An aerospace composite part takes hours to lay up and cure. The mould it cures on takes weeks to machine from a solid billet — and most of that billet ends up as chips. Large-format additive manufacturing builds the mould true to the surface geometry, using only the material that's structurally required. The slicer is the difference between that promise and a warped tool face.
Traditional mould production for aerospace composites follows a painful sequence: machine a pattern, cast or machine the mould from it, iterate on fit, then wait. Lead times are measured in weeks. Material waste is enormous — a metre-scale autoclave mould machined from a solid block can throw away 80% of the stock as swarf. And if the part design changes, the mould starts over.
LFAM — large-format pellet extrusion on a robotic arm or gantry — eliminates the pattern stage entirely. You print a near-net mould, machine only the tool face, and cure composites on it. But the toolpath quality determines everything downstream: dimensional accuracy under autoclave temperature and pressure, internal stiffener placement for thermal stability, and whether the surface needs hours of finishing or minutes.
Most slicers treat a mould like any other part: flat layers, uniform infill, no awareness that this geometry will be loaded thermally at 180 °C under six bar of pressure. The result is warpage, over-machining, and moulds that don't hold tolerance through the cure cycle.
The tool face gets optimized toolpaths — minimal stair-stepping on the mould surface so CNC finishing removes millimetres, not centimetres.
Internal ribs and stiffener geometry placed automatically based on mould dimensions and thermal load, not hand-modelled in CAD.
Infill density and bead orientation chosen to minimize CTE mismatch across the mould body — the tool holds shape through the cure cycle.
Path planning tuned for CF-reinforced pellet compounds like Dahltram C-250CF — autoclave-rated to 135 °C, dimensionally stable, recyclable.
Print the mould body in a shift, machine the tool face the next day. No pattern stage, no multi-step casting, no six-week dependency on an external tool shop.
Motion programs for the LFAM cell you already run — KUKA, ABB, Fanuc, gantry — not a proprietary format that locks you to one vendor.
A printed mould is not an end-use part — it's a manufacturing tool that has to survive thermal cycling, vacuum pressure, and autoclave conditions while holding micron-level surface tolerance. Every path-planning decision echoes downstream: bead orientation affects CTE, layer timing affects crystallinity, and surface quality determines machining cost.
This is exactly where automated, multi-axis-native slicing earns its keep. The slicer decomposes the mould into functional regions — tool face, stiffeners, base — and assigns the right strategy to each. No manual parameter tuning per feature. No trial-and-error on a metre-scale part that takes twelve hours to print. Get the toolpath right the first time, because the cost of a failed mould isn't a kilogram of wasted pellets — it's a week of lost schedule.
Send us your mould geometry and the autoclave spec. We'll show you what an LFAM toolpath optimized for thermal stability and surface finish looks like.