How to Prevent PLA Warping. Useful Tips & FAQ’s.

by Mike Brooks | Last Updated: March 6, 2022

What happens when you’ve spent endless hours waiting for your 3D model to finish printing only for it to turn out deformed?

I, for one, would definitely be frustrated because all that effort and patience has gone to waste. Such an issue with 3D prints is referred to as warping and typically occurs due to temperature changes that cause shrinkage in your material.

Making these 3D prints isn’t a simple task because one can expect things to take a turn for the worst.

PLA Warping Problem

When it comes to PLA warping, you stand a low chance of experiencing 3D warping since this material, Polylactic Acid (PLA), is least prone to such complications.

That doesn’t mean that your print is guaranteed safety. The only way to fix or prevent such problems is to understand, in detail, why it occurs and the necessary measures to take. Stick around to learn more about warping and how to prevent it in the future!

When a PLA 3D print cools too quickly and unevenly, parts of the print can detach from the print bed and curl upwards. 

Causes of PLA Warping

Warping or curling is a problem that has been affecting 3D prints since the origin of these printers. Simply, 3D warping is caused by temperature changes or uneven cooling.

The technology used in these printers requires heat to melt the filaments into layers that depict the design. The temperature of heating the filaments, and the fan speed to provide the required cooling effect determine the overall quality of your print.

The warping issue is more defined in the first filament layer when it fails to cool down uniformly. Hence, it exposes the outer edges to a cold environment forcing them to contract faster than the inner edges.

The imbalances in contractions cause stress in the print corners leading to warping.

Even though the filaments used in these printers are prone to the problem, there are special measures to prevent warping. These measures are also straightforward and don’t need high-end machines to work.

The following is a summarized list of the possible causes of PLA 3D warping:

• The poorly heated print bed
• Extreme and rapid temperature changes
• Poor adhesion on the print surface
• Dirty build surface
• Lack of an enclosure to prevent cold air
• Low cooling settings
• Unleveled build plate

10 Useful Tips to Prevent PLA Warping

Once you understand why and how the problem occurs, finding a solution to prevent warping becomes an easy task.

What are the techniques used to eliminate warping? 

They’re much simpler to implement than you think. Below is a list of the various measures you can take to reduce warping problems.

1. Z-offset

If the distance between the nozzle and the print bed is too large, only a small part of the filament strand will adhere to the print bed. Additionally, it will cool down too quickly on its way there.

But if the distance is too small, the filament has too little space and has to escape to the sides.

However, there’s a delicate balance in setting the initial Z coordinates of the printer nozzle: if set too close to the build platform it will lead to another set of problems.

To hit the perfect setting, you should lower the initial height of the nozzle in increments of 0.05 mm until you see a pronounced improvement in bed adhesion.

2. Use an Enclosed Print Chamber

An enclosed print chamber is useful for maintaining an ambient temperature difference within your printer. That prevents the material from fast cooling. Similarly, it reduces the drafts that blow cool air into the chambers from cooling your print too early.

You can always acquire a customized 3D printer enclosure from online retailers. Not only do they reduce corner curling in your prints, but also tone down the notice produced by the machine.

3. Add a Raft

A raft is a thin, horizontal layer that is added to the bottom of the design. This layer is deposited directly to the build platform, improving bed adhesion and making it easier to get the first layer right.

Although adding a raft can solve the warping problem, it also has a few drawbacks.

Rafts are meant to be removed after the printing process and are usually designed to be strong and stable; removing them tends to be difficult and can even cause smaller components of your print to break off.

4. Use a Design With Rounded Corners

A PLA warping problem is usually more defined in the corners of prints. When uneven contractions occur, they cause stress onto the filament’s corners forcing each of them to bear the pressure from at least two different directions.

Using a rounded edge for your design can significantly reduce the stress on one specific area and distribute it more evenly along the edges of your print. However, this method doesn’t completely guarantee that your print will never warp again.

5. Clean the Printing Bed

Before using any adhesives, you must ensure that the heating bed is spot-free. Traces of oil or grease are an enemy of good adhesion.

The most recommended cleaning measure is to use an ammonia-based cleaning agent like Windex.  You can also opt for a homemade remedy of water mixed with isopropyl alcohol for maximum effect.

6. Use a Strong Adhesive Material

Getting a good adhesive for your build plate can prevent materials on your heated bed from moving due to shrinking.

There are various adhesives you can try with the most recommended one being glue sticks. There are specially curated glue sticks designed for 3D printing that you can acquire to help reduce warping.

Masking tape is also another good alternative for an adhesive material.

7. Use a Heated Printing Bed

Getting a heated printing bed is probably the most reliable solution to your warping problem. A heated bed gives you a lot of flexibility to work with more filament types.

It allows you to lay down the filament material on a build platform with a temperature higher than ambient. The conventional advice when using a heated printing bed is to set it at a temperature below the glass transition temperature of the material you are working with.

That keeps the filament material in a solid-state while keeping it just soft enough to adhere to the surface of the bed.

The recommended bed temperature for printing PLA is 60 °C. For best results, a heated glass bed will all but eliminate any issues with PLA warping.

Aside from providing a massive improvement in bed adhesion, prints down on a glass heated bed also come out with a smooth and shiny bottom layer.

8. Properly Level Your Build Plate

An imbalanced build plate leads to a weaker foundation and adhesive, which increases the likelihood of warping problems. Therefore, you should always ensure that your build plate is perfectly leveled to reduce the pressure from shrinking materials.

9. Don’t Use a Cooling Fan – At Least for the First Few Layers

Our aim is to prevent rapid or uneven cooling that causes stress and thereafter, warping.  You can try turning off the cooling fan for the first few layers to allow each layer to stick to its adjacent counterpart perfectly before cooling begins.

However, PLA filaments require constant cooling so it would be to keep the fan speed optimized for better results.

10. Print in a Warm Room

For better results, you need more control of the temperature in your printer. Therefore, you should always consider the room temperature at which you’re printing.

For example, suppose you’re printing a model in a cold air-conditioned room during the summer; you are more likely to experience warping than if you turned off the A/C.

FAQ’s

Why Is My PLA Warping?

Your PLA is warping due to material shrinkage while 3D printing, which causes the corners of the print to lift and detach from the build plate.

When plastics are printed, they firstly expand slightly but contract as they cool down. If material contracts too much, this causes the print to bend up from the build plate.

PLA Warping Temperature. At What Temperature Does PLA Warp?

PLA undergoes quite significant dimensional changes even at 70 °C (158 °F).

Does PLA Warp in the Sun?

The degree to which the sun will affect your filament varies, but if any part of your PLA model is exposed to the sun or indirectly to heat, it can start to soften and warp.

Why Is It Important to Maintain a Glass Transition Temperature?

The glass transition temperature is the temperature below which your print material solidifies. This temperature is important because it keeps the material flat and attached to the heated bed thus, reducing the chances of warping.

Can You Use a Glue Stick on a Heated Bed?

It’s okay to use a glue stick on your heated bed as an adhesive as it’ll help prevent moving caused by the shrinking of filament corners or edges.

Why Is the First Layer Considered Very Important to the Entire Print?

The first layer tends to determine the overall results of your print. One of the best ways of getting the best first layer is to ensure your Z Coordinates are in the right settings.

Why Should the Fan Speed Be Low for the First Few Layers?

We don’t want the bottom layer of the filaments to be cooled excessively and cause warping. Maintaining a low fan speed for the first few layers keeps a constant temperature in check without any variations.

How Do You Stop PLA From Warping?

• Use a heated bed.
• Print in an enclosed print chamber.
• Turn off the material fan for the first few layers.
• Improve bed adhesion with adhesives or a suitable bed surface.

Does PLA Melt Easily?

PLA’s melting temperature is at around 160°C to 180°C, meaning that it will never melt in the sun, regardless of where you live.

How Hot Can PLA Get Before Deforming?

PLA is a tough, resilient material with a matte, opaque quality, but it is not as tolerant of heat as ABS is. PLA begins to deform at temperatures above 60 degrees c.

How to Fix a Warped Print?

While not all warped prints can be fixed, if the print bottom warping is slight, and your print isn’t too thick or large in volume, you might just be able to salvage it.

To do this, you’ll need to heat up the print close to its glass transition temperature (where it’ll get soft enough to mold back down).

You’ll need a large metal surface, like a frying pan, big enough to place the print in bedside down (the way up is how it came off your print bed).

Get a hairdryer and place the print in the pan. Heat it up on full power, and move the dryer around to evenly heat it.

After a minute or so, you can turn off the dryer and you should be able to hold the print down to bend it back to a flat shape. You’ll need to hold it for a few minutes until it’s cooled a bit.

Repeat this process until it works sufficiently. Don’t bother putting the print back on a heated bed, or worse, heating the pan— this will only heat the bottom of the print instead of heating it up evenly all over.

At What Temp Does PLA Get Soft?

PLA plastic becomes soft as low as 50°C and will deform quickly in this limited heat.

Conclusion

3D printing is an exciting adventure that also comes with its complications just like any other printer. If you’re determined to perfect your prints and ensure good quality results, these problems shouldn’t pose much of a challenge to you.

While the above tips can significantly help you achieve better results, they do not eliminate the possibilities of warping problems. You can always do research to find out more on how to fix such problems yourself.

Michael Brooks is the founder of M3DZone.com. He sees a very bright future for 3D printing that's why his mission is to try and make this easy for everyone. Discover your hidden talent and creativity. You can follow here: Facebook, Twitter & Pinterest.