The amount of electronics waste is increasing rapidly, and replacing traditional electronics
materials with biodegradable alternatives is essential where possible. In this research
work, PLA (polylactic acid) based substrates with different fillers (pure PLA and
ones filled with Licocene™, wool fibres or keratin powders) and with different thicknesses
(ranging from 0.9 to 1.9 mm) were investigated from their mechanical point of view.
The mechanical behaviour was addressed by measuring the flexural behaviour of these
substrates with a 3-point bending test. The bending tests were carried out loosely
following EN ISO 178 and IEC 60068-2-21 standards. These demand the precise measurement
of the test specimen’s deflection and the required force. For this purpose, a custom
measurement equipment was developed, in which the deflection is measured by a Balluff
incremental linear encoder and a deflection gauge, whereas the force was measured
with an L6P aluminium planar beam having a combined error of ≤±0.023%FS at 450 N maximum
load. The force sensor was calibrated up to 120 N using reference weights. The samples
were tested then at two loading speeds to address time-dependent behaviour and measure
the flexural modulus. A motorised stage was also developed to aid the repeatability
of the measurements.
