MOKHTAR ANIS (MY)
ABDUL AZIZ ASTIMAR (MY)
WAN HASSAN WAN HASSAMUDDIN (MY)
CHOO YUEN MAY (MY)
SI JOON LEE (MY)
SOO BANG EU (MY)
OMAR ROSMAZI (MY)
TABARI AHMAD SIRAJUDDIN (MY)
DONGWHA MALAYSIA HOLDINGS SDN BHD (MY)
IBRAHIM ZAWAWI (MY)
MOKHTAR ANIS (MY)
ABDUL AZIZ ASTIMAR (MY)
WAN HASSAN WAN HASSAMUDDIN (MY)
CHOO YUEN MAY (MY)
SI JOON LEE (MY)
SOO BANG EU (MY)
OMAR ROSMAZI (MY)
TABARI AHMAD SIRAJUDDIN (MY)
| WO2000059697A1 | 2000-10-12 |
| US20030160349A1 | 2003-08-28 | |||
| JP2002248610A | 2002-09-03 | |||
| US7157138B2 | 2007-01-02 | |||
| US6197414B1 | 2001-03-06 |
| CLAIMS 1. A method for producing fibreboards, the method includes steps of : i) chipping of oil palm trunk (OPT) within size range of 0.012 to 0.050m; ii) treating the chipped OPT obtained from step (i) under steam pressure between 2 to 8 bar at temperature between 150 to 180° C for a period between 100 to 400 seconds; iii) converting the OPT chips obtained from step (ii) to refined fibres under steam pressure between 2 to 8 bar at temperature between 150 to 180° C; iv) applying resin between 6 to 12% by dry weight of fibres and/or wax between 0.5 to 2.5% by dry weight of fibres to the OPT refined fibres obtained from step (iii); v) transforming the resinated fibres obtained from step (iv) into mat; vi) pressing the mat obtained from step (v) at temperature between 160 to 220° C for a period time of 2 to 5 minutes. 2. The method for producing fibreboards as claimed in claim 1 wherein the mat in step (vi) is pressed to a thickness of 0.003 to 0.032m. 3. The method for producing fibreboards as claimed in claim 1 wherein the OPT refined fibres obtained from step (iv) are prepared in a pre-determined amount before being introduced into a forming machine for forming of the mat in step (v). 4. The method for producing fibreboards as claimed in claim 3 wherein the predetermined amount of the refined fibres will ensure production of high density fibreboard (HDF), medium density fibreboard (MDF) or low density fibreboard (LDF). 5. The method for producing fibreboards as claimed in claim 1 wherein the refined fibres obtained from step (iii) are subjected to a chemical treatment. 6. The method for producing fibreboards as claimed in claim 5 wherein the chemical treatment includes the steps of mixing the OPT refined fibres with a mixture of urea, acetic acid and water. The method for producing fibreboards as claimed in claim 1 wherein the fibreboard obtained after step (vi) is cooled. 8. The method for producing fibreboards as claimed in claim 1 wherein the resin is urea formaldehyde (UF), melamine urea formaldehyde (MUF), phenol formaldehyde (PF) or any combination thereof. 9. The method for producing fibreboards as claimed in claim 1 wherein the wax is selected from synthetic amide, paraffin, paraffin/EAA, paraffin/micro and paraffin/PE. 10. The method for producing fibreboards as claimed in claim 1 wherein the applied simultaneously with the resin or before the resin in step (iv). 11. Fibreboards produced according to any of claims 1-10. 12. A method for producing fibreboards, the method include steps of : i) chipping of oil palm trunk (OPT), rubber wood (RW) and mixed tropical hardwood (MTH) within size range of 0.012 to 0.050m; ii) blending the OPT chips with RW and MTH chips at a blending ratio of 5 to 50% of chipped OPT, 5 to 50% of RW and 5 to 50% MTH; iii) treating the mixture obtained from step (ii) under steam pressure between 2 to 8 bar at temperature between 150 to 180° C for a period between 100 to 400 seconds; iv) converting the mixture of OPT, RW and MTH chips obtained from step (iii) to refined fibres under steam pressure between 2 to 8 bar at temperature between 150 to 180° C; v) applying resin between 6 to 12% by dry weight of fibres and/or wax between 0.5 to 2.5% by dry weight of fibres to the OPT refined fibres obtained from step (iv); vi) transforming the resinated fibres obtained from step (v) into mat; vii) pressing the mat obtained from step (vi) at temperature between 160 to 220° C for a period time of 2 to 5 minutes. 13. The method for producing fibreboards as claimed in claim 12 wherein the mat in step (vii) is pressed to a depth of 0.003 to 0.032m. 14. The method for producing fibreboards as claimed in claim 12 wherein the mixed OPT, RW and MTH refined fibres obtained from step (v) are prepared in a predetermined amount before being introduced into a forming machine for forming of the mat in step (vi). 15. The method for producing fibreboards as claimed in claim 14 wherein the predetermined amount of the refined fibres will ensure production of high density fibreboard (HDF), medium density fibreboard (MDF) or low density fibreboard (LDF). 16. The method for producing fibreboards as claimed in claim 12 wherein the refined fibres obtained from step (iv) are subjected to a chemical treatment. 17. The method for producing fibreboards as claimed in claim 16 wherein the chemical treatment includes the steps of mixing the mixture of OPT, RW and MTH refined fibres with a mixture urea, acetic acid and water. 18. The method for producing fibreboard as claimed in claim 12 wherein the fibreboard obtained after step (vii) is cooled. 19. The method for producing fibreboards as claimed in claim 12 wherein the resin is urea formaldehyde (UF), melamine urea formaldehyde (MUF), phenol formaldehyde or any combination thereof. 20. The method for producing fibreboards as claimed in claim 12 wherein the wax is selected from synthetic amide, paraffin, paraffin EAA, paraffin/micro and paraffin/PE. 21. The method for producing fibreboards as claimed in claim 12 wherein the wax is applied simultaneously with the resin or before the resin in step (v). 22. Fibreboards produced according to any of claims 12-21. |
FIELD OF THE INVENTION
The present invention relates to a method for producing fibreboards utilizing palm biomass.
BACKGROUND OF THE INVENTION
For many years, wood composite industry in Asia has focused on rubber wood (RW) and pine as traditional resource material in panel manufacturing especially in fibreboard production. General trend show that these traditional raw materials are declining on the supply and subsequently increasing cost of the raw materials. For maintaining manufacturing capacity, it is necessary to look for innovative ways of using non-traditional raw material such as oil palm biomass. Oil palm plantation area in Malaysia is estimated around 4.7 million hectares in 2010, and it is estimated that almost 5% of this area is due for replanting. From estimated 0.2 million hectares replanting area and an average of 134 palm trees/ha, it is calculated that around 26.8 million oil palm trees will be available, which is equivalent to 8 million tonnes dry weight of oil palm trunk (OPT). Currently fibreboard industry in Malaysia is using admixture of hardwood species with RW in manufacturing fibreboard to sustain production capacity. Raw materials are obtained from sawmill and other wood based activities residue that will be mixed up with different proportion of the RW. Therefore fibreboard production would sometimes results in inconsistent of color and physical/mechanical properties. Substitution of one raw material for another or significant shifts in species mix can cause large variations in mechanical properties of the fibreboard. In the fibreboard manufacturing, quality of refined fibers depends on many factors including species of wood/fibers, size and distribution, pre-treatment condition of steam pressure, retention time in digester, applied power, geometry of refining plates, refining intensity, disc speed, and dwell time within plate zone. SUMMARY OF INVENTION
The present invention relates to a method for producing fibreboards utilizing palm biomass. The method includes steps of:
i) chipping of OPT within size range of 0.012m to 0.05m;
ii) treating the chipped OPT obtained from step (i) under steam pressure between 2 to 8 bar at temperature between 150 to 180° C for a period between 100 to 400 seconds;
iii) mechanically refining the OPT chips obtained from step (ii) in a steam pressurized refiner at steam pressure between 2 to 8 bar at temperature between 150 to 180° C where the OPT chips are converted to refined fibres;
iv) applying resin between 6 to 12% by dry weight of fibres and/or wax between 0.5 to 2.5% by dry weight of fibres to the OPT refined fibres obtained from step (iii); v) transforming the resinated fibres obtained from step (iv) into mat;
vi) pressing the mat obtained from step (v) at temperature between 160 to 220° C for a period time of 2 to 5 minutes.
The refined fibres obtained from step (iii) are optionally subjected to a chemical treatment. The chemical treatment includes the steps of mixing the OPT refined fibres with a mixture of urea, acetic acid and water.
The mat obtained from step (v) is pressed to a thickness of 0.003m to 0.032m. The OPT refined fibres blended with resin and/or wax obtained from step (iv) are prepared in a pre-determined amount before being introduced into a forming machine for forming of the mat in step (v). The pre-determined amount of the refined fibres will ensure production of high density fibreboard (HDF), medium density fibreboard (MDF) or low density fibreboard (LDF). The fibreboard obtained after step (vi) is cooled.
The resin is urea formaldehyde (UF), melamine urea formaldehyde (MUF), phenol formaldehyde (PF) or any combination thereof. The wax is selected from synthetic amide, paraffin, paraffin/EAA, paraffin/micro and paraffin/PE. The wax is applied simultaneously with the resin or before the resin in step (iii). In another embodiment, the present invention relates to a method for producing fibreboard using mixture of oil palm trunk (OPT), rubber wood (RW) and mixed tropical hardwood (MTH). The method includes the steps of:
i) chipping of oil palm trunk (OPT), rubber wood (RW) and mixed tropical hardwood (MTH) within size range of 0.012 to 0.05m;
ii) blending the OPT chips with RW and MTH chips at a blending ratio of 5 to 50% by dry weight of chipped OPT, 5 to 50% by dry weight of RW and 5 to 50% by dry weight of MTH;
iii) treating the mixture obtained from step (ii) under steam pressure between 2 to 8 bar at temperature between 150 to 180° C for a period between 100 to 400 seconds;
iv) mechanically refining the mixture of OPT, RW and MTH chips obtained from step (iii) in a steam pressurized refiner at steam pressure between 2 to 8 bar at temperature between 150 to 180° C where the chips are converted to refined fibres;
v) applying resin between 6 to 12% by dry weight of fibres and/or wax between 0.5 to 2.5% by dry weight of fibres to the refined fibres of mixed OPT with RW and MTH obtained from step (iv);
vi) transforming the resinated fibres obtained from step (v) into mat;
vii) pressing the mat obtained from step (vi) at temperature between 160 to 220° C for a period time of 2 to 5 minutes.
The refined fibres obtained from step (iv) are optionally subjected to a chemical treatment. The chemical treatment includes the steps of mixing the mixture of OPT, RW and MTH refined fibres with a mixture of urea, acetic acid and water.
The mat obtained from step (vi) is pressed to a thickness of 0.003 to 0.032m. The mixture of OPT, RW and MTH refined fibres blended with resin and/or wax obtained from step (v) are prepared in a pre-determined amount before being introduced into a forming machine for forming of the mat in step (vi). The pre-determined amount of the refined fibres will ensure production of high density fibreboard (HDF), medium density fibreboard (MDF) or low density fibreboard (LDF). The fibreboard obtained after step (vii) is cooled.
The resin is urea formaldehyde (UF), melamine urea formaldehyde (MUF), phenol formaldehyde (PF) or any combination thereof. The wax is selected from synthetic amide, paraffin, paraffin/EAA, paraffin/micro and paraffin/PE. The wax is applied simultaneously with the resin or before the resin in step (v).
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given herein below and accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, wherein:
Figure 1 shows a flowchart of fibreboard production from mixture of oil palm trunk (OPT), rubber wood (RW) and mixed tropical hardwood (MTH);
Figure 2 shows a flowchart of fibreboard production from 100% oil palm trunk (OPT); and
Figure 3 shows the properties of the fibreboard subjected to chemical treatment during refining process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to a method for producing fibreboards utilizing solely 100% of oil palm trunk (OPT) and a mixture of OPT. The present invention also relates to a method for producing fibreboards utilizing rubber wood (RW) and mixed tropical hardwood (MTH) with different blending ratio. OPT is used as an alternative raw material for fibreboards production to replace RW due to depleting supply of this material. A detailed description of preferred embodiments of the invention is disclosed herein. It should be understood, however, that the disclosed preferred embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as the basis for the claims and for teaching one skilled in the art of the invention. In order to maintain production capacity, fibreboard manufacturers are using other material as alternative way to substitute RW. Currently fibreboard industry is mostly using mixed RW to blend with MTH for their production. Due to increase in pricing and scarcity of supply of these material, the usage of OPT is inevitable in the future.
The OPT is a waste material which is generated as a by-product during replanting after trees reaching 25 years. Up to now the OPT is used as organic and used as raw material for plywood industry. OPT fibres also have comparable length with RW fibres. This shows that OPT is a potential raw material for production of fibreboards.
Fibreboard is a composite wood product formed by braking wood down into fibres and combining the fibres with wax and resin and forming fibreboards by applying high temperature and pressure. In contrast to particleboard, fibreboard has more uniform density throughout the board. Besides that, the fibreboard has smooth and tight edges which can be machined. It can be finished to smooth surface and grain printed, therefore eliminating the need for veneers and laminates.
Fibreboards are useful for many applications, from cabinetry to molding, because it is smooth, uniform and doesn't warp. Builders use fibreboards for applications such as furniture, shelving, laminate flooring, decorative molding and doors. Fibreboard is valued for its insular qualities in sound and heat. Also it can be nailed, glued, screwed, stapled or attached with dowel, making it as versatile as plank wood.
An essential element of the present invention is the utilization of 100% OPT and OPT blended with RW and MTH with high pressure steam during digesting or softening step or during refining or preferably during both digesting and refining for production of fibreboards.
Firstly, original form of OPT is converted into chips form by means of normal wood chipper with sizes ranging from 0.012 to 0.050m. Generally oil palm logs undergo similar preparations as other normal wood materials used in fibreboard production such as RW and MTH. Figure 1 shows the flow chart of the production of fibreboards from mixture of oil palm trunk (OPT), rubber wood (RW) and mixed tropical hardwood (MTH). The OPT that has been chipped are blended with chipped RW and MTH. Mixing ratio of the chipped OPT: RW: MTH is 5 to 50% by weight: 5 to 50% by weight: 5 to 50% by weight respectively. The mixing ratio is done based on dry weight calculation. The mixture of chipped OPT, RW and MTH are converted to refined fibres during thermo-mechanical refining process. The mixture is subjected to high pressure steam treatment in a digester and in a refiner. The steam treatment is performed at steam pressure between 2 to 8 bar and temperature between 150 to 180° C for duration of 100 to 400 seconds. The steam treatment may take place in any pressurized vessel and may further include a continuous digester. The continuous digester includes a screw conveyer to move the OPT blended with RW and MTH chips through the digester and into refiner. At the refiner under steam pressure between 2 to 8 bar and temperature between 150 to 180° C, the treated chips are broken down into fibres like threads (refined fibres) suitable for manufacturing into fibreboards. Optionally the mixture of chipped OPT, RW and MTH in the refining process is subjected to chemical treatment. The chemical treatment includes the steps of mixing the mixture of chipped OPT, RW and MTH with a mixture of urea, acid and water. The chemical treatment further increases properties of the fibreboards as shown in Table 3 and Figure 3.
The refined fibres are then dried to a moisture content of about 12% or less with a time period of 1 to 2 minutes. Tube dryers are typically used to reduce the moisture content of the refined fibres to desired levels. Conventional fibreboard dryers such as blowpipes in blow-line systems having inlet temperatures between about 120 to 170° C can also be used for drying the refined fibres.
For blending, resin and/or wax emulsions are sprayed to the fibres just before entering the dryer. Any other desired additives can also be applied to the fibres. Application of a wax is ranged between 0.5 to 2.5% by dry weight of fibres to improve the flow-ability of resin, as well as providing additional moisture resistance. The wax emulsion is preferably added to impart water resistance and to assist in dispersing the resin on all surfaces of the fibres. The wax emulsions are well known in the art. The examples of wax emulsions are such as synthetic amide, paraffin, paraffin/EAA, paraffin/micro, paraffin/PE, etc. The resin and wax may also be applied by other conventional means known in the art, i.e. spray nozzles, tube, or atomizers. The wax emulsion is preferably added to impart water resistance and to assist in dispersing the resin on all surfaces of the fibres. The resin and the wax can be applied separately, although it is preferred to add them simultaneously for uniformity.
The preferred resin used in the present invention is urea formaldehyde (UF) resin. UF is relatively inexpensive, transparent, thermosetting resin made from urea and formaldehyde heated in the presence of a mild base, such as ammonia or pyridine. UF has a high tensile strength, bending strength, low water absorption and mould shrinkage, higher surface hardness, elongation at break and volume resistance. It is also preferred to incorporate melamine urea formaldehyde (MUF) resin along with or instead of the UF resin in order to impart additional water resistance to the fibres.
Instead or in addition to UF, other resins known in the art such as phenol formaldehyde (PF) resin can also be used in the present invention. PF resin is relatively inexpensive, red/black-colored resin that is used in pressed wood product such as softwood plywood and flake or oriented fibreboard for exterior applications. The UF or other resins are applied to the fibres in a concentration of at least 6% by weight of the fibres, preferably 6 to 12% by weight.
The Urea-Formaldehyde (UF) resins are widely used in fibreboard industries as binders. It is usually employed as aqueous colloidal solution with 50 to 70% solids content. Preparation of the UF resins is as follows:
a) methylolation : pre-condensing urea and formaldehyde at adequate molar ratio (F:U ratio) of 1.0 to 5.0, preferably 1.0 to 3.0, under aqueous acidic/or basic condition. b) condensation : increasing molecular weight with additional urea at elevated temperature and pH 3.0 to 5.0.
c) neutralization : optionally adding urea for bringing molar ratio down to 1.2 to 1.8, and adjusting pH 7.0 to 9.0 if necessary.
Resinated fibres are pneumatically transferred into a forming machine which will continuously transforms the resinated fibres into an evenly distributed density mat. Amount of the resinated fibres are determined before the fibres is introduced into the forming machine. The amount will determine the formation of high density fibreboard (HDF), medium density fibreboard (MDF) or low density fibreboard (LDF). The mat is pre-pressed to a thickness of about 0.1m to 0.25m prior to hot pressing.
The hot pressing applies heat and pressure to the resinated mat in order to cure the resin and bond the fibres into a solid board. Pressing time generally range between 2 to 5 minutes. Temperatures for the hot pressing range from about 160 to 220° C depending on the type of fibreboard being produced. The fibreboard is pressed to a thickness, range 0.003 to 0.032m.
After pressing, the fibreboards are cooled prior to stacking. The fibreboards are then sanded and/or trimmed to final desired dimensions prior to packaging for shipment.
In another embodiment, 100% OPT is used for producing the fibreboards. The OPT is firstly chipped into OPT chips within size range of 0.012 to 0.050m and thereafter converted to refined fibres during thermo-mechanical refining process. The 100% OPT chips are subjected to high pressure steam in a digester and in a refiner. The other processes for producing the fibreboard using 100% OPT fibres are the same as the steps (as mentioned above) involved in producing the fibreboards using OPT fibres blended with RW and MTH. Figure 2 shows the flowchart of the production of fibreboards from oil palm trunk (OPT),
The following examples are offered to illustrate but not limit the invention. Example 1
Resin Preparation:
Aqueous formaldehyde solution (37%) and urea are treated in an aqueous sodium hydroxide solution (33%). The mixture, which is of pH 8 to 9 and has molar ratio 3.8, is stirred and heated to elevated temperature for 30 minutes. An aqueous acid is added for adjusting pH 4.7 within 90 minutes. When reaching adequate viscosity, aqueous NaOH solution is added to bring pH to 8.5. Water is removed under vacuum for until desired solid content is achieved. Solid content is cooled to a temperature of 30°C, followed by adding urea for giving F:U molar ratio of 1:5. Thereafter resin mixture is stirred for 60 minutes. The resulting resin obtained from the stirring is water soluble and slight opaque. The resin has the following properties:
Solid content: 55%, Viscosity at 25° C : 30 cps
Fibreboard Preparation:
OPT chips are treated with different steam pressure and preheating time during refining process without any chemical treatment. The steam pressure used to treat the OPT chips is between 2 to 8 bar while cooking time is set at 100 to 400 seconds. The fibres produced are used for the production of 12 mm lab scale fibreboard after mixing with urea formaldehyde (UF) resin. Average values of fibreboard properties are presented in Table 1 and Table 2.
Table 1 : The Steam Pressure and Fibreboard Properties
Thickness swelling, EN 622-5-European standard, N/mm 2 -Newton over millimeter square.
Table 2: Preheating Time and Fibreboard Properties
Thickness swelling, EN 622-5-European standard, N/mm 2 -Newton over millimeter square.
The properties of fibreboards can be improved via chemical treatment with high steam pressure in refiner process.
[UAW: Urea (40-50% ) + acetic acid (1-10%) + water (about 50%)]
UAW mixed in fiber (OPT + RW + MTH) after digester process
The results of the properties of the fibreboard with chemical treatment are showed in Table 3 and Figure 3. Table 3: Properties of the Fibreboards with Chemical Treatment
Fiber: UAW ratio
No UAW UAW 1% UAW 2% UAW 3% UAW 4% (weight %)
Internal bond (N/mm ) 0.603 0.682 0.680 0.585 0.506
Emission (mg/lOOg) 18.15 13.46 10.69 8.33 7.53