Not every part is cut with a router or a laser. When the material is soft, thin or transparent and the edge has to stay clean, the work is done with a knife. A knife does not melt, does not burn and does not remove material — it passes through the sheet and leaves the edge as it was.
What we cut with a knife
- PVC foil — advertising foil for opening hours, graphics and signs. Thin, cut with a scalpel.
- Vinyl — thicker than foil, from 0.3 to 5 mm. Cut with a scalpel so the transparent grades keep a crystal edge; 5 mm is the ceiling for the 4-axis scalpel knife.
- EVA foam — inserts for tool cases and drawers, protectors.
- Sound-absorbing felt — from 1 to 55 mm. The standard sheet is 2500 × 1250 mm and the machine takes up to 4000 × 2000 mm. Wall and ceiling panels, including complex geometry.
- Corrugated cardboard — packaging, cut and creased in one cycle.
- Textiles — upholstery, filters, gaskets.
- Silicone and technical foams.
- Thick PVC.
Which tool
Scalpel knife
For PVC foil, for vinyl and for very small parts. It removes no material — unlike a 3 mm router bit, which takes 3 mm out of every cut. Across a grid of hundreds of parts that difference adds up. The scalpel also travels about five times faster than a router is allowed to.
Oscillating knife
For soft and thick materials. It cuts EVA foam up to 55 mm and felt from 1 to 55 mm. The machine picks the tool up from the tool changer itself and supplies the air for the oscillation itself.
Creasing wheel
For corrugated cardboard. Cutting and creasing happen in one cycle, from one drawing — with no die. Every next box can differ from the one before it.
On which machine
On the two 4-axis HARMUTH machines, with a 4150 × 2060 mm work area. Tool changes are automatic, from a tool changer. The bed is fixed and runs adaptive vacuum — the pumps regulate their own speed as needed, which holds the sheet without vibration. On pre-printed material the machine picks up the registration marks with a laser, so the cut lines up with the print.
Why not a router or a laser
A laser darkens the edge. On transparent materials that shows immediately and the part becomes unusable where it will be seen.
A router removes material. Every cut eats as much as the tool diameter, and it does not give a crystal edge on transparent vinyl.
A knife does neither. That is why on soft foam, felt, corrugated cardboard and transparent vinyl it is the tool, not the compromise.