CN101204822A - Manufacturing method of cedar veneer laminated lumber - Google Patents

Abstract

The invention discloses a method for manufacturing fir veneer laminated lumber used as a composite material for wind power blades. Apply glulam glue between the glulam wood squares; 2) slice the glulam wood squares into fir thin veneers of appropriate thickness along the radial direction; 3) impregnate the fir veneer with epoxy mixed impregnating resin; The veneer is assembled along the grain, and the fir veneer is glued together by a hot press. The method of the invention is not only simple and convenient, but also through the method of the invention, the cedar veneer laminated wood meeting the requirements of wind power blade composite materials can be produced in large quantities.

Description

Manufacturing method of cedar veneer laminated lumber

technical field

The invention relates to a manufacturing method of fir veneer laminated wood used for wind power generation blade composite materials.

Background technique

At present, the blades used for wind power generation are generally made of glass fiber reinforced plastic (referred to as FRP) composite materials. Although the manufacturing process of this material is mature, it also has the problem of high cost (100,000-200,000 yuan/ton), and the waste products of FRP are difficult to handle, not only difficult to burn, but also difficult to decompose. Lots of land. Therefore, it is necessary to develop a new low-cost, recyclable and environmentally friendly blade to replace the glass fiber reinforced plastic blade currently used in large quantities.

my country is a country rich in timber resources. Chinese fir is one of the main species of timber widely grown in southern my country. It has a wide range of sources, a large amount of timber storage, and relatively fast growth. The directional mechanical properties are good, but the cross-grain direction strength of fir is low, and the compressive strength along the grain direction is also relatively low. It can be considered to replace this expensive FRP composite material by reorganizing fir.

Patent application 200710178373.8 "Visual inspection and mechanical grading method of Chinese fir sapwood sapwood composite materials for wind power blades" discloses a grading method for Chinese fir rough slabs, through which the specifications of Chinese fir sapwood with a flexural elastic modulus greater than 12000Mpa can be classified plate.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for manufacturing fir veneer laminated lumber used as a composite material for wind power blades. fir laminated lumber.

In order to solve the above-mentioned problems, the invention provides a kind of manufacturing method of the Chinese fir veneer laminated wood that is used for wind power blade composite material and comprises the following steps:

1) Assembling the graded Chinese fir sapwood quarter-cut size boards to make glulam wood squares parallel to each other along the grain direction, and applying glue-glued glue between the graded fir sapwood diameter-cut size boards;

2) Cut the glulam wood square into fir veneers of appropriate thickness along the radial direction;

3) impregnating the fir veneer with epoxy mixed impregnating resin;

4) Assemble the fir veneers along the grain, and glue the fir veneers together with a hot press.

Preferably, before the step 2), the step of placing the graded fir sapwood quarter-cut gauge board in a water pool for soaking is also included.

Preferably, during the assembling of the step 1), in the process of forming the slabs of graded Chinese fir sapwood quarter cut to size, the mitering process is performed in the direction along the grain according to the mitering angle of 2-6°, and the The position of the miter seam is staggered up and down, left and right.

Preferably, the miter angle is 3.81°.

Preferably, the proportioning of the glulam adhesive is: synthetic latex: curing agent = 100:15, the percentage is by weight, and the synthetic latex is a two-component LK-DN60 (please give the Chinese name) Synthetic latex.

Preferably, the coating amount of the adhesive in the step 1) is 120-220 g/m ² , the aging time is 5-15 minutes, the pressure is 5-15 kgcm ² , and the cold pressing time is 60-120 minutes.

Preferably, the amount of glue applied is 170/m ² , the aging time is 10 minutes, the pressure is 10 kg/cm ² , and the cold pressing time is 90 minutes.

Preferably, the proportion of the epoxy impregnating resin is: 30% of 618 epoxy resin, 30% of SK3 epoxy resin, and 40% of 2124 phenolic resin; the percentages are percentages by weight.

Preferably, when hot pressing is carried out by a hot press in said step 4), the upper and lower layers of the backing plate of the hot press are also coated with 800-1000 centipoise silicone oil, the hot-pressing temperature is 100-140 °C, and the pressure 10-20Mpa, and the hot-pressing time is 60-120 minutes.

Preferably, the polysilicone oil is 1000 centigrade, the hot pressing temperature is 120° C., the pressure is 15 MPa, and the hot pressing time is 100 minutes.

The method of the present invention is not only simple and convenient, but also through the method of the present invention, it is possible to mass-produce fir veneer laminated wood meeting the requirements of composite materials for wind power generation blades, and to process and test the specimens according to the requirements of the GB1935-91 test method for compressive strength of wood along the grain ; Then process and test the specimen according to the requirements of NASA CR-174910, UDR-TR-85-45 tensile strength test method along the grain, the average tensile strength along the grain direction> 130MPa, the average compressive strength along the grain direction >70MPa, Young's modulus along the wood grain direction >15GPa, which fully meets the strength requirements of wind power blades. Therefore, the present invention makes it possible for Chinese fir to be used in large quantities for processing wind power generation blades.

Description of drawings

Fig. 1 is the group blank drawing of fir veneer glulam rough square;

Fig. 2 is the miter-jointed blank assembly diagram of the fir veneer laminated lumber rough side;

Fig. 3 is a schematic diagram of the formation of fir veneer laminated lumber.

Detailed ways

The present invention specifically carries out material selection and processing according to the following steps:

Firstly, according to the patent application 200710178373.8, carry out the grading of the fir sapwood diameter-cut specification board, which specifically includes the following steps:

Step 1: Select a number of new Chinese fir logs with a diameter of more than 30 cm, a straight trunk, and no defects in appearance (including decay, bending, etc.);

Step 2: Carry out "rice" font blanking on the selected material;

Step 3: Saw the standard fir sapwood quarter-cut rough board, dry it in a drying kiln until the moisture content is lower than 12%, remove various wood defects, and finish it into 500mm×20mm×20mm (length×width×thickness) The standard slats are spare;

Step 4: Through visual inspection, the selected rough plate meets the following requirements: straight texture, uniform material, annual ring width less than 2mm and uniform distribution, no growth defects and processing defects in appearance, and the number of "mountain" patterns formed on the radial surface is less than 2 and The angle with the plane greater than 75° is qualified.

Then make according to the preparation steps of the present invention, the concrete steps are:

Step 5: As shown in Figures 1 and 2, assemble the fir 4. When forming the blanks, it is necessary to ensure that the positions of the miter joints are staggered up and down, left and right, and the length direction is in accordance with the oblique The miter joint is performed at a joint angle of 2-6°, and the best miter joint angle is 3.81° (slope 1/15). Glulam glue is applied between the fir sapwood diameter-cut specification boards. The adhesive uses two-component synthetic latex (LK-DN60) as the glue for the glued timber. The proportion is (weight percent): 70% to 90% of synthetic latex, The curing agent is 10-30%, and the preferred proportion is: LK-DN60: curing agent=100:15. The glue amount is 120-220g/m ² , the aging time is 5-15 minutes, the pressure is 5-15kgcm ² , the cold pressing time is 60-120 minutes; the best glue amount is 170g/m ² (single side) , the aging time is 10 minutes, the pressure is 10kg/cm ² , and the cold pressing time is 90 minutes.

Step 6: Place the pressed fir glulam wood cube 3 for 24 hours, then place the wooden cube 3 in a pool, press a heavy object, so that the wooden cube 3 is completely submerged in water, take it out after 48 hours and slice it radially The 1mm thick veneer is spare.

Step 7: According to the proportion (percentage by weight): 15-35% of 618 epoxy resin, 15-35% of SK3 epoxy resin, and 25-45% of phenolic resin to prepare the impregnating resin; the preferred proportion is: 618 epoxy resin : SK3 epoxy resin: 2124 phenolic resin: curing agent=30: 30: 40; measure the solid content of the prepared epoxy mixed impregnated resin, then add thinner acetone to adjust the solid content of the epoxy mixed impregnated resin to 30% .

Step 8: Add the prepared epoxy mixed impregnating resin to the flattened and dried fir veneer, add heavy objects to completely immerse the veneer in the impregnating resin, take it out after 15 minutes and drain it until the glue on the surface of the veneer is no longer Send the resin-impregnated veneer into the oven to dry until it sticks to hands again, turn on the oven blower, set the oven temperature to 60°C for 120 minutes.

Step 9: As shown in Figure 3, the fir veneer 1 that has been dried at low temperature is assembled along the grain, and the compression ratio of the fir veneer 1 is 55%, and the material that has been assembled is put into a hot press for hot pressing. The upper and lower layers of the hot-pressed backing plate are coated with 800-1000 centipoise silicone oil, the hot-pressing temperature is 100-140°C, the pressure is 10-20Mpa, and the hot-pressing time is 60-120 minutes; 1. The lower two layers are coated with 1000 centipoise silicone oil, the hot pressing temperature is 120°C, the pressure is 15Mpa, and the time is 90 minutes.

Step 10: Take out the processed fir veneer laminated lumber, and after standing for 24 hours, process and test the specimen according to the requirements of GB1935-91 test method for wood compressive strength along the grain; then according to NASACR-174910, UDR-TR-85 -45 Requirements of the tensile strength test method along the grain Process and test the specimen, the average tensile strength along the grain direction> 130MPa, the average compressive strength along the grain direction> 70MPa, the Young's modulus along the grain direction> 15GPa.

Through the above steps, it is possible to conveniently mass-produce fir veneer laminated lumber meeting the requirements of composite materials for wind power generation blades, thereby fully satisfying the requirement of using Chinese fir in large quantities for wind power generation blades.

Claims (10)

1. A method for manufacturing a Chinese fir veneer laminated timber for wind power blade composites, characterized in that it comprises the steps: 1) Assembling the graded Chinese fir sapwood quarter-cut size boards to make glulam wood squares parallel to each other along the grain direction, and applying glue-glued glue between the graded fir sapwood diameter-cut size boards; 2) Cut the glulam wood square into fir veneers of appropriate thickness along the radial direction; 3) The fir veneer is impregnated with epoxy mixed impregnating resin; 4) Assemble the fir veneers along the grain, and glue the fir veneers together with a hot press. 2. The method according to claim 1, characterized in that, before the step 2), it also includes the step of placing the glued timber square in a pool for soaking. 3. The method according to claim 1, characterized in that, when forming the blanks in the step 1), the fir sapwood quarter-sawn boards are assembled in the length direction according to a miter angle of 2 to 6° . 4. The method of claim 3, wherein the optimum miter angle is 3.81°. 5. The method according to claim 1, wherein the proportioning of the adhesive is: synthetic latex: curing agent=100: 15, and the percentage is by weight, and the synthetic latex is a double compound of LK-DN60. Composition Synthetic latex. 6. The method according to claim 1, characterized in that the amount of the adhesive applied in the step 1) is 120-220g/m ² , the aging time is 5-15 minutes, and the pressure is 5-15kgcm ² , The cold pressing time is 60-120 minutes. 7. The method according to claim 6, characterized in that, the optimal glue application amount is 170/m ² , the aging time is 10 minutes, the pressure is 10 kg/cm ² , and the cold pressing time is 90 minutes. 8. The method according to claim 1, wherein the proportioning of the resin is: 30% of 618 epoxy resin, 30% of SK3 epoxy resin, 40% of 2124 phenolic resin, and the percentage is by weight; Measure the solid content of the prepared epoxy mixed impregnating resin, and then add diluent acetone to adjust the solid content of the epoxy mixed impregnating resin to 30%. 9. The method according to claim 1, characterized in that, in said step 4) when hot pressing is carried out by a hot press, the upper and lower layers of the backing plate of the hot press are also coated with 800-1000 centipoise For silicone oil, the hot-pressing temperature is 100-140° C., the pressure is 10-20 MPa, and the hot-pressing time is 60-120 minutes. 10 . The method according to claim 9 , wherein the porosity of the silicone oil is 1000 centigrade, the hot pressing temperature is 120° C., the pressure is 15 MPa, and the hot pressing time is 100 minutes. 11 .