Does ABS Filament Absorb Moisture? How To Deal With It!


3D printing can be a delicate process. It requires careful attention to small details that can have a big impact on the quality of the print. The more attention you pay to the details, the better your prints will be.

One such detail is moisture or the effect of moisture on print quality. ABS filament absorbs moisture which can drastically reduce the quality of the print.

But how exactly will the print be affected? In this guide, we look into how ABS reacts when exposed to moisture. How quickly can you expect it to absorb moisture and do you need to dry it if it does?

Finally, we will look at alternative filaments. Are there other filaments that do not absorb moisture that you can use in place of ABS?

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How Quickly Does ABS Absorb Moisture?

ABS is one of several filaments that has quick absorption of moisture. ABS, Nylon, PVA, and certain types of flexible filaments absorb moisture quicker than PLA for example.

Two main factors determine how quickly a filament will absorb moisture.

The first is your climate or environment. Naturally, if your climate has higher humidity, this creates an environment where you can expect there to be greater moisture absorption than in a drier climate with lower humidity.

There are ways to reduce or counter this which we will explore later in the article so keep reading to the end if you want to find out how to protect your filament from ambient humidity.

The second factor which determines moisture absorption is the type of filament. Some filaments absorb moisture at a quicker rate. The type of filament is the variable that affects moisture absorption the most.

Generally, PVA, Polycarbonate, Nylon, and ABS have a higher rate of absorption. Nylon, for example, absorbs humidity at an extremely fast rate. It can become fully saturated in between 2 to 24 hours. Once saturated the filament becomes completely unusable.

Fortunately, especially if you’re a beginner 3D printer, ABS isn’t as fast as Nylon. This is fortunate because ABS is one of the two most commonly used and easily available filaments when you’re new to 3D printing.

PLA is possibly the most recommended filament for beginners. It is cheap and easy to work with making it ideal for anyone taking their first steps into 3D printing. PLA, ASA, and Polypropylene have a slower rate of moisture absorption compared to ABS. Source

But how does moisture affect ABS filament and why should you be worried about it?

Is ABS Filament Affected By Moisture?

Moisture on the filament might not be visible even when it is there. However, the quality of the print is a telltale sign of the presence of moisture even where it is not visible. In such cases, moisture will result in a poorer print. This is evident as bubbles, cracks, or other visible defects in the print.

What usually happens is during printing, the heat from the hot end of the printer will bring the moisture in the filament to boil while the filament itself melts. The boiling water will naturally bubble. This is how you get the cracks and air pockets forming in the print.

Moisture affects prints in several other ways including:

  1. Inconsistency in the prints.
  2. Holes and other visible blemishes.
  3. Weaker prints that are easily susceptible to impact or pressure.
  4. The poor adhesiveness of the filament.
  5. Extruder malfunctions such as jamming, the filament delays coming out, or the motor stops while the filament keeps coming out.

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How Do You Tell if The Filament Has Moisture?

Moisture will introduce unwanted results in your print and even cause malfunctions in your printer. If the filament is wet, these are the signs you should expect to see:

  1. A popping or cracking sound when you extrude a length of filament through the printer.
  2. Sometimes there may be visible bubbles on the filament as it passes out of the extruder.
  3. A rough consistency or texture of the filament and your builds.
  4. Brittle prints that break easily.
  5. If you have had it for a long time and have not stored it properly, there is a high chance of moisture. Source

We also highly recommend that you check out our post “Can 3D Printing Filament Go Bad? How Can You Tell & Deal With It!

Do I Need To Dry ABS Filament?

Drying filament is advised if it is wet or if there is a chance it may be wet. A dry filament produces a better print finish while a wet filament produces prints with defects like cracks or bubbles. There are several ways to dry filament. The most common ways are using an oven, a dehydrator, or a filament dryer.

Oven drying filament

This is possibly the most convenient since most people have an oven. All you have to do is put the filament in the oven and set it to about 65 degrees Celsius (149 degrees Fahrenheit). The length of time depends on how much filament there is. A 1kg spool should be dried for between 6-8 hours.

Drying with a dehydrator

A food dehydrator is the next easiest option. It’s also safer since it operates at lower temperatures. The lower temperatures mean longer drying times, however.

Filament dryers

Filament dryers are a better option than both an oven and food dehydrator. This is because they were designed specifically for drying filaments. Dryers offer several advantages in this regard.

With a filament dryer, you can dry the filament while you print. With an oven or dehydrator, you first have to dry before you print. Dryers are compatible with different types of printers and filaments, with specific settings for the type and weight of filament you may be dealing with.

It’s less of an inconvenience to use a dryer than it is to use an oven or dehydrator. You don’t want to be spending 8 hours trying to dry filament when someone else wants to use the oven to make a casserole!

Prevention is always better than cure. This is why it’s better to keep your filament dry rather than have to dry it out after it has absorbed moisture. There are several storage methods you can use to keep your filament moisture free.

The simplest is to use airtight bags. The pricier option is to use a dry box. Keeping filament dry is better than drying because repeated drying will weaken and ultimately ruin the filament.

What Filament Does Not Absorb Moisture?

All filaments are hygroscopic. They all absorb moisture although at different rates. Certain filaments like Nylon, PVA, and ABS are more hygroscopic. Others like PLA are less so. Of all the filament types, HIPS is considered the least hygroscopic.

As all filament absorbs moisture, the smart thing to do is to store filament in a way that keeps it dry. A dry box is by far the best way to keep your filament moisture free.

sherifjallad

I am a very well experienced techie civil engineer who's extensively interested in 3D printing technology and even more captivated by the potential of 3D printing livable structures

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