CNC Machining ROHACELL® PMI Structural Foam

‍

ROHACELL® Machinability
‍

ROHACELL® is a closed-cell polymethacrylimide (PMI) structural foam that machines exceptionally well using CNC milling, routing, and cutting processes. Its material structure is specifically suited to high-precision machining where dimensional accuracy and surface quality are critical.

When machined correctly, ROHACELL® produces clean features with minimal edge breakout and requires little to no secondary finishing.
‍

Material Structure and Behaviour Under the Spindle
‍

ROHACELL® has a rigid, closed-cell microstructure that provides a high stiffness-to-weight ratio. This structure resists local deformation during machining, even at high feed rates or under aggressive cutting parameters.

Under the spindle, this results in:

• Stable cutting behaviour
• Reduced chatter and vibration
• Accurate feature reproduction
• Consistent part geometry

The material does not smear, tear, or collapse under cutting forces in the way softer or open-cell foams can.
‍

Dimensional Accuracy and Repeatability
‍

Dimensional stability is a defining characteristic of ROHACELL® during CNC machining.

Key benefits include:

• Tight tolerance control across multiple parts
• Repeatable results from batch to batch
• Stable geometry during and after machining

This makes ROHACELL® particularly suitable for precision components such as spacers, cores, tooling inserts, and structural dielectric parts.
‍

Surface Finish and Edge Quality
‍

ROHACELL® machines with clean edges and well-defined features. Tool paths are reproduced accurately, and surface finishes are typically uniform.

Typical outcomes include:

• Minimal edge chipping or tearing
• Low surface roughness without post-processing
• Excellent bond-ready surfaces

In many applications, machined ROHACELL® parts can be bonded or assembled directly without additional surface preparation.
‍

Tool Wear and Machining Efficiency
‍

ROHACELL® is not abrasive and does not contain fillers that accelerate tool wear.

Machining advantages:

• Long tool life
• Reduced heat generation
• Stable cutting conditions

This supports high-throughput machining and consistent quality in production environments.
‍

CNC Machining Parameters and Methods
‍

ROHACELL® is compatible with:

• High-speed CNC milling
• 3-axis and 5-axis machining
• Routing and profiling
• Drilling and pocketing operations

The material supports high feed rates while maintaining accuracy, making it well suited to both prototyping and series production.
‍

Applications of CNC-Machined ROHACELL®
‍

CNC-machined ROHACELL® components are used in applications where precision and performance are non-negotiable.

Common applications include:

• Motorsport aerodynamic cores and inserts
• Aerospace sandwich structures
• RF and antenna spacers
• Composite tooling and patterns
• Lightweight structural components

These applications demand repeatability, accuracy, and predictable material behavior.
‍

ROHACELL® delivers predictable, high-quality results under CNC machining due to its closed-cell PMI structure, stiffness-to-weight efficiency, and dimensional stability. Clean edges, minimal tool wear, and consistent surface finish make it a preferred material in environments where precision and repeatability matter.

For manufacturers working in F1, aerospace, and advanced composites, ROHACELL® remains a proven material that performs reliably under the spindle.

‍