CA2252042C - Method for production of lignocellulosic composite materials - Google Patents
Method for production of lignocellulosic composite materials Download PDFInfo
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- CA2252042C CA2252042C CA002252042A CA2252042A CA2252042C CA 2252042 C CA2252042 C CA 2252042C CA 002252042 A CA002252042 A CA 002252042A CA 2252042 A CA2252042 A CA 2252042A CA 2252042 C CA2252042 C CA 2252042C
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N1/00—Pretreatment of moulding material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
- B27N3/007—Manufacture of substantially flat articles, e.g. boards, from particles or fibres and at least partly composed of recycled material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
- B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
- B27N3/08—Moulding or pressing
- B27N3/28—Moulding or pressing characterised by using extrusion presses
Abstract
Fibres of annual plants e.g. straw for use in forming composite products are improved by hydrothermal treatment at 40~ to 120 ~C with or followed by high shear treatment. The process enables the use of annual plant fibrous materials not hitherto usable successfully.
Description
CA 022~2042 Isss-lo-os W097l38833 PCT/GRs7/00012 METHOD FOR PRODUCTION OF LIGNOCELLULOSIC
COMPOSITE MATERIALS
This invention relates to the production of lignocellulosic fibres and formation of composite materials therefrom. It particularly relates to the production of such fibres and bonding with synthetic binders into composite materials.
There is considerable pressure on the world's fibre resource. World-wide economic growth and development have created needs for converted forest products. While global fibre production systems are capable of meeting these overall demands there are some serious local and regional fibre shortages and resource management conflicts.
Many developing countries do not possess adequate forest reserves to cover their needs for fuelwood, industrial wood, sawn wood, and wood-based composition panels. However, many of these countries do have relatively large quantities of lignocellulosic materials available in the form of agricultural residues from annual crops. Annual plant fibres like cereal straw and the like are difficult to bond using conventional adhesives such as UF resins, PF-resins and PMDI binders.
The present invention is related, therefore, to a method of improving the bondability of lignocellulosic materials from annual plant fibres such as cereal straw by synthetic binders.
Composite materials such as particleboards, medium and high density fibreboards are mainly made from wood using binders such as acid curing amino-formaldehyde resins, alkaline curing phenol-formaldehyde resins, as well as , CA 022~2042 Isss-lo-os polyisocyanate adhesives. Medium density fibreboards are fibreboards prepared using a dry technique as follows:
Wood is subjected to thermomechanical pulping at a temperature of about 160 to 180~C, then mixed with the resin and dried. Thereafter mats are formed from the fibres and pressed to form fibreboards. Particleboards, on the other hand, can be prepared from chips which are mixed with resins and the glued particles are spread to mats and pressed at high temperature to particleboards.
Recently, interest has been developed on using agricultural residues like wheat and rice straw and sunflower as a starting material for particleboards and medium density fibreboards. The main difficulty in using annual plant residues such as straw as a raw material for composites, is their poor bondability particularly using urea-formaldehyde resins. The reason for this is probably the specific morphological structure of the straw, where the waxy and silica layer encirculating the straw stem inhibit sufficient direct contact between the binder and the straw fibres. Other types of adhesives for example polymeric isocyanates have been tried. However, the mechanical strength as well as the water resistance of the boards made from straw and isocyanates are much lower than those made from wood using the same bonding conditions.
Therefore, it was the main aim of the invention to find a practical method to improve the bondability of ~nn~l plant residues towards bonding agents in general and particularly towards acid curing aminoplastic resins and also polyisocyanate binders.
While fibrous/particulate ligno/c-llulosic materials have been treated by water/steam treatments with simultaneous or subsequent high shear treatment, use of lower temperatures has only been in the context of treatments for the manufacture of paper or similar CA 022~2042 Isss-lo-os materials and there has been no suggestion that this treatment when applied to lignocellulosic materials in the context of producing composites would enhance the fibrous or particulate material for forming into composite material. The process of the invention is also to be distinguished from producing composite materials from lignocellulosic materials in which there is an initial treatment at high temperature of at least 150~C, usually 150~C to 170~C followed by defibration.
Thus many treatments have been described in the literature to improve the bondability of lignocellulosic materials in both particle and fibre form with synthetic resins. D.H. GARDNER and T.J. ELDER: (Bonding surface activated hardwood flakeboard with phenolformaldehyde resin - Holzforschung 44(3): 201 - 206, 1990) added hydrogen peroxide, nitric acid or sodium hydroxide to enhance bonding characteristics of flakes using phenol-formaldehyde resins as a binder. Dimensional stability and internal bond strength were significantly reduced and it was shown that the chemicals did not change the wood surface, but rather they reacted with the resin.
J. McLAUGHLAN and C.R. ANDERSEN: (In-Line fibre pretreatments for dry process medium density fibreboard:
Initial Investigations - Paper presented at the Symposium Pacific Rim Bio-Based Composites, Rotorua, New Zealand 9-13 November 1992, Symposium Proceedings, page 91 - 99, 1992) tried many treatments to enhance the bondability of fibres towards bonding with urea-formaldehyde resins for the production of medium density fibreboards. The treatments include exposure to wet and dry heat, compression with heat and heat in combination with chemicals. The chemicals include 1~ and 10~ addition of aluminum sulphate, which is used in the hard board manufacture to control the pH value of the stock and 1% and 10~ chromium trioxide. Almost all the treatments resulted in boards with reduced properties .
CA 022~2042 Isss-lo-os compared to the control.
SIMON AND L. PAZNER): (Activated self-bonding of wood and agricultural residues - Holzforschung 48: 82 - 90, 1994) investigated the influence of the hemicellulose content of the self-bonding behaviour of different raw materials including annual plants and concluded that there is a straightforward relation between the hemicellulose content in the raw materials and the bonding strength of composites prepared therefrom. According to this work hemicelluloses do have adhesive properties, however, bonds created using hemicellulose adhesives have almost no wet strength.
In a recent publication LIAN ZHENGTIAN and HAO BINGYE:
(Technology of rice-straw particleboards bonded by Urea-formaldehyde resin modified by isocyanate - Paper presented at the Symposium Pacific Rim Bio-Based Composites, Rotorua, New Zealand 9 - 13 November 1992 Symposium Proceedings, page 295 - 301, 1992) mentioned that slight improvement of bondability of straw can be achieved by destroying the waxy layers encircling the stem of straw, however, the bondability was still very poor and the boards made still could not meet the requirements of common standards.
In DE-A-36 09 506 is described a modified standard dry process for the production of MDF in which UF resin is injected treatment with overheated steam and separation of steam from the treated fibres. The treatment of the fibres is by a conventional disc refiner.
In US-A-3 843 431 composite panels are produced from fibres prepared using as starting material scraps, shavings, sawdust. The raw material is blended with water and ground with the use of a double-disc attrition mill.
In WO-A-93 25358 MDF is produced according to the CA 022~2042 Isss-lo-os standard dry process involving wood chips pre-treated prior to defibration. The pre-treatment procedure involves the impregnation of raw material with Na2SO3/NaHSO3 and heating at a temperature between 150-200~C.
The aim of the present invention to develop a method for the treatment of ~nnl~l plant fibres, so that their bondability to synthetic resins is significantly improved and the production of composite panels with properties that meet the requirements of common standards is effected.
It has been discovered that thermal treatment of straw or other Annll~l plant fibres with water or steam at temperatures between 40 - 120~C, and preferably between 60 - 100~C accompanied by or followed by defibration of the fibres using high shear force~ destroys the morphological structure of the straw and increases tremendously its affinity towards bonding.
According to the invention, therefore, there is provided a method for producing composite materials wherein a lignocellulosic material which is an annual plant fibre residue is subjected to treatment with water or steam at 40~ to 120~C and simultaneously or subsequently is subjected to a high shear treatment and thereafter is formed into a composite material. The invention also relates to a lignocellulosic material which is an annual plant fibre residue which has been subjected to such water/steam treatment and high shear treatment and is in a form suitable for bonding into a composite. The invention also relates to a composite material in which at least part of the fibre content is derived from said treated ~nn plant fibre residue.
Defibration in the sense of this invention means disruption of the morphological structure of straw leading to the creation of individual fibres. The treatment CA 022~2042 Isss-lo-os destroys the waxy and silica layer of straw, leading to higher accessibility of individual fibres to the binder.
Lignocellulosic annual plant fibre residues which can be used in this invention are to be distinguished from wood products or other plant products which do not grow on an annual basis. They include rice straw, rice husks, wheat straw, rye straw, cotton stalks, miscanthus, sorghum and sunflower.
Binders or bonding agents are those conventionally employed in forming composite products and include both acidic and alkaline type binders. Typical bonding agents are amino resins, phenolic resins, resorcinol resins, tannin resins, isocyanate adhesives or mixtures thereof.
Thus resins which can be used to bond treated straw fibres include urea-formaldehyde resins (UF-resins), melamine-urea-formaldehyde resins (MUF-resins), melamine resins (MF-resins), phenol-formaldehyde resins (PF-resins), resorcinol-formaldehyde resins (RF-resins), tannin-formaldehyde resins (TF-resins), polymeric isocyanate binders (PMDI) and mixtures thereof. The resins can be added in the amount of 5-15~ based on dry straw materials employed in the final composite.
The hydro-thermal treatment can be with water alone or with water and treating agents as will be later described.
High shear treatment is an application to the fibre of interaction between mechanical surfaces which imposes a high shear force on the fibre as distinct from prior art low shear grinding or similar attrition treatments. Those skilled in the art are well aware of high shear devices which are exemplified by twin screw extruders, disc refiners, ultra turrax or any other suitable high shear mill. The rate of extrusion depends upon the conditions used and also the type of machine applied and can differ CA 022~2042 Isss-lo-os from 5kg/h to 20t/h.
The intensity of shearing applied must be such that, depending upon the type of composite which is to be prepared from the straw, one achieves a substantial defibration of the straw. For MDF and high density fibreboard, it is necessary to reach more or less complete defibration of the straw, so as to produce treated straw that displays sufficient bonding affinity towards a UF
resin, to enable formation of boards having certain desired properties. Medium density fibreboards cover a wide range of densities between 0.6 and 0.8g/cm3 depending on their thickness and field of application. Boards with density lower than 0.5b/cm3 are not common, but can be produced.
The quality required depends on the field of application of the board and its thickness:
For ~6-12mm thicknessFor ~12-19mm thickness Internal Bond (IB), N/mm2 0.65 0.60 ~ending strength (MOR), N/mm2 35 30 For particleboards on the other hand, partial difibration would be sufficient. Particleboards are prepared in the density range of 0.4 to 0.85g/cm3 depending upon their field of application and thickness. Boards with density lower than 0.5g/cm3 are low-density boards, between 0.5 and 0.7g/cm3 are medium density and greater than 0.7g/cm3 are high density boards. Also, in the case of particleboards, the requirements depend on the field of application and thickness of the boards.
For ~6-13mm thicknessFor ~13-20mm thickness Internal Bond (IB), N/mm2 0.40 0.35 Bending strength (MOR), N/mm2 17 15 CA 022~2042 1998-lO-09 The properties of the boards made from straw can be further improved if the straw is treated with various chemicals which are fibrous property lignocellulose modification agents. These reagents can be used either alone or in combination and include metal hydroxides, such as lithium, sodium, potassium, magnesium and aluminium hydroxide, organic and inorganic acids, such as phosphoric, hydrochloric, sulphuric, formic and acetic acid, salts, such as sodium sulphate, sodium sulphite and sodium tetraborate, oxides, such as alnm-nnm oxide; various amines and urea, Ammonia, as well as ~mmQn;um salts. These reagents can be used in the form of water solution or suspension in quantities of from 0.01 to 10~ based on dry material.
The chemical treatment and the defibration can be carried out in one step, by subjecting the straw to a stream of water during the high shear stage, containing the amount of chemical needed to upgrade the properties of the amino resin bonded boards. After the defibration, the fibres produced can be dried using conventional dryers used in particleboard factories, e.g. a drum dryer or a tube dryer, like that used in medium density fibreboard mills.
From then onwards, the dried fibres follow the conventional procedures as for the production of particleboard or medium density fibreboard.
It is also one of the embodiments of this invention to mix the ~nnll~l plant fibres with a binder or a binder mixture already in the high shear machine. UF, MUF, MF, PF, RF and TF resins can be employed for this purpose. In the case of amino resins, the adhesive can be added in a pre-catalysed or latently catalysed or non-catalysed state.
A catalyst can also be added separately in the high shearing stage. Mixtures of resins like UF-polyisocyanates can also be used in the same way.
CA 022~2042 1998-10-09 W097/38833 PCT/~R97/00012 The addition of a sizing agent is not obligatory.
However, it can be added, if appropriate, either in the high shear machine or separately. Other components of a standard glue mixture like formaldehyde scavengers and extenders can also be added in the same way.
The final composite materials can be panel products, reconstituted lumber products and moulded articles including particleboard, waferboard and fibreboard.
The resulting composition boards produced from treated straw fibres are very different from the boards produced using standard chopped straw. The appearance, surface smoothness and core density profile are superior, approaching the quality of medium density fibreboards.
Excellent edge properties and improved board machineability are further advantages of the process. High density boards can be produced, without the need to apply high board forming pressures.
In a further embodiment of the invention, treated straw fibres can be used as a partial substitute for wood chips in the production of wood particleboards. The benefit is an improvement of board general appearance, density profile and machineability. Wood substitution levels of between 1-50~, and preferably between 10-30~ can be employed. The conventional procedure for the production of particleboards is applied.
The following examples demonstrate the invention, without limiting its scope of application.
PRODUCTION OF REFERENCE BOARDS
Reference boards were produced in the laboratory by conventional techniques using untreated chopped wheat straw. The target board thickness was both 16 and 8mm and CA 022~2042 Isss-lo-os three types of binders were employed: UF resin, PF resin and PMDI. The first two resins were used at a level of 10~
in their catalysed form, while PMDI at a level of 3~ on a dry basis. The pressing temperature was 180~C and the press pressure was 35Kg/cm2. Three replicate boards were produced in each case and their properties were subsequently determined. The average values of board properties are presented below.
108mm 16mm PMDI PF UF PMDI PF UF
IB,N/mm2 0.45 0.25 0.04 0.39 0.20 0.03 MOR,N/mm2 17.6 12.1 3.2 15.1 10.9 3.0 HCHO,mg/lOOg 1.2 1.0 3.5 1.4 1.1 3.8 Swell 24h,~ 54.2 63.2 79.0 48.0 56.0 83.0 Density,Kg/m3 710 695 680 601 600 550 The formaldehyde (HCHO) emission was determined using the perforator method.
From these tests it can be seen that it is difficult to meet the requirements of common standards even when PMDI
binder is used. The resultant board density values exemplified were almost the highest that could be achieved by these techniques.
Wheat straw was treated in a twin screw extruder device with water at 55~C and steam at 100~C. The straw fibres were produced at a rate of lOkg/h. In order to produce boards, the resultant fibres were mixed with both UF resin and PMDI binder. The target board thickness was 16mm and the rest of the production conditions were the same as above. The average values of board properties are presented below.
CA 022~2042 l998-lO-09 55~C 100~C
PMDI UF PMDI UF
IB,N/mm2 0.55 0.27 0.60 0.32 ~ HCHO, mg/lOOg 0.3 8.2 0.4 6.2 Swell 24h,% 30.0 39.7 27.1 39.4 Density, Kg/m3 680 715 684 720 The above results reveal that bonding was strongly enhanced by treating the straw according to the present invention. As the results show, treating the straw at 55~C
has led to a significant improvement in the bonding strength and thickness swelling. Further increase in the temperature during the extrusion stage upgraded the properties of the boards less significantly.
Wheat straw was treated in a twin screw extruder device at 60~C by injecting water solutions of 1.3% NaOH, 0.5% urea and combination of 0.5% NaOH and 0.5% H2SO4. The fibres produced were used for the production of 16mm lab scale boards after mixing with UF resin. The rest production conditions were the same as above. For comparison purposes, fibres produced in the extruder by using only water were also tested. The average values of board properties are presented below.
H20 NaOH Urea NaOH-H2SO4 IB,N/mm2 0.30 0.34 0.31 0.38 HCHO, mg/lOOg 5.3 7.1 6.4 5.4 Swell 24h,% 40.5 43.0 38.9 46.3 Density, Kg/m3 686 684 683 678 CA 022~2042 Isss-lo-os By treating the straw with various chemicals during the extrusion, a further improvement of the mechanical strength of the resultant boards was achieved.
Wheat straw was treated in a twin screw extruder device at 60~C by injecting water solutions of 0.2~ NaOH
and 1.0~ Na2SO3. The fibres produced were used for the production of 8mm lab scale boards after mixing with UF
resin and/or PMDI. For comparison purposes, fibres produced in the extruder using only water were also tested.
The rest of the production conditions were the same as above. The average values of board properties are presented below.
H20 NaOH Na2SO3 PMDI UF PMDI UF UF
IB,N/mm2 0.74 0.65 0.83 0.58 0.41 MOR,N/mm2 13.1 17.7 18.9 14.5 11.8 HCHO, mg/lOOg 0.5 7.5 0.3 9.0 8.3 Swell 24h,~ 21.8 45.2 23.4 46.0 46.1 Density, Kg/m3 650 800 750 800 750 A similar test was carried out by treating the wheat straw in the extruder with a combination of 0.5~ NazSO3 and 0.1~ H2SO4. In this case, three resin types were used for the production of 8mm boards: UF, MUF and PF resin.
Results were presented in the following table.
CA 022~2042 l998-lO-09 W O 97/38833 PCT/G ~ 7/00012 UF MUF PF
IB,N/mm2 0.34 0.43 0.68 MOR,N/mm2 17.6 20.1 35.6 HCHO, mg/lOOg 7.6 3.7 2.2 Swell 24h,~ 46.3 37.2 24.8 Density, Kg/m3 790 795 792 Boards with properties that meet the re~uirements of common standards can be produced from treated straw fibres according to the present invention, when high performance resins are applied.
~MPLE 5 Another test was carried out using as starting materials rice and flax residues. The materials had been treated in a twin screw extruder device with 0.3~ NaOH at 100~C. 8mm boards were produced in the lab from the extruded fibres and PMDI or UF resins. Results from the testing of board properties are presented in the following table.
Rice Flax PMDI UF PMDI
IB,N/mm2 0.52 0.34 0.90 MOR,N/mm2 15.3 13.1 12.7 HCHO, mg/lOOg 1.5 9.4 1.3 Swell 24h,~ 20.1 33.7 22.5 Density, Kg/m3 800 700 700 From the above results it can be concluded that the process can be applied to a wide variety of plant residues or agricultural fibres.
Wheat straw was treated in an ultra turrax device at 70~C, by employing an aqueous NaOH solution of 2~. The fibres produced were used for the production of 8mm lab scale boards after mixing with UF resin. The other production conditions were as above. For comparison purposes, fibres produced in the extruder by using 1.3~
NaOH were also tested. The average values of board properties are presented below.
Extruder Ultra turrax treated straw treated straw IB, N/mm2 0.38 0.29 MOR, N/mm2 18.3 16.1 HCHO, 6.8 5.4 mg/lOOg Swell 24h, ~ 30.4 60.5 Density, Kg/m3 745 754 From the above-mentioned figures one can see that boards produced by both methods are equivalent. Even though mechanical and swelling values are somewhat worse, when the ultra turrax is used, the free formaldchyde values are improved.
Particleboards were produced by partially substituting wood chips with a quantity of wheat straw fibres, produced in a twin screw extruder device with 0.5~ Na2SO3 and 0.1~
H2SO4 at 100~C. Two resin types were used for the board production: MUF and UF resin. The substitution levels of fibre for wood employed for each type of glue were:
CA 02252042 1998-lO-09 ~ MUF - 10 and 20~
~ UF - 10 and 15%
The assessment of board properties provided the results shown below.
Resin Wood Density MOR IB Swell Substitution Kg/m3 N/mm2 N/mm2 2h%
MUF 0% 666 19.3 0~67 2.5 MUF 10% 657 17.0 0.69 2.8 MUF 20% 642 16.7 0.60 3.6 UF 0~ 633 14.1 0.49 5.1 UF 10% 633 15.3 0.47 5.1 UF 15% 622 14.1 0.46 5.6 The above results indicate that particleboards can be effectively produced by substituting part of the wood chips with extruded straw fibres. Advantages are an improvement of the general appearance of the board and of corresponding board properties.
,
COMPOSITE MATERIALS
This invention relates to the production of lignocellulosic fibres and formation of composite materials therefrom. It particularly relates to the production of such fibres and bonding with synthetic binders into composite materials.
There is considerable pressure on the world's fibre resource. World-wide economic growth and development have created needs for converted forest products. While global fibre production systems are capable of meeting these overall demands there are some serious local and regional fibre shortages and resource management conflicts.
Many developing countries do not possess adequate forest reserves to cover their needs for fuelwood, industrial wood, sawn wood, and wood-based composition panels. However, many of these countries do have relatively large quantities of lignocellulosic materials available in the form of agricultural residues from annual crops. Annual plant fibres like cereal straw and the like are difficult to bond using conventional adhesives such as UF resins, PF-resins and PMDI binders.
The present invention is related, therefore, to a method of improving the bondability of lignocellulosic materials from annual plant fibres such as cereal straw by synthetic binders.
Composite materials such as particleboards, medium and high density fibreboards are mainly made from wood using binders such as acid curing amino-formaldehyde resins, alkaline curing phenol-formaldehyde resins, as well as , CA 022~2042 Isss-lo-os polyisocyanate adhesives. Medium density fibreboards are fibreboards prepared using a dry technique as follows:
Wood is subjected to thermomechanical pulping at a temperature of about 160 to 180~C, then mixed with the resin and dried. Thereafter mats are formed from the fibres and pressed to form fibreboards. Particleboards, on the other hand, can be prepared from chips which are mixed with resins and the glued particles are spread to mats and pressed at high temperature to particleboards.
Recently, interest has been developed on using agricultural residues like wheat and rice straw and sunflower as a starting material for particleboards and medium density fibreboards. The main difficulty in using annual plant residues such as straw as a raw material for composites, is their poor bondability particularly using urea-formaldehyde resins. The reason for this is probably the specific morphological structure of the straw, where the waxy and silica layer encirculating the straw stem inhibit sufficient direct contact between the binder and the straw fibres. Other types of adhesives for example polymeric isocyanates have been tried. However, the mechanical strength as well as the water resistance of the boards made from straw and isocyanates are much lower than those made from wood using the same bonding conditions.
Therefore, it was the main aim of the invention to find a practical method to improve the bondability of ~nn~l plant residues towards bonding agents in general and particularly towards acid curing aminoplastic resins and also polyisocyanate binders.
While fibrous/particulate ligno/c-llulosic materials have been treated by water/steam treatments with simultaneous or subsequent high shear treatment, use of lower temperatures has only been in the context of treatments for the manufacture of paper or similar CA 022~2042 Isss-lo-os materials and there has been no suggestion that this treatment when applied to lignocellulosic materials in the context of producing composites would enhance the fibrous or particulate material for forming into composite material. The process of the invention is also to be distinguished from producing composite materials from lignocellulosic materials in which there is an initial treatment at high temperature of at least 150~C, usually 150~C to 170~C followed by defibration.
Thus many treatments have been described in the literature to improve the bondability of lignocellulosic materials in both particle and fibre form with synthetic resins. D.H. GARDNER and T.J. ELDER: (Bonding surface activated hardwood flakeboard with phenolformaldehyde resin - Holzforschung 44(3): 201 - 206, 1990) added hydrogen peroxide, nitric acid or sodium hydroxide to enhance bonding characteristics of flakes using phenol-formaldehyde resins as a binder. Dimensional stability and internal bond strength were significantly reduced and it was shown that the chemicals did not change the wood surface, but rather they reacted with the resin.
J. McLAUGHLAN and C.R. ANDERSEN: (In-Line fibre pretreatments for dry process medium density fibreboard:
Initial Investigations - Paper presented at the Symposium Pacific Rim Bio-Based Composites, Rotorua, New Zealand 9-13 November 1992, Symposium Proceedings, page 91 - 99, 1992) tried many treatments to enhance the bondability of fibres towards bonding with urea-formaldehyde resins for the production of medium density fibreboards. The treatments include exposure to wet and dry heat, compression with heat and heat in combination with chemicals. The chemicals include 1~ and 10~ addition of aluminum sulphate, which is used in the hard board manufacture to control the pH value of the stock and 1% and 10~ chromium trioxide. Almost all the treatments resulted in boards with reduced properties .
CA 022~2042 Isss-lo-os compared to the control.
SIMON AND L. PAZNER): (Activated self-bonding of wood and agricultural residues - Holzforschung 48: 82 - 90, 1994) investigated the influence of the hemicellulose content of the self-bonding behaviour of different raw materials including annual plants and concluded that there is a straightforward relation between the hemicellulose content in the raw materials and the bonding strength of composites prepared therefrom. According to this work hemicelluloses do have adhesive properties, however, bonds created using hemicellulose adhesives have almost no wet strength.
In a recent publication LIAN ZHENGTIAN and HAO BINGYE:
(Technology of rice-straw particleboards bonded by Urea-formaldehyde resin modified by isocyanate - Paper presented at the Symposium Pacific Rim Bio-Based Composites, Rotorua, New Zealand 9 - 13 November 1992 Symposium Proceedings, page 295 - 301, 1992) mentioned that slight improvement of bondability of straw can be achieved by destroying the waxy layers encircling the stem of straw, however, the bondability was still very poor and the boards made still could not meet the requirements of common standards.
In DE-A-36 09 506 is described a modified standard dry process for the production of MDF in which UF resin is injected treatment with overheated steam and separation of steam from the treated fibres. The treatment of the fibres is by a conventional disc refiner.
In US-A-3 843 431 composite panels are produced from fibres prepared using as starting material scraps, shavings, sawdust. The raw material is blended with water and ground with the use of a double-disc attrition mill.
In WO-A-93 25358 MDF is produced according to the CA 022~2042 Isss-lo-os standard dry process involving wood chips pre-treated prior to defibration. The pre-treatment procedure involves the impregnation of raw material with Na2SO3/NaHSO3 and heating at a temperature between 150-200~C.
The aim of the present invention to develop a method for the treatment of ~nnl~l plant fibres, so that their bondability to synthetic resins is significantly improved and the production of composite panels with properties that meet the requirements of common standards is effected.
It has been discovered that thermal treatment of straw or other Annll~l plant fibres with water or steam at temperatures between 40 - 120~C, and preferably between 60 - 100~C accompanied by or followed by defibration of the fibres using high shear force~ destroys the morphological structure of the straw and increases tremendously its affinity towards bonding.
According to the invention, therefore, there is provided a method for producing composite materials wherein a lignocellulosic material which is an annual plant fibre residue is subjected to treatment with water or steam at 40~ to 120~C and simultaneously or subsequently is subjected to a high shear treatment and thereafter is formed into a composite material. The invention also relates to a lignocellulosic material which is an annual plant fibre residue which has been subjected to such water/steam treatment and high shear treatment and is in a form suitable for bonding into a composite. The invention also relates to a composite material in which at least part of the fibre content is derived from said treated ~nn plant fibre residue.
Defibration in the sense of this invention means disruption of the morphological structure of straw leading to the creation of individual fibres. The treatment CA 022~2042 Isss-lo-os destroys the waxy and silica layer of straw, leading to higher accessibility of individual fibres to the binder.
Lignocellulosic annual plant fibre residues which can be used in this invention are to be distinguished from wood products or other plant products which do not grow on an annual basis. They include rice straw, rice husks, wheat straw, rye straw, cotton stalks, miscanthus, sorghum and sunflower.
Binders or bonding agents are those conventionally employed in forming composite products and include both acidic and alkaline type binders. Typical bonding agents are amino resins, phenolic resins, resorcinol resins, tannin resins, isocyanate adhesives or mixtures thereof.
Thus resins which can be used to bond treated straw fibres include urea-formaldehyde resins (UF-resins), melamine-urea-formaldehyde resins (MUF-resins), melamine resins (MF-resins), phenol-formaldehyde resins (PF-resins), resorcinol-formaldehyde resins (RF-resins), tannin-formaldehyde resins (TF-resins), polymeric isocyanate binders (PMDI) and mixtures thereof. The resins can be added in the amount of 5-15~ based on dry straw materials employed in the final composite.
The hydro-thermal treatment can be with water alone or with water and treating agents as will be later described.
High shear treatment is an application to the fibre of interaction between mechanical surfaces which imposes a high shear force on the fibre as distinct from prior art low shear grinding or similar attrition treatments. Those skilled in the art are well aware of high shear devices which are exemplified by twin screw extruders, disc refiners, ultra turrax or any other suitable high shear mill. The rate of extrusion depends upon the conditions used and also the type of machine applied and can differ CA 022~2042 Isss-lo-os from 5kg/h to 20t/h.
The intensity of shearing applied must be such that, depending upon the type of composite which is to be prepared from the straw, one achieves a substantial defibration of the straw. For MDF and high density fibreboard, it is necessary to reach more or less complete defibration of the straw, so as to produce treated straw that displays sufficient bonding affinity towards a UF
resin, to enable formation of boards having certain desired properties. Medium density fibreboards cover a wide range of densities between 0.6 and 0.8g/cm3 depending on their thickness and field of application. Boards with density lower than 0.5b/cm3 are not common, but can be produced.
The quality required depends on the field of application of the board and its thickness:
For ~6-12mm thicknessFor ~12-19mm thickness Internal Bond (IB), N/mm2 0.65 0.60 ~ending strength (MOR), N/mm2 35 30 For particleboards on the other hand, partial difibration would be sufficient. Particleboards are prepared in the density range of 0.4 to 0.85g/cm3 depending upon their field of application and thickness. Boards with density lower than 0.5g/cm3 are low-density boards, between 0.5 and 0.7g/cm3 are medium density and greater than 0.7g/cm3 are high density boards. Also, in the case of particleboards, the requirements depend on the field of application and thickness of the boards.
For ~6-13mm thicknessFor ~13-20mm thickness Internal Bond (IB), N/mm2 0.40 0.35 Bending strength (MOR), N/mm2 17 15 CA 022~2042 1998-lO-09 The properties of the boards made from straw can be further improved if the straw is treated with various chemicals which are fibrous property lignocellulose modification agents. These reagents can be used either alone or in combination and include metal hydroxides, such as lithium, sodium, potassium, magnesium and aluminium hydroxide, organic and inorganic acids, such as phosphoric, hydrochloric, sulphuric, formic and acetic acid, salts, such as sodium sulphate, sodium sulphite and sodium tetraborate, oxides, such as alnm-nnm oxide; various amines and urea, Ammonia, as well as ~mmQn;um salts. These reagents can be used in the form of water solution or suspension in quantities of from 0.01 to 10~ based on dry material.
The chemical treatment and the defibration can be carried out in one step, by subjecting the straw to a stream of water during the high shear stage, containing the amount of chemical needed to upgrade the properties of the amino resin bonded boards. After the defibration, the fibres produced can be dried using conventional dryers used in particleboard factories, e.g. a drum dryer or a tube dryer, like that used in medium density fibreboard mills.
From then onwards, the dried fibres follow the conventional procedures as for the production of particleboard or medium density fibreboard.
It is also one of the embodiments of this invention to mix the ~nnll~l plant fibres with a binder or a binder mixture already in the high shear machine. UF, MUF, MF, PF, RF and TF resins can be employed for this purpose. In the case of amino resins, the adhesive can be added in a pre-catalysed or latently catalysed or non-catalysed state.
A catalyst can also be added separately in the high shearing stage. Mixtures of resins like UF-polyisocyanates can also be used in the same way.
CA 022~2042 1998-10-09 W097/38833 PCT/~R97/00012 The addition of a sizing agent is not obligatory.
However, it can be added, if appropriate, either in the high shear machine or separately. Other components of a standard glue mixture like formaldehyde scavengers and extenders can also be added in the same way.
The final composite materials can be panel products, reconstituted lumber products and moulded articles including particleboard, waferboard and fibreboard.
The resulting composition boards produced from treated straw fibres are very different from the boards produced using standard chopped straw. The appearance, surface smoothness and core density profile are superior, approaching the quality of medium density fibreboards.
Excellent edge properties and improved board machineability are further advantages of the process. High density boards can be produced, without the need to apply high board forming pressures.
In a further embodiment of the invention, treated straw fibres can be used as a partial substitute for wood chips in the production of wood particleboards. The benefit is an improvement of board general appearance, density profile and machineability. Wood substitution levels of between 1-50~, and preferably between 10-30~ can be employed. The conventional procedure for the production of particleboards is applied.
The following examples demonstrate the invention, without limiting its scope of application.
PRODUCTION OF REFERENCE BOARDS
Reference boards were produced in the laboratory by conventional techniques using untreated chopped wheat straw. The target board thickness was both 16 and 8mm and CA 022~2042 Isss-lo-os three types of binders were employed: UF resin, PF resin and PMDI. The first two resins were used at a level of 10~
in their catalysed form, while PMDI at a level of 3~ on a dry basis. The pressing temperature was 180~C and the press pressure was 35Kg/cm2. Three replicate boards were produced in each case and their properties were subsequently determined. The average values of board properties are presented below.
108mm 16mm PMDI PF UF PMDI PF UF
IB,N/mm2 0.45 0.25 0.04 0.39 0.20 0.03 MOR,N/mm2 17.6 12.1 3.2 15.1 10.9 3.0 HCHO,mg/lOOg 1.2 1.0 3.5 1.4 1.1 3.8 Swell 24h,~ 54.2 63.2 79.0 48.0 56.0 83.0 Density,Kg/m3 710 695 680 601 600 550 The formaldehyde (HCHO) emission was determined using the perforator method.
From these tests it can be seen that it is difficult to meet the requirements of common standards even when PMDI
binder is used. The resultant board density values exemplified were almost the highest that could be achieved by these techniques.
Wheat straw was treated in a twin screw extruder device with water at 55~C and steam at 100~C. The straw fibres were produced at a rate of lOkg/h. In order to produce boards, the resultant fibres were mixed with both UF resin and PMDI binder. The target board thickness was 16mm and the rest of the production conditions were the same as above. The average values of board properties are presented below.
CA 022~2042 l998-lO-09 55~C 100~C
PMDI UF PMDI UF
IB,N/mm2 0.55 0.27 0.60 0.32 ~ HCHO, mg/lOOg 0.3 8.2 0.4 6.2 Swell 24h,% 30.0 39.7 27.1 39.4 Density, Kg/m3 680 715 684 720 The above results reveal that bonding was strongly enhanced by treating the straw according to the present invention. As the results show, treating the straw at 55~C
has led to a significant improvement in the bonding strength and thickness swelling. Further increase in the temperature during the extrusion stage upgraded the properties of the boards less significantly.
Wheat straw was treated in a twin screw extruder device at 60~C by injecting water solutions of 1.3% NaOH, 0.5% urea and combination of 0.5% NaOH and 0.5% H2SO4. The fibres produced were used for the production of 16mm lab scale boards after mixing with UF resin. The rest production conditions were the same as above. For comparison purposes, fibres produced in the extruder by using only water were also tested. The average values of board properties are presented below.
H20 NaOH Urea NaOH-H2SO4 IB,N/mm2 0.30 0.34 0.31 0.38 HCHO, mg/lOOg 5.3 7.1 6.4 5.4 Swell 24h,% 40.5 43.0 38.9 46.3 Density, Kg/m3 686 684 683 678 CA 022~2042 Isss-lo-os By treating the straw with various chemicals during the extrusion, a further improvement of the mechanical strength of the resultant boards was achieved.
Wheat straw was treated in a twin screw extruder device at 60~C by injecting water solutions of 0.2~ NaOH
and 1.0~ Na2SO3. The fibres produced were used for the production of 8mm lab scale boards after mixing with UF
resin and/or PMDI. For comparison purposes, fibres produced in the extruder using only water were also tested.
The rest of the production conditions were the same as above. The average values of board properties are presented below.
H20 NaOH Na2SO3 PMDI UF PMDI UF UF
IB,N/mm2 0.74 0.65 0.83 0.58 0.41 MOR,N/mm2 13.1 17.7 18.9 14.5 11.8 HCHO, mg/lOOg 0.5 7.5 0.3 9.0 8.3 Swell 24h,~ 21.8 45.2 23.4 46.0 46.1 Density, Kg/m3 650 800 750 800 750 A similar test was carried out by treating the wheat straw in the extruder with a combination of 0.5~ NazSO3 and 0.1~ H2SO4. In this case, three resin types were used for the production of 8mm boards: UF, MUF and PF resin.
Results were presented in the following table.
CA 022~2042 l998-lO-09 W O 97/38833 PCT/G ~ 7/00012 UF MUF PF
IB,N/mm2 0.34 0.43 0.68 MOR,N/mm2 17.6 20.1 35.6 HCHO, mg/lOOg 7.6 3.7 2.2 Swell 24h,~ 46.3 37.2 24.8 Density, Kg/m3 790 795 792 Boards with properties that meet the re~uirements of common standards can be produced from treated straw fibres according to the present invention, when high performance resins are applied.
~MPLE 5 Another test was carried out using as starting materials rice and flax residues. The materials had been treated in a twin screw extruder device with 0.3~ NaOH at 100~C. 8mm boards were produced in the lab from the extruded fibres and PMDI or UF resins. Results from the testing of board properties are presented in the following table.
Rice Flax PMDI UF PMDI
IB,N/mm2 0.52 0.34 0.90 MOR,N/mm2 15.3 13.1 12.7 HCHO, mg/lOOg 1.5 9.4 1.3 Swell 24h,~ 20.1 33.7 22.5 Density, Kg/m3 800 700 700 From the above results it can be concluded that the process can be applied to a wide variety of plant residues or agricultural fibres.
Wheat straw was treated in an ultra turrax device at 70~C, by employing an aqueous NaOH solution of 2~. The fibres produced were used for the production of 8mm lab scale boards after mixing with UF resin. The other production conditions were as above. For comparison purposes, fibres produced in the extruder by using 1.3~
NaOH were also tested. The average values of board properties are presented below.
Extruder Ultra turrax treated straw treated straw IB, N/mm2 0.38 0.29 MOR, N/mm2 18.3 16.1 HCHO, 6.8 5.4 mg/lOOg Swell 24h, ~ 30.4 60.5 Density, Kg/m3 745 754 From the above-mentioned figures one can see that boards produced by both methods are equivalent. Even though mechanical and swelling values are somewhat worse, when the ultra turrax is used, the free formaldchyde values are improved.
Particleboards were produced by partially substituting wood chips with a quantity of wheat straw fibres, produced in a twin screw extruder device with 0.5~ Na2SO3 and 0.1~
H2SO4 at 100~C. Two resin types were used for the board production: MUF and UF resin. The substitution levels of fibre for wood employed for each type of glue were:
CA 02252042 1998-lO-09 ~ MUF - 10 and 20~
~ UF - 10 and 15%
The assessment of board properties provided the results shown below.
Resin Wood Density MOR IB Swell Substitution Kg/m3 N/mm2 N/mm2 2h%
MUF 0% 666 19.3 0~67 2.5 MUF 10% 657 17.0 0.69 2.8 MUF 20% 642 16.7 0.60 3.6 UF 0~ 633 14.1 0.49 5.1 UF 10% 633 15.3 0.47 5.1 UF 15% 622 14.1 0.46 5.6 The above results indicate that particleboards can be effectively produced by substituting part of the wood chips with extruded straw fibres. Advantages are an improvement of the general appearance of the board and of corresponding board properties.
,
Claims (9)
1. A method for producing a composite material, comprising the steps of:
(a) subjecting a fibrous lignocellulosic material, being an annual plant fibre residue, to treatment with water or steam at 40° to 120° C;
(b) subjecting said fibrous lignocellulosic material to a high shear treatment to produce a fibrous material; and (c) subjecting said fibrous material to heat and pressure in the presence of a resin bonding agent.
(a) subjecting a fibrous lignocellulosic material, being an annual plant fibre residue, to treatment with water or steam at 40° to 120° C;
(b) subjecting said fibrous lignocellulosic material to a high shear treatment to produce a fibrous material; and (c) subjecting said fibrous material to heat and pressure in the presence of a resin bonding agent.
2. A method according to claim 1, wherein method step (b) is carried out simultaneously with step (a).
3. A method according to claim 1 or claim 2, wherein said annual plant fibre residue is a straw.
4. A method according to any one of claims 1 to 3, wherein said annual plant fibre residue is treated with a lignocellulose modification agent.
5. A method according claim 4, wherein said lignocellulose modification agent is selected from the group consisting of metal hydroxides, organic acids, inorganic acids, salts, oxides, amines or urea.
6. A method according to claim 4 or claim 5, wherein said lignocellulose modification agent is added during the high shear treatment stage of hydrothermal treatment.
7. A process according to any one of claims 1 to 6, wherein at least part of the resin bonding agent is added during the high shear treatment stage of hydrothermal treatment.
8. A process according to any of one claims 1 to 7, wherein a sizing agent is added to said fibrous lignocellulose material or with the addition of said resin bonding agent.
9. A process of any one of claims 1 to 8, wherein said fibrous lignocellulose material is combined with wood particles.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
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| US1528396P | 1996-04-12 | 1996-04-12 | |
| US60/015,283 | 1996-04-12 | ||
| GBGB9607566.8A GB9607566D0 (en) | 1996-04-12 | 1996-04-12 | Method for improving the bondability of annual plant fibres |
| GB9607566.8 | 1996-04-12 | ||
| PCT/GR1997/000012 WO1997038833A1 (en) | 1996-04-12 | 1997-04-10 | Method for production of lignocellulosic composite materials |
Publications (2)
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| CA2252042A1 CA2252042A1 (en) | 1997-10-23 |
| CA2252042C true CA2252042C (en) | 2003-09-23 |
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| CA002252042A Expired - Fee Related CA2252042C (en) | 1996-04-12 | 1997-04-10 | Method for production of lignocellulosic composite materials |
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| US (2) | US6346165B1 (en) |
| EP (1) | EP0918601B1 (en) |
| JP (1) | JP3192151B2 (en) |
| KR (1) | KR20000005400A (en) |
| CN (1) | CN1087213C (en) |
| AT (1) | ATE197567T1 (en) |
| AU (1) | AU718426B2 (en) |
| BR (1) | BR9708659A (en) |
| CA (1) | CA2252042C (en) |
| DE (1) | DE69703552T2 (en) |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102001113A (en) * | 2010-11-28 | 2011-04-06 | 任玉虎 | Glued series plate pressed by using plant straws and preparation method thereof |
Families Citing this family (44)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2234889A1 (en) * | 1997-07-24 | 1999-01-24 | Lars Bach | Structural board of cereal straw |
| US6083623A (en) | 1997-09-19 | 2000-07-04 | Carbocol Systems Inc. | Bonding of solid lignocellulosic materials |
| DE19822485A1 (en) * | 1998-05-19 | 1999-11-25 | Kvaerner Panel Sys Gmbh | Fabrication method for fiber/chip board panels |
| US6131635A (en) * | 1998-07-20 | 2000-10-17 | Alberta Research Council Inc. | Device for longitudinally splitting pieces of straw into separated strands |
| CA2250645A1 (en) * | 1998-10-16 | 2000-04-16 | Wayne Wasylciw | Process for the production of articles from treated lignocellulosic particles and binder |
| CA2376796C (en) * | 1999-06-18 | 2006-05-23 | Akzo Nobel N.V. | Method of treating surface of fibreboard with hydrogen peroxide |
| DE19945466B4 (en) * | 1999-09-22 | 2004-09-23 | Pfleiderer Ag | Device and method for the digestion of wood-based materials |
| ATE368017T1 (en) | 2000-03-14 | 2007-08-15 | James Hardie Int Finance Bv | FIBER CEMENT CONSTRUCTION MATERIALS WITH LOW DENSITY ADDITIVES |
| PL365829A1 (en) * | 2000-10-04 | 2005-01-10 | James Hardie Research Pty Limited | Fiber cement composite materials using sized cellulose fibers |
| WO2002033164A2 (en) * | 2000-10-17 | 2002-04-25 | James Hardie Research Pty Limited | Method for reducing impurities in cellulose fibers for manufacture of fiber reinforced cement composite materials |
| US20050126430A1 (en) * | 2000-10-17 | 2005-06-16 | Lightner James E.Jr. | Building materials with bioresistant properties |
| DE60219443T2 (en) * | 2001-03-09 | 2007-12-20 | James Hardie International Finance B.V. | FIBER REINFORCED CEMENT MATERIALS USING CHEMICALLY MODIFIED FIBERS WITH IMPROVED MIXABILITY |
| WO2002081160A1 (en) * | 2001-04-03 | 2002-10-17 | Alberta Research Council Inc. | Methods of straw fibre processing |
| DE10116686C2 (en) * | 2001-04-03 | 2003-08-21 | P & T Gmbh Projekt Und Technol | Process for the preparation of straw and other annual plants for the production of fiberboard, chipboard and insulation boards as well as wall elements and other molded parts and process for the production of fiberboard, chipboard and insulation boards as well as wall elements and other molded parts |
| US20060174798A1 (en) * | 2001-05-04 | 2006-08-10 | Greencor Composites, Llc | Fire-resistant wall and method of manufacture |
| US6886306B2 (en) * | 2001-05-04 | 2005-05-03 | Greencor Composites, Llc | Fire-resistant material and method of manufacture |
| KR100700634B1 (en) * | 2002-05-03 | 2007-03-27 | 재단법인서울대학교산학협력재단 | Agricultural waste-wood particle composite board |
| KR100517591B1 (en) * | 2002-06-01 | 2005-09-28 | 유중형 | Corn-Stalk Board and method for preparing the same |
| KR20020075340A (en) * | 2002-08-27 | 2002-10-04 | 김수현 | Put agricultural by-products ( wheat straw, rice straw, corn straw) to practical use, specia processing, new material development and manufacturing techinique. |
| US7993570B2 (en) | 2002-10-07 | 2011-08-09 | James Hardie Technology Limited | Durable medium-density fibre cement composite |
| US7942964B2 (en) * | 2003-01-09 | 2011-05-17 | James Hardie Technology Limited | Fiber cement composite materials using bleached cellulose fibers |
| US6755460B1 (en) * | 2003-02-28 | 2004-06-29 | Paccar Inc. | Vehicle body panel mounting system |
| US7998571B2 (en) | 2004-07-09 | 2011-08-16 | James Hardie Technology Limited | Composite cement article incorporating a powder coating and methods of making same |
| US8412671B2 (en) * | 2004-08-13 | 2013-04-02 | Hewlett-Packard Development Company, L.P. | System and method for developing a star schema |
| EP2010730A4 (en) | 2006-04-12 | 2013-07-17 | Hardie James Technology Ltd | A surface sealed reinforced building element |
| WO2007124400A2 (en) * | 2006-04-21 | 2007-11-01 | Greenvalue S.A. | Methods for producing modified aromatic renewable materials and compositions thereof |
| US20070287795A1 (en) * | 2006-06-08 | 2007-12-13 | Board Of Trustees Of Michigan State University | Composite materials from corncob granules and process for preparation |
| CA2731073C (en) * | 2007-12-05 | 2014-05-20 | Shandong Fuyin Paper & Environmental Protection Technology Co., Ltd | Grass type unbleached paper product and preparation method thereof |
| US8052842B2 (en) * | 2008-01-24 | 2011-11-08 | Agriboard Industries | Method for making a compressed structural fiberboard |
| US20090288792A1 (en) * | 2008-05-20 | 2009-11-26 | Buhler Ag | Method for producing pressed products from fiber-containing raw materials |
| FR2957936B1 (en) * | 2010-03-29 | 2012-05-04 | Valagro Carbone Renouvelable Poitou Charentes | PROCESS FOR OBTAINING A FERMENTABLE PRODUCT FROM A POLLUTED LIGNOCELLULOSIC BIOMASS |
| CN101823280A (en) * | 2010-04-21 | 2010-09-08 | 吴仪 | Production method of green environmental-friendly artificial wood |
| KR101034603B1 (en) * | 2010-07-26 | 2011-05-12 | 김재철 | Method for fabricating agricultural waste particle and method for fabricating the particle |
| CN102120333B (en) * | 2010-12-20 | 2014-01-22 | 山东贺友集团有限公司 | Method for manufacturing melamine board with low formaldehyde content |
| WO2013092963A2 (en) * | 2011-12-23 | 2013-06-27 | Basf Se | Lignocellulosic materials with lignocellulosic fibers in the outer layers and expanded plastics particles present in the core |
| NZ701271A (en) * | 2012-04-27 | 2016-10-28 | Georgia Pacific Chemicals Llc | Composite products made with lewis acid catalyzed binder compositions that include tannins and multifunctional aldehydes |
| CN103450505A (en) * | 2013-09-16 | 2013-12-18 | 内蒙古大学 | Method for preparing board from waste polyurethane foam, waste plant fiber and waste xylonite |
| CN104526832A (en) * | 2014-12-16 | 2015-04-22 | 上海振森木业机械有限公司 | Method for manufacturing high-density fiber board by crop straws |
| KR101769900B1 (en) * | 2015-12-07 | 2017-08-22 | 상진에이알피(주) | The prefabricated conveyance cart |
| JP6494129B2 (en) * | 2017-06-26 | 2019-04-03 | 株式会社能代資源 | Wrinkle-containing molded article, and method of producing wrinkle-containing molded article |
| US11046057B2 (en) | 2017-11-07 | 2021-06-29 | Masonite Corporation | Articles made from lipophilic-rich cellulosic material and methods therefor |
| DE102018129394A1 (en) | 2018-11-22 | 2020-05-28 | Georg-August-Universität Göttingen Stiftung Öffentlichen Rechts | Process for the production of glued fiberboard |
| JP6821724B2 (en) * | 2019-02-22 | 2021-01-27 | 株式会社事業革新パートナーズ | Resin composition and molding method using the resin composition |
| US10414064B1 (en) | 2019-03-14 | 2019-09-17 | Agriboard International, Llc | Efficient method and apparatus for producing compressed structural fiberboard |
Family Cites Families (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3627629A (en) * | 1970-05-06 | 1971-12-14 | Bauer Bros Co | Refining system and process |
| SE359332B (en) * | 1971-12-20 | 1973-08-27 | Reinhall Rolf | |
| US3843431A (en) * | 1972-06-23 | 1974-10-22 | Dostalik N | Process for making fibrous composition board |
| US4022965A (en) * | 1975-01-13 | 1977-05-10 | Crown Zellerbach Corporation | Process for producing reactive, homogeneous, self-bondable lignocellulose fibers |
| FR2319737A1 (en) * | 1975-07-31 | 1977-02-25 | Creusot Loire | PAPER PULP MANUFACTURING PROCESS AND MACHINE |
| DE3107589C2 (en) * | 1981-02-27 | 1986-01-30 | Bison-Werke Bähre & Greten GmbH & Co KG, 3257 Springe | Device for the continuous production of chipboard, fiberboard or similar boards |
| US4490517A (en) * | 1983-10-03 | 1984-12-25 | Olin Corporation | Solid TDI residue-dicarboxylic ester binder composition and lignocellulosic composite materials prepared therefrom |
| DE3609506A1 (en) * | 1985-03-25 | 1986-10-30 | Koppers Co., Inc., Pittsburgh, Pa. | Process for producing a composition from cellulose particles and resin for the production of fibre boards |
| US4869783A (en) * | 1986-07-09 | 1989-09-26 | The Mead Corporation | High-yield chemical pulping |
| EP0292584B1 (en) * | 1987-05-23 | 1991-12-04 | Mario Miani | Method of making panels, apparatus for carrying out the method and panels obtained thereby |
| US5338402A (en) * | 1987-05-25 | 1994-08-16 | Societe Atochem | Process for preparing a bleached chemithermomechanical pulp |
| US4906484A (en) * | 1988-01-22 | 1990-03-06 | Boise Cascade Corporation | Electrically conductive lignocellulose particle board |
| US4997488A (en) * | 1988-02-05 | 1991-03-05 | The United States Of America As Represented By The Secretary Of Agriculture | Combined physical and chemical treatment to improve lignocellulose digestibility |
| DE68923350T2 (en) * | 1988-12-16 | 1996-01-18 | Shell Int Research | Cellulose fiber aggregate and process for its manufacture. |
| SE466060C (en) * | 1990-02-13 | 1995-07-11 | Moelnlycke Ab | Absorbent chemitermomechanical mass and preparation thereof |
| DE4211888A1 (en) * | 1992-04-09 | 1993-10-14 | Wulf V Dr Bonin | Moulded prods. from whole plants - by harvesting whole plant, homogenising by crushing process and moulding by methods used in baking or chipboard mfr. |
| US5348620A (en) * | 1992-04-17 | 1994-09-20 | Kimberly-Clark Corporation | Method of treating papermaking fibers for making tissue |
| SE470330B (en) | 1992-06-11 | 1994-01-24 | Sunds Defibrator Ind Ab | Process for making fiberboard according to the dry method |
| WO1995000304A1 (en) * | 1993-06-23 | 1995-01-05 | Georgy Yakovlevich Gibul | Process for manufacturing building panels or other articles from plant matter and a production line for carrying out the said process |
| JP3002214U (en) | 1994-03-15 | 1994-09-20 | 有限会社シノダ | Ultrasonic processing tool |
| DE19515734A1 (en) | 1995-05-03 | 1996-11-07 | Schenkmann & Piel Verfahrenste | Process for the production of wood fibers |
| US5656129A (en) * | 1995-05-31 | 1997-08-12 | Masonite Corporation | Method of producing fibers from a straw and board products made therefrom |
-
1997
- 1997-01-06 PL PL97329294A patent/PL184356B1/en not_active IP Right Cessation
- 1997-04-10 DE DE69703552T patent/DE69703552T2/en not_active Expired - Fee Related
- 1997-04-10 BR BR9708659-2A patent/BR9708659A/en not_active IP Right Cessation
- 1997-04-10 DK DK97915624T patent/DK0918601T3/en active
- 1997-04-10 RU RU98120601A patent/RU2142877C1/en not_active IP Right Cessation
- 1997-04-10 IL IL12626097A patent/IL126260A/en not_active IP Right Cessation
- 1997-04-10 WO PCT/GR1997/000012 patent/WO1997038833A1/en active IP Right Grant
- 1997-04-10 RO RO98-01468A patent/RO119188B1/en unknown
- 1997-04-10 AT AT97915624T patent/ATE197567T1/en not_active IP Right Cessation
- 1997-04-10 US US09/171,087 patent/US6346165B1/en not_active Expired - Fee Related
- 1997-04-10 EP EP97915624A patent/EP0918601B1/en not_active Expired - Lifetime
- 1997-04-10 JP JP53688997A patent/JP3192151B2/en not_active Expired - Fee Related
- 1997-04-10 ES ES97915624T patent/ES2153660T3/en not_active Expired - Lifetime
- 1997-04-10 TR TR1998/02006T patent/TR199802006T2/en unknown
- 1997-04-10 CA CA002252042A patent/CA2252042C/en not_active Expired - Fee Related
- 1997-04-10 CN CN97193730A patent/CN1087213C/en not_active Expired - Fee Related
- 1997-04-10 KR KR1019980708132A patent/KR20000005400A/en active IP Right Grant
- 1997-04-10 AU AU23036/97A patent/AU718426B2/en not_active Ceased
-
2001
- 2001-02-01 GR GR20010400174T patent/GR3035349T3/en not_active IP Right Cessation
- 2001-11-30 US US09/999,179 patent/US20030041965A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102001113A (en) * | 2010-11-28 | 2011-04-06 | 任玉虎 | Glued series plate pressed by using plant straws and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| US6346165B1 (en) | 2002-02-12 |
| EP0918601B1 (en) | 2000-11-15 |
| AU2303697A (en) | 1997-11-07 |
| BR9708659A (en) | 2000-01-04 |
| CA2252042A1 (en) | 1997-10-23 |
| DE69703552T2 (en) | 2001-06-28 |
| IL126260A (en) | 2001-05-20 |
| US20030041965A1 (en) | 2003-03-06 |
| ES2153660T3 (en) | 2001-03-01 |
| JP3192151B2 (en) | 2001-07-23 |
| KR20000005400A (en) | 2000-01-25 |
| DK0918601T3 (en) | 2001-03-05 |
| CN1087213C (en) | 2002-07-10 |
| IL126260A0 (en) | 1999-05-09 |
| PL329294A1 (en) | 1999-03-15 |
| EP0918601A1 (en) | 1999-06-02 |
| RO119188B1 (en) | 2004-05-28 |
| TR199802006T2 (en) | 1999-01-18 |
| GR3035349T3 (en) | 2001-05-31 |
| DE69703552D1 (en) | 2000-12-21 |
| PL184356B1 (en) | 2002-10-31 |
| CN1215362A (en) | 1999-04-28 |
| AU718426B2 (en) | 2000-04-13 |
| JPH11513944A (en) | 1999-11-30 |
| ATE197567T1 (en) | 2000-12-15 |
| RU2142877C1 (en) | 1999-12-20 |
| WO1997038833A1 (en) | 1997-10-23 |
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| EEER | Examination request | ||
| MKLA | Lapsed |