3D Prints Farming  Tuned Biodegradable Plastics System

Precision Agriculture and Research

  • Sensors and IoT devices: 3D printing can be used to create housings for IoT (Internet of Things) sensors that monitor conditions like soil moisture and nutrient levels. This allows for customized and affordable monitoring systems.

  • Biodegradable containers: You can create biodegradable pots or containers for seeds and seedlings, which can reduce environmental impact and make planting easier.   Video  Remove wit wood.   Sticking

Finding ideal 3D printing settings for any filament, including Polar Filament's PHA, often requires a bit of fine-tuning for your specific printer. However, based on information from the manufacturer and user communities, here are some recommended starting points for printing with Polar PHA filament:

General Recommendations:

  • PHA is not PLA: While it has some similarities to PLA, especially in terms of user-friendliness, PHA (Polyhydroxy Alkenoate) has different properties. It is a true biodegradable polymer and requires a different approach to avoid issues like warping. The most important difference is that PHA needs to be cooled as rapidly as possible to prevent crystallization and warping.

  • Warping is the main challenge: Users often report significant warping with PHA, especially on larger prints. This is the primary issue to address with your settings.

  • Calibration is key: The most successful users of PHA have a dialed-in profile for their specific printer. Starting with a temp tower and retraction tests is highly recommended.

Specific Settings:

  • Nozzle Temperature:

    • Recommended range: 190-220°C.

    • Starting point: A good starting point is around 200°C.

    • Note: Some users have found success with even lower temperatures (as low as 195°C) to help with rapid cooling, while others have found higher temperatures (up to 215°C) to be more effective for flow and layer adhesion. It's a balance.

  • Bed Temperature:

    • Recommended: Cold bed (0°C).

    • Important: This is a key setting for PHA. Unlike many other filaments that rely on a heated bed for adhesion, PHA benefits from a cold bed to promote rapid cooling and prevent warping. Some users report that even with a textured plate, the print will stick with the bed heat turned off.

    • Adhesion: While a cold bed is recommended, you'll likely need a bed adhesion method. Options that have been successful for users include:

      • Masking tape.

      • A thin layer of PVA (Elmer's) glue stick or diluted wood glue.

      • Polyimide (Kapton) tape.

      • A brim or raft is also highly recommended to help with corner adhesion.

  • Fan Speed:

    • Recommended: 100% cooling fan speed.

    • Rationale: The goal is to cool the filament as quickly as possible once it's extruded. This helps prevent warping and gives the best results.

    • When to activate: Start with the fan at 100% after the first layer or two.

  • Print Speed:

    • Recommended range: 40-100 mm/s.

    • Note: A faster print speed can be beneficial as it reduces the amount of time the hot nozzle is over a single area, which helps with rapid cooling.

  • Retraction:

    • Distance: PHA may require slightly less retraction than PLA. Some users have found success with retraction distances of 2.4-3mm.

    • Speed: A retraction speed of 40-50mm/s is a good starting point.

    • If you see gaps: If you notice small gaps on the outer surface of your print, it may be a sign that your retraction values are set a bit too high.

  • Bridging:

    • Settings: Bridging with PHA can be tricky. Some users have found that a faster bridging speed (e.g., 60-100 mm/s) helps, while others have had better results by slightly reducing fan speed for bridging.

  • Environment:

    • No enclosure: If you have an enclosure, it's best to open it or keep it cool. PHA performs better in a cooler environment.

PHA is a natural polymer that has not been chemically modified. Because it is an all-natural product, PHA is biodegradable (faster & easier than PLA) and therefore minimizes pollution.
Significant breakdown one year.
Sometimes faster. No microplastics

  • feedstock: The process starts with a feedstock, which serves as a carbon source for the microbes. Historically, this has included plant-based sugars and vegetable oils from crops like corn, sugarcane, and palm. However, to reduce costs and competition with food sources, the industry is increasingly using waste streams from agriculture and industry. Common feedstocks now include:

    • Food waste and wastewater

    • Agricultural byproducts like molasses and straw

    • Used cooking oils and crude glycerol from biodiesel production

    • Lignocellulosic biomass (plant materials like wood chips and corn stover)

  • Microbial Fermentation: In a controlled environment called a bioreactor, a specific type of bacteria (such as Cupriavidus necator or Pseudomonas) is fed the carbon-rich feedstock. Under nutrient-limiting conditions (e.g., a lack of nitrogen or phosphorus), the microbes switch their metabolism from growth to energy storage. As a result, they start to produce and store PHA as water-insoluble granules within their cells.

  • Extraction and Purification: Once the microbes have accumulated a significant amount of PHA (which can be up to 85% of their dry weight), they are harvested. The PHA polymer is then extracted and purified from the microbial cells, resulting in a powdered or pelletized material that can be melted down and processed into a variety of products.


    • Drones and robots: Components for agricultural drones and robots can be 3D printed, which helps with tasks like crop monitoring and the precise application of fertilizers or pesticides.

    • Research models: Scientists can 3D print models of soil structures to study properties like porosity and pore shape, which helps them better understand soil health.

    Watch this video to see some examples of 3D-printed accessories for livestock, including bee feeders and chicken coop parts. Upgrade your livestock

    Upgrade your livestock: 3D printed accessories for chickens, bees, cows, horses and more!
    Prusa 3D · 62K views



    Polyhydroxyalkanoates, or PHAs, are a class of biopolymers produced by microorganisms, primarily bacteria, through a natural fermentation process. Instead of being synthesized from petroleum like conventional plastics, PHA is created by microbes as an energy and carbon storage mechanism.

    How it's Made 🦠

    The process of making PHA is a lot like how a microbe stores up fat. Here's a simple breakdown:

    1. Feedstock: The process starts with a feedstock, which serves as a carbon source for the microbes. Historically, this has included plant-based sugars and vegetable oils from crops like corn, sugarcane, and palm. However, to reduce costs and competition with food sources, the industry is increasingly using waste streams from agriculture and industry. Common feedstocks now include:

      • Food waste and wastewater

      • Agricultural byproducts like molasses and straw

      • Used cooking oils and crude glycerol from biodiesel production

      • Lignocellulosic biomass (plant materials like wood chips and corn stover)

    2. Microbial Fermentation: In a controlled environment called a bioreactor, a specific type of bacteria (such as Cupriavidus necator or Pseudomonas) is fed the carbon-rich feedstock. Under nutrient-limiting conditions (e.g., a lack of nitrogen or phosphorus), the microbes switch their metabolism from growth to energy storage. As a result, they start to produce and store PHA as water-insoluble granules within their cells.

    3. Extraction and Purification: Once the microbes have accumulated a significant amount of PHA (which can be up to 85% of their dry weight), they are harvested. The PHA polymer is then extracted and purified from the microbial cells, resulting in a powdered or pelletized material that can be melted down and processed into a variety of products.


      • Industrial Composting: PHAs can degrade relatively quickly, typically within weeks to months, in industrial composting facilities where conditions such as temperature (exceeding 50°C), moisture, and microbial activity are carefully controlled and optimized.
      • Home Composting: In home composting environments, which often have less regulated conditions, the degradation process can be slower, potentially taking several months to a year.
      • Anaerobic Digestion: PHAs can still break down in anaerobic conditions (without oxygen), such as in landfills or specialized digesters, but may release methane as a byproduct.
    • PHA Properties:
      • Crystallinity: Highly crystalline PHAs tend to degrade more slowly than amorphous or less crystalline variants.
      • Polymer Type: Different types of PHA, such as homopolymers (e.g., PHB) or copolymers (e.g., PHBV), can exhibit varying degradation rates depending on their composition and structure. Copolymers like PHBV, with a higher percentage of hydroxyvalerate, degrade more readily due to their increased amorphous regions.
      • Shape and Thickness: Thin films generally biodegrade faster than bulky granular materials due to a higher surface-to-volume ratio, facilitating microbial access.
    • Environmental Factors:
      • Microbial Activity: The presence and activity of PHA-degrading microorganisms are crucial for efficient breakdown.
      • Temperature: Higher temperatures generally enhance microbial activity and accelerate degradation.
      • Moisture and Humidity: Adequate moisture and humidity promote hydrolysis and overall decomposition.
      • Oxygen Availability: Aerobic conditions (presence of oxygen) are often preferred and result in the production of carbon dioxide and water, while anaerobic conditions can lead to methane production. 
    In summary: While some studies suggest PHA can start degrading within days under ideal conditions like high microbial activity and temperature, the complete digestion time varies significantly. In industrial composting, it's typically within weeks to months, while in home composting, it may take several months to a year. 
    It's important to note that certifications like ASTM D6400 (US) and EN 13432 (Europe) verify that PHA products meet standards for industrial compostability, ensuring they degrade within a specific timeframe and leave no toxic residues.

    PHA biodegradation rates can vary significantly depending on several factors, including the type of PHA, environmental conditions, and the specific microorganisms involved. 
    While a single "fastest" strain is difficult to name definitively, certain bacterial genera are recognized for their efficient PHA degradation. These include Pseudomonas species, such as Pseudomonas aeruginosa, Pseudomonas fluorescens, and Pseudomonas putida, which produce extracellular enzymes that break down PHA. Various Bacillus species, including Bacillus sp. strain B-14911 and Bacillus megaterium, also demonstrate effective degradation, even in challenging conditions. Other genera known for PHA degradation include Burkholderia, Cupriavidus, and Microbacterium. Some strains exhibit particularly rapid degradation under specific circumstances, such as Pseudomonas sp. DSDY0501, which quickly degraded PHB films in a liquid culture, and Priestia aryabhattai A34 and Priestia megaterium, which show activity against PHB polymers. 
    Factors influencing the speed of PHA degradation include the polymer's composition, with copolymers like PHBV often degrading faster than PHB. Environmental conditions like temperature, moisture, and oxygen availability can also impact degradation rates. The physical form of the material, such as films versus pellets, and the presence of additives can also play a role. 
    Ultimately, the most effective bacteria for PHA degradation depend on the specific PHA type and the surrounding environment. Ongoing research continues to identify new strains and explore the mechanisms behind efficient PHA breakdown. 

    Numerous academic studies and research papers have investigated the composting and biodegradation of Polyhydroxyalkanoates (PHAs). Here are some key findings and types of studies you can look into to learn more:

    1. Degradation in Controlled Composting Environments

    • Focus: These studies often follow international standards like ISO 14855 or ASTM D5338-98. They measure the rate of biodegradation by monitoring the amount of carbon dioxide (CO2) released as the material breaks down.

    • Key Findings: Research consistently shows that PHAs biodegrade efficiently and rapidly in industrial composting conditions, which are characterized by high temperatures and a rich, active microbial community. For example, a study by Weng et al. (2011) investigated the biodegradation of PHAs with different chemical structures and found that they were fully compostable within the required timeframe.

    • Study to look for: "Biodegradation behavior of PHAs with different chemical structures under controlled composting conditions"

    2. Home vs. Industrial Composting

    • Focus: This research compares the degradation of PHAs in a professional, high-heat facility versus a less-controlled home compost pile.

    • Key Findings: While most "bioplastics" like PLA require industrial composting to break down, PHAs are known to degrade effectively in home composts as well, though the process is often slower. The lower temperatures and varying microbial activity in a home setting mean the degradation can take longer, but it still occurs, unlike with many other polymers. This is a significant advantage of PHA.

    • Study to look for: "Biodegradation behavior of amorphous polyhydroxyalkanoate-incorporated poly(l-lactic acid) under modulated home-composting conditions" or similar studies that compare different composting scenarios.

    3. Factors Affecting Degradation Rate

    • Focus: These studies examine how different variables—both material properties and environmental conditions—influence the speed of PHA degradation.

    • Key Findings:

      • PHA Type: Different types of PHAs (e.g., PHB vs. PHBV) have varying degradation rates. The chemical structure and crystallinity of the polymer play a major role.

      • Temperature: Higher temperatures significantly accelerate the process by increasing microbial activity.

      • Moisture: Adequate moisture is essential for microbial growth and the hydrolysis of the polymer chains.

      • Microbial Community: The specific types and density of microorganisms present in the compost are crucial. Some studies have found that PHAs can actually enrich the microbial diversity of the soil as they degrade, further promoting the breakdown of other organic matter.

    • Study to look for: "Factors affecting polyhydroxyalkanoates biodegradation in soil" or "Biodegradation of Polyhydroxyalkanoates in Natural Soils"

    How to Find These Studies

    To access these and other studies, I recommend using academic search engines and databases:

    • Google Scholar: A simple and effective tool for finding academic papers.

    • PubMed / PubMed Central (PMC): Excellent for biomedical and life sciences research.

    • ResearchGate: A social networking site for scientists and researchers to share their work. Many full-text articles are available for download.

    • University Library Databases: If you are affiliated with a university, you can use their library's access to paid databases like Scopus or Web of Science for more comprehensive search results.

    Search Terms to Use:

    • "Polyhydroxyalkanoate composting"

    • "PHA biodegradation compost"

    • "PHA degradation kinetics compost"

    • "Poly(3-hydroxybutyrate) composting"

    • "Biodegradability of PHA in soil"

    By searching these terms, you will find a wealth of peer-reviewed research that provides detailed data on the composting and degradation of PHA polymers.