Properties of Particleboard from Wood Wastes and...

Key words: cashew nut shell residue (CNSR), flammability, particleboard, strength properties, wood

Properties of Particleboard from Wood Wastes and Cashew Nut Shell Residue

Erlinda L. Mari and Edgar M. Villena

Forest Products Research and Development InstituteDepartment of Science and Technology

College, Laguna 4030

Cashew nut shell residue (CNSR) obtained after extraction of the liquid was combined with mixed species of wood particles at different wood to CNSR proportions (100/0, 75/25 and (50/50) to produce one-layer particleboard. The strength properties, dimensional stability, and flammability of the boards were determined to evaluate the technical feasibility of producing wood-CNSR particleboards with acceptable properties. Results indicate that the type of adhesives and wood/CNSR ratios had a significant effect on the boards’ strength properties and dimensional stability. Isocyanate resin-bonded boards exhibited the highest modulus of rupture and modulus of elasticity but the urea formaldehyde resin-bonded boards had the highest internal bond and face screw holding strength. Most of the boards met the minimum standard for internal bond strength of base particleboard. The rest of the properties failed. Replacing wood with CNSR adversely affected the strength as well as the dimensional stability of the boards. In terms of flammability, however, the ember of boards with CNSR extinguished at a shorter time than the pure wood boards, thus causing a smaller area of damage on the board.

*Corresponding author: [email protected]

Philippine Journal of Science145 (1): 1-8, March 2016ISSN 0031 - 7683Date Received: ?? Feb 20??

INTRODUCTIONIt is estimated that 0.75 Metric Tons (MT) of cashew shell is generated for every MT of cashew nut produced in the Philippines (Fidel et al. 1998). Based on this estimate, more than 200,000 MT of shells have been generated locally since 1994. From the shells, cashew nut shell liquid (CNSL) is extracted for the manufacture of friction dust for clutch lining and brake lining of vehicles.

The cake remaining after CNSL extraction is the cashew nut shell residue (CNSR), which India, the largest producer and exporter of cashew products, disposes mainly as fuel material (Ramanan et al. 2008). Such situation is similar to the local cashew industry as

it is the easiest way to dispose waste biomass. CNSR, however, releases irritant fumes when burned, as observed at the Forest Products Research and Development Institute (FPRDI) when it was used as additional fuel with woodwastes and also in the production of charcoal briquettes by Bisana and Laxamana (1998). Moreover, burning should be the last recourse in managing biomass waste and should be done only when alternative uses for the waste have been explored and exhausted.

Moran et al. (2004), on the other hand, chemically modified CNSR for use as heavy metal adsorbent in wastewater treatment. As these technologies have not been adopted, the problem of how to dispose the waste material remains.

Production of composite boards is one waste management or recycling method that is usually explored before a biomass

1

waste is disposed or even used as fuel. Wood wastes from the processing of logs for primary products such as lumber, veneer, and plywood are the usual materials for particleboard. Agricultural wastes such as rice straw and bagasse are also recommended for commercial particleboard production (Youngquist et al. 1996; Green Seal 2001).

In Turkey, research indicates that hazelnut husk (Coryllus arellana L.) can be used for the production of particleboard (Copur et al. 2007) and medium density fiberboard (Copur et al. 2008) with properties meeting product standards.

In the case of CNSR, earlier attempt by the authors to use it as sole material for particleboard was not successful. This was attributed to residual oil that only volatilized during hot-pressing. Thus, this study aimed to determine the technical feasibility of producing particleboards, not purely from the material, but with different proportions of woodwastes to serve as substrate for polymerization reaction with CNSR’s excess organic compounds and the resin binder. This paper focuses on the strength properties and dimensional stability of the experimental boards, as well as the flame resistance imparted by CNSR.

MATERIALS AND METHODS

MaterialsCNSR generated from the processing of CNSL was milled and dried to about 7-8 % moisture content (MC). Material from the -6+14 mesh fraction was used.

Wood particles were provided by PHILCOMPAK, a particleboard manufacturing plant located in southern Philippines. Accordingly, the material was processed from wood processing and plywood mill wastes, which is a common practice in particleboard manufacture. For this study, an attempt to identify some wood species was made from visually different samples of the larger particles. Material from the -6+14 mesh fraction was obtained from the bulk and similarly dried to about 7-8 % MC.

The bulk density (net weight of wood particles in a 1-L graduated cylinder) of the two materials was determined for consideration in the target density of the boards to be produced. The compaction ratio or the ratio between board density and furnish material’s density is usually 1.3 to allow for sufficient compression during pressing (Maloney 1993).

The urea-formaldehyde (UF) and phenol-formaldehyde (PF) resins were provided by Resins, Inc. while the isocyanate (IC) resin was from Premiere Adhesives & Coatings, Inc.

Production of Wood-CNSR particleboardsCNSR was mixed with the wood particles at 100/0, 75/25 and 50/50 weight ratios. The wood-CNSR mixtures were sprayed with UF, PF, or IC resins and formed into mats using a 40 cm x 40 cm forming box. The formed mats were pressed to 12 mm thickness under the laboratory hot press to produce the one-layer particleboards to a target density of 500 kg/m3. Five boards per treatment were produced for a total of 45 boards.

The amount of resin applied and the pressing conditions were specific to each adhesive as follows:

Table 1. Amout of resin applied and pressing conditions on boards.

Adhesive % Resin content

(based on oven-dry wt.)

Press Temp.,

°C

Press time, min

(step-down)

Pressure, kPa

(step-down)

Urea-Formaldehyde Resin (UF)

8 160 8 Closing at 2350

Phenol Formaldehyde Resin (PF)

6 180 6

Isocyanate Resin (IC)

3 150 5

Testing of board propertiesAfter pressing, the boards were left to condition for two weeks at room conditions. Figure 1 shows the cutting diagram designed to obtain from each of the five boards per treatment condition all the test specimens required by the test methods

Figure 1. Cutting diagram for specimens. Notes: IB and WA/TS specimens were cut after completing the bending strength test.

Bending Strength (BS): (15 t + 5cm) x 5 cm; 3 pc/boardInternal Bond Strength (IB) & Water Absorption (WA)/Thickness Swell (TS): 5 cm x 5 cm; 3 pc/boardFace Screw-Holding Strength (FSH): 10 cm x 5 cm; 3 pc/boardFlammability (FL):35 cm x 10 cm; 2 pc/board t = thickness, cm

Mari and Villena: Wood and Cashew from Nutshell Residue

Philippine Journal of ScienceVol. 145 No. 1, March 2016

2

Physical and mechanical propertiesSpecimens for the testing of bending strength (BS) in terms of modulus of rupture/elasticity (MOR/MOE), internal bond strength (IB), face screw-holding (FSH), and water absorption/thickness swelling (WA/TS) were tested using the JIS A 5908 Standards for Particleboard (2003) as reference.

Flammability Flammability tests for housing materials require specimens that are much larger than boards in laboratory experiments. To obtain an indicator of board flammability using only small specimens, the flammability test for interior materials of vehicles, Standard No. 302 from the US Motor Carrier Vehicle Safety Standards similar to MS CF 050C (Mazda Motor Corporation 1997) was adapted with modifications.

Specimens measuring 10 cm x 35 cm were cut from the boards. Each specimen was placed between U-shaped stainless steel jigs then exposed to a flame for 20 minutes (Figure 2).

Figure 2. Fire-test set up.

Figure 3. Measurement of burnt portion. D – depth, mm; W – width, mm

RESULTS AND DISCUSSION

Wood and CNSR particlesThe wood particles were obtained from the wastes of wood processing and plywood mills. These were found to consist of different species, namely, moluccan sau [Paraserianthes falcataria (L.) Nielsen], yemane (Gmelina arborea Roxb.), mahogany [Swietenia macrophylla (L.) Jaqc.], ipil-ipil [Leucaena leucocephala (Lam.) de Wit.], antipolo [Artocarpus blancoi (Elmer) Merr.], toog [Petersianthus quadrialatus (Merr.) Merr.], Vitex sp., nato (Palaquium sp.), bitaog (Calophyllum sp.), and Litsea sp.

The densities of these wood species varied greatly but since it was not possible to measure the proportion of each species in the mix, the average density could not be estimated. The bulk density was, therefore, measured which was found to be 0.17 g/mL, while CNSR was 0.40 g/mL.

The low value for the mixed wood wastes suggests the greater proportion of the lower density veneer log cores of the low density species (like moluccan sau with about 0.25 relative density) and other wood processing/forest wastes of lower density. Such other species may have not been identified since sampling was difficult with materials already in particle form. Target density of the boards was placed at 0.50 g/mL or 500 kg/m3 to allow for sufficient compression even of CNSR particles. The ratio between the target board density and CNSR’s bulk density is 1.25.

Effect of wood/CNSR ratio and adhesive type on board propertiesThe ANOVA generally indicated a highly significant effect of adhesive type (A) and wood/CNSR (B) ratio on the physical and mechanical properties of the wood-CNSR particleboards (Table 1). Despite the single density target, variation occurred due probably to the uneven distribution of the heavier CNSR particles within the

The time (min.) for the ember to die out was measured from the time the source of flame was removed. Then, weight loss (WL %) was calculated from the weight before and after the ember completely extinguished. The depth and width of the burnt area were then measured with a ruler (Figure 3).

Data AnalysisAnalysis of variance in completely randomized design (ANOVA in CRD) and Duncan Multiple Range Test (DMRT) were conducted to evaluate the effects of wood/CNSR proportion and binder on the boards’ strength and physical properties. Flammability was also evaluated by ANOVA on weight loss, time for ember to die out, and depth and width of the burnt area.



3

mix. This caused a generally highly significant effect on the board properties. The Interaction between the two variables (A x B) was, however, highly significant only on IB, FSH, and WA.

Ranking of means by DMRT indicates the individual effect of adhesive type, wood/CNSR ratio, and their interaction (Table 2). Results showed that the IC-bonded boards with the highest MOR and MOE and lowest TS and WA values significantly differed from the PF- and UF-bonded

boards. This was not unexpected as isocyanate resin is versatile and imparts strong bonds by reaction of its NCO groups with the hydroxyl groups of the wood particles (Schollenberg 1977).

On the other hand, the higher IB and SH values of UF-bonded boards are rather unexpected. In the case of IB, it was thought that curing of the glue until the core layer was sufficient with UF but may have gone faster than necessary with IC and PF-bonded boards. The higher FSH could be due to a more uniform coverage of UF adhesive on the wood particles compared with the lesser amounts of PF and IC adhesives.

As to the effect of the raw materials, replacing wood with some CNSR adversely affected all the properties. That is, both strength and dimensional stability diminished. This indicates that the CNSR particles, which were short and rounded and still had some waxy and oily portions, may have resisted bonding or formed other polymerization products with the adhesive and the wood particles that did not have impact on these properties. Moreover, some wood particles were also a bit cylindrical instead of flat.

Figure 4 shows samples of the wood and CNSR particles. Their difference in size and shape may have resulted in poor contact among particles. Optimum compression may have not been achieved which may also be due to the mixed wood species used as materials. The variation

in particle properties may have resulted in insignificant interaction between adhesive type and material ratio, particularly for MOR, MOE and TS.

Except for the IB of all the UF- and IC-bonded boards and the PF-bonded board with 100 % wood particles, all the other values were inferior to the standard values for JIS Type 8 base particleboards. The results cannot be compared with those of composites using hazelnut shell and husk (Copur et al. 2007 and 2008) as the materials and board densities are different. Considering these and the poor quality of the wood particles, experiments on a higher density (about 0.7 -0.8 g/cc) three-layer particleboard should be conducted for an improved surface layer which provides the resistance for tension or bending.

Effect of wood/CNSR ratio and adhesive type on board flammabilityIn the charcoaling of CNSR, Bisana and Laxamana (1998) observed that the rate of carbonization is faster than with other kinds of biomass such that control of the process was critical. The flammability test was conducted on wood-CNSR particleboard to observe how the board behaves in case of exposure to flame.

During the preliminary test, the boards exposed to flame did not ignite after the prescribed time of 15 seconds. Even after a minute of exposure to flame, there was still hardly any damage. Thus, exposure was extended to 20 minutes.

Table 1. Summary of analysis of variance (ANOVA) results on the properties of wood-CNSR particleboards.

Source of Variation dFMean Squares

MOR MOE IB FSH TS WA

Model 9 159.44 ** 2825281 ** 1.449 ** 218.04 ** 204 ** 1445 **

Adhesive (A) 2 118.45 ** 7299636 ** 2.43 ** 194.02 ** 524.8 ** 1474.3 **

Wood/CNSR (B) 2 350.05 ** 488351 ns 1.455 ** 662.58 ** 148 * 873.75 **

A*B 4 4.816 ns 267175 ns 0.783 ** 34.757 ** 26.73 ns 324.45 **

Density 1 66.737 ** 14229 ns 1.244 ** 78.237 ** 36.6 ns 807.91 **

Error 35 4.491 405752 0.161

Total 44

R2, % 90.13 64.16 69.86 92.21 63.04 90.36

CV 9.65 16.05 21.49 12.75 14.6 5.11MOR – Modulus of Rupture; MOE – Modulus of Elasticity; IB - Internal Bond strength;FSH – Face screw-holding; WA - Water absorption; TS - Thickness swelling** - Significant difference at α = 0.01* - Significant difference at α = 0.05 ns - No significant difference



4

IC – Isocyanate resin; PF – phenol formaldehyde resin; UF – urea formaldehyde resinMOR – Modulus of Rupture; MOE – Modulus of Elasticity; IB - Internal Bond strength;FSH – Face screw-holding; WA - Water absorption; TS - Thickness swellingFor each variable, property means in each column followed by the same letter are not significantly different at α = 0.05

Figure 4. Wood and CNSR particles.

Figure 5. Specimens after fire test.

Table 2. Duncan Multiple Range Test (DMRT) on property means of wood-CNSR particleboards.

VariablesMOR MOE IB FSH TS WA

kg/cm2 kg/cm2 kg/cm2 kg % (24h) % (24h)

Adhesive

IC 25.9 a 4868 a 1.91 b 13.72 c 31.12 c 110.81 c

PF 19.0 c 3158 c 1.44 c 16.57 b 45.38 a 135.24 a

UF 21.0 b 3876 b 2.24 a 20.90 a 37.41 b 123.59 b

Wood/CNSR

100/0 27.3 a 4207 a 2.13 a 23.80 a 34.36 a 114.95 a

75/25 22.2 b 3851 a 1.97 a 17.08 b 38.12 ab 122.71 b

50/50 16.3 c 3845 a 1.51 b 10.31 c 41.44 b 131.98 c

Adhesive*Wood/CNSR

IC * 100/0 31.3 a 5247 a 1.90 b 17.00 d 26.51 a 92.67 a

IC * 75/25 25.9 a 4732 a 2.11 b 15.22 de 29.79 a 110.52 cd

IC * 50/50 20.4 a 4627 a 1.73 b 8.99 f 37.06 a 129.25 b

PF * 100/0 25.2 a 3524 a 2.20 ab 25.27 b 40.03 a 129.42 cd

PF * 75/25 18.2 a 2817 a 1.16 c 15.57 de 48.2 a 136.42 e

PF * 50/50 13.6 a 3133 a 0.97 c 8.88 f 47.92 a 139.88 de

UF * 100/0 25.5 a 3850 a 2.28 ab 29.15 a 36.54 a 122.78 c

UF * 75/25 22.5 a 4004 a 2.63 ab 20.46 c 36.36 a 121.18 c

UF * 50/50 15.1 a 3775 a 1.81 b 13.08 e 39.34 a 126.82 c

JIS A 5908 Type 8 8 N/mm2 2000 N/mm2 0.15 N/mm2 300 N < 12 % none

81.6 kg/cm2 20400 kg/cm2 1.53 kg/cm2 30.6 kg < 12 % none

Nonetheless, in all cases, flaming of the board readily stopped as soon as the source of flame was removed, thus, burning only a small portion of the board (Figure 5).

Table 3 shows the ANOVA on data for weight loss, ember life or time of ember to die out, and depth and width of the burnt area. Similar to the preceding results, the type of adhesive and wood/CNSR ratio had highly significant

effects on the flammability parameters, but not their interaction.

In Table 4, ranking of means by DMRT indicates that the UF and IC-bonded boards had significantly lower weight loss after burning. The ember of UF-bonded boards also died out in shorter time (about 12 min) than IC-bonded boards (about 18 min) and PF-bonded boards (more than 26 min). Consequently, the burnt portions (depth and width) of the first two were significantly smaller.



5

Table 3. Summary of ANOVA on the flammability parameters of wood-CNSR particleboards.

Source of Variation dFMean Squares

Wt Loss Ember life Depth Width

Model 8 0.6090 ** 262.692 ** 32.889 ** 31.139 **

Adhesive (A) 2 2.1536 ** 793.099 ** 114.51 ** 98.272 **

Wood/CNSR (B) 2 0.1248 ns 177.556 ** 14.156 ** 15.239 *

A*B 4 0.0788 ns 40.056 ** 1.447 ns 5.522 ns

Error 36 0.0886 8.168 1.786 2.972

Total 44

R2, % 60.42 87.72 80.36 69.95

CV 17.51 14.98 8.71 5.64

** - Significant difference at α = 0.01* - Significant difference at α = 0.05 ns - No significant difference

Table 4. DMRT on flammability means of wood-CNSR particleboards.

VariablesWt. Loss%

Ember lifemin

Depthmm

Widthmm

Adhesive

IC 1.47 a 18.28 b 13.83 a 30.30 b

PF 2.14 b 26.71 c 18.53 b 33.23 c

UF 1.49 a 12.23 a 13.67 a 28.13 a

Wood/CNSR

100/0 1.80 a 22.92 b 16.43 b 31.67 b

75/25 1.68 a 18.03 b 15.03 a 30.30 a

50/50 1.62 a 16.28 a 14.57 a 29.70 a

Adhesive*Wood/CNSR

IC * 100/0 1.53 a 19.1 bc 14.40 a 30.70 a

IC * 75/25 1.36 a 17.55 bc 13.90 a 30.20 a

IC * 50/50 1.53 a 18.21 bc 13.20 a 30.00 a

PF * 100/0 2.23 a 33.59 e 20.20 a 35.70 a

PF * 75/25 2.10 a 24.88 d 18.10 a 32.60 a

PF * 50/50 2.08 a 21.66 cd 17.30 a 31.40 a

UF * 100/0 1.64 a 16.06 bc 14.70 a 28.60 a

UF * 75/25 1.57 a 11.66 a 13.10 a 28.10 a

UF * 50/50 1.27 a 8.98 a 13.20 a 27.70 a

IC – Isocyanate resin; PF – phenol formaldehyde resin; UF – urea formaldehyde resinMOR – Modulus of Rupture; MOE – Modulus of Elasticity; IB - Internal Bond strength;For each variable, property means in each column followed by the same letter are not significantly different at α = 0.05



6

In terms of wood/CNSR ratio, replacing wood with CNSR indicates that the ember of the burned board died out faster than the pure wood board and, therefore, had a smaller burnt portion. This may appear contradictory to the faster rate of carbonization observed by Bisana and Laxamana in their charcoaling experiment (1998). In this study, however, the raw materials wood and CNSR have undergone heating under pressure that may have caused in-situ polymerization of their organic compounds resulting to composites with short-lived embers when burned.

Interaction between the two variables (adhesive x wood/CNSR ratio) did not register significant effect on weight loss and the extent of damage of the burnt portion. However, it is evident that the UF-bonded board with 50/50 wood-CNSR ratio had the least weight loss (1.27 %) corresponding to a significantly shortest (8.98 min) ember life. The IC-bonded board followed while the PF-bonded board with pure wood burned the most.

Moreover, among the IC-bonded boards, ember life was reduced by 0.89-1.55 min, albeit insignificant, by replacing wood with 25-50 % CNSR. Among UF-bonded boards, CNSR significantly reduced ember life by 4.4 - 7.08 min. While the ember life of the pure wood PF-bonded board was the longest (33.59 min), 25 % and 50 % replacement of wood with CNSR significantly reduced this by 8.71 min and 11.93 min, respectively. In view of these results, it is thought that during hot-pressing of the boards, CNSR’s residual polyphenols may have polymerized with excess reactive groups in the adhesives (formaldehyde (HCHO) for UF and PF; cyanate (NCO) for IC) that caused the wood-CNSR boards to be not easily ignited and have short-lived embers, thus limiting their damage to flame. Similar observations are indicated in an on-going investigation on formaldehyde-reacted CNSL as a fire-retardant chemical for coating of wood surface.

In earlier developments, CNSL-derived bio-resin is claimed to provide heat and chemical resistance to composite material that can slow down the spread of flame Ferri (2011).

CONCLUSION AND RECOMMENDATIONSResults of the study indicate that the type of adhesives and proportion of wood to CNSR bear significant effect on the boards’ strength properties and dimensional stability. Specifically, isocyanate resin-bonded boards exhibited the highest modulus of rupture and modulus of elasticity but the urea formaldehyde resin-bonded boards had the highest internal bond and face screw holding strength. Most of the boards met the minimum standard for internal

bond strength of base particleboard. The rest of the properties failed. Replacing wood with CNSR adversely affected the strength as well as the dimensional stability of the boards.

On the other hand, regardless of material ratio, flaming on all boards stopped upon removal of the source of flame. However, the ember of boards with CNSR extinguished at a shorter time, thus causing a smaller damage on the boards.

A study on higher board density (07 - 0.8 g/cc) three-layer particleboard is recommended to improve bending strength and face-screw holding capacity which are strength properties primarily dependent on the surface layer.

ACKNOWLEDGEMENTThe authors gratefully acknowledge the Forest Product Research and Development Institute, Department of Science and Technology (DOST-FPRDI) management for the fund and support for the study; the management of PHILCOMPAK, a particleboard manufacturing plant based in Ozamis, Misamis Occidental, for the wood particles; Resins, Inc, for the urea-formaldehyde and phenol-formaldehyde resins; Premiere Adhesives & Coatings, Inc., for the isocyanate resin; Ms. Socorro Dizon, for the statistical analyses of data; and other FPRDI employees who helped in any way towards the completion of this study.

REFERENCESBISANA BB and NB LAXAMANA. 1998. Utilization

of cashew nut shell residue for the production of charcoal briquettes and activated carbon. FPRDI Journal 24(2):25-38.

ÇÖPÜR Y, GÜLER C, AKGÜL M, TAŞÇIOĞLU C (2007). Some chemical properties of hazelnut husk and its suitability for particleboard production. Build Environ 42:2568–2572. Retrieved from http://dx.doi.org/10.1016/j.buildenv.2006.07.011 on 14 March 2014.

ÇÖPÜR Y, GÜLER C, TAŞÇIOĞLU C, TOZLUOĞLU A. 2008. Incorporation of hazelnut shell and husk in MDF production. Bioresour Technol 99(15):7402–7406. Retrieved from http://dx.doi.org/10.1016/j.biortech.2008.01.021 on 14 March 2014.

FERRI E. 2011. Bio-resins derived from cashew nutshell oil. Reinforced Plastics.com. Retrieved from http://www.reinforcedplastics.com/view/17700/bio-resins-derived-from-cashew-nutshell-oil/ on 11 March 2014.



7

FIDEL MM, PALANGINAN II, DIONGLAY MSP, BATO RC, TAMAYO JP, GARCIA CMC. 1998. Extraction and characterization of cashew nut shell liquid (CNSL). FPRDI Journal 24(2):1-11

GREENSEAL. 2001. Particleboard and Medium-Density Fiberboard. Green Seal’s Choose Green Report. Retrieved from http://www.wbdg.org/ccb/GREEN/REPORTS/ cgrparticleboard. pdf. on 19 February 2014.

[JSA] Japanese Standards Association. JIS A 5908-2003. Japan Industrial Standard for Particleboards. Tokyo, Japan. 26 p.

MALONEY TM. 1993. Modern Particleboard and Dry-Process Fiberboard Manufacturing. San Francisco, USA: Miller Freeman Inc, 672 p.

MAZDA MOTOR CORPORATION. 1997. Mazda Engineering Standard MES CF 050C. Flammability of Interior Parts. 22p.

MORAN MSR, SEVILLA FB, MARI EL. 2004. Chemically modified cashew shell residue as an adsorbent for heavy metal ions. FPRDI Journal 30(Jan-Dec):26-48.

SCHOLLENBERG CS. Polyurethane and isocyanate-based adhesives. In: Handbook of Adhesives. 2nd edition. Skeist, I., Ed. New York, USA: Van Nostrand Reinhold and Co. pp. 446-463.

US Motor Carrier Vehicle Safety Standards, No. 302. Flammability of Interior Materials. Retrieved from http://fmcsa.dot.gov/rules-regulations/administration/fmcsr/ fmcsrruletext.aspx?reg=571.302. on 23 January 2014.

YOUNGQUIST JA, AM KRZYIK, BW ENGLISH, HN SPELTER, CHOW P. 1996. Agricultural Fibers for Use in Building Components. In: The use of recycled wood and paper in building applications: Proceedings of a 1996 symposium sponsored by the U.S. Department of Agriculture Forest Service, Forest Products Laboratory and the Forest Products Society, in cooperation with the National Association of Home Builders Research Center, the American Forest & Paper Association, the center for Resourceful Building Technology, and Environmental Building News. Proc. 7286. Madison, WI: Forest Products Society. pp 123-134; Retrieved from http://www.fpl.fs.fed.us/documnts/pdf1996/young96a.pdf. on 19 February 2014.

R A M A N A N M V, L A K S H M A N A N E , SETHUDHAMAYAN R, RENGANARAYANAN S. 2008. Performance prediction and validation of equilibrium modeling for gasification of cashew nut shell char. Braz J Chem Eng 25(3):585-601. Retrieved from http://www.scielo.br/pdf/bjce/v25n3/a16v25n3.pdf on 10 March 2014.



8

Date post:	17-Apr-2018
Category:	Documents
Upload:	ngodien
View:	219 times
Download:	6 times

Properties of Particleboard from Wood Wastes and...

Documents