Materials and Design 31 (2010) 4229–4236

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Materials and Design

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Development and material properties of new hybrid medium densityfibreboard from empty fruit bunch and rubberwood

H.P.S. Abdul Khalil a,*, M.Y. Nur Firdaus a, M. Jawaid a, M. Anis b, R. Ridzuan b, A.R. Mohamed c

a School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysiab Malaysian Palm Oil Board (MPOB), Biomass Technology Centre, Engineering & Processing Division, Jalan Sekolah, 43000 Kajang, Selangor, Malaysiac School of Arts, Universiti Sains Malaysia, 11800 Penang, Malaysia

a r t i c l e i n f o a b s t r a c t

Article history:Received 19 January 2010Accepted 7 April 2010Available online 11 April 2010

Keywords:B. Hybrid fibreboardA. Empty fruit bunchA. Rubberwood

0261-3069/$ - see front matter � 2010 Elsevier Ltd. Adoi:10.1016/j.matdes.2010.04.014

* Corresponding author. Present address: DivisionSchool of Industrial Technology, University SciencMalaysia. Tel.: +60 4 6532200; fax: +60 4 657367.

E-mail addresses: akhalil@usm.my, akhalilhps@gm

In this research, new hybrid medium density fibreboard (MDF) was produced by using rubberwood (RW)and empty fruit bunch (EFB) based on oven-dried weight. There are two different ratios of hybrid MDFfrom rubberwood and EFB were produced which are EFB:RW, 20:80 and EFB:RW, 50:50 at 65% and93% relative humidity (RH). The effect of storage time and relative humidity on the mechanical and phys-ical properties of new hybrid MDF was studied. It was found that at 93% relative humidity, new hybridMDF exhibited a highest effect on the mechanical and physical properties of panel after 10 weeks storagetime. It observed that, hybrid MDF with ratio of EFB:RW, 20:80 exhibited the highest mechanical (flexuretest and internal bonding) and physical properties [moisture content (MC), thickness swelling (TS), waterabsorption (WA)] as compared to hybrid MDF produced from EFB:RW, 50:50. Thus, the result showedthat addition of higher amount of EFB fibres in hybrid MDF will decreased the composites properties.The property of composites decreases with increase of relative humidity and storage time. The resultshowed that, at 65% humidity new hybrid MDF exhibited lower effect on mechanical and physical prop-erties of the panel.

� 2010 Elsevier Ltd. All rights reserved.

1. Introduction

Medium density fiberboard (MDF) is a dry-formed panel prod-uct manufactured from lignocellulosic fibres combined with a syn-thetic resin such as urea formaldehyde resin (UF), phenolformaldehyde resin (PF) or isocyanate binder under heat and pres-sure in the presence of moisture [1,2]. In recent years, greatchanges have been taken places in the MDF industry. Productionof MDF has increased dramatically and new plants are plannedworldwide. MDF is commercially success due to its superior prop-erties such as environmental friendly, wide applications includingfurniture and moldings, moderate overall density, suitable densityprofile, straight-edged flat conventional composite, good resin con-tent and finishing result [3]. MDF is used extensively in factory-assembled and ready to-assemble furniture as well as cabinets,underlayment, drawer fronts and counter drops. Moreover, MDFis replacing thin plywood and wet-process hardboard in the pro-duction of molded and flush door-skins [1].

In Malaysia, the production of MDF remains intact, at over1.2 million m3. Malaysia is presently one of the highest suppliers

ll rights reserved.

of Bioresource Technology,e Malaysia, 11800 Penang,

ail.com (H.P.S. Abdul Khalil).

of MDF in the world. Presently, the majority of MDF producers inMalaysia are using rubberwood as their raw material. The countrynow has eight MDF mills which are using rubberwood as their ma-jor raw material [4,5]. Rubberwood has a light-straw to lightbrown colour with density varies from 550 to 650 kg/m3 and hasthe strength properties associated with other medium densityhardwoods. The average diameter is normally 30–35 cm and thelength of the trunk is 3–5 m. Due to these superior properties,rubberwood has become one of the major raw materials in manu-facturing MDF lately. Projection shows that in the near future thesupply of rubberwood is not meet the demand for making MDF[6]. Therefore, one possible solution in order to overcome thisproblem is by using oil palm empty fruit bunch (EFB) instead ofrubberwood.

The oil palm industry in Malaysia, with its 6 million hectares ofplantation, produced over 11.9 million tons of oil and 100 milliontons of biomass. The biomass from oil palm residue include theoil palm trunks (OPT) and fronds (OPF), kernel shell, EFB, pressesfruit fibre (PFF) and palm oil mill effluent (POME). In addition,the total crop of fresh fruit bunch is more than 30 million tonsper year, which generate more than 10 million tons of EFB. Only10% of the EFB is used and the rest are abundant [7]. Presently,EFB is mainly used as mulch, but the economic are marginal dueto the high transport cost. It is seldom burnt as fuel, as the shelland fruit fibres are sufficient for oil palm mills [8].

4230 H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236

The mechanical and physical properties of MDF are affected byenvironmental factors such as humidity, storage times and tem-perature same like wood and wood-based composites. For in-stance, it has been shown that exposure to high relativehumidity condition results in an increase in the moisture contentand thickness swelling and decrease in flexural strength and inter-nal bonding strength [9]. Moisture problem arises due to woodbeing a naturally hygroscopic material. In service these productscan be exposed to a range of environmental conditions. The rela-tionship between moisture content and strength properties is veryimportant, if panel products are to be used as structural memberssubjected to atmospheric moisture changes [10].

Some basics aspect that have been inspect by previousresearchers using lignocellulosic fibres in manufacturing MDF havebeen reported by Seco and Barra [9]; Koh and Yeo [11]; Paridahet al. [12]; Krzysik et al. [3]; Pritchard et al. [10]; Ridzuan et al.[6]; Thole and Hora [5]. Moreover, treated EFB use in manufactur-ing other composite also have been reported by Hill and Khalil[13]; Rozman et al. [14]; Sreekala et al. [15]; Hariharan et al. [7].In addition, there are also a study which are focus on the propertiesof MDF from EFB but it only include properties of MDF based ontwo different resin content was reported by Ridzuan et al. [6].However, until now the comprehensive study still have not beendone on the properties changes of new hybrid MDF made formEFB and rubberwood towards relative humidity, temperature andstorage time. All these properties are very important informationabout the possibility of using EFB and rubberwood as an importantmaterial in manufacturing MDF in Malaysia and worldwide.

2. Experimental

2.1. Materials

Thermomechanical pulp Empty fruit bunch Oil palm fibres andrubberwood fibres were obtained were obtained from MalaysiaPalm Oil Board (formerly known as Malaysian Palm Oil ResearchInstitute). The Urea Formaldehyde Resin used was the general-pur-pose grade supplied by Hexion Specialty Chemicals Sdn. Bhd. with64% solid content, 175 viscosity and 8.0 pH value

2.2. Preparation of hybrid medium density fibreboard

Several 12 mm-thick, new hybrid MDF boards made from rub-berwood and EFB were used in this study. The average density ofthese boards was 650 kg/cm3. These boards were manufacturedat Malaysian Palm Oil board (MPOB) in Bangi. The resin used wascommercial urea formaldehyde with 12% resin content. EFB or rub-berwood chips were defibre and refined by using pressurized sin-gle disc refiner, model Andritz 12-1CP with 4000 rpm speed,195–200 �C temperature and 2–8 bars pressure to form thermome-chanical pulp fibre. After defibration, fibre enters the blow line. Fi-bre was mixed uniformly with wax and urea formaldehyde resin.Then, mats were hand-formed in a 550 mm � 550 mm decidebox. The mats were then manually pre-pressed. Mats were consol-idated using steam heated press. The press temperature used was200 �C and pressure at 3500 MPa. After pressed section, boardswere cooled on a star dryer and trimmed.

All boards were cut in the vertical direction according to Amer-ican Society for Testing and Material Standard (ASTM). Then, sam-ples were storage in relative humidity chamber (RH) model GT –7005-T, with fixed temperature at 20 �C and different relativehumidity 65% or 93% for about 10 weeks. The tests were performedevery 2 week. In addition, the board was also exposed at environ-ment condition as a control element (average temperature: 23–33 �C and average RH: 64–80%). The mechanical and physical test

was carried out to determine the effect of this parameter towardthe new hybrid MDF properties.

2.3. Mechanical testing

Mechanical test including three point static bending and Inter-nal bonding strength test. Internal bonding measurement was car-ried out using an Instron universal testing machine, model 1003according to BS EN 319. The crosshead speed was set to 30 mm/min. Averages of 10 samples were used for IB measurement. Sam-ples for IB test were cut into 50 mm � 50 mm � 12 mm sizes be-fore undergo the test. The area of the samples was measuredusing a digital vernier caliper.

The surface of the samples was sand and glued to the steelblocks by using epoxy hot melt adhesive. Once gluing had beencompleted, each assembly was left for at least 24 h to allow theglue to harden. Then, the samples were mounted in turn ontothe Instron Universal Testing Machine (model 1003) and loadeduntil failure occurred. The load at rupture (measured in MPa)was recorded. Then, the fracture samples were removed from thesteel blocks by heating in the oven at 108 �C for approximately30 min until the glue was sufficiently softened to facilitate easy re-moval. For the three point static bending test, samples were cutinto 290 mm � 50 mm � 12 mm sizes. The same Universal TestingMachine, model 1003 was used to determine the value of the flex-ure strength and the modulus.

2.4. Physical testing

The physical tests involved were the dimensional stability andmoisture content (MC). The dimensional stability test involvedwere thickness swelling (TS) and water absorption (WA). The TSand WA were measured according to BS EN 317 method. Averagesof 10 samples were used for TS and WA measurement The sampleof TS and WA were cut into 50 mm � 50 mm � 12 mm sizes beforeundergo the test. The TS was determine by measured thickness ofthe sample before and after immersed in distilled water at roomtemperature (25 �C) for 24 h. The thickness swelling was calculatedas follows:

Thickness swelling ð%Þ ¼ T2 � T1

T1� 100 ð1Þ

where T2 = thickness of the sample after immersion (g) andT1 = thickness of the same sample before immersion (g).

While, water absorption (WA) was calculated by weighing thesamples before and after immersed in distilled water at room tem-perature (25 �C) for 24 h.

The water absorption was calculated according to the Eq. (2):

Water absorption ð%Þ ¼Wa �Wb

Wb� 100 ð2Þ

where Wa = weight of the sample after immersion (g) andWb = weight of the same sample before immersion (g).

Since empty fruit bunch and rubber wood fibers are highlyhygroscopic, moisture analysis were done by oven drying to deter-mine the moisture content of the board. ASTM D4442-07 methodwas used to determine moisture content of the board. The presenceof moisture would also cause detrimental effect on the mechanicalproperties of composite material. The board samples with a dimen-sion of 50 mm � 50 mm � 12 mm were weighed using an analyti-cal balance before placing it in an oven at 108 �C for 24 h. Averagesof three samples were used for moisture content measurement.The board samples were then removed from the oven and wascooled in a desiccator for 30 min followed by reweighing of theboard samples. The moisture content of the board samples was cal-culated as follows:

H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236 4231

MC ð%Þ ¼ ½ðWw �WdÞ=Ww� � 100 ð3Þ

where Ww = wet weight of the sample (g) and Wd = weight of thesample after drying (g).

2.5. Scanning electron microscope (SEM)

Morphology of the new hybrid MDF was carried out using ascanning electron microscope (SEM). SEM micrographs were takenof the fracture surfaces of flexural fracture specimens. The sampleswere mounted onto an SEM holder using double-sided electrically-conducting carbon adhesive tabs to prevent surface charging onthe specimens upon exposure to the electron beam. The sampleswere then coated with gold to a thickness of 20 nano-meters usinga Polaron Equipment Limited model E500, voltage 1.2 kV (10 mA)at vacuum 20 Pa for 10 min. Then the samples were observed ina Leica Cambridge S-360 scanning electron microscopy (SEM).

3. Results and discussion

3.1. Mechanical properties

3.1.1. Flexural strength and flexural modulusFigs. 1 and 2 showed the value of flexural strength and flexural

modulus of hybrid MDF produced from EFB:RW, 20:80 andEFB:RW, 50:50. The results show that the value of flexural strengthfor hybrid MDF from EFB:RW, 20:80 (32.21 MPa) was higher thanhybrid MDF from EFB:RW, 50:50 (30.99 MPa). While, hybrid MDFfrom EFB:RW, 20:80 exhibited the highest value of flexural modu-lus (2634 MPa) as compared to hybrid MDF from EFB:RW, 50:50(2356 MPa). The higher flexural strength and modulus indicatesby hybrid MDF produced from EFB:RW, 20:80 was due to the suf-ficient stress might have been transferred to the fibre to enable fi-bre to be ultimately fractured, thus giving higher bendingproperties [16]. Sreekala et al. [15] also reported that, normallyEFB fibres cannot withstand the heavy load and this lead to the fail-ure of that fibre which results to composite failure. This maybe dueto the lower content of a-cellulose (17.2%) present in EFB fibrescompared to rubberwood fibres that consist of 44.7% of a-cellulose.

As reported earlier, the flexural rigidity of fibres is closely re-lated to their extensibility, since bending results is an extensionof one side and a compression of the other side of a fibre. Creasing

Fig. 1. Comparison of flexural strength between hybrid MDF produced from EFB:RW, 2

occur when this results in the formation of new cross-links, hold-ing the fibre in the bent form. If the structure deforms with a stain-ing of the cross-link, it will resist creasing but if the links change tonew position, a crease will form [17].

It was also observed that the flexural strength and modulus ofboth hybrid MDF stored at 65% RH and 20 �C temperature didnot vary significantly at storage period of 10 weeks. The flexuralstrength and modulus of hybrid MDF were lower at 93% RH com-pared to those samples which stored at normal condition and65% RH. This was due to the samples exhibited higher moisturecontent than those samples stored at lower relative humidity.The reduction of flexure strength of hybrid MDF stored at 93% werehigher in 8 and 10 weeks period. This condition arises due to theextended time in storage, which leads to a higher absorption ofmoisture in a conventional composite. Overall, the values of flex-ural strength and modulus for both hybrid MDF were higher at65% RH compared to normal condition and 93% RH. According toSeco and Barra [9], under long term high humidity (90% RH) condi-tions, the total humidity gain resulting the physico-mechanicaldegradation of the board as compared to lower relative humidity.Besides, the steady conditions of 20 �C and 90% RH seem to bemore destructive for hybrid MDF board than cyclic condition of20 �C and 30–90% RH.

Obtained result was in line with the result obtained by Gillahet al. [16]. They reported that, the flexural strength increased asthe amount of EFB fibres decreased. The maximum strength wasencountered at blending ratio of high matrix content and lowamount of EFB fibres. This maybe due to the properties of EFB fi-bres used in hybrid MDF manufactured. The refined EFB fibres gen-erate higher amount of long fibres and fines. One generalexplanation fines generated in the refining process of EFB fibreswas the presence of nonfibrous plant cell material such as paren-chyma and epidermal tissue that had thinner cell walls comparedwith the fibrous cell types found in rubber wood.

Figs. 3a–3f show the SEM micrograph of hybrid MDF at 10 weekstorage at normal conditions, 65% relative humidity and 93% rela-tive humidity under 20 �C temperature. Hybrid composites storedat 20 �C temperature and 65% RH was suitable condition to storehybrid MDF due to the less deterioration occurred on the compos-ites during storage. Figs. 3b, 3d and 3f clearly reveal the biodegra-dation of hybrid MDF. It is clear from micrograph that fungi ormould appear on hybrid composite during the storage time, it

0:80 and EFB:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

Fig. 2. Comparison of flexural modulus between hybrid MDF produced from EFB:RW, 20:80 and EFB:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

Fig. 3a. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at 65%, at highmagnification, 1000�.

Fig. 3b. SEM for hybrid MDF produced from EFB:RW, 50:50 storage at 65%, at highmagnification, 1000�.

Fig. 3c. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at normalcondition, at high magnification, 1000�.

Fig. 3d. SEM for hybrid MDF produced from EFB:RW, 50:50 storage at normalcondition, at high magnification, 1000�.

4232 H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236

leads to deterioration of the internal structure of hybrid compos-ites that cause decrease in mechanical and physical properties. Itobserved from micrograph that biodegradation of hybrid MDF pro-duced from EFB:RW, 50:50 is higher compared to hybrid MDF pro-duced from EFB:RW, 20:80 after long term storage at highhumidity.

3.1.2. Internal bonding strengthInternal bonding (IB) is defined as the mechanical property that

shows tensile strength between a raw material and an adhesive.The internal bonding strength (IB) values obtained for hybrid

Fig. 3e. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at 93%, at highmagnification, 1000�.

Fig. 3f. SEM for hybrid MDF produced from EFB:RW, 50:50 storage at 93%, at highmagnification, 1000�.

H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236 4233

MDF are shown in Fig. 4. It was observed that the EFB hybridMDF:RW, 20:80 exhibited the highest value of IB strength(0.73 MPa) as compared to the EFB hybrid MDF:RW, 50:50(0.69 MPa).

Fig. 4. Comparison of IB strength between hybrid MDF produced from EFB:RW, 20:

Paridah et al. [12] reported that fibres from EFB and wood havebeen reported to have different properties. Two of the apparent dif-ferences are the pH and buffering capacity. The buffering capacityis defined as the action of an agent that changes the field of aciditythat eventually leads to a less reactive field, thus affecting resinflow. When EFB was bonded with the commercially available UFresin, which is suitable for MDF produced from rubberwood, theboards produced were of poor quality. Moreover, this might bedue to certain factor such as the inconsistency in resin distributionin the panel, pre-cure of resin, resin loss and resin penetration intofibres during manufacturing. Hence, both the degree of pre-cureand carbonization of UF resin during fibre drying contribute tothe loss of resin efficiency [16,18].

The Internal bonding (IB) strength of hybrid MDF was decreasedwith increasing of storage time and relative humidity. It was alsoobserved that IB strength was higher at 65% RH than normal con-dition and 93% RH. Hill and Khalil [13] and Sreekala et al. [15] re-ported that, in conditions of changing relative humidity, cyclinicalswelling and shrinkage of the fibres results in differential move-ment. The relative brittleness and inability of cured UF resin tobe plasticised by water induces stress within the bond, which leadsto failure.

3.2. Physical properties

3.2.1. Moisture contentFig. 5 showed the moisture content (MC) of the hybrid medium

density fibreboard (MDF) produced from EFB:RW, 20:80 andEFB:RW, 50:50 under various relative humidity conditions. The re-sult showed that hybrid MDF produced from EFB:RW, 20:80 exhib-ited higher MC as compared to hybrid MDF from EFB:RW, 50:50.Besides, it was observed that the MC of hybrid MDF were higherat 93% RH than those of the samples stored at normal conditionand 65% RH.

The extremely rises of MC can be seen obviously for MDF pro-duced from EFB for 6–10 weeks period. Razali and Diong [19] alsoreported that moisture content peaked at the end of the storageperiod. Biological activity was intense in the early stage of the stor-age period. At the end of the 8 weeks, the boards were dark grey,almost fully stained by staining and decaying fungi. Generally, un-der conditions of moisture content change, MDF boards are dimen-sionally unstable. They absorb water, which causes dimensionalinstability and reduction in strength properties such as the

80 and EFB:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

Fig. 5. Comparison of MC between hybrid MDF produced from EFB:RW, 20:80 and EFB:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

Fig. 6b. SEM for hybrid MDF produced from EFB:RW, 50:50 storage at 65%, at highmagnification, 1000�.

4234 H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236

modulus of rupture (MOR), modulus of elasticity (MOE) and inter-nal bonding (IB) [16].

The mould growth can be seen obviously on MDF producedfrom EFB compared to MDF from rubberwood and hybrid MDF.The biodegradation of hybrid composite can obviously seen fromweek 6 to 10 due the rises of moisture content. This can be provingwith the presence of mould and fungi growth noted on the surfaceof MDF panels which was 10 weeks stored at high relative humid-ity (93% RH) as showed in Figs. 6a–6f. Micrograph Figs. 6e–6f showclearly the colonization of microorganisms that usually appear onthe hybrid composite is subterranean termites such as Coptotermescurvignathus. The existent of this fungi or mould had lead to thedeterioration of hybrid composite that cause the decreased inmechanical and physical properties.

3.2.2. Thickness swelling and water absorptionThe effect of thickness swelling (TS) of the hybrid MDF pro-

duced from EFB:RW, 20:80 and EFB:RW, 50:50 was showed inFig. 7. While, Fig. 8 showed result of water absorption (WA) respec-tively for hybrid MDF produced from EFB:RW, 20:80 and EFB:RW,50:50. The results showed that hybrid MDF produced fromEFB:RW, 50:50 showed higher TS and WA as compared to hybridMDF from EFB:RW, 20:80. This might be due to the poor distribu-tion of UF resin and EFB fibres in the composites which resulted in

Fig. 6a. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at 65%, at highmagnification, 1000�.

Fig. 6c. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at normalcondition, at high magnification, 1000�.

the formation of fibre lumps. These lumps required more forces todeform during hot press and would result in more stress whenbuilt in the conventional composite. When the composite was ex-posed to water, a greater proportion of this stress was released,causing a pronounced reversal of densification that resulted in high

Fig. 6d. SEM for hybrid MDF produced from EFB:RW, 50:50 storage at normalcondition, at high magnification, 1000�.

Fig. 6e. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at 93%, at highmagnification, 1000�.

Fig. 6f. SEM for hybrid MDF produced from EFB:RW, 20:80 storage at 93%, at highmagnification, 1000�.

H.P.S. Abdul Khalil et al. / Materials and Design 31 (2010) 4229–4236 4235

thickness swelling. Besides, this phenomenon occurs due to theproperties of rubberwood fibres. Rubberwood fibres had lowercontent of free hydroxyl group than EFB fibres due to the lower

Fig. 7. Range of TS for hybrid MDF produced from EFB:RW, 20:80 and EFB

amount of holocellulose and lignin present in the fibre. Therefore,the rubberwood fibres were more stable toward water as com-pared to EFB fibre. EFB fibre was highly hydrophilic due to the freehydroxyl groups from the cellulose and lignin of cell wall of EFB fi-bres. According to Abdul Khalil et al. [8] the free hydroxyl groupcan hold the water molecule through formation of hydrogen bond-ing. Typical examples are the hydroxyl groups in cellulose and the–CONH– groups and some of the side-chain groups in proteins. Thefirst water molecules are strongly absorbed onto these sites andforming a hydrate. The directly absorbed water had the biggest ef-fect on physical properties because it resulted in the breaking ofthe cross-links between the molecules in fibre. However, the indi-rectly attached water will easily evaporated which influence on va-pour pressure

MDF boards stored at 65% RH was seen to have a lower effect onthe TS and WA of the hybrid MDF, whereas the storage of boards at93% RH was eventually seen to result in a marked decreased indimensional stability of the board, as evidenced by dramatic in-creases in TS and WA value after immersion. This result indicatesthat the internal structure of the panel has undergone changesand lost some of its integrity. This behaviour may cause an increasein TS and WA because of deterioration of some of the resin bond

:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

Fig. 8. Range of WA for hybrid MDF produced from EFB:RW, 20:80 and EFB:RW, 50:50 at normal condition, 65% RH and 93% RH environments.

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between the wood fibre of MDF core. These results agree with pre-vious studies on particleboard reported by Chow [20] and Chow[21].

4. Conclusions

The conclusions from the study are summarised as followed:

1. The mechanical properties of the EFB hybrid MDF:RW, 20:80and EFB:RW, 50:50 were decreased with the increase in storagetime and relative humidity.

2. Hybrid MDF produced from EFB:RW, 20:80 showed highermechanical and physical properties compared to hybrid MDFproduced from EFB:W, 50:50.

3. The manufacturing process and type of material used in pro-duced MDF also has a significant effect on the mechanical prop-erties and dimensional stability of the boards.

Acknowledgements

The authors would like to thank the Universiti Sains Malaysia(USM), Penang and Malaysia Palm Oil Board (MPOB), Bangi thathad made this work possible.

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