How to Prevent Warping in PLA Filament: 3D Printing

If you’ve been 3D printing for some time, you’ve surely encountered the famous“warping” problem. Although usually associated with ABS, PLA also exhibits warping if not printed under the right conditions. The good news is that, contrary to what many people think, warping is not an inevitable fate. In reality, the problem lies more in how we set up the printer and in some details of the printing environment.

Preventing warping in PLA is entirely possible, and in this article we’ll break down step-by-step the techniques and settings that really make a difference. From controlling temperature and humidity to optimizing part design and setting up the slicer for perfect adhesion, we’ll cover everything from how to control temperature and humidity to optimizing part design and setting up the slicer for perfect adhesion. With the right tips, you’re sure to achieve warp-free prints.

Fundamentals of Warping in 3D Printing

Definition and Manifestation of Warping

The warping is a phenomenon in 3D printing that manifests itself when the corners or edges of a part begin to lift off the printing surface during the printing process. This deformation not only affects the aesthetics of the part, but can also compromise its functionality and accuracy, usually resulting in a failed print. Generally, warping occurs due to uneven shrinkage of the filament as it cools, creating internal stresses in the part that cause some areas to lose adhesion to the base.

The first layer is the most important in 3D printing, since its correct adhesion depends on the stability and success of the rest of the printing process.

Impact on Print Quality

The impact of warping on print quality is evident from the moment the part begins to peel. By not staying in place, the part loses dimensional accuracy, which can make it unusable for precise assemblies. It often affects structural stability, especially in large parts or those where precision is critical, thus generating problems that affect the quality and durability of the final product.

Physical Principles: Thermal Stresses and Shrinkage

Warping is largely explained by physical principles related to thermal stresses and material shrinkage. During printing, PLA is heated to its “decomposition” point (because PLA does not melt like most materials) to be extruded, and then cools as it comes into contact with the printing surface. This uneven cooling generates stresses that, if not properly controlled, end up causing deformations. Knowing these principles is essential to be able to apply effective preventive strategies, such as adjusting the temperature of the hot bed or controlling air currents in the printing environment.

Critical Factors Contributing to Warping

Factor	Description
Thermal Factors	The temperature of the hotend, hot bed and general environment directly affects the way the filament cools. Too rapid cooling, especially in the first layers, promotes warping.
Adhesion Factors	The printing surface and the adhesion methods used (adhesives, lacquers, specific surfaces) play a vital role in avoiding warping. If the base of the part is not adhered properly, warping is almost inevitable.
Environmental factors	Temperature variations in the printing environment and air currents are also a major risk. If the part is cooled inconsistently, some areas will have greater shrinkage than others, causing lifting.
Material Factors	Each filament has unique characteristics that affect its susceptibility to warping. In the case of PLA, its low printing temperature makes it slightly less prone to warping compared to other materials such as ABS, but it is still vulnerable under certain conditions.
Design Factors	The geometry and internal structure of the part also influence the propensity for warping. Designs with sharp corners or reduced contact areas tend to be more difficult to keep adhered to the print bed. In addition, those designs that consist of a larger first surface area tend to suffer from warping.
Configuration Factors	Parameter settings such as print speed, layer height and fill density can be both the cause of warping and their own solution.
Mechanical Factors	Bed leveling and printer calibration directly impact adhesion quality and thus the likelihood of warping. A poorly leveled or unbalanced bed can result in low adhesion dots.
Software Factors	Slicer software also offers tools to mitigate warping, such as the addition of brims, rafts and compensated shrinkage settings. Ignorance of these tools can lead to a more complex “solution”.

Material and Environmental Factors in PLA Warping

PLA Material Characteristics

PLA is one of the most popular materials in 3D printing, not only for its ease of use, but also for its unique properties that make it a versatile option for multiple applications. However, as with any material, it is necessary to know in depth its characteristics to get the maximum performance, especially if we want to avoid problems such as warping.

PLA Thermal Properties and Behavior

PLA, or polylactic acid, has a low “melt” temperature compared to other materials such as ABS or PETG, which reduces its propensity for warping. However, this advantage also means that it is more sensitive to temperature changes in the printing environment. PLA tends to solidify quickly, which, under adverse conditions, can create internal stresses and cause warping in larger parts or parts with reduced contact areas.

At Figutech, as a producer of premium PLA, our formulation is specially designed to improve the thermal stability of the filament and minimize the risk of deformation. Still, it is critical to use the right printing settings to take full advantage of these properties and achieve perfect prints. What do we mean by this? That if you really try, you can make even the best material on the market suffer warping. It’s a matter of physics.

Moisture Sensitivity and PLA Storage

PLA is a hygroscopic material, which means that it can absorb moisture from the environment. This is a critical factor, as PLA that has absorbed water tends to behave in an unstable manner during printing, generating bubbles and increasing the chances of warping and other defects. It is advisable to store PLA in a dry environment, preferably in airtight containers with desiccants, or in sealed bags that protect the filament from moisture.

As professionals in the filament industry, we at Figutech.com suggest keeping PLA in a relative humidity below 15%, ideally in a controlled environment. In this way, the filament will retain its original properties, providing a more accurate and deformation-free print.

Optimal Extrusion Temperature To Avoid Warping

To minimize the risk of warping, it is essential to set the hotend temperature correctly. The ideal extrusion range for high quality PLA is between 195 °C and 220 °C, although the exact setting depends on individual printer specifications and environmental conditions. Many people try to print at the lowest possible extrusion temperature, it doesn’t make sense! If you print at a temperature too close to the minimum temperature allowed by the material and the precision of your machine is not “Swiss” you may cause a jam. Calibrate your machine starting from an intermediate point, that’s why we recommend temperatures from 195 ºC instead of 190 ºC, as most of them.

Filament Quality Control

Individual skill and mastery of printing techniques are a large percentage of successful prints, but filament quality is critical for trouble-free printing. Poor quality PLA can exhibit diameter variations, impurities and unpredictable behavior during printing. At Figutech.comeach batch of filament undergoes rigorous testing to ensure consistent diameter and composition, providing stable extrusion and reduced warping. By opting for high-quality filaments, such as those produced by Figutech, makers can significantly reduce the risk of warping and other defects.

Environmental Conditions

Environmental conditions during the printing process directly influence the propensity of PLA to experience warping. A controlled environment must be maintained to ensure that the filament cools evenly and that there are no thermal stresses that cause warping.

Ambient Temperature Control

A stable temperature environment contributes to uniform and distortion-free printing. For PLA, an ideal ambient temperature is between 20 °C and 25 °C. When printing in a very cold room or with significant variations, PLA can suffer from sudden cooling, especially in the first layers, which increases the risk of warping. To optimize results, it is advisable to control the temperature of the printing space, especially in winter seasons or in ventilated environments.

Airflow Management

Air currents are the enemy of stable printing, since they cool certain areas of the part in a non-uniform way, favoring the appearance of thermal stresses. Minimizing or eliminating air currents in the printing area is essential, especially when working with PLA, which is a material sensitive to sudden temperature changes. A practical solution is to locate the printer in a draft-free area or to use a draft shield around the printer to mitigate this effect.

Benefits of Closed-Camera 3D Printers

Although PLA does not necessarily require a closed chamber to print optimally, using one can be beneficial in certain situations, such as in cold or persistent drafty environments. Enclosed chambers help maintain a stable temperature around the part and reduce the possibility of warping in the first few layers. If you have a printer with a closed chamber or can build a temporary overlay, this can significantly reduce the risk of warping, especially on larger prints.

Humidity Control

Like storage, controlling humidity in the printing environment is crucial for PLA. A high humidity environment can cause the filament to absorb “water”, affecting its behavior in the extrusion process. Maintaining a low relative humidity(ideally below 40%) in the printing area contributes to better print quality and dimensional stability of the part. We always recommend working in low humidity conditions to avoid complications and to obtain more accurate and durable parts.

Printing Surface and Adhesion

The printing surface and its proper preparation are essential to achieve good adhesion of the first layer, which is the starting point to avoid problems such as warping. There are different types of surfaces and methods to improve adhesion.

Types of Printing Surfaces and their Characteristics

The choice of printing surface directly affects the stability of the first layer. The most common surfaces used for PLA and their characteristics:

• Glass: Glass is a popular surface due to its ease of cleaning and durability. However, for PLA, it may be necessary to apply an adhesive such as lacquer or glue stick to improve adhesion, as smooth glass does not always hold PLA optimally on large prints. Glass provides a flat base and excellent appearance on the underside of the part.
• PEI (Polyetherimide) surface: PEI surfaces are ideal for PLA as they allow good adhesion without the need for additional adhesives and, once the bed cools, the parts come off easily. In addition, PEI is durable and easy to maintain, making it a professional choice for those who print with PLA on a regular basis.
• Textured surfaces: Textured surfaces, such as powder-coated steel, provide excellent adhesion for PLA and leave a uniform finish at the base of the part. These surfaces help prevent warping by providing multiple anchor points for the first layer.

Each surface has its advantages and disadvantages, and your choice will depend on the specific results you want to achieve.

Preparation and Maintenance of the Printing Surface

Keeping the printing surface in good condition is essential for good adhesion. Some preparation and maintenance tips are:

• Regular cleaning: Be sure to clean the surface before each print. Oils from hands, dust or residue from previous prints can affect adhesion. For glass and PEI, isopropyl alcohol is an excellent cleaning option.
• Proper leveling: Accurate bed leveling is critical. An uneven bed not only causes poor adhesion in certain areas, but can also cause stresses in the first layer, increasing the risk of warping. Adjusting manually or using an automatic leveling option (ABL) is essential to ensure a good base.
• Adhesive application: If you are using a surface that does not offer optimal natural adhesion for PLA, such as glass, consider using adhesives such as glue sticks or lacquer. These adhesives help keep the first layer firm without allowing lifting.

Use of Adhesives and Adhesion Enhancers

If you are looking for a really effective solution, using adhesive products may be the best option to solve warping. Some of the products we recommend are:

• Glue stick: One of the most accessible methods. It is easy to apply and clean up, and provides excellent adhesion for PLA on glass or PEI surfaces.
• Lacquer: Aerosol lacquer is another popular alternative for improving adhesion. Applied in a thin layer on the glass, it helps keep the piece firmly adhered, especially on large prints where warping is more likely.
• Adhesive tapes: There are tapes designed for 3D printing surfaces, such as blue painter’s tape, which offers strong adhesion and is easy to remove after printing. While not the most aesthetically pleasing option, it is very effective in ensuring that the PLA stays in place.

These adhesion enhancers are particularly useful for large prints or for parts with complex geometries that tend to deform at the edges. We always recommend experimenting with these products to achieve the best possible adhesion for each project.

Optimal Hotbed Temperature

The heated bed is a key tool to prevent warping in PLA, as by maintaining a proper temperature at the base, sudden temperature changes that cause stresses in the first layer are avoided. For Figutech.com‘s high quality PLA, we recommend keeping the heated bed between 50 °C and 60 °C. This range allows for firm adhesion without risk of deformation due to excessive heat.

In addition, once the printing process is finished, it is recommended to wait for the bed to cool down so that the part can detach naturally, avoiding tensions that could damage the part or the printing surface.

Design Optimization to Reduce Warping

The way we design a 3D printed part has a direct impact on its behavior during the manufacturing process. There are certain design principles that help you reduce internal stresses and improve the adhesion of the first layer, thus reducing the likelihood of warping.

Geometric Considerations

The geometrical design of a part directly influences the stress distribution during printing. Parts with sharp corners and small contact areas are usually more prone to warping, as the bond strength in these areas is lower. To minimize warping, it is recommended:

• Rounding corners: Sharp corners are critical points where warping is most likely to occur, as they generate stress concentrations. Rounding or smoothing corners reduces this concentration, helping the part to stay in place.
• Increase the contact area: If the design allows, the contact area of the part base can be increased. This provides better adhesion and reduces the likelihood of edge lifting.
• Adding anchoring elements: Elements such as brims or rafts can be added to increase the stability of the base. These elements are especially useful in pieces with reduced bases or irregular shapes that tend to peel off.

Stress Distribution

Areas that concentrate too much stress may experience deformation, especially during the cooling stage. Some techniques to better distribute stresses are:

• Reduce mass concentrations: Parts with large concentrations of material in certain areas are more likely to deform due to uneven cooling. Distributing material evenly helps to avoid these problems.
• Design with balanced internal structures: Avoid designs that generate areas of high material density. Instead, opt for structures that distribute weight and volume more evenly.

Optimization of corners and curvatures

Adjustments to the corners and curvatures of the part help reduce the risk of lifting at the edges. Some specific recommendations include:

• Smoothing curves: Smooth curves, rather than straight edges, help the workpiece stay attached to the bed. This is especially useful for large or complexly shaped parts.
• Incorporate curves in areas prone to lifting: Areas where the part is most vulnerable to warping, such as outside corners, benefit from a design that facilitates material flow in these areas.

Strategic Orientation in the Printing Bed

The orientation of the part on the print bed is a decisive factor in the final quality and the possibility of warping. By strategically orienting the model, it is possible to reduce the risk of warping. Consider the following recommendations:

• Orient the part to maximize the contact area: Orient the design so that the surfaces with the largest contact area are on the print bed. This improves adhesion and better distributes stresses on the base.
• Orientation of parts with complex geometry: For parts that have thinner or smaller parts, it is recommended to orient them so that these areas are as close as possible to the base of the bed. This will prevent deformation during printing.

Internal Structure Adjustments

The internal parameters of the part, such as infill and wall thickness, also play an important role in the stability of the model during printing. Some recommended settings are:

• Filler density: A filler density between 15% and 25% is usually sufficient for PLA parts, providing stability without generating too much internal stress. Too dense fillers can cause the part to suffer from deformations.
• Wall thickness: Adequate wall thickness, generally between 1.2 mm and 1.6 mm, contributes to structural strength. This setting allows the walls to maintain good adhesion to the base without generating excessive stress during cooling.

Printing Configurations

There is no secret formula for the perfect 3D printing setup for ALL your projects. But there is a range and some practices that come close to the “perfect” setup. However, the settings vary considerably depending on your printer. It is important to adapt these settings to your specific equipment and rely on sources using the same printer model, as what works for one machine may not be optimal for another.

Slicing Software (Slicer) Settings

Configurations in Cura to Prevent Warping

The first step in using Cura is to configure the “visibility of settings”. By default, the interface shows limited options, as it is set to “basic” mode to make it easy to use for beginners. To access more options and improve control of your prints, select the “Advanced” setting.

1. Shrinkage Configuration

• Retraction speed: This, is one of those parameters that varies depending on your printer, in particular, it varies depending on the bowden tube. Generally, a speed between 25-35 mm/s is ideal, but it is also important to adjust the retraction distance to minimize material recoil without affecting the stability of the print. Be sure to try slightly lower speeds if you notice defects or threads.
• Retraction Distance: Set the distance to 1-2 mm for direct extruders and up to 5-6 mm for Bowden extruders. This helps reduce the risk of stringing and ensures a cleaner printing surface.

2. Printing speed

• General Print Speed: We recommend starting with a speed of 50-60 mm/s for PLA. Adjusting the print speed depending on the complexity of the part can improve adhesion in the first few layers, reducing stresses that contribute to warping.

3. Ironing (Surface Smoothing) Configuration

To improve the quality of the top layer on PLA parts and reduce surface imperfections:

• Ironing Pattern: Zig-zag (recommended option in Cura).
• Ironing Line Spacing: 0.2 mm for good coverage without excess material.
• Ironing flow rate: 26% to ensure a uniform finish.
• Ironing speed: 150 mm/s to maintain a constant flow without affecting adhesion.

4. Fuzzy Skin (Surface Texture)

The Fuzzy Skin option in Cura can add texture to the surface of the part, useful in aesthetic applications. However, to avoid warping on parts where adhesion is critical, avoid using this option on the first few layers of print.

5. Support Configuration

To improve part stability and avoid warping in models with protruding areas:

• Custom Supports: Use custom support blocks for specific areas that require greater stability without generating unnecessary material. This helps maintain flow and reduces the possibility of deformation in contact areas.

Settings in PrusaSlicer to Prevent Warping

The settings in this Slicer are very similar to “Cura” but PrusaSlicer has some different options. Make sure to activate the following:

• Automatic Retraction: In PrusaSlicer, activating the automatic retraction and speed options may be sufficient for high quality PLA. The distance and speed will be automatically adjusted to avoid threads without losing print stability.
• Infill pattern: Open patterns on the lower layers, such as the infill grid or triangular, help reduce stresses, improve stability and minimize the material used without compromising the structure.

First Layer: Critical Parameters

• First coat height: Establishing a thickness of at least 0.2 mm helps improve initial adhesion and prevents edge lifting.
• First layer line width: Increasing the line width between 120% and 150% of the standard width provides a solid base. This extra width creates a stronger base that is better bonded to the bed.
• First layer speed: To allow the material to set up well, adjust the speed of the first layer to between 20-30 mm/s. We always recommend that the first layer be about 50% slower than the normal speed.

Adhesion Configurations (Brim, Raft, Skirt)

These are the most important parameters to improve adhesion and prevent warping in PLA. There are different adhesion techniques that can be useful:

• Brim: Adding a brim of 5-10 lines around the base increases the contact surface with the bed. This setting is especially effective on large pieces, as it better distributes the stresses at the edges.
• Raft: A raft acts as a sacrificial base that helps level and provide stability, especially on small parts or parts with little base contact. Although it increases time and material usage, the raft is very useful for reducing warping on complicated prints.
• Skirt: The “skirt”, is not recommended if you have adhesion problems because there are best practices, as explained above, Raft and Brim. The skirt purges the extruder before printing begins, ensuring a constant flow of material. Although it does not directly affect adhesion, its use ensures that the extruder is ready and free of debris when printing of the main part begins. Experienced makers also use the Skirt to give them time to adjust the print bed on the fly. From figutech we recommend that you use 3 to 5 lines of Skirt, at a short distance from the part, 3mm, ideally.

Temperature Control

Hotend and Hotbed Configuration

The temperature of the hot bed and hotend are really important factors to avoid warping in PLA. Recommendations for high quality PLA filaments, such as those from Figutech, are:

• Hotend: A temperature between 200-220 °C ensures uniform and stable melting.
• Warm bed: Setting the bed at 50-60 °C helps maintain initial adhesion and prevents abrupt cooling in the first layer. Once printing is complete, allow the bed to cool before removing the part to avoid warping.

Cooling Management

Progressive cooling helps to avoid deformation of the PLA. Set the cooling fan to 10-20% during the first layer and then gradually increase to 100% on the top layers. This setting allows the first layers to adhere firmly before full cooling is applied.

Extrusion Adjustments

Shrinkage and Flow Control Configuration

The retraction setting prevents stringing and improves PLA print quality:

• Shrinkage distance: Between 1-2 mm for direct extruders and up to 6 mm for Bowden systems.
• Shrink speed: Setting the speed between 30-40 mm/s helps to avoid excess material and to maintain a clean extrusion.
• Flow control: Setting the flow rate to 100% maintains a constant extrusion, avoiding problems of excess or lack of material.

External Perimeter Velocity

Reducing the speed of the outer perimeters to 20-30 mm/s contributes to better adhesion quality and finishing accuracy.

Other Tricks to Avoid Warping

Raise the temperature in small increments (5°C) to find the optimum adhesion temperature without creating an “elephant foot”. Increase the cross section of the printed filament:

Adjust the layer height (25-75% of the nozzle diameter) and line width (60-200% of the nozzle diameter). A larger line width, about 150-200%, can help increase the pressure of the first layer on the print bed, which improves adhesion and reduces the risk of warping.

1. Coating height: 0.16mm – 0.2 mm (for a standard 0.4 mm nozzle)
2. Line width: 0.5mm – 0.6 mm (120 – 150% of nozzle diameter of 0.4 mm)

Firmware Configuration (Marlin and Creality)

The 3D printer firmware is responsible for the mechanics and precision of the print. The automatic leveling and compensation commands help to improve the adhesion and stability of the first layer. Here are some examples of positive practices:

Marlin Firmware:

• Automatic Bed Leveling (ABL): Automatic leveling allows the bed to adjust dynamically, providing a uniform base. Proper ABL setting reduces the risk of warping and ensures a consistent first layer.
• M420 S1 command: After performing leveling with G28, use M420 S1 to activate and maintain automatic leveling throughout the print, ensuring that any adjustments to the bed are retained throughout the process.

Creality firmware:

• M420 S1 Command Application: On Creality printers, activating M420 S1 after G28 allows fading in the Z-axis, which reduces small variations in height. This improves the uniformity of the first layer, especially useful on parts with fine details.

Preventive Maintenance

Keeping the printer in good condition is key to ensuring consistent print quality. Some essential aspects of preventive maintenance include:

• Cleaning the print bed: Before each print, clean the bed to remove any dust, grease or residue from previous adhesives that may affect the adhesion of the part. Isopropyl alcohol is excellent for cleaning glass or PEI surfaces.
• Hotend and nozzle inspection: Checking the hotend for blockages and the nozzle for debris is important to avoid flow problems and ensure consistent extrusion. Clean the nozzle regularly to maintain an even flow of material.
• Belt tension: Shaft belts must be tensioned to avoid accuracy errors. Check the tension of the belts regularly, as improper tension can lead to layers shifting or alignment problems, affecting part adhesion and stability.

Solving Common Warping Problems

Despite preparation, common problems can arise when printing with PLA. Here are some typical problems related to warping and their solutions:

• Warping at the corners: If the corners of the part tend to lift, try using a brim or increasing the bed temperature to improve adhesion at the edges.
• Initial adhesion problems: If the first coat does not adhere properly, check that the bed is level and that the height and speed settings of the first coat are set properly. Using a glue or lacquer on the bed may improve adhesion.
• Nozzle wear: A worn nozzle can cause inconsistent extrusion. If you notice that extrusion quality has decreased, replacing the nozzle is a simple solution that will improve results.

These maintenance and quality control practices not only help prevent warping in PLA, but also contribute to parts with superior dimensional accuracy and stability, maximizing the quality of each print.

Is it worth testing?

Without testing, you are not going anywhere… Usually the testing phase is needed to adjust the printing parameters and validate that each configuration is fine-tuned to avoid all kinds of problems such as warping. As all makers know, the trial-and-error method is widely used in 3D printing.

First Layer Testing

A stable and well bonded first layer is key to a good print. First layer tests allow to verify the adhesion before starting complex impressions. Some recommended techniques are:

• First layer test: Printing a first layer test, such as a square or grid pattern, allows you to see if the material adheres properly across the entire surface of the bed. Make sure that the filament is well distributed and that no gaps or excess material is visible in the lines.
• Layer height adjustment: If the first layer seems too thin or too high, adjust the height on the slicer or via live adjustment on your printer. A slightly lower first layer increases adhesion, while one that is too high may cause the part to peel off during processing.

FAQ

What is the best temperature setting to avoid warping in PLA?

The best temperature setting for high quality PLA is usually between 200 °C and 220 °C in the hotend and between 50 °C and 60 °C in the hotbed.

What bonding techniques are most effective for large parts?

For large parts, using a 5-10 line brim increases the contact area at the base, helping to prevent lifting at corners. A raft is also effective, although it consumes more material and time. These methods are highly recommended for stabilizing large models.

Is it necessary to use an enclosed chamber to print PLA without warping?

It is not essential, as PLA is not as sensitive as other materials, but in environments with temperature fluctuations or drafts, a closed chamber can be beneficial. This helps maintain a constant temperature and reduces the risk of uneven cooling in the first layer.

How can I tell if the first layer is well bonded?

A well-bonded first coat will have even lines, with no gaps or build-up. You can perform a first coat test with a grid pattern to observe adhesion and make leveling and coat height adjustments as needed.

Does PLA warp under the sun?

Yes, in extreme cases, PLA can warp if exposed to direct sunlight for extended periods of time. Although it has good thermal stability under printing conditions, exposure to the heat of the sun can cause PLA to soften and lose its shape, especially if temperatures exceed 50 °C.