Page 60 - Plastics News Issue September2025
P. 60
TECHNOLOGY NEWS
Metals where metal replacement can provide significant
weight savings while maintaining the required
If you were to put a common metal under the mechanical and thermal properties. In addition,
microscope, you’d see a structure similar to im- these high temperature thermoplastics demon-
age A below. Metals are made up of small grains, strate superior chemical and corrosion resist-
where each grain consists of a crystal lattice (im- ance compared to common in-service metals.
age B). These crystals are made of an array of
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metal atoms that are connected through strong We can see that PEEK and ULTEM offers be-
metallic bonding. The bonding and the organi- tween 50-60% weight reduction, while main-
zation of atoms into crystals is why metals are taining high strength and high heat resistance.
naturally strong and stiff. Often these grains dif- Replacing metals means greater fuel savings,
fer from each other by the size and orientation lower carbon emissions or increased payload
both of which influence the bulk properties of capabilities for the transportation industry. In
the metal. addition, these materials possess high chemical
resistance, high impact resistance, are UL94-V0
In conclusion, semi-crystalline polymers are par- flammability rated, and meets FAR 25.853 flame,
tially made of crystals while metals contain many smoke, and toxicity (FST) requirements, a re-
crystals (grains) that differ in orientation. Since quirement in aerospace and naval applications.
thermoplastic polymer chains are chemically
separate, the attraction force is weaker than the How to 3D Print PEEK and ULTEM TM
metallic bonding between crystals in metals. As a
result, metals are more resistant to elastic defor- Simply 3D printing high performance materi-
mation (stiffer) and generally more temperature als won’t guarantee that the parts will possess
resistant. It’s the reason why metals have been the reported mechanical, thermal, and chemical
the default choice for mechanical and thermal properties. To match these properties, the se-
applications. But as we engineer more advanced lected 3D printer needs a precision-controlled
0
thermoplastics, the effective strength begins to high temperature build chamber (up to 260 C),
0
match and, in some cases, surpass metals. 500 C extruders, and configurable print surfac-
es. Printing at temperatures colder than 140 C
0
Two Suitable Metal Replacement Materials: can significantly reduce part strength, chemi-
PEEK and ULTEM TM cal resistance, and require further annealing in
which warping is unavoidable. AON3D Hylo is a
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PEEK and ULTEM 9085 are two of the most large, high temperature industrial 3D printer op-
popular polymers that have been considered timized to make 3D printing high performance
for replacing metals. The graph below compares materials like PEEK and ULTEM 9085 easy and
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these materials to Aluminum 6061, an alloy used accessible.
in the construction of aircraft structures, auto-
motive parts, marine structures, and consumer
products. CF PEEK contains 10% carbon fiber
which increases the strength and stiffness of
baseline PEEK. These are several industries
60 PLASTICS NEWS September 2025
