Page 78 - Plastics News July 2025
P. 78
PRODUCT NEWS
to develop new hybrid formulations by incorpo- system. This setup allowed the team to validate
rating CNTs into the micronized amide resin. The rheological findings from creep tests, oscillatory
addition of CNTs significantly increased the yield sweeps, and flow curves.
stress—reaching 1400 Pa with 0.5 wt% CNT—
and improved sag resistance. This enables the
resin to bridge spans up to 20 times the noz-
zle diameter. However, extrudability decreased,
making the material too viscous for fine nozzles
(e.g., 18 gauge).
Despite this issue, the formulation with 15 wt%
micronized amide and 0.5 wt% CNT proved to
be the most effective combination.
Formulation Innovations for Superior EDAM Per-
formance
Overall, this study demonstrates the benefits of
combining additives to achieve superior resin
formulations. By mixing micronized amide with
Connecting Lab Rheometer Data to Real-World CNTs, the resin exhibited increased yield stress
Print Performance and enhanced sag resistance. This significantly
improved bridging performance. In the best case,
Beyond developing a new resin formulation for the resin showed excellent sag resistance. The
EDAM, one of the study’s most significant break- total sag measured less than one nozzle height
throughs was the connection between laborato- over a span of 20 times the nozzle diameter.
ry results and real-world printing performance.
The research team conducted rheology and Researchers noted that further studies are
bridging tests to directly link material behavior needed to reduce the shear thinning exponent
to actual print outcomes. and increase the elastic modulus at high shear
rates. Despite this, the results represent a sig-
To physically evaluate span bridging, they built a nificant advancement for EDAM of sparse infill
custom testing apparatus. While lab-scale meas- structures. With these new formulations, such
urements provided controlled, quantifiable data, structures could become not only lightweight
the real-world simulation demonstrated wheth- and cost-effective but also exhibit improved
er those rheological properties translated into mechanical properties. This opens the door to
practical printing success. broader applications across various industries.
The bridging fixture included a syringe pump Source – PLASTICS ENGINEERING
with 18-gauge nozzles, a linear slide table with
an aluminum bridging platform, and a camera
78 PLASTICS NEWS July 2025
