Large format 3D printing knows different variables that can be tweaked to achieve the best results. These can include extruder temperature, type of thermoplastic printing material and layer adhesion to the print bed.

Pellet extruder maintenance, particularly purging the extruder, is one such factors. Purging of pellet extruders is acrucial maintenance step that ensures optimal performance and print quality.

In this article, we dive into the importance of purging pellet extruders and the reasons behind it. In the video below, CEAD co-founder and CTO Maarten Logtenberg elaborates on this topic.

Reasons for purging LFAM pellet extruders

There are various reasons why pellet extruders should be purged by their operators:

1. Material change

Switching materials in your extruder requires a thorough purge to remove any remnants of the previous material. Residual material can contaminate the new material, leading to defects in the printed part. These defects can ruin the print and compromise the integrity of the final product. Ensuring a complete purge eliminates this risk, providing a clean slate for the new material.

2. Maintenance and material degradation

When exposed to high temperatures for a long time, some thermoplastic printing materials can degrade over time. This degradation can result in carbon buildup within the extruder, which can obstruct the flow of material and affect print quality. Regular purging helps to flush out these degraded particles, keeping the extruder clean and ready for the next printing cycle.

The purging process

To effectively purge your extruder, a special purging compound is required. This compound is designed to adhere to residual materials within the extruder and facilitate their removal. The compound resembles thermoplastic pellets and is used in the same manner.

The choice of purging compound depends on the specific material previously used, as different materials require different temperature profiles for effective purging.

CEAD provides access to various purging compounds that have been tested and approved for use with our large format additive manufacturing solutions. These compounds can be obtained directly from CEAD or through our partners.

For those interested in detailed guidance on the purging process, CEAD offers comprehensive manuals and step-by-step instructions available through our customer web portal.