Page 58 - FDMAsia MayJun 2025

56 MATERIALS MAY/JUN 2025 FDM ASIA | www.fdmasia.com

Forbo panel type.
The nail depth corresponded to the panel thickness, and
withdrawal testing was conducted at a crosshead speed of
1.5 mm/min using the UTM. To contextualise these results,

equivalent specific gravity (ESG) values were calculated for
comparison with established engineered wood products.
ESG values were derived using empirical equations from the
Wood Handbook and National Design Specification, correlating
specific gravity with mechanical properties to benchmark the
resin during production. Results were compared between the new material against traditional timber products.
two panel types to evaluate the impact of strand re-resinating The calculated analytical value would also help establish
on bond performance. the functionality of the panels, compared to standard strand-
In addition to IB strength, tensile and bending properties based panels in the market, like OSBs.

were analysed to assess the load-bearing capacities of the These analyses provide comprehensive insights into the
panels for design purposes. mechanical performance of wood-composite panels, including
ASTM D1037-13 was used to determine tensile and flexural their bonding quality, load-bearing capacity, and fastener
properties in both longitudinal and transverse directions. retention properties, enabling practitioners to evaluate their
Five replicates of each panel type were tested for each suitability for various applications while comparing them against
property. Dog bone specimens were cut from panels using established materials through ESG calculations.
a cutting jig on a router machine, with dimensions of 254

mm in length and 50.8 mm in width, featuring a reduced Fire Performance
cross-section and a gauge length of 50.8 mm with 70 mm The fire reaction properties of the panels were analysed to
grip lengths on each side. evaluate how strand recycling and resin reapplication affected
A universal testing machine (UTM) was employed at a thermal stability and combustion behaviour.
crosshead speed of 4 mm/min to calculate tensile strength Thermogravimetric Analysis (TGA) and Derivative
and Young’s modulus using standard equations from ASTM Thermogravimetric Analysis (DTGA) were initially conducted
D1037-13. following ASTM E1131-20.
The same standard was applied to determine the modulus The specimens underwent controlled heating at 10 K/min
of elasticity (MOE) and modulus of rupture (MOR) through in an inert atmosphere, with three replicates per panel type

midpoint bending tests. tested to track normalised mass loss and decomposition rates
Specimen spans were set at 48 times the panel thickness, as functions of temperature. Results revealed compositional
with a width of 50.8 mm and a loading rate of 12.2 mm/min, variations between recycled and virgin materials through
utilising the same UTM for testing. The nail withdrawal properties distinct thermal degradation patterns.
of the panels were also examined to evaluate fastener holding Mass-loss calorimetry tests, following ASTM E2102-17
capabilities and mounting performance. and ISO 17554:2014 standards and using GBH International
This analysis followed ASTM D1037-13 standards using Corp equipment at the University of Idaho, were conducted.

an 8d common nail driven completely through panel samples Five replicates of each panel type were exposed to 50
measuring 76.2 mm by 152.4 mm, with seven replicates per kW/sqm heat flux at 25 mm from a cone heater, with a 3 mm