CN87214339U - Light-weight composite bagasse board - Google Patents

Abstract

The utility model relates to a light-weight composite bagasse board which uses residue bagasse of sugar extracting industry as major raw material; the residue bagasse of sugar extracting industry are processed through expelling marrow and drying, and a sandwich layer of the light-weight composite bagasse board is made through hot pressing process. The frame of the light-weight composite bagasse board adopts wooden bars. The front and the back faces of the light-weight composite bagasse board is pasted with turning single plates. The light-weight composite bagasse board is an ideal furniture backing material which has the advantages of light volume weight, good strength and essentially not hygroscopic.

Description

Lightweight bagasse composite plate

The utility model belongs to the new material of timber comprehensive utilization, furniture is that people are common commonly used, generally be to be raw material with timber, also useful wood-based plate (glued board, flakeboard) or metal material are made, but these materials are lack of material on the one hand, the source difficulty, and price is more expensive, the product heaviness.Also the someone imagines the residue that utilizes sugar industry---and bagasse is made plate and is replaced above-mentioned raw materials, overcomes problems such as insufficient raw material and cost are expensive.But the present bagasse board of producing, unit weight is big, hygroscopicity is strong, and is easily mouldy, damage by worms, and not welcome by the masses.

The utility model provides that a kind of unit weight is light, breadth more greatly, the desirable furniture base material of non-hygroscopic substantially, the no mouldy and phenomenon of damaging by worms.

This product is not seen production at present at home, and through Guangdong Science and Technology Information Inst., by online information retrieval, search " United States Patent (USP) ", 1963-1987 years " world patent ", 1967-1987 " chemical abstracts " and " CAB agricultural digest " database of 1950-1987, all do not find and the same or analogous document of the utility model.

Lightweight bagasse composite plate (Fig. 1 is a front view, and Fig. 2 is a profile) is primary raw material with the bagasse, and through removing processing such as marrow, drying, a hot pressing forms sandwich layer (1), and there is wooden frame (2) on four limits, and table, the back of the body have to revolve makes veneer (3).

Table, backboard can be used rotary cut venner, about 1.25 centimetres of thickness, according to incrustation, can select different brackets for use, if the surface becomes the woodgrained paper veneer with plastic plate, veneer, then the veneer class requirement is not high, is celluloid paint as the surface, then higher to the class requirement of Face veneer, and wish that wood grain is attractive in appearance.

Frame can be with thick about 15 millimeters, and wide about 30 millimeters laths are formed, and the required fitted position of some metal assembling can suitably be widened lath by its size as greater than 30 millimeters, are connected with the air gun nail between lath and the lath.

Bagasse is the solid that sugarcane is left behind powerful pressure, short texture, and intensity is extremely low, become the material of making sheet? we have done following analysis:

1. the chemical composition of bagasse: its component sees Table 1 by analysis

The old pulp water of the new slag of table 1 analysis project divides 44% 20.6% to contain marrow rate 21.7% 25% ash contents 0.78% 0.93% penta candys 26.17% 25.46% lignins 20.80% 21.91% celluloses 44.7% 46.54% cold water extracts 3.45% 0.82% hot water extracts 4.42% 0.34% 1%NaOH extracts 29.53% 30.38% phenol extracts 3.70% 0.94%

2. bagasse granularity and bagasse particle form distribute and see Table 2

Table 2 sieve mesh percentage average length mean breadth length-width ratio length-width ratio

Form length mean value width mean value

Mean value (order/inch) is (millimeter) (millimeter) (millimeter) (millimeter) 6 17.87 (%)

12.20 0.986 12.37 12 25.15 13.97 13.10 0.876 0.917 15.95 14.37

13.14 0.889 14.78 24 24.62 8.50 8.47 0.477 17.82

8.20 0.420 0.450 19.52 18.86

8.70 0.452 19.25 28 6.50 0.350 19.57

13.38 6.42 6.59 0.349 0.34 18.40 19.26

6.85 0.329 20.82 45 4.99 0.280 17.82

13.45 below 4.73 4.94 0.274 0.262 17.26 18.98 45 5.53 5.09 0.233 21.85

Lignin and content of cellulose are abundanter as seen from Table 1, account for 65.5%～68.37% of bagasse total amount, bagasse needs further dry the processing in the making sheet process, its moisture content is controlled at about 10%, the content of sugar part also will be reduced to about 0.2%, and like this, lignin and cellulosic actual percentage are just higher, lignin and cellulose toughness is big, intensity good forms netted being interspersed in plate.

See from table 2 and the bagasse of 6～45 orders/inch to account for 76.6%.Bagasse particle length-width ratio is between 14.37～19.26.Its form is a kind of bar-shaped.The surface area of bagasse particle is bigger, through hot-pressing processing and rely on adhesive glued together securely, adding upper surface, to post the system of revolving dull and stereotyped under the adhesive effect, and frame has batten, therefore, this is a kind of sheet material with certain intensity.

3. the analysis of plate fitment member stress

The characteristics of plate fitment are the plates as member, and the load-bearing of having held concurrently is gone along with sb. to guard him and function such as decoration.Furniture is various in style, and force-bearing situation is the plate complexity also, but the suffered external force of furniture component is main from the weight of carrier and the weight of furniture self.Its direction is constant vertical.Next is that physical activity and other unexpected bumps wait the external force that produces, and these external force all are to have randomness.Be used to carry the furniture of human body, must take into full account this randomness external force.The member of carrying gravity mainly is vertical member and horizontal member, and it is few that oblique member is used to carry gravity.So we only discuss the force-bearing situation of vertical primary structure member and horizontal primary structure member.

(1) vertical primary structure member

The load of vertical primary structure member according to the difference of connected mode, has two kinds of uniform load and concentrfated loads, and the connected mode of Fig. 3 uses the right angle securing member fastening usually.Fig. 4 can be fastening with the right angle securing member, also can support horizontal shelf with the shelf pin.What the former carried is uniform load, and what the latter was carried is concentrfated load.Because the common c of plate＜＜a, c＜＜b, so belong to thin-slab structure.Only act on the thin plate surrounding edge because of active force among Fig. 1, and be parallel to middle face, do not change along thickness direction, so its force-bearing situation can be thought plane stress problem.Because the effect (Free Surface) that two surfaces of plate do not stress is so there is б _z=τ _Zx=τ _Zy=0, again because c is very little, external force is along thickness c no change again, so can think the б that grows on trees in the inside of thin plate _z=0, τ _Zy=τ _Yz=0, τ _Zx=τ _Xz=0.Just remaining three components that are parallel to the xy face of the components of stress, the force-bearing situation (as Fig. 6) of (as Fig. 5) vertical primary structure member, p is the load of unit are.This force-bearing situation belongs to the lath pressurized, its force function:

Its strain is because of б _z=0, б _x=0 ${\mathrm{\ϵ}}_x=\frac{1}{E}\mathrm{\μP}$ ${\mathrm{\ϵ}}_y=-\frac{1}{E}P$ ${\mathrm{\ϵ}}_z=\frac{1}{E}\mathrm{\μP}$

Though б _z=0, б _x=0, τ _Xy=0, τ _Xy=0, but because of composite plate is a heterogeneous body, and capacity is lower, especially plane tensile strength is lower, produces excessive strain, and composite plate is destroyed, so when carrying out the structural design of composite plate, should manage to avoid producing excessive strain.Connected mode for Fig. 4, what plate bore is concentrfated load, but according to Saint Venant's principle, the influence of this load, just in the near zone of the two ends of plate, the distribution of stress is different, is leaving place far away, this influence just can slightly not disregarded, thereby can go to treat as uniform load.

(2) horizontal primary structure member

Horizontal primary structure member carries the member of weight often, as panel, shelf and bed board of desktop, box-type furniture or the like.It is one of important primary structure member of furniture.The geometric shape of these members, also have c＜＜a, c＜＜relation of b, so this class plate also belongs to thin-slab structure.As shown in Figure 7.

With regard to plate fitment and for the plate, the amount of deflection that produces after plate is stressed is also little, the ratio of amount of deflection and thickness exists usually $\frac{w}{c}\&le;\frac{1}{5}$ Scope in, belong to dull and stereotyped small deflection problem.At this moment the membrane stress and the bending stress that produce in dull and stereotyped, with regard to quantity, they are not same magnitudes.When problem analysis, not tension, pressure, shearing in the face in can thinking, thus there is not the interior distortion of middle face.For bed board that resembles long span etc., the ratio of its amount of deflection and thickness, may $\frac{1}{5}<\frac{w}{c}<5$ Scope in.Belong to dull and stereotyped Large Deflection Problems.Membrane stress and bending stress in this moment is dull and stereotyped quantitatively belong to same magnitude.So when analyzing, not only should consider bending stress, and will consider membrane stress.Act on the load on the horizontal primary structure member, normally by the weight of carrier, it is perpendicular to the surface of plate, promptly belong to transverse load perpendicular to middle face, and transverse load will make thin plate produce bending, the stress that they cause, distortion and displacement can be calculated by thin plate bending.The boundary condition of plate can be made such hypothesis because with being connected of biside plate, all connect usually with metal fastenings, can think simple supported edge (be actually simple supported edge with aid the border areas admittedly comprehensive).And free margins can be treated as in the two sides, front and back, though the back plate more or less influences for the distortion of panel, the back plate does not often play supporting role, and this influence is less, can ignore it.

The load condition that is added on panel is extremely complicated, and has randomness.Suppose that it is to be distributed on the whole plate face, equals q ₀, q ₀Be the load on the unit are.According to the analysis of thin plate internal force as can be known: along gauge of sheet, components of stress б _x, б _y, τ _XyMaximum occur in plate face, τ _Xz, τ _YzMaximum occur in middle face, б _zMaximum occur in plate above.Each maximum is: ${\left({\mathrm{\&sigma;}}_x\right)}_z=\frac{C}{2}=-{\left({\mathrm{\&sigma;}}_x\right)}_z=-\frac{C}{2}=\frac{6M_x}{C^2};$ ${\left({\mathrm{\&sigma;}}_y\right)}_z=\frac{C}{2}=-{\left({\mathrm{\&sigma;}}_y\right)}_z=-\frac{C}{2}=\frac{6M_y}{C^2}$ ${\left({\mathrm{\&tau;}}_{\mathrm{xy}}\right)}_z=\frac{C}{2}=-{\left({\mathrm{\&tau;}}_{\mathrm{xy}}\right)}_z=-\frac{C}{2}=\frac{6M_{\mathrm{xy}}}{C^2}$ ${\left({\mathrm{\&tau;}}_{\mathrm{zx}}\right)}_z=0=\frac{3\mathrm{QX}}{2C}$ ${\left({\mathrm{\&tau;}}_{\mathrm{zy}}\right)}_z=0=\frac{3\mathrm{Qy}}{2C}$ ${\left({\mathrm{\&sigma;}}_z\right)}_z=-\frac{C}{2}=-q$

Above direct stress б _x, б _yRespectively with moment M _x, M _yBe directly proportional, thereby be called bending stress.Shear stress τ _XyBe directly proportional with moment of torsion, be called torsional stress, shear stress τ _Zx, τ _ZyRespectively with transverse shearing force Q _x, Q _yBe directly proportional, be called horizontal shear stress.And direct stress б ₂With load q ₀Be directly proportional, be called extrusion stress.In Sheet Bending Problems, bending stress and torsional stress that certain load causes, numerically maximum, thereby be main stress; Laterally the numerical value of shear stress is less, is less important stress; Extrusion stress is numerically littler, is more less important stress.Thereby only need consider bending stress and torsional stress.

According to top analysis and hypothesis, the stress of horizontal primary structure member and boundary condition such as Fig. 8.AB, CD are simple supported edge, and AD and BC are free margins, calculate by two ends freely-supported lath, and boundary condition is

X=0 is during X=a

W＝0，M _x＝0

Its deflection equation is $W=\frac{q_x}{24D}(X^4-2X^{3}a+a^{3}X)$

q _x---along the load intensity of Z direction.

The bending stiffness of D---thin plate.

Moment of flexure is again $M_x=-D(\frac{{\&PartialD;}^{2}W}{\&PartialD;X^2}+\mathrm{\&mu;}\frac{{\&PartialD;}^{2}W}{\&PartialD;y^2})$ $M_y=-D(\frac{{\&PartialD;}^{2}W}{\&PartialD;y^2}+\mathrm{\&mu;}\frac{{\&PartialD;}^{2}W}{\&PartialD;X^2})$

Have according to deflection equation $\frac{{\&PartialD;}^{2}W}{\&PartialD;y^2}=0$ $\frac{{\&PartialD;}^{2}W}{\&PartialD;X^2}=\frac{q_x}{24D}(12X^2-12\&times;a)$

The maximum of amount of deflection and the maximum of moment of flexure appear at $X=\frac{a}{2}$ The cross section in, its value is $W=\frac{5q_x{a}^4}{24D}$ $M_x=\frac{q_x{a}^2}{8}$

M _y=μ M _xμ---Poisson's ratio

Obviously, bending stress at this moment is

б _y=μ б _xCommon μ＜1.

According to the mechanical analysis of plate fitment member, plate fitment base material provided by the utility model is solid and reliable, inexpensive material benefit.

4. the structure of lightweight bagasse composite plate

The structure of composite plate is mainly formed by three ones.Table, backboard, wooden frame, sandwich layer.

Table, backboard rotary cut venner, 1.25 millimeters of thickness.According to incrustation, select different brackets for use.If the surface is with plastic plate, veneer or woodgrained paper veneer, then the veneer class requirement is not high, is celluloid paint as the surface, and is then higher to the class requirement of Face veneer, and wishes that wood grain is attractive in appearance.

Frame can be with thick 15 millimeters, and wide 30 millimeters lath is formed, and the required fitted position of some metal assembling can suitably be widened lath by its size as greater than 30 millimeters, are connected with the air gun nail between lath and the lath.

5. lightweight bagasse composite plate the key technical indexes

1. central layer moisture content (%) 13.3～16.5.

2. central layer unit weight is not more than 0.40 gram/cubic centimetre.

3. plane tensile strength: 0.43～1.12 kg/cm.

4. MOR, vertically: 67.3～116.8 kg/cm

Horizontal 37.9～58.2 kg/cm.

5. thickness swelling rate 3.1%.

The utility model can be implemented like this:

1. bagasse screening: make lightweight bagasse composite plate and select through the old bagasse of packing contain more than one month better.Bagasse can screen with mesh sieve, removes 6 orders/inch above coarse grain and following marrow grain of 45 orders/inch and dust.

2. bagasse drying: available dry kiln or other drying instruments make bagasse be dried to moisture content below 12%.

3. bagasse glue mixing: bagasse after drying adds adhesive, and adhesive can be with urinating the Chuo resin.The adhesive addition: the glue mixing amount is 10～12%; Bagasse weight is calculated with the over dry bagasse.

4. hot-press gluing: the frame that closes symbol specification lattice by the designing requirement binding, put into the bagasse of glue mixing in the frame, the bagasse amount of putting into is not more than 0.4 gram/cubic centimetre for over dry unit weight, the upper and lower blanket glued veneer that all is placed with, about 300 gram/square metre (single faces) of veneer glue-spread, veneer should be bigger slightly than frame, places the hot press pressurization, adds hot gluing, hot pressing temperature: 110 ℃～120 ℃; Gummed pressure: 5 kilograms/square centimeter; Gluing time: 15～20 minutes.

5. cutting edge, polish or scrape, incrustation promptly becomes a useful person.

Claims (3)

1. a lightweight bagasse composite plate is characterized in that with the bagasse being sandwich layer, and batten is a frame, revolves the system veneer and is table, the back side.

2. according to the said lightweight bagasse of claim 1 composite plate, the aridity that it is characterized in that bagasse is that the bagasse water content is below 12%.

3. according to the said light composite board of claim 1, it is characterized in that sandwich layer over dry unit weight is not more than 0.4 gram/cubic centimetre.

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