WO2003000475A1

WO2003000475A1 - High performance composite material production

Info

Publication number: WO2003000475A1
Application number: PCT/NZ2002/000088
Authority: WO
Inventors: Deane William Smart; Michael Robert Reaburn; Donald John Jenkin; Sen Thin Chen; Xixian Deng, (Aka James); Patrick Lyle Anthony
Original assignee: Fletcher Building Products Limited
Priority date: 2001-05-09
Filing date: 2002-05-07
Publication date: 2003-01-03
Also published as: NZ511607A

Abstract

Composite material production where woodchips (optionally after free steam pretreatment) are subjected to thermohydrolysis in an MDF type digester at elevated temperature(s), the thus treated woodchips are, in a refiner, reduced mechanically to smaller accumulations of chemically modified fibres, the mechanically reduced materials are air dried, at temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, suitable thermoset curable binder material(s) are associated with the chemically modified fibres (before, during and/or after the drying), mattress accumulations of the chemically modified fibres and the associated binder material(s) are then prepared, the mattress accumulations are hot pressed to their pressed form(s) at elevated temperatures sufficient to at least initiate the thermoset curing of the binder material(s) and to at least initiate curing of the fractioned and/or hydrolysed hemicellulose and lignin, and the pressed form(s) are maintained still above ambient temperature for a period sufficient to allow curing or further curing of fractioned and/or hydrolysed hemicellulose and lignin of the chemically modified fibres.

Description

"High Performance Composite Material Production"

TECHNICAL FIELD

The present invention relates to the production of modified fibre and to the incorporation of the same fibre modification process into composite material production process to produce composite materials of enhanced character.

The present invention more particularly relates to processes for producing modified cellulosic fibres, processes for producing composite materials incorporating such fibres (eg; high performance with respect to dimensional stability and/or biodurability in the presence of moisture), methods for integrating the two aforementioned processes as one, products of either of the aforementioned processes and related methods, products and plant.

BACKGROUND ART

New Zealand Patent Specification 229080 of Convertech Group Limited discloses a process for preparing a hydrolysed lignocellulosic material which involves steam entrainment systems first to hydrolyse the lignocellulosic material (eg; wood chips) in conditions of elevated temperature and pressure conducive to hydrolysis at saturated steam conditions and thereafter, in a reduced pressure environment which gives rise to explosive disintegration (at least in part) of the hydrolysed matrix, to dry the entrained fibres in superheated steam conditions. The treated material in a process analogous to that of Canadian Patent 1213711 of K Shen is thereafter capable of being pressed into a solid without a need for any added adhesive and/or binder.

The Convertech conditions are more specifically disclosed in their New Zealand Patent Specification 248884. In NZ248854 there is disclosed a sequence of hydrolysis conditions, viz. (I) treatment at 24 bar (about 222°C), (ii) treatment at 35 bar (about 242°C) and (iii) at

35 bar with superheating (eg; 10 to 30°C superheating). Brief dwell times are disclosed. In NZ 248884 the drying is at a very much reduced pressure. Here there is reference to a pressure of the order of 2 bar with about 150°C superheated steam.

Shell Internationale Research Maatschappij BV New Zealand Patent Specification No. 231798 discloses a process for rendering the cellulosic fibres of solid wood forms more moisture resistant. Such a procedure involves subjecting a light wood or the equivalent source of lignocellulosic material to first a softening stage and thereafter a curing stage. The softening stage comprises exposing the discrete wooden masses to the action of an aqueous softening agent (eg; water and/or steam) at a temperature in the range of from 150°C to 220°C and at a pressure of at least the equilibrium vapour pressure of the softening agent at the operating temperature thereby at least partially disproportionating and hydrolysing the hemicellulose and lignin present in the cellulosic starting material. The curing stage comprises drying the product of the softening stage at a temperature in the range of from 100°C to 220 °C to yield a cross linked cellulosic masses each still in the general form of the initial wooden masses.

The Shell process of NZ 231798 has a characteristic in that if the starting material is green sections of wood ranging in length from 25 to 65 cm and with a width (diameter in the case of branches) ranging from 3 to 12 cm the resultant products correspond to those shapes.

Such treated sections can be used as the aggregate.

Shell NZ 231798 discloses also the use of the output material in a lamination process to provide (by aggregation using appropriate adhesive) larger aggregate material.

Also disclosed in Shell NZ 231798 is a prospect of incorporating into the aggregate, either during its formation or after, one or more monomers and, if necessary, one or more polymerisation catalysts. It is stated that the monomer is preferably incorporated during formation of the aggregate before the curing stage and that the aggregate is then subjected to conditions under which polymerisation of the monomer occurs. Particularly preferred monomers for inclusion in the aggregate are those which, when added during the process before the final curing stage, polymerise at the conditions prevailing in the curing stage either by themselves or by the addition of one or more polymerisation catalysts or temperature sensitive polymerisation starters. Examples disclosed are styrene and low molecular weight epoxy compounds.

Also stated in Shell NZ 231798 is a preference to conduct both the softening and curing stage under an inert or substantially inert atmosphere, ie; one from which all or a substantial portion of the air has been displaced.

New Zealand Patent Specification No.329324 of Plato Beheer B.V. takes the technology of Shell NZ 231798 further in that the heat input to the softening stage is stated as being as a result of heat exchange contact from an aqueous steam, the initial temperature of which is substantially equal to the operating temperature of the softening agent, eg; 150 to 220°C (more preferably 160 to 200 °C). Again however discreet end materials corresponding to the discreet input materials results from the operation of the process. Objects of the present invention include the provision of processes for treating lignocellulosic material (such as wood chips or other lignocellulosic furnish) which will generate as a preliminary product chemically modified fibres capable of subsequent reduction to individual fibres and heat curing or to provide in an overall process for providing a fibre including composite material fibres therein ensuring high performance of the composite material insofar as dimensional stability is concerned in the presence of moisture and/or biodurability as a result of either a property use of such chemically modified fibres or the integration of the processes aforesaid.

It is still a further and/or alternative object of the present invention to provide form forming methodologies (e.g. panels, mouldings, etc) utilising input lignocellulosic materials that will (if desired) allow plant such as that traditionally used for the manufacture of MDF (medium density fibre board) to be used to provide more stable form in the presence of moisture. See, for example, Sunds process detailed in Figure 1 from their MDF Update of 1997. Still other objects will be apparent from the disclosure herein. These include modified or adjusted plant (eg a modified or adjusted MDF plant) useful for performing part or all of a fibre modification process in accordance with the present invention and intermediate and end point products resulting from such other objects are to provide chemically modified fibres and/or high performance composite materials embodying such modified fibres having characteristics determinable by reference to the products of the process of the present invention.

SUMMARY OF THE INVENTION

In a first aspect the present invention consists in a process for producing a chemically modified fibrous material from masses of lignocellulosic material, said process comprising or including subjecting the masses (whether after an optional pretreatment or not) to an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify or lead to chemical modification, at least in part (eg by thermohydrolysis), the lignocellulosic material masses, mechanically reducing the thus treated masses to individual fibres and/or smaller accumulations of fibres, and drying the mechanically reduced materials. The drying may be above ambient temperature(s). Such temperature(s) [ideally less than 100°C] should not be sufficient high to cure the fibres.

The aqueous environment treatment is a softening procedure associated it is believed with at least partial thermal hydrolysis of some of the hydrolysable material thereof. As used herein the terms "thermal hydrolysis" and "thermohydrolysis" should be construed as meaning hydrolysis at elevated temperature. Such a procedure it is believed leads to a chemical breaking down of the hemicellulose and/or lignin of the input lignocellulosic masses sufficient to enable the resultant material once dried sufficiently to be heat cured to provide cellulose having fewer sites for bound water. The term "cured" therefore takes the appropriate meaning(s) .

The term "chemically modify" in respect of the precured fibres or "chemically modified fibres" prior to curing thereof means that complete or those still ensuing change(s) to the cellulosic fibres insofar as at least the associated hemicellulose(s) and/or lignin(s) thereof are (is) concerned, such change(s) meaning that subsequently when taken in non aqueous conditions to a sufficiently high temperature for curing to ensure, there is a reformation which results in fewer sites on the cellulose for binding moisture. Subsequently presented thereto. The term "fraction" or "fractioned" in respect of such changed takes any appropriate meaning.

The terms "stable" and "stability" as used herein refers to dimensional stability under fluctuating moisture or humidity conditions. Preferably said aqueous environment is a steam environment (i.e. rather than a water environment).

Preferably said aqueous environment is at a temperature in the range of from 165 to 200°C.

Preferably the elevated pressure(s) is such as to provide saturated steam conditions at said preferred elevated temperature(s).

Preferably said masses are subjected to thermohydrolysis conditions over a time period of from 3 to 20 minutes.

Preferably optional pretreatment occurs.

Preferably said pretreatment comprises or includes pre-steaming at ambient pressure conditions.

Preferably said pre-steaming is for a time less than 40 minutes and is at a temperature above ambient conditions but not exceeding 165 °C. Preferably said pre-steaming is to a temperature in the range from ambient conditions to 100° C (inclusive).

Preferably said masses of lignocellulosic material are woodchips. Other masses include saw dust, sawmill residues, flax, hemp, etc. Preferably said woodchips have a moisture content of from 12 to 180% (on a dry material basis, ie; OD).

Preferably said input masses are woodchips typically of a size no greater than about 25 x about 20 x about 5 mm.

Preferably said thermohydrolysis is performed in a continuous or batch digester into which the masses are introduced.

Preferably said mechanical reduction is performed at least in part in a steam environment.

Preferably said mechanical reduction is performed using a refiner, eg; a Sunds L44 defibrator. Preferably said mechanical reduction reduces the material to fibres of length from 0.5 to 3.0 mm.

Preferably said drying is conducted using a cocurrent airflow the input air being above 100°C and the output being below 100°C.

Preferably the drying is such that the chemically modified fibres preferably do not reach a temperature beyond that at which the fractioned hemicellulose and lignin chemically modified fibres prematurely cure e.g. not beyond 100°C.

Preferably the time under the drying conditions is less than 20 seconds and most preferably less than 10 seconds (eg; from 3 to 6 seconds).

Optionally we add in a wax (e.g. paraffin) with a 50 to 70°C melting range used in a rate of from 0 to 2% by weight (OD-ovendry basis) of the modified fibres (e.g. more preferably

MP of 50 to 55°C and a rate of 0.5 to 1% by weight OD of the modified dry fibres).

The wax may be incorporated molten or emulsified e.g. in an aqueous carrier.

In another aspect the present invention consists in the fibrous material produced by such a process. In still a further aspect the present invention consists in the use of the fibrous material as aforesaid in a downstream procedure whereby, in conjunction with appropriate binders and/or adhesives, a composite material is manufactured, eg; using hot pressing and hot curing. In still a further aspect the present invention consists in a method for providing composite material forms which method comprises or includes subjecting individual masses of lignocellulosic material (whether after an optional pretreatment or not) to an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify or lead to chemical modification of, at least in part, (eg by thermohydrolysis) the lignocellulosic material masses, thereby at least partially fractioning and at least partially hydrolysing the hemicellulose and lignin present, mechanically reducing the thus treated masses to individual fibres and/or smaller accumulations of fibres, drying the mechanically reduced materials at a temperature or temperatures insufficient to cure the (at least part) fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin,

(optionally) before and/or after the drying associating a suitable wax, before, during and/or after the drying associating suitable thermoset curable adhesive and/or binder material(s) with the individual fibres and/or smaller accumulations of fibres, preparing an accumulation of the individual fibres and/or smaller accumulations of fibres and the associated adhesive and/or binder material(s) for pressing, hot pressing to a form the thus accumulated material at an elevated temperature or temperatures above that or those of the drying step sufficient to (i) at least initiate the thermoset cure of the adhesive and/or binder material(s), and (ii) initiate the cure of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and holding the still hot pressed form [preferably in an environment low in oxygen] for a period where the material of the form is still above ambient temperature sufficient to allow the curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin.

Preferably said aqueous environment is a steam environment.

Preferably the elevated pressure(s) is such as to provide thermohydrolysis conditions at saturated steam conditions at said preferred elevated temperature(s). Preferably said subjection to at least some thermohydrolysis is over a time period of from 3 to 20 minutes.

Preferably optional pretreatment occurs.

Preferably said pre-steaming is for a time less than 40 minutes and is at a temperature above ambient conditions but not exceeding 165 °C.

Preferably said pre-steaming is to a temperature in the range from ambient conditions to 100°C (inclusive). Preferably said masses of lignocellulosic material are woodchips.

Preferably said woodchips have a moisture content of from 12 to 180% (on a dry material basis, ie; OD).

Preferably said input masses are woodchips typically of a size no greater than about 25 x about 20 x about 5 mm. Preferably said aqueous environment treatment and/or thermohydrolysis is performed in a batch or continuous digester into which the masses are introduced.

Preferably said mechanical reduction is performed using a refiner, eg; a defibrator such as the Sunds L44.

Preferably said mechanical reduction reduces the material to chemically modified fibres of length from 0.5 to 3mm.

Preferably said drying is conducted using a cocurrent airflow the input air being above 100°C and the output being below 100°C. Preferably the drying is such that the modified fibres and/or any of the adhesive/binder system preferably do not reach a temperature beyond 100°C.

Preferably the adhesive and/or binder material(s) is added prior to or subsequent to the drying.

Preferably said adhesive and/or binder material(s) is added in a blow line which conveys the individual chemically modified fibres and/or smaller accumulations of chemically modified fibres to the dryer. Preferably the adhesive and/or binder material(s) is selected from urea formaldehyde, melamine urea formaldehyde, melamine formaldehyde and phenol formaldehyde and isocyanate systems or any combination thereof.

Preferably said preparing of an accumulation of the fibres is the preparation of a so called "mattress" form to be subsequently hot pressed.

Preferably said hot pressing is at a temperature greater than 105 °C.

Preferably said hot pressing is in a single daylight, multi daylight (ie; multi panel forming) or continuous hot press.

Preferably the adhesive system comprises on a weight to weight basis from 5 to 30 % (more preferably 5 to 25%) of the dry modified fibre weight.

A particularly preferred adhesive/binder system is of phenol formaldehyde and/or phenol urea formaldehyde (available from Dynea NZ Limited) and which is preferably used in the range of from 8 to 18% weight of modified dry fibres.

Optionally we add in a wax (e.g. paraffin) with a 50 to 70°C melting range used in a rate of from 0 to 2% by weight (OD) of the chemically modified fibres (e.g. more preferably MP of 50 to 55 °C and a rate of 0.5 to 1% by weight of the chemically modified fibres). Such addition can be both before or after or both the drying step.

The wax may be incorporated molten or emulsified e.g. in an aqueous carrier.

Preferably the pressed form from the hot press without any substantial cooling (preferably none) enters or is in a curing zone to reduce temperature loss [and preferably also access of oxygen] (eg; 200°C to ambient for up to 7 days).

Preferably in any such curing zone there is preferably insulation about the form.

Preferably (whether by gas flushing or evacuation or appropriate contact with a surrounding medium) oxygen access to any part of any panel or other form in the cure zone is reduced.

Preferably the cure zone input temperature is from 75°C to 180°C and after a cure zone hold period of from at least 1 hour to 7 days the temperature is still above 55°C.

Preferred for pinus radiata is from 97°C to 108°C for 24 hours.

In yet a further aspect the present invention consists in a method of providing a composite material forms which comprises or includes associating dried mechanically reduced individual chemically modified fibres and/or smaller accumulations of chemically modified fibres that have been prepared by a process as previously defined for producing a fibrous material from masses of lignocellulosic material with an appropriate thermoset curable adhesive and/or binder material(s), preparing an accumulation of such chemically modified fibres with the associated adhesive and/or binder material(s) for pressing, hot pressing the thus accumulated material to the form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s) and to encourage at least the initiation of the cure of the fractioned hemicellulose and lignin of such chemically modified fibres, and holding the still hot pressed form or forms in a cure zone [preferably in an environment low in oxygen] for a period where the material of the form(s) is still above ambient temperature sufficient to allow curing or further curing of the chemically modified fibres.

Preferably the cure zone input temperature is from 75°C to 180°C and still in that range after a cure zone hold period of from at least 1 hour.

Preferred for pinus radiata is from 97 °C to 108°C for 24 hours. Preferably the temperature is still above 55°C at 7 days.

Preferably said preparing of an accumulation of the chemically modified fibres is the preparation of a so called "mattress" form to be subsequently hot pressed (whether initially in discrete mattresses or as a continuous mattress).

Preferably the adhesive and/or binder material(s) is selected from urea formaldehyde, melamine urea formaldehyde, melamine formaldehyde and phenol formaldehyde and isocyanate systems or any combination thereof.

Preferably said hot pressing is at a temperature greater than 105°C. Preferably said hot pressing is in a multi daylight (ie; multi panel forming) or continuous hot press. Preferably the pressed form from the hot press without any substantial cooling

(preferably none) enters or is in a curing zone to reduce both temperature loss [and preferably access of oxygen]. Preferably in any such curing zone there is preferably insulation provided for the curing form or forms.

Preferably (whether by gas flushing or evacuation or appropriate contact with a surrounding medium) oxygen access to any part of any panel or other form in the curing zone is reduced.

In still a further aspect the present invention consists in a composite material provided by any of the methods previously defined.

In still a further aspect the present invention consists in a panel form prepared by a process as previously described. In still a further aspect the present invention consists in a method for providing composite material which comprises or includes subjecting individual masses of woodchips (preferably after free steam pretreatment prior to digester entry) to an aqueous environment in a (batch or continuous) digester at elevated temperature(s) in the range 165 °C to 200 °C to modify or lead to chemical modification of the hemicellulose and/or lignin or fibres thereof ("the chemically modified fibres"), mechanically reducing the thus treated masses thereof in a refiner to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, air drying the mechanically reduced materials, at temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, before, during and/or after the air drying associating suitable thermoset curable adhesive and/or binder material(s) with the chemically modified fibres, preparing mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), hot pressing the mattress accumulations to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset curing of the adhesive and/or binder material(s) and to at least initiate curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and

(preferably in an environment low in oxygen) maintaining the pressed form(s) for a period where the material of the form is still above ambient temperature sufficient to allow curing or further curing of fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin of the chemically modified fibres. The maintaining step may be in an environment low in ambient oxygen for (all or some of) each form.

Preferably said form(s) is(are) that of a panel or panels.

Preferably the operating conditions are any one or more of those previously disclosed. In yet a further aspect the present invention consists in an MDF plant at least in part modified to perform any of the processes of the present invention.

In yet a further aspect the present invention consists in apparatus for performing a method for providing composite material (which method comprises or includes subjecting individual masses of woodchips to an aqueous environment in a digester at elevated temperature(s) in the range 165 ° C to 200 ° C, mechanically reducing the at least partially modified masses in a refiner to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, air drying the mechanically reduced materials, before, during and/or after the air drying associating suitable thermoset curable adhesive and/or binder material(s) with the fibres, preparing mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), hot pressing the mattress accumulations to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s), and to at least initiate curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and maintaining the pressed form(s) in an environment (preferably low in ambient oxygen) for a period where the material of the form is above (or preferably still above) ambient temperature sufficient to allow curing or further curing of the chemically modified fibre system in the material, said apparatus comprising or including a (batch or continuous) digester for receiving and subjecting individual masses of woodchips to an aqueous environment at elevated temperature(s) in the range 165 °C to 200°C, a refiner (e.g. defibrator) to receive the solids stream from the digester for mechanically reducing the at least partially thermohydrolysed masses to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, a drier for air drying the mechanically reduced materials at temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, mixing apparatus or mixing means for associating suitable thermoset curable adhesive and/or binder material(s) with the chemically modified fibres before, during and/or after the drying, mattress forming apparatus for preparing a mattress or mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), pressing apparatus for hot pressing the mattress or mattress accumulations or divisions thereof to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s) and at least sufficient to initiate the cure of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and a curing zone whereby the still hot pressed forms can be maintained in an environment (preferably low in oxygen) for a period where the material of the form is still above ambient temperature sufficient to allow curing or further curing of the chemically modified fibres.

Preferably said apparatus includes apparatus to heat and moisten the woodchips prior to digester entry using live steam.

Preferably said aqueous environment is substantially steam and preferably the thermohydrolysis is performed at substantially saturated steam conditions.

Preferably a blow-line transports the fibres to the drier from the refiner (e.g. a defibrator).

An example of a dryer is a dryer with a SKKV furnace or a FLAKT drier.

Preferably the mixing apparatus comprises the addition of the adhesive and/or binder material(s) into the process in such blow-line, (ie; prior to the drier) preferably using input nozzles.

In addition or alternatively there can be addition of adhesive and/or binder materials into the solids stream after the drier, eg; using a mechanical blender.

Preferably a pre-press apparatus is provided for pre-pressing and thus degassing the formed mattresses for hot pressing.

Preferably said hot press is any one of a single opening hot press, a multi daylight hot press (ie; can provide pressing one mattress above the other without adhesion one to the other) or continuous. Preferably the curing zone is zone where the forms can be congregated. In yet another aspect the present invention consists in apparatus for providing a composite material, said apparatus comprising or including apparatus or means to receive material of a chemically modified fibrous nature prepared by a process whereby masses of lignocellulosic material have been subjected to

(i) treatment in an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify by thermohydrolysis the lignocellsic material masses, (ii) mechanical reduction of the resultant masses to individual chemically modified and/or smaller accumulations of chemically modified fibres, and

(iii) drying to some extent at a temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, apparatus or means for mixing such fibrous material with thermoset adhesive and/or binder material(s), apparatus or means for providing a mattress or mattresses of such mixed materials, hot press apparatus to hot press the mattress or mattresses, and a curing zone whereby the (preferably still hot) pressed forms can be maintained in an environment (preferably low in oxygen) for a period where the material of the form is (preferably still) above ambient temperature sufficient to allow curing or further curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin.

Preferably a pre-press apparatus is provided for pre-pressing the formed mattresses for mattress feed to the hot press. This preferably degasses the material.

Preferably said hot press is any one of a single opening hot press, a multi daylight hot press (ie; can provide pressing one mattress above the other without adhesion one to the other) or continuous.

Preferably the means providing the curing zone allows forms to be congregated and preferably there is means provided or techniques can be used (whether with or without gas flushing and/or evacuation) whereby at least in part said environment low in oxygen.

Preferably said curing zone is thermally insulated (optionally where necessary with optional heat exchange).

Preferably the curing zone input temperature is from 75°C to 180°C and after a curing zone hold period of from at least 1 hour.

Preferably the temperature is still above 55°C at 7 days. In yet a further aspect the present invention consists in panels formed from a thermoset of wood fibres that have been subject to any one of the processes of the present invention and/or operatively using apparatus as hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred forms of the present invention will now be described with reference to the accompanying drawings in which;

Figure 1 is prior art MDF apparatus of a Sunds MDF process flowline,

Figure 2 is Figure 19.5 from MODERN PARTICLE BOARD and DRY-PROCESS FIBREBOARD MANUFACTURING by Thomas M Maloney which shows a flow diagram of a European MDF plant (Wiecke 1990).

Figure 3 shows a process in accordance with the present invention for providing a composite material in a board form,

Figure 4 is a process for producing substantially dry chemically modified fibres or chemically modified fibre accumulations for subsequent use or useful for subsequent use to provide a composite material including such chemically modified fibres or chemically modified fibre accumulations or both,

Figure 5 is a more detailed flow diagram showing a full process to (by way of example) a board form (eg; useful as exterior furniture grade panels or internal and/or external wall panels [whether to provide horizontal, vertical or other surfaces] and/or as exterior cladding) that best makes the use of converted plant from an MDF manufacturing plant of a kind typically available and which provides the option of providing a process from the initial input lignocellulosic material masses fully through to the cured forms (eg; panels or other moulded forms) or to chemically modified fibres or chemically modified fibre accumulations in their dry post aqueous treatment state which can subsequently be used by third parties (if desired) or by the same plant operator as a midway input material, and

Figure 6 is a flow diagram commencing as in Figure 5 but showing how, if desired, the air dried chemically modified fibres can be subjected to heating and a fibre curing process (for example in an appropriate oven) to thereby provide already cured fibres or fibre accumulations that have reduced water binding sites for subsequently presenting moisture and how, if desired, such product can be used at a same plant or different plants, figure 6 also giving examples of three (A, B and C) of many options available for the usage of such cured chemically modified fibres, option A showing how as a variation of the downstream procedure at the top of bottom of Figure 5 and adhesive and/or bind it systems with appropriate hot pressing or other arrangements (no longer essential for curing the chemically modified fibres) can be used to form a composite product such as automobile doors or other components, showing also how such cured chemically modified fibres can be combined with appropriate cementitious materials to form by way of example more stable fibre reinforced cementitious panels or board, and showing how if desired such cured chemically modified fibres can be combined with gypsum and any other components that might be necessary to form (by way of example) a more stable gypsum fibre board,

Figure 7 to be read in conjunction with the examples and tables hereafter, shows the effect varying the thermo hydrolysis time, the pressure of the hydrolysis zone (and thus the temperature of substantially saturated steam condition(s) of the thermo hydrolysis zone) and cure zone at 20 °C for pinus radiata input as described hereafter when rated by a 24 hour thickness swell of panels of the form hereafter described, Figure 8 similar to Figure 7 shows such effects on the same materials that the same parameters (but this time at a temperature of 105°C in the curing zone) has on the 24 hour thickness swell of the same panel types,

Figure 9 in a manner similar to Figures 7 and 8 show for a higher temperature (180°C in the curing zone rather than the 105°C of Figure 8) similar results expressed in 24 hours thickness swell for the same panel types.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described with respect to panel or board forms having improved stability with respect to dimension in the presence of moisture than would be the case were the same adhesive and/or binder system utilised with raw wood fibre such as that traditionally used without high cost acetylation in, for example, an MDF plant. It is also believed to provide better biodurality (e.g. against fungal and/or insect challenge) because of its lower equilibrium moisture content. Whilst reference is made to MDF, of course the system of the present invention lends itself to other panel or form forming technologies. In a preferred form of the present invention the apparatus is deployed so that, preferably with little in the way of expensive change, plant available for general MDF production can be retrofitted or reused for the production of moisture stabilised forms (particularly panels and/or boards - "boards" being used herein as being inclusive of panel forms and irrespective of whether or not of constant thickness).

In the preferred arrangement as shown in Figure 3 there is shown the use of a refiner such as Sunds Defibrator L44. The output from this refiner is shown as going to two possibilities. One is to the production of a dry fibre (eg; less than or equal to about 8% moisture content OD) that can be dealt with as a commodity (eg for preparing fibrocement products moulded packaging components, moulded automobile components etc) or as a retained product which might subsequently be reintroduced into the process (or a modification of the process if the fibres are already heat cured) should that at any stage prove desirable which may be the case where, for example, there is a desire to provide preventative maintenance to upstream plant components yet still run downstream plant components.

Many forms of lignocellulosic material can be provided as the feed material and each will have desired perimeters of hydrolysis for best usage downstream. Options of sources of such materials include woodchips from tree stems, branch of trees, mill wastes (whether a sawmill or otherwise eg. sawdust) and the species of tree need not be restricted to soft wood conifers nor to conifers at all. By way of example of non conifer species that might be utilised wasted lignocellulosic materials from for example rubber plantations in for example Malaysia if broken down to appropriate masses for treatment could provide an excellent furnish. Other harder wood species can be utilised. In the preferred form of the present invention the masses referred to are preferably those above woodchips but could by way of example include sawdust or wood shavings or strands such as might be used in particle board or oriented strand board. In each of these examples the degree of mechanical reduction of the chemically modified fibres will vary. However there is nothing to prevent the mechanical reduction of masses of lignocellulosic materials to themselves favour the preparation of strands of the already chemically modified fibre masses to a form suitable for oriented strand board. There is also no reason why sawdust or smaller particles can not be offered in as furnish in conjunction with larger masses which will require mechanical reduction.

In the preferred form of the present invention the feedstock materials is a source of lignocellulosic masses preferably in the form of woodchips. Preferably such chips are from a conifer. Most preferably such a conifer is a soft wood conifer such as that typified by pinus radiata. Without being restrictive however the wood source extends at least to other choices of softwood pine (eg; Loblolly et al.) and to firs (eg. Douglas Fir). Preferably chips of a conifer up to a maximum dimension of about 50 mm and preferably about 25mm only are used as the source lignocellulosic material. The input chips are most preferably of a kind generally of a dimension of about 25 x 20 x 5 mm.

Preferably the moisture content of the input chips ranges from 12 to 180% OD. Preferably to bring the temperature of the chips up (eg; 75 °C to 95 °C) to allow an easier control of thermo hydrolysis in the digester at higher temperatures still an optional pre- steaming step is provided whereby in an appropriate hopper or bin live steam at ambient pressures is played through the accumulated chips for a period of less than 40 minutes thereby raising the temperature of the chips above ambient but not above 100°C. Upon entry into the digester (preferably a gravity feed or a screw feed) at an infeed temperature of 75 °C to 95 °C preferably a higher temperature environment of 165° to 200° is provided. This is a steam environment to thermohydrolyse the preheated chips in about saturated steam conditions for a period of 3 to 20 minutes to fraction and/or hydrolyse the hemicelluloses and/or lignins. A typical MDF type digester (modified to higher pressure and residence time if required) can be used as the digester.

From the digester the solids stream of at least partly thermohydrolysed masses is then fed to a refiner such as a defibrator typically used in an MDF plant, eg; Sunds L44 defibrator. Here the masses are mechanically reduced to individual or small accumulations of fibre relative to the greater masses of any such accumulations provided in the input material.

Thereafter the material preferably is past by a blowline into a continuous cocurrent suspension air drier where over a period of from 3 to 6 seconds the fibrous material is lowered in temperature significantly from an input temperature which may be up tp 200 °C (eg; about

180°C). A typical output temperature of such fibres or fibre accumulations is less than 100°C and may be, for example, about 65 °C.

As can be seen that can be the output product if such treated chemically modified fibres are required. They can be led off to a fibre storage system or for blending with other fibres (eg; unmodified or acetylated).

In the fully carried through process to a composite board, preferably thermoset adhesive binder materials (such as those previously exemplified) are added to the chemically modified fibres in the blowline or a blender and/or subsequent to the air drier (in a blender). At this stage other functional inclusions (eg; fungicides and insecticides can be added). Preferably a wax to act as a sizing agent is added (preferably as a melt or as an aqueous suspension or other suspension).

Thereafter the blended material is formed as a mattress form to a much greater thickness than that required in the resultant composite board. That mattress form is then subjected to pre-pressing to degas the material prior to passing into a hot press which, for example, for already discreet mattress forms that have been subjected to pre-pressing is preferably of the multi daylight type that can receive accumulations thereof one above the other (but preferably spaced apart for pressing) at a temperature greater than ambient and (preferably a temperature of from 135 °C to 210°C) which is sufficiently hot and for sufficiently long to ensure at least the commencement of the curing of the fractioned hemicelluloses and/or fractioned lignins and to at least initiate the thermoset cure the adhesive/binder system.

After sufficient hot pressing the panel like forms, without any substantial cooling, are then in, taken to, positioned in or pass through means providing an insulated curing zone environment.

The curing zone preferably excludes some if not all ambient gaseous oxygen.

If necessary a low pressure can be drawn about the forms to remove any gases being generated and/or to maintain a oxygen low status against ambient air infusion.

Ideally however the curing zone is such that the temperature regime previously described is maintained for a period of up to 7 days (but could be longer). At least 1 hour at or near the pressing temperature is desirable to allow the appropriate curing.

A corresponding system is preferably utilised optionally with pre-pressing for any recommencement of the composite board forming procedure whether carried out at the same plant or by a customer of the treated fibre feedstock.

Examples

Radiata pine green chip typically used in an MDF plant was used as raw material. It originated from Kaingaroa Forest. The moisture content was about 134% (OD basis) with screen size distribution as in Table 1.

Table 1

The chip was thermohydrolysed in conditions shown on the bottom axis of each of the plots of Figures 7, 8 and 9.

The masses treated by each set of conditions shown in Figures 7, 8 and 9 were passed through the refiner from whence the individual or smaller accumulations of chemically modified fibres pass into a blowline where a phenol formaldehyde resin and a wax emulsion were introduced to the chemically modified fibres into the blowline.

The resin loading was 10% w/w and wax 0.5% w/w (solid content based on dry fibre).

The resin/wax associated chemically modified fibres were then dried through a drier with an inlet temperature of 150°C and outlet temperature about 100°C.

The resinated fibres were formed into a mat and hot pressed into a 13.5 mm panel.

The panels were pressed at 175°C using a press cycle time of 220 seconds. The density of the panel was 750 kg/m3.

After pressing, the panel was immediately stored for 24 hours at the temperatures of 20°C, 105°C and 180°C. Such curing condition(s) were with or without exposure to substantial quantities of ambient oxygen. Preferably low in oxygen at the higher temperatures to avoid unwanted pyrolysis complications.

The performance of such panels is shown in each of Figures 7, 8 and 9.

With this process and technology, the dimensional stability of the panels was improved significantly over conventional MDF panels using the same resin and wax system (control samples). Typical improvement was between 70% to 75% reduction in the 2 hours 70°C thickness swell and 24 hours 20°C thickness swell respectively, and EMC of the panel was half that of the control at 25°C and 85% RH.

Table 2 shows enhanced biodurability arising from the use of the process with Pinus

Radiata. Table 2

Table 3 shows thickness swell of MDF lab panels that were prepared using different wood species at the preparative conditions expressed.

Table 3:

Optimisation of a hardwood species (such as Aspen) will involve digester temperatures below (eg; about 10°C less) those for softwood species (eg; the conifers referred to in Table 3).

Claims

CLAIMS:

1. A process for producing a chemically modified fibrous material from masses of lignocellulosic material, said process comprising or including subjecting the masses (whether after an optional pretreatment or not) to an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify or lead to chemical modification by thermalhydrolysis of, at least in part, the lignocellulosic material masses, mechanically reducing the thus treated masses to individual fibres and/or smaller accumulations of fibres, and drying the mechanically reduced materials.

2. A process of claim 1 where the drying is at above ambient temperature(s).

3. A process of claim 1 or 2 wherein said drying is at a temperature or temperatures not be sufficiently high to cure the fibres.

4. A process of any one of claims 1 to 3 wherein said aqueous environment is primarily a steam environment (i.e. rather than primarily a liquid water environment).

5. A process of claim 4 wherein said aqueous environment is at a temperature in the range offrom l65 to 200°C.

6. A process of claim 4 or 5 wherein the elevated pressure(s) is such as to provide saturated steam conditions at said preferred elevated temperature(s).

7. A process of any one of the preceding claims wherein said masses are subjected to thermohydrolysis conditions over a time period of from 3 to 20 minutes.

8. A process of any one of the preceding claims wherein optional pretreatment occurs.

9. A process of claim 8 wherein said pretreatment comprises or includes pre-steaming at ambient pressure conditions.

10. A process of claim 8 wherein said optional pretreatment is pre-steaming for a time less than 40 minutes at a temperature or temperatures above ambient conditions but not exceeding

165°C.

11. A process of claim 10 wherein said pre-steaming is to a temperature in the range from ambient conditions to 100° C (inclusive).

12. A process of any one of the preceding claims wherein said masses of lignocellulosic material are woodchips.

13. A process of claim 12 wherein said woodchips have a moisture content of from 12 to

180% (on a dry material basis, ie; OD).

14. A process of claim 12 or 13 wherein said input masses are woodchips typically of a size no greater than about 25 x about 20 x about 5 mm.

15. A process of any one of the preceding claims wherein said thermohydrolysis is performed in a continuous or batch digester into which the masses are introduced.

16. A process of any one of the preceding claims wherein said mechanical reduction is performed at least in part in a steam environment.

17. A process of claim 16 wherein said mechanical reduction is performed using a refiner.

18. A process of any one of the preceding claims wherein said mechanical reduction reduces the material to fibres of length from 0.5 to 3.0 mm.

19. A process of any one of the preceding claims wherein said drying is conducted using a cocurrent airflow the input air being above 100°C and the output being below 100°C.

20. A process of any one of the preceding claims wherein the drying is such that the chemically modified fibres do not reach a temperature beyond 100°C at which the fractioned hemicellulose and lignin chemically modified fibres prematurely cure.

21. A process of claim 19 or 20 wherein the time under the drying conditions is less than

20 seconds.

22. A process of any one of the preceding claims wherein a wax with a 50 to 70°C melting range is used as a sizing agent at a rate of from 0 to 2% by weight (OD-ovendry basis) of the modified fibres.

23. A process of claim 22 wherein the wax is a paraffin wax with a 50 to 55°C melting range used at a rate of 0.5 to 1% by weight OD of the modified dry fibres).

24. A process of claim 22 or 23 wherein the wax may be incorporated molten or emulsified (e.g. in an aqueous carrier).

25. The fibrous material produced by a process of any one of the preceding claims.

26. The use of the fibrous material of claim 25 in a downstream procedure whereby, in conjunction with appropriate binders and/or adhesives, a composite material is manufactured using hot pressing and hot curing.

27. A method for providing composite material forms which method comprises or includes subjecting individual masses of lignocellulosic material (whether after an optional pretreatment or not) to an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify or lead to chemical modification by thermohydrolysis of, at least in part, the lignocellulosic material masses, thereby at least partially fractioning and at least partially hydrolysing the hemicellulose and lignin present, mechanically reducing the thus treated masses to individual fibres and/or smaller accumulations of fibres, drying the mechanically reduced materials at a temperature or temperatures insufficient to cure the (at least part) fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin,

(optionally) before and/or after the drying associating a suitable wax as a sizing agent with the individual and/or smaller accumulations of fibres, before, during and/or after the drying (and whether before, during and/or after any sizing agent association) associating suitable thermoset curable adhesive and/or binder material(s) with the (sized and/or unsized) individual fibres and/or smaller accumulations of fibres, preparing an accumulation of the individual fibres and/or smaller accumulations of fibres (sized and/or unsized) and the associated adhesive and/or binder material(s) for pressing, hot pressing to a form the thus accumulated material at an elevated temperature or temperatures above that or those of the drying step sufficient to (i) at least initiate the thermoset cure of the adhesive and/or binder material(s), and

(ii) initiate the cure of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and holding the still hot pressed form for a period where the material of the form is still above ambient temperature sufficient to allow the curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin.

28. A method of claim 27 wherein said aqueous environment is a steam environment.

29. A method of claim 28 wherein said aqueous environment is at a temperature in the range of from 165 to 200 °C.

30. A method of claim 28 or 29 wherein the elevated pressure(s) is such as to provide thermohydrolysis conditions at saturated steam conditions at said preferred elevated temperature(s).

31. A method of any one of claims 27 to 30 wherein said subjection to at least some thermohydrolysis is over a time period of from 3 to 20 minutes.

32. A method of any one of claims 27 to 31 wherein said holding is carried out in such a way the material of the form is an environment low in oxygen.

33. A method of any one of claims 27 to 32 wherein an optional pretreatment occurs which comprises or includes pre-steaming at ambient pressure conditions.

34. A method of claim 33 wherein said pre-steaming is for a time less than 40 minutes and is at a temperature above ambient conditions but not exceeding 165 °C.

35. A method of claim 33 wherein said pre-steaming is to a temperature in the range from ambient conditions to 100°C (inclusive).

36. A method of any one of claims 27 to 35 wherein said masses of lignocellulosic material are woodchips.

37. A method of claim 36 wherein said woodchips have a moisture content of from 12 to 180%) (on a dry material basis, ie; OD).

38. A method of claim 36 or 37 wherein said input masses are woodchips typically of a size no greater than about 25 x about 20 x about 5 mm.

39. A method of any one of claims 27 to 38 wherein said aqueous environment treatment and/or thermohydrolysis is performed in a batch or continuous digester into which the masses are introduced.

40. A method of any one of claims 27 to 39 wherein said mechanical reduction is performed at least in part in a steam environment.

41. A method of any one of claims 27 to 40 wherein said mechanical reduction is performed using a refiner.

42. A method of any one of claims 27 to 41 wherein said mechanical reduction reduces the material to chemically modified fibres of length from 0.5 to 3mm.

43. A method of any one of claims 27 to 42 wherein said drying is conducted using a cocurrent airflow the input air being above 100°C and the output being below 100°C.

44. A method of claim 43 wherein the drying is such that the modified fibres and/or any of the adhesive/binder system preferably do not reach a temperature beyond 100°C.

45. A method of any one of claims 27 to 44 wherein the time under the drying conditions is less than 20 seconds and most preferably less than 10 seconds (eg; from 3 to 6 seconds).

46. A method of any one of claims 27 to 45 wherein the adhesive and/or binder material(s) is added prior to or subsequent to the drying.

47. A method of any one of claims 27 to 46 wherein said adhesive and/or binder material(s) is added in a blow line which conveys the individual chemically modified fibres and/or smaller accumulations of chemically modified fibres to the dryer.

48. A method of any one of claims 27 to 47 wherein the adhesive and/or binder material(s) is selected from urea formaldehyde, melamine urea formaldehyde, melamine formaldehyde and phenol formaldehyde and isocyanate systems or any combination thereof.

49. A method of any one of claims 27 to 48 wherein said preparing of an accumulation of the fibres is the preparation of a so called "mattress" form to be subsequently hot pressed.

50. A method of any one of claims 27 to 49 wherein said hot pressing is at a temperature greater than 105 °C.

51. A method of any one of claims 27 to 50 wherein said hot pressing is in a single daylight, multi daylight (ie; multi panel forming) or continuous hot press.

52. A method of any one of claims 27 to 51 wherein the adhesive and/or binder material(s) comprises on a weight to weight basis from 5 to 30 % of the dry modified fibre weight.

53. A method of any one of claims 27 to 52 wherein the adhesive and/or binder materials is of phenol formaldehyde used in the range of from about 8 to about 18% weight of modified dry fibres.

54. A method of any one of claims 27 to 53 wherein a wax with a 50 to 70°C melting range is used as a sizing agent in a rate of from 0 to 2% by weight (OD) of the chemically modified fibres before, during and/or after the drying step.

55. A method of claim 54 wherein the wax is incorporated molten or emulsified.

56. A method of any one of claims 27 to 55 wherein the pressed form from the hot press, without any substantial cooling, enters or is in a curing zone to reduce or reduce the rate of temperature loss to ambient.

57. A method of claim 56 wherein in any such curing zone there is insulation about the form.

58. A method of claim 56 or 57 wherein, whether by gas flushing or evacuation or appropriate contact with a surrounding medium oxygen access to any part of any pressed form in the curing zone is reduced.

59. A method of any one of claims 55 to 58 wherein the curing zone input temperature is from 75°C to 180°C and after a curing zone hold period of from at least 1 hour to 7 days the temperature is still above 55°C.

60. A method of providing a composite material forms which comprises or includes associating dried mechanically reduced individual chemically modified fibres and/or smaller accumulations of chemically modified fibres that have been prepared by a process as previously defined for producing a fibrous material from masses of lignocellulosic material with an appropriate thermoset curable adhesive and/or binder material(s), preparing an accumulation of such chemically modified fibres with the associated adhesive and/or binder material(s) for pressing, hot pressing the thus accumulated material to the form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s) and to encourage at least the initiation of the cure of the fractioned hemicellulose and lignin of such chemically modified fibres, and holding the still hot pressed form or forms in a cure zone for a period where the material of the form(s) is still above ambient temperature sufficient to allow curing or further curing of the chemically modified fibres.

61. A method of claim 60 wherein the curing zone input temperature is from 75°C to 180°C and after a curing zone hold period of from at least 1 hour is still in the range of from 75 °C to 180°C.

62. A method of claim 61 wherein the curing zone temperature is still above 55°C at 7 days.

63. A method of any one of claims 60 to 62 wherein said preparing of an accumulation of the chemically modified fibres is the preparation of a so called "mattress" form to be subsequently hot pressed (whether initially in discrete mattresses or as a continuous mattress).

64. A method of any one of claims 60 to 63 wherein the adhesive and/or binder material(s)

("the adhesive system") is selected from urea formaldehyde, melamine urea formaldehyde, melamine formaldehyde and phenol formaldehyde and isocyanate systems or any combination thereof.

65. A method of claim 64 wherein the adhesive system comprises on a weight to weight basis from 5 to 30 % of the dry modified fibre weight.

66. A method of claim 64 wherein a adhesive system is of phenol formaldehyde in the range of from 8 to 18%) weight of modified dry fibres.

67. A method of any one of claims 60 to 66 wherein said hot pressing is at a temperature greater than 105 °C.

68. A method of claim 67 wherein said hot pressing is in a multi daylight (ie; multi panel forming) or continuous hot press.

69. A method of any one of claims 60 to 68 wherein the pressed form from the hot press without any substantial cooling enters or is in a curing zone to reduce both temperature loss and access of oxygen.

70. A method of claim 69 wherein said curing zone has insulation provided for the curing form or forms.

71. A method of claim 69 or 70 wherein whether by gas flushing or evacuation or appropriate contact with a surrounding medium oxygen access to any part of any panel or other form in the curing zone is reduced.

72. A composite material provided by a method claimed in any one of claims 27 to 71.

73. A panel form prepared by a method of any one of claims 27 to 71.

74. A method for providing composite material which comprises or includes subjecting individual masses of woodchips (optionally after free steam pretreatment prior to digester entry) to an aqueous environment in a (batch or continuous) digester at elevated temperature(s) in the range 165 °C to 200 °C to modify or lead to chemical modification of the hemicellulose and/or lignin or fibres thereof ("the chemically modified fibres"), mechanically reducing the thus treated masses thereof in a refiner to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, air drying the mechanically reduced materials, at temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, before, during and/or after the air drying associating suitable thermoset curable adhesive and/or binder material(s) with the chemically modified fibres, preparing mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), hot pressing the mattress accumulations to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset curing of the adhesive and/or binder material(s) and to at least initiate curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and maintaining the pressed form(s) for a period where the material of the form is still above ambient temperature sufficient to allow curing or further curing of fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin of the chemically modified fibres.

75. A method of claim 74 wherein said form(s) is(are) that of a panel or panels.

76. A method of claim 74 or 75 which is also a method of any one of claims 27 to 71.

77. An MDF plant at least in part modified or adjusted to perform a process of any one of claims 1 to 24 or a method of any one of claims 27 to 71 and 74 to 76.

78. Apparatus for performing a method for providing composite material (which method comprises or includes subjecting individual masses of woodchips to an aqueous environment in a digester at elevated temperature(s) in the range 165 °C to 200 °C, mechanically reducing the at least partially modified masses in a refiner to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, air drying the mechanically reduced materials, before, during and/or after the air drying associating suitable thermoset curable adhesive and/or binder material(s) with the fibres, preparing mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), hot pressing the mattress accumulations to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s), and to at least initiate curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and maintaining the pressed form(s) in an environment (preferably low in ambient oxygen) for a period where the material of the form is above (or preferably still above) ambient temperature sufficient to allow curing or further curing of the chemically modified fibre system in the material, said apparatus comprising or including a (batch or continuous) digester for receiving and subjecting individual masses of woodchips to an aqueous environment at elevated temperature(s) in the range 165°C to

200°C, a refiner (e.g. defibrator) to receive the solids stream from the digester for mechanically reducing the at least partially thermohydrolysed masses to individual chemically modified fibres and/or smaller accumulations of chemically modified fibres, a drier for air drying the mechanically reduced materials at temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, mixing apparatus or mixing means for associating suitable thermoset curable adhesive and/or binder material(s) with the chemically modified fibres before, during and/or after the drying, mattress forming apparatus for preparing a mattress or mattress accumulations of the chemically modified fibres and the associated adhesive and/or binder material(s), pressing apparatus for hot pressing the mattress or mattress accumulations or divisions thereof to their pressed form(s) at an elevated temperature sufficient to at least initiate the thermoset cure of the adhesive and/or binder material(s) and at least sufficient to initiate the cure of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, and a curing zone whereby the still hot pressed forms can be maintained in an environment for a period where the material of the form is still above ambient temperature sufficient to allow curing or further curing of the chemically modified fibres.

79. Apparatus of claim 78 wherein it includes apparatus to heat and moisten the woodchips prior to digester entry using live steam.

80. Apparatus of claim 78 or 79 adapted whereby said aqueous environment is substantially steam and the thermohydrolysis is performed at substantially saturated steam conditions.

81. Apparatus of any one of claims 78 to 80 wherein a blow-line transports the fibres to the drier from the refiner (e.g. a defibrator).

82. Apparatus of any one of claims 78 to 81 wherein the dryer is a dryer with a SKKN furnace or a FLAKT drier.

83. Apparatus of claim 81 wherein the mixing apparatus enables the addition of the adhesive and/or binder material(s) into the process in such blow-line.

84. Apparatus of any one of claims 78 to 83 wherein there is means enabling an addition of adhesive and/or binder materials into the solids stream after the drier.

85. Apparatus of any one of claims 78 to 84 wherein a pre-press apparatus is provided for pre-pressing and thus degassing the formed mattresses for hot pressing.

86. Apparatus of any one of claims 78 to 84 wherein said hot press is any one of a single opening hot press, a multi daylight hot press (ie; can provide pressing one mattress above the other without adhesion one to the other) or continuous.

87. Apparatus of any one of claims 78 to 86 wherein the curing zone is zone where the forms can be congregated to reduce oxygen access and to reduce temperature loss.

88. Apparatus for providing a composite material, said apparatus comprising or including apparatus or means to receive material of a chemically modified fibrous nature prepared by a process whereby masses of lignocellulosic material have been subjected to (i) treatment in an aqueous environment at elevated temperature(s) and elevated pressure(s) to chemically modify by thermohydrolysis the lignocellsic material masses, (ii) mechanical reduction of the resultant masses to individual chemically modified and/or smaller accumulations of chemically modified fibres, and (iii) drying to some extent at a temperature(s) insufficient to cure the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin, apparatus or means for mixing such fibrous material with thermoset adhesive and/or binder material(s), apparatus or means for providing a mattress or mattresses of such mixed materials, hot press apparatus to hot press the mattress or mattresses, and a curing zone whereby the (still hot) pressed forms can be maintained in an environment (low in oxygen) for a period where the material of the form is (preferably still) above ambient temperature sufficient to allow curing or further curing of the fractioned and/or hydrolysed hemicellulose and the fractioned and/or hydrolysed lignin.

89. Apparatus of claim 88 wherein a pre-press apparatus is provided for pre-pressing the formed mattresses for mattress feed to the hot press.

90. Apparatus of claim 88 or 89 wherein said hot press is any one of a single opening hot press, a multi daylight hot press (ie; can provide pressing one mattress above the other without adhesion one to the other) or continuous.

91. Apparatus of any one of claims 88 to 90 wherein the means providing the curing zone allows forms to be congregated (whether with or without gas flushing and/or evacuation) in an environment low in oxygen.

92. Apparatus of claim 91 wherein said curing zone is thermally insulated (optionally, where necessary, with optional heat exchange).

93. Apparatus of any one of claims 88 to 92 wherein the curing zone input temperature is from 75°C to 180°C and after a curing zone hold period of from at least 1 hour is still in that range.

94. Apparatus of claims 92 or 93 wherein the temperature is still above 55°C at 7 days.

95. Panels formed from a thermoset of wood fibres that have been subject to any one of the processes or methods of any one of claims 1 to 24, 27 to 71 and 74 to 76 and/or operatively using apparatus as claimed in any one of claims 77 to 94.