Enhancing 3D Printed Parts: A Comprehensive Guide to Annealing UltiMaker's PET CF

by Christian Behrens-Thomsen on Sep 15, 2023

Enhancing 3D Printed Parts: A Comprehensive Guide to Annealing UltiMaker's PET CF

In the rapidly advancing domain of 3D printing, UltiMaker has introduced its innovative PET CF—a carbon fiber composite material meticulously engineered for high-performance applications. This article delves into the technicalities of enhancing the properties of PET CF through the process of annealing.

The Technical Foundations of Annealing

Annealing, a heat treatment process with roots in metallurgy, has been traditionally employed to alleviate stresses, augment ductility, and optimize material properties. When applied to semi-crystalline materials like PET CF, annealing can significantly enhance mechanical attributes, including tensile strength, stiffness, and thermal resistance.

Rationale for Annealing UltiMaker PET CF

PET CF's semi-crystalline structure makes it particularly amenable to annealing. Unlike amorphous polymers, such as ABS and PETG, which have randomly arranged polymer chains, crystalline structures consist of ordered chains, resulting in superior strength properties. By heating PET CF to its glass transition point, the polymer chains can be further organized, enhancing its inherent strength.

Quantifiable Benefits of Annealing

Upon successful annealing, PET CF exhibits:

  • An increase in strength by approximately 30%.
  • A rise in stiffness by around 10%.
  • An enhancement in heat resistance, ranging from 80°C to 180°C.

Such advancements position PET CF as a competitive alternative to traditionally manufactured metal and carbon fiber components.

Considerations and Best Practices for Annealing

  1. Design Parameters: It's imperative to eschew designs with thin walls (below 4 mm) and to judiciously select the part's orientation to ensure optimal mechanical properties post-annealing.
  2. Slicing Protocols: Utilizing UltiMaker Cura's specialized annealing intent profile can automatically account for the anticipated shrinkage during the annealing process.
  3. Annealing Procedure: Employing a precision annealing oven, such as the Binder FP115, is recommended. The duration of annealing is contingent upon the part's thickness, and specific protocols can be programmed based on the material's technical specifications.

Potential Limitations of Annealing

While annealing offers tangible benefits, it's crucial to be cognizant of potential challenges:

  • Parts may undergo slight dimensional changes due to shrinkage.
  • There might be a reduction in specific mechanical properties, notably impact resistance and Z-adhesion resistance.


Annealing, when executed with precision and adherence to guidelines, can substantially elevate the performance of UltiMaker's PET CF parts. It is a testament to the evolving capabilities of 3D printing, merging traditional material science principles with modern manufacturing techniques.