This study evaluated the technical feasibility of making block board from Melia dubia. Block board from Melia dubia was produced with phenol formaldehyde resin employing hot pressing conditions as required for the resin formulation. Block boards thus produced were subjected for evaluation of physical and mechanical properties as per relevant specifications (IS 1659, 2004). The test results revealed that the modulus of elasticity (MoE) obtained is 7446 N/mm2 (average) against the required value of 5000 N/mm2 and 6865 N/mm2 (Minimum individual) against standard value of 4200 N/mm2. The modulus of rupture (MoR) obtained is 58.7 N/mm2 (average) against the required value of 50 N/mm2 and 45.2 N/mm2 (Minimum individual) against standard value of 42 N/mm2. All other requirements such as variation in dimensions, Surface defects and dimensional changes caused due to humidity stays well within the limits as specified in the Indian standard. From the outcome of the tests carried out, it is found that the block boards from Melia dubia conforms to the requirements as laid in the Indian standards. From this study, it can be concluded that Melia dubia timber can be used for manufacturing block board which meets the requirements of Indian standards as prescribed in IS: 1659 – 2004 (specifications for block boards).

1. Block Board from Melia dubia
IJFWS
Block Board from Melia dubia
*M.P. Singh1, Prakash. V2, Uday. D. N3, Sujatha. D4, Kiran. M. C5 and Narasimhamurthy6
1Director, Indian Plywood Industries Research and Training Institute (Bengaluru) and Director, Institute of Wood Science
and Technology (Bengaluru).
2,3 Process Development, Engineering, Sawmilling and Saw Doctoring Division, IPIRTI, Post Bag No.2273, HMT Link Road
OFF Tumkur Road, Yeshwanthpur, Bengaluru - 560022
4Adhesive Technology Division, IPIRTI, Post Bag No.2273, HMT Link Road OFF Tumkur Road, Yeshwanthpur, Bengaluru
- 560022
5Center for Testing and Evaluation of Wood Composites - Division, IPIRTI, Post Bag No.2273, HMT Link Road OFF
Tumkur Road, Yeshwanthpur, Bengaluru - 560022
6 Biology - Division, IPIRTI, Post Bag No.2273, HMT Link Road OFF Tumkur Road, Yeshwanthpur, Bengaluru - 560022
This study evaluated the technical feasibility of making block board from Melia dubia. Block board
from Melia dubia was produced with phenol formaldehyde resin employing hot pressing
conditions as required for the resin formulation. Block boards thus produced were subjected for
evaluation of physical and mechanical properties as per relevant specifications (IS 1659, 2004).
The test results revealed that the modulus of elasticity (MoE) obtained is 7446 N/mm2
(average)
against the required value of 5000 N/mm2
and 6865 N/mm2
(Minimum individual) against standard
value of 4200 N/mm2
. The modulus of rupture (MoR) obtained is 58.7 N/mm2
(average) against the
required value of 50 N/mm2
and 45.2 N/mm2
(Minimum individual) against standard value of 42
N/mm2
. All other requirements such as variation in dimensions, Surface defects and dimensional
changes caused due to humidity stays well within the limits as specified in the Indian standard.
From the outcome of the tests carried out, it is found that the block boards from Melia dubia
conforms to the requirements as laid in the Indian standards. From this study, it can be concluded
that Melia dubia timber can be used for manufacturing block board which meets the requirements
of Indian standards as prescribed in IS: 1659 – 2004 (specifications for block boards).
Keywords: Block board, Phenol formaldehyde resin, Modulus of Elasticity (MoE), Modulus of Rupture (MoR), Melia dubia.
INTRODUCTION
Tremendous pressure of the ever-increasing population
and impact of economic growth has put burden on the
forest resources for various end uses. The current supply
of raw material for wood-based industries in the country is
lagging behind the demand (Chauhan RS et al., 2018).
Melia dubia belongs to the family meliaceae which also
has its trade name as Malabar neem and locally called as
Hebbevu (Kannada), Malai Vembu (Tamil). It’s an
indigenous fast-growing tree species with multipurpose
usage such as for packaging and as raw materials for
plywood, pulpwood, particleboard, laminated veneer
lumber (LVL) (Prakash V et al., 2019) etc. The species is
suitable for plantation viz. farm forestry and agro forestry
under various agro climatic conditions. Thus, in the current
scenario further studies on suitability of this timber for other
panel products like Block board will help this species to
gain greater attraction by farmers, foresters and plantation
growers. Inadequate raw materials and stringent forest
policies have forced the wood-based industries to become
self-reliant in terms of acquiring their own raw materials.
The growing demand for timber can be met to some extent
by utilizing fast growing species and increasing the timber
production through intensive silviculture management.
*Corresponding Author: Prakash Vijay kumar, Process
Development, Engineering, Sawmilling and Saw Doctoring
Division, Indian Plywood Industries Research and Training
Institute, Post Bag No.2273, HMT Link Road OFF Tumkur
Road, Yeshwanthpur, Bengaluru - 560022.
Email: prakashv@ipirti.gov.in
Co-Author 1
Email: director@ipirti.gov.in
3
Email: nduday@ipirti.gov.in
4
Email: dsujatha@ipirti.gov.in
5
Email: kiranmc@ipirti.gov.in
6
Email: nmurthy@ipirti.gov.in
Research Article
Vol. 7(2), pp. 096-100, August, 2020. © www.premierpublishers.org. ISSN: 2167-0465
International Journal of Forestry and Wood Science

2. Block Board from Melia dubia
Singh et al 97
Melia dubia is currently being promoted as a fast-growing
plantation timber species which is emerging as a
promising source of raw material for wood-based panel
industries and the results are encouraging as more
number of farmers are taking up large scale plantations in
almost every part of India. The performance of this species
greatly depends on the plantation density (Patil H Y et al.,
2017) and the environment in which they grow
(Swaminathan et al., 2012).
Plywood has long been an integral part of light-frame wood
construction and furniture, but other composite materials,
such as block board, are increasingly being substitute for
solid wood and plywood (Morrell et al., 2002). Block board
consists of a central layer (core) made up of solid wood
strips that may contain defects undesirable for the face of
the finished panels. The facing on block board is stiffened
and bound together by glued, hot-pressed rotary-cut
veneers. Adjacent veneers are oriented perpendicular to
the grain (Laufenberg et al., 2006).
Block board is one of the alternatives to plywood, which
withstands bending better than plywood. The main
advantage of block board is that the heart of the board is
produced from thick sections of sawn wood assembled
edge wise with in a frame which is sandwiched with cross
bands and face veneers on either sides as shown in figure
1 and figure 2 (Teixeira et al., 2017), the core can also be
made of short slats with different end-to-end joints
(Moazami et al., 2014) the core and the veneers being
glued under high pressure and temperature. Because of
the way it is made, block board is considered a distinct type
of plywood (Zanuttini et al., 2002). The left out portion of
logs during veneer peeling which is also known as peeler
core or lumber cores can be sawn and used as core for
block boards and thus reducing cost and manufacturing
time. Typical applications of block boards are in
manufacturing furniture, backs of cabinets and centre
panels for framed doors, kitchen cupboards, core for flush
doors, lightweight and decorative doors etc. apart from
these applications partitioning, exhibition panelling,
kitchen cabinets, bedroom and dining room furniture,
loudspeaker boxes can also be manufactured from block
board (Kartal and Ayrilmis, 2005; Laufenberg et al., 2006).
SCOPE
For any wood based industry to survive in the market,
uninterrupted supply of timber raw materials is the key.
Shortage of raw materials have forced many wood based
industries to operate below their installed production
capacities. In such situations, the Forest research
laboratories are working on to identify various fast growing
plantation timber species which can substitute the timber
from natural forests as raw material source for wood based
panel industries on the other hand, wood based panel
industry oriented research institutes are working on to
make most use of the plantation timbers by reducing the
wastage. Melia dubia is one such fast growing plantation
timber species which is suitable for producing panel
products like plywood, particleboard, laminated veneer
lumber (LVL), medium density fibreboard (MDF) etc. This
research work is an extension of the previous woks to find
out the suitability of Melia dubia for manufacturing block
board.
OBJECTIVES
1. To optimize the process parameters for manufacturing
block boards from Melia dubia
2. To optimize the resin formulation to achieve required
bonding in block board as per the relevant standard
3. To Evaluate the physical and mechanical properties as
per the relevant standard (IS 1659, 2004).
Figure 1 – Cross sectional view of a Block board
Figure 2 – Pictorial view of a Block board
Figure 3 – 3D view of a Block board showing the Edge
strip, core, cross bands and face veneer
MATERIALS AND METHODS
Melia dubia logs sourced from Hunsur and Periyapatana
region were sawn using through and through technique as
this technique yields more timber with minimal losses
during sawing operation. The sawn pieces were subjected
to air seasoning to bring down its moisture content slowly
to 10% in order to avoid warping, bending and cracking of
the sawn pieces. If the quantity of timber to be seasoned
is sufficiently large enough to be accommodated in

3. Block Board from Melia dubia
Int. J. For. Wood Sci. 98
seasoning chambers, then seasoning schedules needs to
be worked out in order to avoid defects arising due to rapid
removal of moisture. The planks thus obtained were
subjected to ripping in a multiple rip saw and reduced in to
battens of thickness and width of approximately 26.5 mm.
These battens were assembled between the edge strips of
width 45 mm and thickness 26.5 mm in such a manner to
avoid significant gaps and where the strips were smaller,
the joints were staggered. Melia dubia veneers of
thickness 1.6 mm were used as cross bands on both the
sides of the core and rotary peeled Melia dubia veneer of
0.5 mm was used as face veneers on both the surfaces. A
typical construction of block board is shown in figure 3.
PHENOL FORMALDEHYDE RESIN
Adhesive selection begins by considering the types of
wood adhesives, along with their strength and durability,
preparation and use characteristics, and typical
applications. Phenol-formaldehyde is a fully exterior
(withstands long-term water soaking and drying) based
resin (Vick C B., 1999). The properties of Phenolic resin
are they possess high dry and wet strength; very resistant
to water and damp atmospheres; more resistant than
wood to high temperatures and chemical aging. They are
the primary adhesive for exterior softwood plywood, flake
board, hardboard and other such wood based panels. For
this study 100 parts of phenol and 180 parts of formalin of
37 percent formaldehyde were charged into a resin
reactor. Reaction was carried out in presence of a catalyst
i.e., sodium hydroxide, at a temperature of 82oC for about
90 minutes. The resin thus prepared had a flow time of 24
seconds when measured in IS 3944, (1982) - B4 flow cup
and a solid content of about 49% at ambient temperature.
The conventional resin formulation was adopted in this
study.
MANUFACTURE OF BLOCK BOARD
A core of size 2440 mm X 1300 mm X 26.5 mm (Length X
Width X Thickness) was prepared using the battens of
Melia dubia, rotary peeled Melia dubia veneers of
thickness 1.6 mm coated with Phenol formaldehyde (PF)
resin was used as cross bands on either side and rotary
peeled veneer of Melia dubia was used as face veneer on
both the surface. The assembly was subjected to hot
pressing at 1450C with a specific pressure of 14 kg/cm2 for
a time duration of 20 mins. The board was allowed to
stabilize for 24 hours after pressing. The board was
subjected to trimming and sanding to obtain a block board
of dimensions 2383mm X 1237mmX28mm (Lenght X
width X Thickness).
RESULTS AND DISCUSSIONS
TESTING
The block board produced was subjected to tests as per
IS 1659 (2004) and the results of the tests are tabulated in
the table 1.
TEST RESULTS
Table 1: Test results as per IS:1659-2004 for Block board from Melia dubia
S/No Test Prescribed Value Results
1 Dimensions
a) Length
b) Width
c) Thickness
d) Variation in thickness
e) Squareness (%)
f) Edge straightness (%)
Tolerance
+ 6mm – 0 mm
+ 3mm – 0 mm
± 5%
Max 0.5 mm
Max 0.2%
Max 0.2%
0
+ 1
+ 2.4 %
0.4 mm
0.05
0.05
2 Surface Defects As per clause 6.3.3 conforms
3 Dimensional Changes caused by humidity
a) Changes in length, mm
From 65% RH to 90% RH
From 65% RH to 40% RH
b) Changes in Thickness, mm
From 65% RH to 90% RH
From 65% RH to 40% RH
c) Local planeness
d) At extreme ranges of humidity
± 1
± 1
± 1
± 1
< 1/150
No delamination
+ 0.31
- 0.24
+0.27
-0.61
1/178.8
No delamination
4 Adhesion of Plies (Knife Test) Min. Pass Standard Pass Std
5. Resistance to water (72 hr boiling) Min. Pass Standard Pass Std
7 Modulus of elasticity, N/mm2
a) Average
b) Minimum individual
5000
4200
7446
6865
8 Modulus of rupture, N/mm2
a) Average
b) Minimum individual
50
42
58.7
45.2

4. Block Board from Melia dubia
Singh et al 99
Figure 4 – Graph showing Min. Standard Value and
Obtained value of MoE
Figure 5 – Graph showing Min. Standard Value and
Obtained value of MoR
Block board produced from Melia dubia was subjected to
tests as per IS:1659 – 2004 and the results obtained are
tabulated in Table 1. From Table 1, it is clear that the
variation in dimensions are very well within the prescribed
limits, variation in thickness achieved is 0.4mm against
max ±5% required as per the standard. Surface defects
conforms to the standard. Dimensional changes caused
due to humidity stays well within the limits, local planeness
value achieved is 1/178 against the required value of 1/150
and no delamination is observed at extreme ranges of
humidity. The sample also conforms to the knife test
carried out to check the adhesion of plies.
The block board with stood 72 hours boiling test without
any delamination there by conforming to the requirement
of resistance to water. The modulus of elasticity (MoE)
obtained is 7446 N/mm2 (average) against the required
value of 5000 N/mm2 and 6865 N/mm2 (Minimum
individual) against standard value of 4200 N/mm2. The
modulus of rupture (MoR) obtained was 58.7 N/mm2
(average) against the required value of 50 N/mm2 and 45.2
N/mm2 (Minimum individual) against standard value of 42
N/mm2.
As the timber from Melia dubia is anti-termite by nature
(Swaminathan et.al, 2012), this species does not require
any additional preservative treatment and no spot test was
conducted on the samples since chemical preservation
was not employed.
CONCLUSION
From the above discussions it is evident that block boards
manufactured from Melia dubia is conforming to IS:1659 –
2004, the Indian Standards for Block boards and can be
concluded that Melia dubia is suitable for manufacture of
block board. Since it is a fast growing species that can be
grown in a wide range of climatic conditions and as an
encouraging number of farmers are taking up Melia dubia
plantations, this species can be regarded as the need of
the hour for ensuring uninterrupted supply of raw materials
for wood based panel industries. Farmers can be greatly
benefitted by taking up Melia dubia plantations as it
supports them economically with good returns for minimal
planting and maintenance expenditure involved. This
study may be further extended to find the suitability of
Melia dubia for producing flush door.
ACKNOWLEDGEMENT
This paper is being published with the kind permission of
the Director, IPIRTI, Bengaluru.
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Accepted 24 June 2020
Citation: Singh MP, Prakash V, Uday DN, Sujatha D,
Kiran MC, Narasimhamurthy (2020). Block Board from
Melia dubia. International Journal of Forestry and Wood
Science, 7(2): 096-100.
Copyright: © 2020 Singh et al. This is an open-access
article distributed under the terms of the Creative
Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium,
provided the original author and source are cited.