Meaning
Ultra-short pulse optical machining removes solid material through direct photo-ablation without transferring thermal energy into surrounding substrates. Mold cavity fabricators employ femtosecond laser ablation to micro-structure steel inserts for hydrophobic surface functionality and optics moulding. Ultra-fast energy delivery prevents molten rim formation around micro-cavities, yielding sharp geometric boundaries.
Conventional datasheet thermal conductivities do not govern material removal rates under sub-picosecond laser pulses.
Cold Machining
Sub-picosecond laser pulses ionize target atoms before thermal energy dissipates into the crystal lattice. Absorbed optical energy bypasses liquid phase melting to convert solid metal directly into expanding plasma. Clean pulse boundaries eliminate heat affected zones and micro-cracking in hardened tool steel.
High repetition rate laser systems maintain economic material removal speeds during micro-patterning operations.
Micro Texturing
Direct laser writing generates sub-micron riblets and hierarchical pillar arrays on cavity surfaces. Micro-textured mould inserts transfer functional biomimetic structures onto polypropylene parts during injection molding. Fine surface features alter molten resin wetting dynamics and reduce demoulding friction without chemical release agents.
Precise pulse energy control yields consistent feature depths across complex three dimensional tool geometries.
Tooling Performance
Cold processing maintains steel hardness and dimensional accuracy across thin cavity rib sections. Micro-structured tools resist abrasive wear from glass filled resins better than chemical etched finishes. Process monitoring tracks laser fluence degradation to prevent depth variations across large insert arrays.
