PLA HT: The evolution of PLA for technical applications

Conventional PLA is easy to print, biodegradable, and the emissions produced during printing are much less harmful than those of other materials, but it suffers deformation at relatively low temperatures. In fact, it begins to soften around 55°C and loses its shape near 60–70°C. This low thermal resistance of PLA limits its use in functional parts subjected to heat or stress. To overcome this limitation, high-temperature PLA filaments (HT-PLA) have emerged, which maintain the ease of printing of standard PLA but withstand heat much better.

PLA vs HT-PLA: how the new material works

Image 1: comparing an object printed in HT-PLA (left) with another in generic PLA (right) after exposure to heat. Source: Polymaker

Several manufacturers, such as Polymaker and Spectrum, describe HT-PLA as a next-generation PLA capable of maintaining its shape even under extreme heat (up to 150°C), "without warping, sinking, or compromises." At the same time, this material prints just as easily as standard PLA, using conventional PLA parameters (extruder temperatures of ~210–230°C and bed 25–60°C) and without the need for an enclosed chamber. This means it offers the convenience of PLA (it does not warp or shrink noticeably during printing) along with much higher heat resistance. Additionally, Polymaker notes that its HT-PLA does not require post-processing heat treatment: "just print and go." Optionally, for demanding applications, an annealing heat treatment can be applied, subjecting the part to 30 minutes at ~100°C, which further increases its softening point. Currently, this can be done in an advanced filament dryer like the Sunlu Filadryer E2. In summary, HT-PLA combines the printing simplicity of PLA with thermal performance close to industrial materials.

Key features of HT-PLA

Image 2: Model printed with HT-PLA color “Tropical” from Polymaker. Source: Polymaker

The properties of different HT-PLA filaments vary depending on fiber reinforcement and manufacturer. Their most common key properties include:

• High thermal stability: withstands up to ~100–150°C without deforming, far above the ~60°C of standard PLA.
• Easy printing: uses generic PLA settings (nozzle 210–230°C, bed 25–60°C, fan on); does not require an enclosed chamber or additional special materials.
• Mechanical strength: tensile strength is comparable to reinforced PLA (e.g., ~42.8 MPa on X-axis) depending on material and manufacturer, without sacrificing smooth finishes or layer adhesion.
• Speed and flow: allows very fast prints (up to 300 mm/s), matching or surpassing many commercial PLAs.
• Easy post-processing: no chemical treatments or additional coatings required; however, in Polymaker HT-PLA, a post annealing increases its Vicat/HDT to around 150°C.
• Eco-friendly: maintains the biodegradability of the original PLA (specifically, Polymaker indicates its matrix is mainly PLA with minimal non-biodegradable components).
• Color variety: available in very attractive matte and semi-gloss tones, suitable even for professional-looking final parts.

Thanks to these features, HT-PLA allows printing complex and detailed parts for technical applications that previously would have required ABS/ASA or other demanding polymers, but without sacrificing the convenience of PLA workflow.

HT-PLA-GF: high-temperature PLA reinforced with glass fiber

While other manufacturers offer HT-PLA variants, such as Add:north with its PLA-HT Pro, a PLA that withstands high temperatures, Polymaker also offers HT-PLA-GF (Glass Fiber), a version reinforced with approximately 12% glass fiber.

Image 3: A spool of HT-PLA-GF. Source: Polymaker

This variant maintains the easy printing of standard HT-PLA but adds extra rigidity and mechanical strength. According to Polymaker, after annealing, HT-PLA-GF achieves “thermal resistance similar to ABS” and can withstand high mechanical loads at temperatures up to ~130°C without softening. In practice, this means HT-PLA-GF parts (e.g., shelves, mounts, or functional components) can operate in environments so hot that previously only materials like ABS or nylon could tolerate.

It should be noted that glass fiber makes it slightly abrasive for standard nozzles: Polymaker recommends using hardened steel nozzles for HT-PLA-GF. In return, the gain in stability and rigidity usually offsets this extra requirement. In general, HT-PLA-GF is intended for professional uses where maximum dimensional stability under heat is needed (e.g., silicone molds for hot casting, machinery parts subjected to friction or heat) without losing the printing simplicity of PLA.

Printing and annealing of HT-PLA

Printing with HT-PLA is very similar to standard PLA. Typical parameters include nozzle at 210–230°C, moderately heated bed (25–60°C), and layer fan on. Prolonged preheating or special adhesives are not necessary (although a slightly heated bed or tape can improve initial adhesion). No enclosed chamber is required, as the material barely deforms during printing. Thanks to this, large parts can be printed on open printers without significant warping.

Video 1: HT-PLA-GF and the annealing process. Source: Polymaker

After printing, thermal resistance can be improved through annealing. The typical procedure is to bake the part at around 80–100°C for 30 minutes. This annealing partially crystallizes the base PLA, raising the Heat Deflection Temperature (HDT) from around 60°C (printed) to over 150°C. It is important to anneal on a surface that does not radiate heat (glass, ceramic) and allow cooling inside the oven to avoid distortion. Specifically, Polymaker confirms that both HT-PLA and HT-PLA-GF can be annealed to improve thermal stability, although the GF version achieves more noticeable HDT increases.

Regarding equipment, no special recommendations are required apart from a hardened nozzle for HT-PLA-GF. Standard HT-PLA is non-abrasive and compatible with any conventional FDM printer. In summary, usual PLA printing settings work almost without modifications but allow parts to withstand much higher temperatures.

Professional applications and practical examples

Image 4: A drill battery organizer printed in HT-PLA-GF. Source: Polymaker.

Polymaker highlights this example: after annealing the part, it achieves “mechanical strength superior to ABS.” This illustrates how HT-PLA-GF can be used for tool mounts, fixtures, and workshop parts that need to withstand impacts and heat (e.g., storing hot batteries or parts in sunny areas).

Other use examples include cases and mounts for heat-exposed electronics (equipment fans, drones, vehicles), rapid silicone molds at temperature (thanks to high hardness), or prototypes and assembly tools that work in the sun or warm environments (automotive, light aircraft, automation). For professional makers, HT-PLA opens the door to projects previously reserved for ABS/ASA: workshop jigs and fixtures, light factory tooling, thermally stable models, or even aesthetic outdoor components.

Of course, it is not a universal replacement for engineering plastics (it does not have chemical or flame resistance like polysulfone, for example). However, its advantage is maintaining the benefits of PLA (easy printing, relative biocompatibility, no special ventilation required) with heat tolerance previously offered only by harder-to-print polymers.

Other alternatives and similar brands

Although Polymaker is a pioneer in the HT-PLA family, it is not the only company exploring this category. Manufacturers such as Add:north, Spectrum, or 3DXTech have experimented with modified PLA to improve thermal resistance. The general trend is clear: through additives or special formulations, several suppliers aim to combine PLA ease with higher heat stability.

However, each material has nuances (for example, some high-temperature PLAs can be more brittle or require optimal impregnation). For this reason, Polymaker has invested in testing and optimization (such as well-dispersed glass fiber technology) to ensure consistency and ease of use. In any case, the emergence of HT-PLA on the market expands possibilities: users can now choose among several commercial options for projects where heat was an issue, selecting the one that best fits their printer and needs.

Conclusion

The development of HT-PLA (and its HT-PLA-GF variant) represents a significant advancement for makers and professionals looking to print functional parts without the sacrifices of ABS and other traditional materials. Thanks to innovations like those from Polymaker, it is now possible to print with the simplicity of PLA while achieving thermal resistance close to ABS. This expands the use range of PLA, allowing applications under intense heat (automotive components, tools, industrial prototypes) that were previously restricted. At the same time, HT-PLA retains PLA advantages: it prints on common FDM printers, at high speeds, without a heated chamber, and barely increases process complexity. In short, HT-PLA takes PLA’s easy printing to new performance frontiers.