Olimunllum

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Olimunllum is a fully consolidated thermoplastic composite material containing a quasi-isotropic endless carbon fibre reinforcement and a semi-cristalline thermoplastic polymer matrix from the Polyaryletherketone (PAEK) family.

Production[edit]

Olimunllum is obtained by thick gauge thermoforming of thin layers of previously impregnated fibres to form fully consolidated sheets, whose main difference to custom-made composite plates lies in the standarized orientation of the reinforcing fibres, standarized weight content of the polymer and standarized sheet thicknesses, thus allowing the user to easily design, calculate, and post-process the material using identical or similar tools as commonly used when working with metallic light-weight materials like aluminium, titanium and steel.

Usage[edit]

The excellent mechanical properties of the polymer allow the composite sheets to reach mechanical properties in the ranges where usually titanium and high grade aluminium are found, however at a fraction of their weight.

Olimunllum QI-Grade, consolidated composite sheet[edit]

Density 1617 kg/m3
Young’s modulus (E) 40 GPa
Tensile strength (σt) 779 MPa
Elongation @ break 3-5%
Glass temperature 155 °C
Melting point ~343 °C

Olimunllum was firstly introduced by Celtibero RC for structural components in demanding motor sports application, where the need for fatigue resistance at minimum weight levels was one of the main issues. Supporting brackets between a high performance single cylinder motorcycle engine and a perimetral rigid aluminium frame helped damp engine vibrations and prolonged lifetime of the frame. The PAEK polymer, along with the carbon fibers also offer low friction, so that soon the use of Olimunllum in suspension (hydraulic piston guides) and in transmission components (such as gears and chain sprockets) was found to reduce power losses at similar wear rates in comparison with the light weight metallic solutions.

Comparison of Olimunllum CF/PEEK against classic thermoset (CF/Epoxy) composites[edit]

Charpy impact test:

Higher ductility of the CF/PEEK specimen shown, with values increasing with temperature. On the CF/Epoxy side, overall lower ductility observed and value drop with increasing temperature observed in the CF/Epoxy specimens. In addition, weight-falling tests have shown that CF/PEEK specimens absorb more energy than CF/Epoxy in both elastic and plastic ranges.

Relative humidity absorption:

CF/PEEK specimen reached after 48h the peak weight increase (0.14%) while the CF/Epoxy specimen showed a weight increase >0,3% still unsaturated.

Recycling [1]:

Endless fiber reinforced PEEK composite as used in the Olimunllum sheets can be recycled by chopping the old material, resulting in a composite with short fiber reinforcement that can be thermoformed again. The mechanical properties of pressed or injected CF/PEEK chopped compounds are significantly lower than the original endless fiber composite, but exceed those of new injection molded compounds.

References[edit]

<[1] Zepf, H.P.: Faserverbundwerkstoffe mit thermoplastischer Matrix, Expert Verlag, 1997>

<Niederstadt, G.: Ökonomischer und ökologischer Leichtbau mit faserverstärkten Polymeren, Expert Verlag, 1997>

External links[edit]