The pressing force of a metal briquetting press is its most critical specification, as it directly determines what materials it can process and the density/quality of the briquettes produced.

There is no single answer, as forces range from as low as 10-20 tons for small aluminum turnings to over 6,000 tons for heavy-duty steel mill scrap.

Here’s a detailed breakdown:

Key Factors Determining Required Force

Material Type & Hardness:

Soft Metals (Al, Mg, Cu): Lower force (50-300 tons). They compress and bind more easily.

Cast Iron: Moderate force (200-500 tons). Brittle, compacts into dense, stable briquettes.

Steel & Stainless Steel: High force (500-2,500+ tons). Tough, springy, and resistant to deformation. Stainless steel requires the most force in its category.

Exotic Alloys (Inconel, Titanium): Very high force, similar to or greater than stainless steel.

Chip Characteristics:

Size & Shape: Long, stringy, "bushy" chips are harder to compress than short, granular chips.

Moisture & Contamination: The presence of coolant, oil, or water can act as a lubricant, sometimes requiring slightly less force, but it must be managed.

Desired Briquette Density:

Handling/Transport: Lower density may be acceptable, requiring less force.

Smelting/Remelting: Maximum density is required to reduce oxidation and improve melting yield, necessitating maximum force.

Briquette Size:

A larger briquette (e.g., 120mm diameter vs. 75mm) requires a significantly higher total force to achieve the same pressure (Force/Area).

How Force is Measured and Applied

Unit of Measure: Metric tons (tonnes) or US tons (1 metric ton = 1.102 US tons). KiloNewtons (kN) is also used in engineering (1,000 kN ≈ 100 metric tons).

Pressure Calculation: The key engineering parameter is specific pressure (pressure on the material).

Area = π × (50mm)² ≈ 7,854 mm²

Pressure = 500 tons / 7,854 mm² ≈ 0.0636 tons/mm² or 63.6 kg/mm².

Formula: Pressure = Force / Area of the Briquette

Example: A 500-ton press making a 100mm diameter briquette:

Application: Force is generated by a hydraulic system (most common) or a mechanical system. The hydraulic pressure (in bar or psi) acting on the piston area of the hydraulic cylinder determines the final pressing force.

Consequences of Insufficient Force

Spongy, low-density briquettes that fall apart.

Poor "spring-back" recovery, where the briquette expands after ejection and loses density.

Inability to process tougher materials.

Low oil removal efficiency (for wet chips).

Industry Rule of Thumb

For common carbon steel chips, a specific pressure of 40-60 kg/mm² is often targeted for a good transport briquette. For stainless steel, this can be 60-80 kg/mm² or higher.

In summary: The pressing force is a carefully selected parameter based on the specific material, desired output, and economic considerations. When selecting a press, manufacturers will test your material to recommend the optimal force, which balances briquette quality, production rate, and machine cost. Always consult with a manufacturer for an application-specific analysis.