Polymaker, a developer of 3D printing materials, has launched two high-temperature PLA filaments: HT-PLA and HT-PLA-GF (glass fiber reinforced). Designed for superior thermal resistance, they are ideal for producing functional prototypes and end-use parts exposed to elevated temperatures.
PLA (polylactic acid) is one of the most widely used materials in FDM 3D printing, valued for its ease of use, low cost, strong layer adhesion, and recyclability. However, its relatively low melting point limits performance in functional use cases. PLA typically begins to lose structural integrity above 60°C and melts between 150°C and 160°C.
Polymaker’s new 3D printing filaments address these limitations by enhancing their temperature resistance to over 150°C. These materials maintain PLA’s ease of printing while delivering greater thermal stability. HT-PLA offers the same user-friendly properties as standard PLA but withstands higher temperatures. HT-PLA-GF goes a step further by incorporating glass fibers to improve dimensional stability, mechanical strength, and heat deflection temperature (HDT).
In this article, we put Polymaker’s new materials through their paces, testing whether these filaments can handle the heat. Our engineering team pitted HT-PLA and HT-PLA-GF against alternative 3D printing filaments in a series of temperature-related challenges. We also tested the materials in real-world scenarios to assess their performance under everyday temperature exposure.
Prospective customers can find more information and purchasing options for the new filaments on the official Polymaker website. The materials offer a competitive price point that is cheaper than most other HT PLA’s on the market. A 1 kg spool of Polymaker’s HT-PLA Regular Colors costs $24.99 (€24.99), while 1 kg of both HT-PLA Gradient Colors and HT-PLA-GF Regular Colors are priced at $29.99 (€29.99) each.
Introducing Polymaker’s new HT-PLA and HT-PLA-GF filaments
Polymaker HT-PLA (High Temperature Polylactic Acid) is designed to retain structural integrity at higher temperatures than its conventional PLA counterparts. The filament offers an impressive melting temperature of 177.23°C and a softening temperature of 152°C straight off the print bed. This property makes the material ideal for high-temperature, no-load applications, such as soldering stations, heat mats, or components shipped to hot climates.
HT-PLA-GF uses the same technology but introduces glass fibers into the formula, offering a softening temperature of 148°C off the print bed. The purpose of the glass fibers is to add rigidity and provide dimensional stability during the annealing process, which causes most PLA parts to deform. When annealed at 100°C for 30 minutes, the filament achieves an elongation at break of 2.3% and a heat deflection temperature (HDT) of 114.7°C without changing shape. HT-PLA-GF withstands heat and mechanical loads comparable to ABS, making it ideal for applications such as power tool mounts, RC car parts, and fixtures.
Despite its elevated thermal performance, HT-PLA offers excellent printability comparable to standard PLA filament, with no post-processing required for basic applications. Significantly, the new high-temp material is compatible with standard PLA print settings, allowing easy integration into existing production workflows.
Polymaker’s new PLA filament also demonstrates strong repeatability, an essential trait for batch production. To illustrate this, our team 3D printed 12 identical hexagonal parts using consistent print settings, then measured each against the target dimensions. High-performance materials typically show an average dimensional deviation of less than 0.1 mm and a standard deviation below 0.05 mm.
HT-PLA 3D printed repeatability test parts. Photos by 3D Printing Industry.
The results showed excellent dimensional consistency. The average deviation measured just 0.01 mm, well below the 0.1 mm threshold, while the standard deviation stood at 0.009 mm, comfortably within the 0.05 mm benchmark. These figures indicate a high level of part-to-part accuracy with minimal variation. Therefore, Polymaker’s HT-PLA offers strong repeatability and dimensional stability, positioning it as a reliable choice for high-precision applications.
Polymaker’s HT-PLA repeatability test results. Images by 3D printing Industry.
Polymaker’s HT-PLA-GF is a high-performance composite filament, reinforced with glass fibres to enhance the thermal stability of its base HT-PLA formulation. This improves dimensional stability, mechanical strength, and heat deflection temperature (HDT). These attributes position HT-PLA-GF as a strong candidate for functional prototypes, jigs, fixtures, and end-use parts operating in high-temperature environments.
HT-PLA-GF boasts a melting temperature of 174.87°C, a crystallization temperature of 81.56°C, and a 59.8°C glass transition temperature. As standard, the filament features a 50.09 MPa tensile strength, 3.77 elongation at break, and 75°C heat deflection. However, after annealing, these figures jump to 50.2 MPa, 2.3, and 114.7°C, respectively.
The mechanical and thermal properties of Polymaker’s new HT-PLA and HT-PLA-GF filaments are included in the table below.
| Mechanical & Thermal Properties HT-PLA | ||||||||
| Properties along the X/Y | As Printed | Annealed | ||||||
| Young’s Modulus | 2945.75 MPa | 3267.16MPa | ||||||
| Tensile Strength | 42.86 MPa | |||||||
| Elongation at break | 0.97% | 1.87% | ||||||
| Heat deflection | 69.9°C | 106.5°C | ||||||
| Glass transition temperature | 59.8°C | |||||||
| Melting temperature | 177.23°C | |||||||
| Crystallization temperature | 77.21°C | |||||||
| Mechanical & Thermal Properties HT-PLA-GF | ||||||||
| Properties along the X/Y | As Printed | Annealed | ||||||
| Young’s Modulus | 3793.85 MPa | 4206.91 MPa | ||||||
| Tensile Strength | 50.09 MPa | 50.2 Mpa | ||||||
| Elongation at break | 3.77 | 2.3 | ||||||
| Heat deflection | 75°C | 114.7°C | ||||||
| Glass transition temperature | 59.8°C | |||||||
| Melting temperature | 174.87°C | |||||||
| Crystallization temperature | 81.56°C | |||||||
Polymaker High-temp PLA vs other filaments: what melts first?
We conducted heat-resistance tests to evaluate how Polymaker’s high-temperature PLA filaments compare with alternative 3D printing materials. In the first trial, we 3D printed five identical flag-shaped parts using Polymaker’s HT-PLA and HT-PLA-GF, alongside ASA, PETG, and standard PLA. Each flag was heated individually until it began to deform or melt. We recorded the time to failure and the temperature at which each material lost structural integrity.
3D printed flag test before (first image) and after (second) heating. Photos by 3D Printing Industry.
Standard PLA deformed the quickest, failing at 7.81 seconds and 149°C. PETG offered a slight improvement, deforming at 8.17 seconds and 162°C. Polymaker’s HT-PLA significantly outperformed both, withstanding 20.07 seconds before deformation at 171°C, indicating enhanced thermal endurance.
HT-PLA-GF emerged as the top performer, withstanding heat for 23.45 seconds before failure. It began to melt at a relatively modest 161°C, likely due to the altered thermal conductivity from the glass fibre reinforcement. ASA deformed after 11.01 seconds but recorded the highest failure temperature at 174°C. These results underscore the superior time-to-failure performance of HT-PLA and HT-PLA-GF, positioning them as strong candidates for applications requiring prolonged high-temperature exposure.
| Flag HDT and times | ||
| Material | Time (seconds) | Temp (°C) |
| PLA | 7.81 | 149 |
| PETG | 8.17 | 162 |
| HT-PLA | 20.07 | 171 |
| HT-PLA-GF | 23.45 | 161 |
| ASA | 11.01 | 174 |
3D printed flag test results table.
Next, we 3D-printed two functional air vent prototypes, one in HT-PLA and the other in standard PLA, and exposed them to a concentrated heat source. We measured both the surface temperature and the time to deformation.
The standard PLA model deformed quickly under localized heat. Surface bulging became visible at 16.57 seconds, when the material reached approximately 180°C. This temperature exceeds PLA’s typical melting range, and the rapid deformation reinforces its known limitations in high-temperature environments.
Polymaker’s HT-PLA air vent demonstrated markedly better thermal resistance. It maintained structural integrity for 20.71 seconds before deforming, with the surface temperature reaching 214°C. This reflects a 4.14-second improvement over standard PLA, indicating that HT-PLA offers greater durability under direct, high-temperature airflow.
We next 3D printed four 45 mm bridges in Polymaker’s new filaments and standard PLA. These were placed inside a filament dryer set to 100°C internal temperature, and a 200-gram static weight was placed on top. We then timed how long it took for each bridge to collapse. This test simulated scenarios where parts must retain their form and strength while under mechanical stress in a heated environment, such as components in enclosures, fixtures, or functional prototypes.
After annealing the HT-PLA-GF bridge for 30 minutes at the recommended temperature of 100°C, we observed a significant improvement in the material’s heat resistance. Impressively, after over 600 seconds (10+ minutes), the bridge continued to support the weight.
Upon removal and cooling, only a minor deflection of approximately 3-4 mm was observed, indicating excellent thermal and structural stability. On the other hand, Regular PLA deformed in just 59 seconds, while unannealed HT-PLA and HT-PLA-GF failed at 72 seconds and 85 seconds, respectively.
These results clearly demonstrate the effectiveness of annealing in enhancing the performance of HT-PLA-GF for load-bearing applications in elevated temperature environments.
| Deformation time per material | |
| Material | Time (seconds) |
| Regular PLA | 59 |
| HT-PLA | 72 |
| HT-PLA-GF No Aneal | 85 |
| HT-PLA-GF Annealed | No Deformation at 600+ |
3D printed bridge test deformation times.
In our final comparison challenge, we assessed the heat and flame resistance of HT-PLA, HT-PLA-GF, standard PLA, and PETG. Identical candle holders were produced in each material and fitted with standard wax candles. Once lit, the candles were allowed to burn fully.
Given that PLA and PETG are thermoplastic materials with low ignition temperatures, we did not expect their candle holders to withstand direct flame exposure. Surprisingly, both materials were slow to ignite and did not exhibit prolonged burning.
In contrast, HT-PLA and HT-PLA-GF ignited quickly and remained alight for a prolonged period. Although both materials are engineered for thermal resistance, the results suggest the presence of additives that may worsen their combustion behaviour. This was further evidenced by bubbling observed in the HT-PLA-GF sample during combustion.
These findings underscore the critical importance of material selection in environments with elevated fire risk. While HT-PLA performs reliably in controlled thermal conditions, it should not be exposed to open flame.
3D printed candle holder before (first image) and after (second image) burning. Photos by 3D Printing Industry.
Testing high-temp 3D printing applications
For our first application challenge, we 3D printed two AMS-style desiccant dryboxes using standard PLA and HT-PLA. These components are designed to hold moisture-absorbing desiccant, which requires periodic reactivation through heating, typically in an oven or dehumidifier.
Both 3D printed dry boxes were placed inside a dehumidifier and heated to 70°C for 24 hours. The PLA drybox exhibited clear signs of thermal degradation. Deformation and warping were observed on the surface and body of the part, indicating a loss of dimensional stability under prolonged heat exposure. In contrast, the HT-PLA model remained completely unaffected, retaining its original geometry and surface quality with no visible changes.
These results confirm that Polymaker’s HT-PLA can endure sustained high temperatures without compromising structural integrity. This confirms the material is well-suited for applications involving thermal cycling or continuous exposure to heat, where standard PLA would typically degrade.
Next, we evaluate the geometric stability of Polymaker HT-PLA for an electronics housing. Our team 3D printed an enclosure to store electronic hardware components that may heat to 70°C during operation. In real-world scenarios, such enclosures must maintain structural integrity and a precise fit to ensure protection and airflow management.
Our enclosure demonstrated excellent geometric accuracy, with all components assembling as intended. The parts exhibited no warping, shrinkage, or fitment issues, highlighting HT-PLA’s reliability for prints requiring tight tolerances. The structural integrity and accuracy of the 3D printed model indicate that it would perform effectively as a functional housing in a real electronics application.
3D printed electronics housing. Photos by 3D Printing Industry.
HT-PLA-GF was then used to 3D print a soldering iron jig. The resulting part showed excellent print quality, with precise dimensional accuracy and clean snap-fit tolerances that ensured full functionality. Its rigidity and thermal resistance provided a stable platform capable of withstanding light mechanical stress and close-range heat during soldering operations. Therefore, this test confirmed that Polymaker HT-PLA-GF is well-suited to functional desktop tools and jigs demanding mechanical reliability and heat resilience.
Polymaker HT-PLA-GF 3D printed soldering jig. Photos by 3D Printing Industry.
Lastly, we 3D printed a heat mat using HT-PLA. This device acts as a buffer between hot kitchen appliances and delicate work surfaces. We placed a pan of freshly boiled water on the mat, which showed no signs of deformation or softening, confirming the material’s resistance to heat.
Polymaker HT-PLA-GF 3D printed heat mat. Photos by 3D Printing Industry.
Overall, Polymaker’s new high-temp filaments demonstrated strong heat resistance and thermal stability. This exceeded standard PLA in all our tests, impressively outperforming ASA and PETG in the flag challenge.
Throughout testing, both materials proved easily printable across standard FDM systems, exhibiting low warping and strong bed adhesion. Print precision and dimensional accuracy were consistently high, as demonstrated in our repeatability test, where HT-PLA achieved an average deviation of just 0.01 mm and a standard deviation of 0.009 mm. Once printed, HT-PLA and HT-PLA-GF displayed strong mechanical performance, which can be further enhanced through annealing. These characteristics make both filaments well-suited for functional prototypes and end-use applications requiring reliability and structural integrity.
During testing, we identified limitations with fire resistance. Both materials ignited quickly and burned for an extended period when exposed to an open flame. While they remain safe for controlled high-temperature environments, users should avoid using the filaments in applications with potential fire exposure.
Despite this, Polymaker’s HT-PLA and HT-PLA-GF represent a strong addition to the FDM 3D printing materials market. They provide a compelling alternative for users seeking the thermal performance of advanced polymers while retaining the broad printer compatibility and ease of use associated with PLA.
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Featured image shows Polymaker high-temperature filaments and test parts. Photo by 3D Printing Industry.
