Which Release Agent Should You Use in Aluminum Extrusion? Technical Comparison of Technologies

Choosing the right release agent for aluminum extrusion is not just a matter of lubrication — it's a decision that impacts plant safety, profile quality, production efficiency, and total operating costs. Below, we explore five technologies used in the industry, detailing how they work, their benefits, and drawbacks. We conclude with a modern, highly technical option: Interforge KI-C by Interlub.

1. Acetylene Flame

The acetylene flame is based on the direct combustion of acetylene gas in front of the hot billet. As it burns, it produces a thin layer of carbon black that temporarily lubricates between the aluminum and the dummy block. This is an automated, low-cost solution commonly used in older presses or systems with basic controls.

However, this technology has serious drawbacks. The soot produced contains ultrafine particles classified as carcinogenic. This poses health risks for workers if proper ventilation and respiratory protection are not in place. Additionally, having an open flame near hot machinery increases the risk of fire. In terms of quality, the soot can stain profiles, interfering with finishes such as anodizing.

Advantages:

Automated system with no manual intervention per cycle.
Very low operational cost per application.

Disadvantages:

Fire hazard due to continuous flame presence.
Emission of hazardous airborne particles.
Stains extruded profiles, affecting aesthetics.
Does not lubricate other components such as the shear.
Requires flaming each billet individually.

2. Boron Nitride (BN)

Boron nitride is a high-temperature white ceramic used as a solid coating to prevent aluminum adhesion. It is applied either as an electrostatic powder or as a water-based liquid suspension. One major advantage is durability: a single application can last several extrusion cycles, reducing reapplication time.

BN powder requires special equipment (electrostatic guns, dry air, hoppers) and careful handling, as the fine particles are difficult to control and pose inhalation risks. The liquid suspension is easier to apply but may contain additives that burn and cause defects such as surface blisters. In both cases, material cost is high and implementation requires technical expertise.

Advantages:

High durability: can last 3 to 5 billets.
Non-flammable with no toxic smoke.

Disadvantages:

Very high unit cost (especially powder).
Inhalation risk or defects from poor suspension.
Requires specialized equipment and maintenance.
May cause surface defects if not formulated properly.

3. Graphite Suspension

This technology uses fine graphite particles suspended in a liquid medium like oil or a water-oil emulsion. Graphite offers excellent high-temperature lubrication by forming a heat-resistant film that protects against aluminum sticking. It is relatively low-cost and widely available.

However, the organic component burns on hot surfaces, producing smoke, soot, and residue. These contaminants can impact both safety and profile quality. Graphite is also electrically conductive, posing a risk to electronic equipment. It is typically applied manually, leading to variability and ergonomic risks for operators.

Advantages:

Excellent high-temperature lubrication.
Low cost and widely available.

Disadvantages:

Generates smoke and carbon residue.
Can cause profile defects (porosity, stains).
Electrically conductive: a hazard for electronics.
Manual application per cycle increases inconsistency.

4. Solid Graphite or BN Sticks

Solid sticks are manually rubbed onto the dummy block. They are made of compressed graphite or sintered boron nitride, sometimes mixed with waxes. This is a simple, low-cost solution that requires no equipment or complex setup.

The main downside is safety: operators must approach the hot dummy block, risking burns. Application is inconsistent and depends on the operator's skill and caution. Over- or under-lubrication can cause profile defects, and stick residue (fragments, waxes) can dirty the press area.

Advantages:

Low purchase cost.
No additional systems or installation needed.

Disadvantages:

High risk of burns from contact with hot surfaces.
Inconsistent, imprecise manual application.
Profile and press contamination from residues.
Not automatable; unsuitable for continuous operation.

5. Water-Based Solution – Interforge KI-C (Interlub)

Interforge KI-C is a water-based solution free of graphite and flammable compounds, specifically designed to eliminate common issues found in other technologies. It forms a micrometric film on the dummy block with excellent adhesion and thermal resistance. It contains no suspended solids, avoiding sedimentation and nozzle clogging.

Its formula is optimized for total safety: non-flammable, no smoke or toxic residues, and leaves no trace on the profile. It is applied via automatic spray systems with low per-cycle consumption (10–15 g), reducing operational costs and keeping the press clean. It’s stable in storage, doesn’t require agitation or mixing, and can also be used on other points like the shear, standardizing products throughout the plant.

Advantages:

Zero smoke, particles, or VOC emissions.
Maximum cleanliness and operator safety.
Low per-cycle usage; reduces profile defects.
Ready-to-use product; no mixing or agitation.
Compatible with automatic systems; no nozzle clogging.
Multi-use: dummy block, shear, etc.
Improves environmental indicators and eliminates residues.

Disadvantages:

Cannot be applied manually; requires application system.

Conclusion: Technical Comparison and Recommendation

A technical comparison of the five main technologies for aluminum extrusion demolding reveals wide variability in performance, safety, extrusion quality, and ease of implementation. Technologies like the acetylene flame or solid sticks offer low upfront costs but significant trade-offs in terms of safety, cleanliness, and consistency. Others, like boron nitride, excel in technical performance but are costly and complex to implement.

In this landscape, the water-based technology offered by Interforge KI-C stands out as the most balanced and technologically advanced alternative. Its combination of high lubrication efficiency, zero environmental impact, ease of application, and total safety positions it as the ideal standard for modern extrusion operations. Its versatility also allows multiple products to be replaced by a single lubricant, simplifying processes and reducing inventory.

From a technical standpoint, Interforge KI-C avoids the common disadvantages of traditional technologies: no smoke or residue, no mixing required, no system clogging, and completely clean profile surfaces. As a result, it contributes to improved final product quality, operator well-being, and plant sustainability.

Ready to Modernize Your Extrusion Process?

Interforge KI-C by Interlub is more than a release agent — it's an integral solution for plants seeking quality, safety, and efficiency without compromise. Implementing it can mean: