Multi-Cavity Inspection in Aluminium Extrusion

Measure Every Cavity. Compare Every Result. 

Multi-cavity extrusion dies allow several profiles to be produced during the same extrusion process. Maintaining consistent geometry across all cavities is essential for stable production and reliable product quality. 

With Scan Fit & Measure (SFM), manufacturers can perform multi-cavity inspection by inspecting several profiles from the same multi-cavity extrusion die in a single scan. Each profile is identified by its cavity number and measured individually against the nominal CAD drawing. 

This creates two levels of aluminium extrusion quality control: individual profile inspection and cavity-to-cavity analysis. 

Compare Each Extruded Profile with the CAD Drawing 

SFM compares the scanned geometry of each profile with its nominal CAD definition and evaluates the predefined dimensions and tolerances. 

This allows the quality team to identify: 

• dimensional deviations; 

• profile geometry deviations; 

• wall thickness variations; 

• form, position and orientation deviations; 

• out-of-tolerance dimensions; 

• differences between the actual profile and the nominal CAD geometry. 

The result is an immediate view of how each individual cavity performs against the required specification. This makes it easier to identify deviations in individual aluminium profiles before analysing how the cavities perform as a group. 

Compare the Cavities with Each Other 

Multi-cavity inspection does not stop with the comparison to the CAD drawing. 

Once the measurements are stored in the Measurement Data Center (MDC), the results from the different cavities can be analysed together. 

For example, profiles from a four-cavity extrusion die can be tracked as: 

Cavity 1 | Cavity 2 | Cavity 3 | Cavity 4 

The quality team can then compare the measurement results between cavities and identify whether one cavity consistently behaves differently from the others. 

MDC provides charts and statistical information for profiles and dimensions, including average, minimum, maximum, standard deviation, range and Cpk. This makes it possible to see not only whether a profile is within tolerance, but also how its measurements compare with profiles produced by the other cavities. 

The result is a clearer view of cavity-to-cavity variation and the overall performance of the multi-cavity extrusion die. 

From Individual Deviations to Production Trends 

A single profile measurement tells you whether that particular profile meets the specification. 

A series of measurements tells you much more. 

By analysing cavity-specific results in MDC, quality and production teams can identify: 

• systematic differences between cavities; 

• trends in dimensional variation; 

• cavities that consistently perform differently; 

• changes in critical dimensions over time; 

• increasing variation that may require attention; 

• differences in process stability between cavities. 

This turns multi-cavity inspection from a simple pass/fail check into a tool for extrusion process monitoring and continuous improvement. 

Instead of reacting only when a profile moves outside its tolerance limits, manufacturers can use the accumulated measurement data to understand how individual cavities behave over time. 

See the Difference — Don't Just Measure It 

For example, imagine four profiles produced by a four-cavity extrusion die. 

SFM can compare each profile against the same CAD drawing and show the deviations for each one. 

MDC can then bring those results together so the team can see the measurement data and statistical trends for the different cavities. 

Instead of asking only: 

“Is this profile within tolerance?” 

the quality team can also ask: 

“How does Cavity 3 perform compared with Cavities 1, 2 and 4?” 

and: 

“Is the difference between the cavities increasing over time?” 

This additional level of analysis can help aluminium extrusion manufacturers identify variation earlier and make better-informed decisions about the extrusion process and die performance. 

One Measurement Process. Two Levels of Insight. 

SFM provides the detailed inspection of each individual profile against its CAD drawing. 

MDC transforms those individual measurement results into comparable data, charts and statistics that reveal differences and trends between cavities. 

Together, they provide a complete approach to multi-cavity quality control in aluminium extrusion — from CAD-to-profile deviation to cavity-to-cavity comparison and process analysis.