℃, the mass ratio of polyethylene and polypropylene is 60:40, and the mass ratio of the wood single-layer board to polymer plastic alloy is 50:30.

A method for preparing the above-mentioned durable wood-plastic laminate for wood buildings in a high-humidity environment, comprising the following steps:

(1) Raw material preparation

① Control the moisture content of the wood single-layer board at 15%;

②The thermoplastic polymer plastic alloy is granulated according to a predetermined mass ratio to make a plastic alloy sheet with a thickness of 0.8mm;

③ Configure an aqueous solution of larch tannin and lignosulfonate mixture, wherein the mass percentages of calcium lignosulfonate, larch tannin and water are 5%, 10% and 85% respectively;

④ The number of layers of wood single-layer boards and polymer plastic sheets is determined according to the thickness and density of wood and plastic, as well as the target thickness and density of laminated boards;

(2) Wood single-layer board pretreatment

impregnating the wood single-layer board in an aqueous solution of a mixture of larch tannin and calcium lignosulfonate, and then drying the impregnated wood single-layer board until the moisture content is 12%;

(3) Preparation of wood-plastic laminates

①Use volatile non-toxic organic solvents to clean and remove dust and other negatively-affected accumulations on the surface of polymer plastic sheets;

②The wood single-layer board and the polymer plastic sheet are laminated alternately to form a single-layer board and plastic composite configuration; when focusing on the mechanical properties of a certain main direction in the board surface, the wood texture is arranged along the grain direction; When emphasizing on the use of the mechanical properties of the primary and secondary vertical directions in the plane of the board, the texture of the wood is arranged vertically for the adjacent wood single-layer boards;

③The laminated board composed of wood single-layer board and polymer plastic sheet is placed in the gap of the hot pressing plate of the hot press for hot pressing. The hot pressing temperature is 162°C and the hot pressing time is 1.2min/mm.

Example 3

A durable wood-plastic laminated board for wooden buildings in high-humidity environments, the laminated board includes a wood single-layer board and a polymer plastic alloy, and the polymer plastic alloy is arranged in the wood single-layer board and a plurality of wood single-layer boards between the laminates;

The wood single-layer board is a low-density fast-growing wood veneer with a thickness of 3mm; the wood single-layer board is domestic fast-growing masson pine;

The polymer plastic alloy is composed of polyethylene with a melting temperature of 130-140°C and polypropylene with a melting temperature of 160-170°C, the mass ratio of polyethylene and polypropylene is 50:50, and the wood single-layer board and polymer The mass ratio of the plastic alloy is 30:70.

A method for preparing the above-mentioned durable wood-plastic laminate for wood buildings in a high-humidity environment, comprising the following steps:

(1) Raw material preparation

① Control the moisture content of the wood single-layer board at 25%;

②The thermoplastic polymer plastic alloy is granulated according to a predetermined mass ratio to make a plastic alloy sheet with a thickness of 1.0mm;

③ Configure an aqueous solution of larch tannin and lignosulfonate mixture, wherein the mass percentages of calcium lignosulfonate, larch tannin and water are 5%, 10% and 85% respectively;

④ The number of layers of wood single-layer boards and polymer plastic sheets is determined according to the thickness and density of wood and plastic, as well as the target thickness and density of laminated boards;

(2) Wood single-layer board pretreatment

impregnating the wood single-layer board in an aqueous solution of a mixture of larch tannin and calcium lignosulfonate, and then drying the impregnated wood single-layer board until the moisture content is 15%;

(3) Preparation of wood-plastic laminates

①Use volatile non-toxic organic solvents to clean and remove dust and other negatively-affected accumulations on the surface of polymer plastic sheets;

②Stack wood single-layer boards and polymer plastic sheets alternately to form a composite configuration of single-layer boards and plastics, in which the texture of wood is vertically arranged for adjacent wood single-layer boards;

③The laminated board composed of wood single-layer board and polymer plastic sheet is placed in the gap of the hot pressing plate of the hot press for hot pressing. The hot pressing temperature is 165 °C and the hot pressing time is 1.0 min/mm.

It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components that are not specified in this embodiment can be realized by existing technologies.

Claims (1)

1. the preparation method moulding laminate towards the permanent seal cooling structure wood of high humidity environment Wood construction, described laminate includes timber lamina and high molecular plastic alloy, and described high molecular plastic alloy is arranged in timber lamina and between polylith timber lamina；

Described timber lamina is thickness low-density fast growing wood veneer within the scope of 1-3mm；

Described high molecular plastic alloy is made up of the melt temperature polyethylene within the scope of 130-140 DEG C respectively and the polypropylene within the scope of 160-170 DEG C, polyethylene and polyacrylic mass ratio range for 80:20～50:50, the mass ratio of described timber lamina and high molecular plastic alloy range for 70:30～30:70；

It is characterized in that: described preparation method comprises the following steps:

(1) raw material prepares

1. by timber lamina moisture control in 10～25% scopes；

2. thermal plastic high polymer plastic alloy is according to making plastic alloy sheet material after predetermined mass ratio pelletize, and thickness is 0.2～0.6mm；

3. configuration larch tannin and the aqueous solution of lignin sulfonic acid salt mixture, the wherein weight/mass percentage composition of calcium lignosulfonate, larch tannin and water respectively 5%, 10% and 85%；

4. the number of plies of timber lamina and polymer plastic media sheet is according to timber and plastic thickness and density, and laminate target thickness and density calculation are determined；

(2) timber lamina pretreatment

Timber lamina is placed in the aqueous solution of larch tannin and lignin sulfonic acid calcium compound and impregnates, then the timber lamina after dipping is dried to moisture content in 10～15% scopes；

(3) wood is moulded laminate and is prepared

1. adopt volatile nonpoisonous organic solvent cleaning to remove the dust of high molecule plastic sheet surface and other has the enriched substance of negative effect；

2. by timber lamina and the alternate overlapping of polymer plastic media sheet, composition lamina and plastics complex configuration；When stressing the mechanical property utilizing some principal direction in sheet side, the texture of timber is the configuration of rift grain direction；When stressing the mechanical property utilizing the vertical both direction of primary and secondary in sheet side, the texture of timber is adjacent layer timber lamina arranged perpendicular；

3. being placed in hot press heating platen gap by the laminate that timber lamina and polymer plastic media sheet form and carry out hot pressing, hot pressing temperature is 160～165 DEG C, and hot pressing time is 1.0-1.5min/mm.