Process

Purge Tower & Prime Pillar

Updated August 2026
3D Printing Definition
Definition

A purge tower (or prime tower) is a sacrificial geometric block sliced alongside a 3D model during multi-color or multi-material prints. It provides a controlled surface where the nozzle discharges residual old-color filament, builds chamber pressure, and re-stabilizes melt flow before resuming print perimeters.

Functionality in Multi-Color Filament Swaps

When switching from dark black to bright white filament, the nozzle must purge old pigmented plastic to avoid muddy streaks. The prime tower equalizes nozzle backpressure, ensuring the printhead returns to the model with crisp extrusion.

Slicer Waste Reduction Techniques

Advanced slicers reduce purge tower waste by flushing purged plastic into interior model infill or non-visible support structures, shrinking tower size and conserving filament.

Material Overhead & Impact on Job Cost Quoting

On tall models with frequent color swaps, prime towers can consume more filament than the actual model. Estimator algorithms factor in purge tower mass when pricing multi-color quotes.

Calculate 3D Print Costs in Real Time

Estimate exact filament gram rates, machine hours, and profit margins for any MakerWorld design or 3MF/STL upload.

Calculate Now