CN1861341A - Method for prodn. of high strength high elastic wood composite material by using wood from quick growing species trees as raw material - Google Patents

Abstract

A high-strength and -elasticity wooden material is prepared from the quickly growing trees, such as poplar and China fir through compressing fir wood for strengthening it, using the strengthened fir wood as the surface layer, filling the poplar wood between surface layers, and pressing.

Description

The method of the high-strength high-elasticity composite wooden material that quick growing species of trees material is made

Technical field

The present invention relates to a kind ofly manufacture and design the structural design and the process of high-strength high-elasticity material, belong to composite wooden material design and application with quick growing species of trees timber.

Background technology

Quick growing species of trees timber, as poplar, material is soft, density is low, processing performance is poor, moisture content height and skewness, easily produces manufacturing deficiencies such as crimping distortion.In addition, because the cultivation safeguard measure is improper, its timber has material defectives such as knot is many, evil mind, small holes caused by worms more, and directly influence speed is given birth to the quality and the price of industrial woods willow timber.So quick growing species of trees timber is mainly used in the central layer of producing glued board now, added value of product is low, and some structures and load-bearing material nearly all are from external import.For the composite wooden material of laminate structures, as glued board,, reach whole material mechanical performance and improve by improving the intensity of skin-material, this approach is verified in actual research and production.

Summary of the invention

In order to have improved the quick growing species of trees (as poplar, China fir) value-added content of product, the present invention will compress on the basis of enhancing technology at China fir, design a kind of laminated plate structure by Compound Material Engineering laminate correlation theory: top layer or top layer and the China fir solid wood of time skin-material for the compression enhancing up and down up and down, all the other intermediate layers are board using poplar board.This structure is made up of quick growing species of trees material entirely, but the intensity of whole material can require to manufacture and design high strength, high resiliency composite wooden material according to different materials and product strength.

The present invention takes following technical scheme to realize:

The method of the high-strength high-elasticity composite wooden material that quick growing species of trees material manufactures and designs, its step is as follows:

The compression of described step 1 China fir strengthens that to handle be that China fir with the certain size specification at first carries out the surface processing of scraping, and guarantees surfacing, then the China fir of surfacing is put into the hot press that has steam generation device and is carried out high-temperature steam compression processing.Technical process and technological parameter that high-temperature steam is handled are: quick-make press and with finger gauge control compression back China fir thickness, press is rapidly heated to 160～180 ℃, make and produce steam between lower platen on airtight, steam pressure is 0.25～0.35MPa, the time of keep-uping pressure is 40～60min, and plate was got in release after pressurization was finished;

Described step 2 material structure design is: in Compound Material Engineering, laminate is by the synthetic whole construction unit of two-layer or two-layer above lamina.(1), 1., 2., 3. determines the elastic parameter of lamina by respective formula according to the basic parameter of each lamina.Wherein, determine that lamina rift grain tensile modulus of elasticity formula is:

$E_L=\frac{1}{1-\mathrm{Tv}/100}(\frac{D_0}{D_f}{E}_f+\frac{A_g}{1000t_0{D}_g}-E_g)$ ①

Determine that lamina band tensile modulus of elasticity formula is:

$E_T=\frac{D_0}{D_f(1-\mathrm{Tv}/100)}{E}_{\mathrm{Tf}}+[\frac{A_g-A_{\mathrm{gp}}}{1000t_0(1-\mathrm{Tv}/100)D_g}+{\mathrm{kk}}_2(1-\mathrm{Tv}/100)]E_m$ ②

Determine that lamina inplane shear modulus formula is:

$G_{\mathrm{LT}}=\frac{D_0}{D_f(1-T_v/100)}{G}_{\mathrm{LTf}}+[\frac{A_g-A_{\mathrm{gp}}}{1000t_0(1-\mathrm{Tv}/100)D_g}+{\mathrm{kk}}_2(1-T_{v}100)]G_m$ ③

(2) according to the composite laminated plate theory, the rigidity value after 4. the regularization of computation layer plywood is handled by formula.The rigidity value formula of determining laminate is:

$\left.\begin{array}{c}{A}_{\mathrm{ij}}=\frac{1}{h}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k-Z_{k-1})\\ B_{\mathrm{ij}}=\frac{1}{h^2}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k-Z_{k-1})\\ D_{\mathrm{ij}}=\frac{4}{h^3}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k^3-Z_{k-1}^3)\end{array}\right\}(i,j=1,2,6)$ ④

(3) mechanical performance index of rigidity value that will 4. be calculated by formula and requirement is relatively adjusted laminated plate structure, finally designs the laminated plate structure that meets the demands.

Described step 3 composite compacting is to carry out individual layer gluing, assembly, hot pressing process operation according to the slab structure that designs.For the related process that uses phenolic resin glue as adhesive be: glue-spread 250～350g/m ²(two-sided), hot pressing time 55～65s/mm, hot pressing pressure 1.0～1.5MPa, 130～140 ℃ of hot pressing temperatures.

The method of the high-strength high-elasticity composite wooden material that aforesaid quick growing species of trees material manufactures and designs, it is characterized in that wherein said high-temperature steam processing produces certain vapour pressure, hot pressing temperature is more than 110 ℃, compression ratio increase along with fir wood plank, the density of sheet material increases, and its elastic modelling quantity and MOR also increase more thereupon.

The invention has the beneficial effects as follows, top layer up and down or the China fir solid wood that strengthens for compression of top layer and time skin-material been have up and down have been manufactured and designed, all the other intermediate layers are the composite wooden material of board using poplar board, the intensity of whole material can require to manufacture and design the composite wooden material of high-strength high-elasticity according to different materials and product strength, has improved the quick growing species of trees (as poplar, China fir) value-added content of product.

The specific embodiment

Implementation example:

The method of the high-strength high-elasticity composite wooden material that quick growing species of trees material manufactures and designs, its step is as follows:

Step 1 China fir compression strengthens that to handle be that size is thick in the China fir plate of 10mm at first carries out the surface processing of scraping, and then the China fir of surfacing is put into the hot press that has steam generation device and is carried out high-temperature steam and compress processing.The technological parameter that high-temperature steam is handled is 160 ℃ of hot pressing temperatures, steam pressure 0.3MPa, and 60 minutes dwell times, obtaining the China fir compression ratio is 50%.

Step 2 material structure design is (1) basic parameter according to each lamina: parameters such as the thick thickness for the thick China fir for the board using poplar board of 1mm and the thick 10mm of being of size of the board using poplar board of 2.2mm, size of size, glue-spread, compression ratio are imported formula, and 1., 2., 3. to obtain thickness be that the elastic parameter of the poplar lamina of 1mm is rift grain tensile modulus of elasticity 7721MPa, band tensile modulus of elasticity 1668MPa, inplane shear modulus 992MPa, Poisson's ratio 0.35; Thickness is that the elastic parameter of the poplar lamina of 2.2mm is rift grain tensile modulus of elasticity 8212MPa, band tensile modulus of elasticity 1296MPa, inplane shear modulus 965MPa, Poisson's ratio 0.35; The elastic parameter of compression China fir is rift grain tensile modulus of elasticity 9050MPa, band tensile modulus of elasticity 1729MPa, inplane shear modulus 1066MPa, Poisson's ratio 0.4.(2) the design composite structure is: ground floor is the board using poplar board of thickness 1mm, the angle of mating formation 0 degree, the second layer is the China fir of thickness 5mm, the angle of mating formation 0 degree, the 3rd to layer 7 be the board using poplar board of thickness 2.2mm, the angle of mating formation is respectively 90,0,90,0,90 degree, the 8th layer is the China fir of thickness 5mm, the angle of mating formation 0 degree, and the 9th layer is the board using poplar board of thickness 1mm, the angle of mating formation 0 degree, 9 layers of the total numbers of plies of laminate.With every layer of elastic parameter substitution formula 4. in, calculate the regularization bending stiffness matrix D of this kind structural wood composite material ₁₁=8531MPa, D ₂₂=2156MPa.

Step 3 composite compacting be according to the slab structure that step 2 is determined carry out the lamina gluing, assembly becomes composite structure.At hot pressing time 1min/mm, hot pressing pressure 1.5MPa, slab is hot-forming under 140 ℃ of conditions of hot pressing temperature.Result of the test: vertical bending strength 58Mpa, vertical quiet modulus in elasticity in bending 8376Mpa, transverse bending strength 36Mpa.

The foregoing description limits the present invention never in any form, and the technical scheme that form obtained that all employings are equal to replacement or equivalent transformation all drops within protection scope of the present invention.

Claims (3)

1, the method for the high-strength high-elasticity composite wooden material that manufactures and designs of quick growing species of trees material, its step is as follows:

The compression of described step 1 China fir strengthens that to handle be that China fir with the certain size specification at first carries out drying, is dried to moisture content 10～12%, then dried China fir is put into the hot press that has steam generation device and is carried out the high-temperature steam compression and handle;

Described step 2 material structure design is: in Compound Material Engineering, laminate is by the synthetic whole construction unit of two-layer or two-layer above lamina; (1) according to the basic parameter of each lamina, wherein, determine that lamina rift grain tensile modulus of elasticity formula is:

$E_L=\frac{1}{1-\mathrm{Tv}/100}(\frac{D_0}{D_f}{E}_f+\frac{A_g}{1000t_0{D}_g}{E}_g)$ ①

Determine that lamina band tensile modulus of elasticity formula is:

$E_T=\frac{D_0}{D_f(1-\mathrm{Tv}/100)}{E}_{\mathrm{Tf}}+[\frac{A_g-A_{\mathrm{gp}}}{{1000t}_0(1-\mathrm{Tv}/100)D_g}+{\mathrm{kk}}_2(1-\mathrm{Tv}/100)]E_m$ ②

Determine that lamina inplane shear modulus formula is:

$G_{\mathrm{LT}}=\frac{D_0}{D_f(1-T_v/100)}{G}_{\mathrm{LTf}}+[\frac{A_g-A_{\mathrm{gp}}}{1000t_0(1-\mathrm{Tv}/100)D_g}+{\mathrm{kk}}_2(1-T_v/100)]G_m$ ③

(2) according to the composite laminated plate theory, by the 4. rigidity value of computation layer plywood of formula; The rigidity value formula of determining laminate is:

$\left.\begin{array}{c}{A}_{\mathrm{ij}}=\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k-Z_{k-1})\\ B_{\mathrm{ij}}=\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k-Z_{k-1})\\ D_{\mathrm{ij}}=\frac{1}{3}\underset{k=1}{\overset{n}{\mathrm{\Σ}}}{\stackrel{\‾}{Q}}_{\mathrm{ij}}^{\left(k\right)}(Z_k^3-Z_{k-1}^3)\end{array}\right\}(i,j=\mathrm{1,2,6})$ ④

(3) mechanical performance index of rigidity value that will 4. be calculated by formula and requirement is relatively adjusted laminated plate structure, finally designs the laminated plate structure that meets the demands;

Described step 3 composite compacting is to carry out individual layer gluing, assembly, hot pressing process operation according to the slab structure that designs.

2, the method for the high-strength high-elasticity composite wooden material that manufactures and designs of quick growing species of trees material according to claim 1, it is characterized in that wherein said high-temperature steam processing produces certain vapour pressure, hot pressing temperature is more than 110 ℃, compression ratio increase along with fir wood plank, the density of sheet material increases, and its elastic modelling quantity and MOR also increase more thereupon.

3, the method for the high-strength high-elasticity composite wooden material that manufactures and designs of quick growing species of trees material according to claim 1 is characterized in that wherein said step 3 can be for the related process that uses Lauxite as adhesive: glue-spread 250-300g/m ²Two-sided, hot pressing time 55-65S/mm, hot pressing pressure 1.0-1.5MPa, 130～140 ℃ of hot pressing temperatures.