How to Fix Weak Layer Adhesion When Printing with ASA Filament

As we know, ASA (Acrylonitrile Styrene Acrylate) is prized for its excellent UV/weather resistance and thermal stability, making it a better choice for outdoor and functional 3D printing. However, weak layer adhesion is one of the most common problems encountered by many users. If you have tried printing with ASA and noticed your parts cracking or splitting between layers, you are not alone. Usually, the layer adhesion issue is not caused by the material itself, but by uneven temperature during printing.

This article will explain why it happens and provide practical and easy-to-implement solutions to improve layer bonding when printing with ASA.

Identify the Problem

• Visible layer separation – the lines between printed layers become clear
• Parts are broken easily – prints break with little force, especially along the layer lines
• Cracking under stress – functional parts are easily damaged during use or handling

Why Does ASA Layer Adhesion Become Weak?

Weak layer adhesion is usually caused by one or more of the following factors:

• Low nozzle temperature: Insufficient fusion of ASA
• Too fast printing: Insufficient bonding time for layers
• Rapid cooling: weak bonds between layers
• Unstable ambient temperature

The low nozzle temperature and unstable ambient temperature are the two most common causes.

Simple & Effective Solutions

1. Increase Nozzle Temperature
What to do:
📍 Increase 5–10°C from default setting (260-270°C)
📍 Recommended range: 265-280°C
🧩 Why it works: The high-temperature nozzle allows the ASA to melt more completely and bond more easily with the layer below. If stringing occurs, you may go too high.

2. Reduce Print Speed
What to do:
📍 Reduce print speed: from default setting 50-100mm/s to 40-90mm/s
📍 Attention Points: outer walls and structural layers
🧩 Why it works: The reduced speed allows the melted ASA material more time to adhere to the previous layer.

3. Increase Bed Temperature
What to do:
📍 Increase 10°C from default setting (80–100°C)
📍 Recommended range: 90–110°C
🧩 Why it works: A higher-temp bed helps maintain base layers warm, reducing thermal shrinkage and preventing layer separation, especially for long-time prints.

Additional Tips – enhance the success rate:
📌 Use an enclosure – keeps ambient temperature stable and prevents drafts
📌 Minimize part cooling – turn off or reduce fan speed to 10-20%
📌 Keep filament dry – moisture can weaken layer bonding
📌 Increase extrusion width/height – stronger fusion for layers

These subtle adjustments often have a significant impact, especially on large or tall parts.

The above settings are for reference only. Final adjustments will need to be made based on your printer and other specifications.

Achieving Strong and Reliable ASA Prints

Weak lay adhesion is a common but solvable issue when printing with ASA. By adjusting the printing settings, to find the better balance that suits your printer, ASA filaments can better utilize its advantages – remarkable mechanical strength and long-lasting performance.

If you’re new to ASA filament or want a full overview of its properties, applications, and printing settings, our complete ASA filament guide covers everything.