When it comes to creating custom parts for your car, especially with the rise of 3D printing, it’s tempting to use readily available materials like PLA (Polylactic Acid). However, for many automotive applications, particularly parts exposed to the heat inside a vehicle, PLA simply isn’t the best choice. Understanding material limitations is crucial to ensure the longevity and functionality of your 3D printed car components.
The Problem with PLA and Car Interior Heat
PLA is a popular 3D printing filament known for its ease of use and biodegradability. Unfortunately, these benefits don’t translate well to the harsh environment inside a car, especially when parked in the sun. On a moderately warm day, the interior temperature of a car can quickly climb to over 50°C (122°F), and in direct sunlight, localized temperatures can be even higher. PLA, with its relatively low glass transition temperature, starts to soften and deform at temperatures as low as 50°C (122°F). This means any PLA part left in a car exposed to sunlight or heat is highly susceptible to warping and losing its shape.
Real-World Example: Sun Visor Hinge Pin Failure
Consider a common scenario: printing a sun visor hinge pin for your car. Even if the part isn’t in direct sunlight, the ambient temperature inside the car can be enough to cause problems. One user experienced this firsthand, printing a sun visor hinge pin from PLA. Despite ambient temperatures only reaching around 29°C (85°F), the PLA pin deformed after just one day in the sun. While a PETG (Polyethylene Terephthalate Glycol-modified) pin offered slightly better performance, even it showed some deformation under intense heat. This example highlights that even parts not directly exposed to sunlight can be affected by the elevated temperatures within a car.
Better Material Options for Durable Car Parts
For car parts that need to withstand heat and maintain their structural integrity, it’s essential to choose more temperature-resistant materials. Several alternatives to PLA are well-suited for automotive applications:
- Nylon (Polyamide, PA): Nylon offers excellent strength, durability, and significantly higher temperature resistance compared to PLA. It can withstand temperatures up to around 80°C (176°F), making it a much better choice for many car parts.
- ABS (Acrylonitrile Butadiene Styrene): ABS is another popular engineering plastic known for its toughness and heat resistance. It can generally handle temperatures up to 85°C (185°F), making it suitable for various automotive components.
- Enhanced Co-Polymers and ASA (Acrylonitrile Styrene Acrylate): These materials offer even higher temperature resistance, with ASA often capable of withstanding up to 100°C (212°F) and enhanced co-polymers reaching similar levels.
- Polypropylene (PP) and Polycarbonate (PC): For demanding applications requiring very high heat resistance, materials like Polypropylene (up to 105°C or 221°F) and Polycarbonate (up to 110°C or 230°F) are excellent choices.
Material Temperature Resistance Overview
To summarize, here’s a general guideline for the maximum prolonged exposure temperatures of various 3D printing materials commonly used for car parts:
- Basic Co-Polymers: 70°C (158°F)
- ABS: 85°C (185°F)
- Enhanced Co-Polymers and ASA: 100°C (212°F)
- Polypropylene (PP): 105°C (221°F)
- Polycarbonate (PC): 110°C (230°F)
- Nylon: Up to 80°C (176°F) (as mentioned earlier, and may vary slightly based on specific nylon type)
- PLA: Not suitable for applications exceeding 50°C (122°F).
While PLA might be suitable for non-load-bearing, low-stress components that are not exposed to heat, for most car parts, especially interior components, it’s best to opt for more temperature-resistant materials like Nylon, ABS, ASA, or Polycarbonate to ensure durability and prevent deformation under typical car operating conditions and sun exposure. Always consult the technical data sheets for specific filaments to understand their temperature limitations and suitability for your intended “Part For Car” application.
