When it comes to creating car parts with a 3D printer, selecting the right filament is crucial for durability and performance. Several types of filament stand out for their suitability in automotive applications, each with unique properties to consider. Let’s explore some of the best options available.
ABS and ASA: Robust Choices for Automotive Components
Acrylonitrile Butadiene Styrene (ABS) and Acrylonitrile Styrene Acrylate (ASA) are strong contenders, particularly ASA, often regarded as “a better ABS.” ASA excels due to its superior resistance to ultraviolet (UV) radiation and sunlight, making it ideal for exterior car parts that face prolonged sun exposure. Furthermore, ASA is generally easier to print than ABS, exhibiting less warping during the printing process.
Both ABS and ASA benefit from printing in a well-ventilated area. While an enclosure can enhance print quality, especially for larger parts, successful prints are achievable even without a fully enclosed setup, sometimes with just a simple cardboard box to minimize drafts and maintain a stable temperature.
PET: Enhancing Heat Resistance Through Annealing
Polyethylene Terephthalate (PET), distinct from the more common PETG, presents another compelling option. While genuine PET filament might be less readily available, and its initial heat resistance might be moderate, it possesses a significant advantage: it can be annealed. This post-printing heat treatment process, conducted with minimal dimensional change, dramatically boosts its heat resistance to 100°C (212°F) or even higher.
Although annealing is theoretically possible with Polylactic Acid (PLA), achieving successful results without significant deformation is challenging. It typically requires 100% infill and embedding the PLA part in a medium like sand or salt during annealing to maintain shape. It’s important to note that Polyethylene Terephthalate Glycol (PETG) is intentionally engineered to resist crystallization (annealing), and has a lower softening and melting point compared to standard PET, making it unsuitable for this heat resistance enhancement technique.
TPU: Flexible Durability for Specific Applications
Thermoplastic Polyurethane (TPU) offers a different set of advantages. TPU does not have a glass transition temperature within typical ambient ranges. Effectively, it resists permanent deformation up to temperatures near its printing temperature. Its heat resistance is demonstrated by successful use as molds for melting crayons in ovens at 175°F (80°C) without issues.
Printing with TPU can be perceived as either easier or more challenging than ABS, depending on your 3D printer setup. Extruders not optimized for flexible filaments might necessitate slower print speeds or experience jamming during retraction. However, TPU eliminates the warping and heat management concerns associated with ABS. It can be printed even on unheated beds and does not require specialized ventilation, although standard precautions for minimizing fumes are always advisable.
While generally flexible, TPU’s rigidity can be significantly increased by using high infill percentages with rigid infill patterns like triangles or cubic structures, or by printing parts at 100% solid infill. Furthermore, harder TPU variants are available, with 95A being common and 98A sometimes found, allowing for a tailored balance of flexibility and stiffness.
