How Humidity Affects 3D Printer Filament
Wet PLA filament becoming brittle and snapping mid print.
Humidity is a well-known factor that can significantly affect the quality and performance of 3D printer filaments. This is because many 3D printer filaments are made from hygroscopic materials, which are materials that readily absorb moisture from the surrounding environment. The presence of moisture in the filament can lead to a range of issues, such as poor print quality, clogs in the printer nozzle, and even damage to the filament. In this article we will go through how humidity affects 3D printer filament and what you can do to reduce the exposure to moisture.
Hygroscopicity is an important property of many 3D printing filaments because it allows them to absorb moisture from the air, which can be beneficial for certain types of filaments, such as Nylon. The absorbed moisture can act as a plasticizer, making the filament more pliable and easier to work with. However, for filaments that are not designed to be hygroscopic, moisture absorption can cause significant problems during the printing process.
Hygroscopicity is an important property of many 3D printing filaments because it allows them to absorb moisture from the air, which can be beneficial for certain types of filaments, such as Nylon. The absorbed moisture can act as a plasticizer, making the filament more pliable and easier to work with. However, for filaments that are not designed to be hygroscopic, moisture absorption can cause significant problems during the printing process.
Why does humidity affect 3D filament?
When filament absorbs moisture, it can cause the filament to swell or warp, which can lead to inconsistent extrusion and poor adhesion between layers. Moisture can also cause bubbles to form within the filament, which can lead to weak points in the printed object and can even cause the filament to break mid-print. In addition, moisture can also cause filament to clog the printer nozzle, which can result in costly downtime for the printer and wasted filament.
One of the primary ways that humidity affects 3D printer filaments is through the hydrolysis of certain polymers, such as polylactic acid (PLA). Hydrolysis is a chemical process that occurs when a material reacts with water, and in the case of PLA, it can cause the filament to break down and become brittle. This can lead to poor print quality, as the filament is more likely to snap or break during the printing process.
To go a little deeper we would say the moisture absorption process occurs due to the presence of hydrophilic functional groups in the polymer structure, which readily bond with water molecules. The absorption of moisture leads to the degradation of the material's mechanical and physical properties, making it challenging to use for 3D printing applications.
One of the primary ways that humidity affects 3D printer filaments is through the hydrolysis of certain polymers, such as polylactic acid (PLA). Hydrolysis is a chemical process that occurs when a material reacts with water, and in the case of PLA, it can cause the filament to break down and become brittle. This can lead to poor print quality, as the filament is more likely to snap or break during the printing process.
To go a little deeper we would say the moisture absorption process occurs due to the presence of hydrophilic functional groups in the polymer structure, which readily bond with water molecules. The absorption of moisture leads to the degradation of the material's mechanical and physical properties, making it challenging to use for 3D printing applications.
How to protect humidity affecting 3D Printer Filament
To prevent these issues, it is important to store 3D printer filaments in a dry environment. This can be achieved by using filament dryers or desiccant packs to remove moisture from the filament before it is used in the printing process. Filament dryers work by heating the filament to a specific temperature, which drives off any moisture that may be present. Desiccant packs work by absorbing moisture from the surrounding environment, keeping the filament dry and free from moisture.
In addition to storage, it is also important to minimize exposure to moisture during the printing process. This can be achieved by ensuring that the printing environment is dry and free from moisture. For example, printing in a room with high humidity levels can increase the likelihood of filament absorbing moisture and causing printing issues.
In addition to storage, it is also important to minimize exposure to moisture during the printing process. This can be achieved by ensuring that the printing environment is dry and free from moisture. For example, printing in a room with high humidity levels can increase the likelihood of filament absorbing moisture and causing printing issues.
What are the signs that filament has been affected by moisture?
filament that has absorbed moisture exhibits a range of signs that indicate it has been affected. Some common signs of moisture-affected filament include:
Popping or hissing sounds during printing: When filament absorbs moisture, it can release steam during the printing process, causing popping or hissing sounds.
Poor print quality: Moisture in the filament can cause inconsistent extrusion, leading to poor print quality, such as under-extrusion or over-extrusion, gaps in the printed object, and even complete failure to print.
Stringing: Moisture in the filament can cause it to be stringy or web-like, leading to unsightly and weak connections between printed parts.
Brittle or weak filament: When filament absorbs moisture, it can become brittle and weak, causing it to snap or break easily, even before or during printing.
Bubbles or steam: If the filament has been exposed to moisture for an extended period, it can cause bubbles or steam to form within the filament, which can lead to weak spots and breakages in the printed object.
Popping or hissing sounds during printing: When filament absorbs moisture, it can release steam during the printing process, causing popping or hissing sounds.
Poor print quality: Moisture in the filament can cause inconsistent extrusion, leading to poor print quality, such as under-extrusion or over-extrusion, gaps in the printed object, and even complete failure to print.
Stringing: Moisture in the filament can cause it to be stringy or web-like, leading to unsightly and weak connections between printed parts.
Brittle or weak filament: When filament absorbs moisture, it can become brittle and weak, causing it to snap or break easily, even before or during printing.
Bubbles or steam: If the filament has been exposed to moisture for an extended period, it can cause bubbles or steam to form within the filament, which can lead to weak spots and breakages in the printed object.
What's more important Relative Humidity or Absolute Humidity?
In 3D printing, relative humidity is generally considered more important than absolute humidity when measuring humidity levels. Relative humidity refers to the amount of moisture in the air compared to the amount of moisture the air can hold at a specific temperature, while absolute humidity refers to the actual amount of water vapor in the air.
The reason relative humidity is more important in 3D printing is that it directly affects the moisture content of the filament. As relative humidity increases, the likelihood of filament absorbing moisture also increases. Therefore, it is important to monitor and control relative humidity levels in the environment where filament is stored and printed.
While absolute humidity is still relevant in determining the overall moisture content in the air, it is not as directly linked to filament moisture absorption as relative humidity. That being said, it is still important to ensure that the absolute humidity levels are not too high, as this can lead to condensation and water droplets forming on the printer and filament, causing issues with print quality.
To maintain optimal printing conditions, it is recommended to keep the relative humidity below 50%, and the absolute humidity below 70°F dew point. Using a hygrometer to measure relative humidity levels and a dew point calculator to determine absolute humidity levels can help ensure the proper environment for 3D printing. We use the PST Dew Point Calculator which is a fantastic resource.
The reason relative humidity is more important in 3D printing is that it directly affects the moisture content of the filament. As relative humidity increases, the likelihood of filament absorbing moisture also increases. Therefore, it is important to monitor and control relative humidity levels in the environment where filament is stored and printed.
While absolute humidity is still relevant in determining the overall moisture content in the air, it is not as directly linked to filament moisture absorption as relative humidity. That being said, it is still important to ensure that the absolute humidity levels are not too high, as this can lead to condensation and water droplets forming on the printer and filament, causing issues with print quality.
To maintain optimal printing conditions, it is recommended to keep the relative humidity below 50%, and the absolute humidity below 70°F dew point. Using a hygrometer to measure relative humidity levels and a dew point calculator to determine absolute humidity levels can help ensure the proper environment for 3D printing. We use the PST Dew Point Calculator which is a fantastic resource.
