Lubricating Dummy Blocks, Billets And Dies In Aluminium Extrusion
Aluminium sticks to hot steel. On an extrusion press that shows up as the billet welding to the dummy block, dross building up on the container seal, and black graphite or acetylene marks on the profile. Hexagonal boron nitride solves all three because semi-solid aluminium will not wet it, it is white and carbon-free, and it keeps lubricating to about 900 °C in air. Pyroflux India supplies boron nitride for extrusion in three forms made in Noida: a water-based spray (Pyrolube 20) for billets and dummy blocks, wax sticks for the shear, seal and die, and h-BN powder for electrostatic systems. This page compares the options and gives the settings our customers run, so you can trial it on your press without changing the press.
Five Ways To Lubricate a Dummy Block, Compared
| Option | Film | Equipment | Cleanliness | Safety | Typical use |
|---|---|---|---|---|---|
| Acetylene soot | Carbon black | Sooter, gas | Poor: black marks on profiles, soot in the press | Open flame; carcinogenic soot | Being phased out |
| Graphite-in-oil paste | Graphite + oil | Brush or swab | Poor: oil mist, black residue | Oil smoke | Dummy block, moving parts |
| BN powder, electrostatic | Dry h-BN | Electrostatic gun, feeder | Good | Dust control needed | Automated presses |
| BN wax stick | h-BN in wax, wiped on the hot tool | None | Good | None | Shear blade, container seal, die face, dummy block |
| Water-based BN spray (Pyrolube 20) | Dry h-BN film after the water flashes off | Siphon spray lance | Good | Water-based | Every billet on a running press |
What Works On a Running Press
| Billet surface at spray | About 450 °C |
|---|---|
| Spray pass | One pass of about 1.5 seconds per billet from a two-tube siphon lance on shop air |
| Cycle | One billet every 3 minutes on a mid-size press; the lance keeps up without an operator |
| Automation | Lance trigger locked open; compressed air switched upstream by a solenoid valve triggered by billet detection |
| Shear and container seal | BN wax stick wiped on at an interval set by what the operator sees: a clean, dry blade means stretch it; pickup means shorten it |
| Die | A light BN film on the face and bearing from the aerosol or a stick eases the start of each billet and protects the die in storage |
What Pyroflux Supplies For Each Step
Pyrolube 20
Water-based h-BN spray, 20–22% BN, silicone- and carbon-free, for billets and dummy blocks through the lance you already have.
Pyrolube 20 →BN Wax Sticks
Solid h-BN sticks wiped onto the shear, seal, die and dummy block; no equipment, no overspray. A hand holder is available.
Wax sticks →h-BN Powder
Free-flowing grades for electrostatic dummy-block systems and for mixing into your own spray.
Powder →An extruder running graphite-in-oil paste on dummy blocks and press moving parts moved billet release to Pyrolube 20 and the shear to BN sticks on the same press; Pyroflux is now developing a cleaner replacement for the paste used on the moving parts themselves.
Common Questions
Can boron nitride be used on the die?
Yes. A thin BN film on the die face and bearing eases the start of each billet and protects the die against corrosion in storage; use the aerosol or a wax stick.
Will BN contaminate the profile?
No. It is white, inert and leaves no carbon; it is the reason graphite marks disappear when extruders switch.
How much does switching cost?
Nothing on the equipment side for sprays and sticks: the lance you have works and sticks need nothing. Send us your press size and billets per shift and we will estimate consumption and quote a trial pack.
Do I still need acetylene for anything?
No. The spray covers the billet and dummy block, sticks cover the shear, seal and die. Most presses retire the sooter in the first week.
What about the moving parts of the press?
Graphite-in-oil pastes are still common there. Pyroflux is formulating a cleaner alternative; ask us about it when you enquire.
Tell Us The Process; We Will Recommend The Grade
Substrate, process temperature, atmosphere and how you prefer to apply it. That is everything we need to point you at the right product, send a sample, or quote.
- Phone
- +91 98181 87838
- sales@pyroflux.in
- Office
- G-5, Sector 63, Noida 201301, Uttar Pradesh, India
- Factory
- G-15, Sector 63, Noida 201301, Uttar Pradesh, India
- Hours
- Monday to Saturday, 9 am to 6 pm IST