Laser Processing of Solvay Ajedium Film Ultem 1000-1000 Polyetherminde (PEI)

Introduction

Solvay Ajedium™ Film Ultem® 1000-1000 Polyetherimide (Solvay PEI) is a rigid, high-temperature thermoplastic with excellent thermal, mechanical, and electrical properties, very low flammability and low levels of smoke evolution during combustion. Solvay PEI is well suited for electrical and electronic insulator applications, as well as applications requiring high strength and rigidity at elevated temperatures. Solvay PEI consists of a 127μm thick orange amber amorphous polymer. Solvay PEI was selected for laser compatibility testing. A diagram depicting Solvay PEI is shown in Figure 1.
Solvay Ajedium Film Ultem 1000-1000 Polyetherimide (PEI) Layers

Figure 1. Solvay PEI diagram showing the consistent nature of the sheet at 127µm thick.

Solvay PEI is suitable for laser cutting. The non-contact nature of laser cutting allows applications to be processed with small features and fine geometry, which might be difficult to achieve with traditional mechanical methods. Processes other than laser cutting are not indicated as they are not conducive to the intended use of Solvay PEI. Universal Laser Systems (ULS) makes it possible to consistently and repeatedly process this material to a high degree of dimensional accuracy, with virtually no material deformation during processing.

Laser Processing Notes

Solvay PEI was tested to assess laser processing compatibility and determine the best system configuration of laser peak power and wavelength. Solvay PEI readily absorbs the 9.3µm energy more efficiently than other laser wavelengths available from ULS. With the configuration of 75 watts of 9.3μm laser energy, laser processing of Solvay PEI produces a consistent edge along the processed path. Laser cutting Solvay PEI results in a small amount of debris along the edge, requiring some cleaning by wiping the edge with a solvent such as isopropyl alcohol after laser cutting. A microscopy image taken at 300x magnification of the edge of PEI is shown in Figure 2. The 3D image in Figure 3 depicts how the film responds to laser cutting with the recommended system configuration of a single 75 watt 9.3μm CO2 laser source.
Solvay Ajedium Film Ultem 1000-1000 Polyetherimide (PEI) Figure 2

Figure 2. Microscopy image (300x) of the edge after laser cutting Solvay PEI. The heat-affected zone measures 75μm.

Solvay Ajedium Film Ultem 1000-1000 Polyetherimide (PEI) Figure 3

Figure 3. 3D Microscopy image (300x) of the edge of Solvay PEI.

Solvay PEI was also tested with an alternate system configuration of 10.6μm laser energy at an equivalent laser wattage. The results of these tests were compared by analyzing the heat effects, edge quality, and post-processing requirements. The results of the comparison of these system configurations are listed in tabular form in Table 1 and shown photographically in Figure 4. The 9.3μm configuration produces a noticeably better edge when laser cutting this material and is the recommended configuration.

Table 1. System Configuration Comparison

System ConfigurationHeat-Affected ZoneProcess CharacteristicsPost-Processing Requirements
9.3µm (Recommended)Minimal heat-affected zone of approximately 75μm The 9.3μm laser energy has the advantage of better absorption by the material resulting in a consistent edge along the process path with a reduced heat-affected zone Post-processing requirements include the removal of slight deposition from the surface using light abrasion and a solvent such as isopropyl alcohol
10.6µmIncreased heat-affected zone of approximately 100μmThis configuration results in an increased heat-affected zone and less consistency in the edge along the processed path
Solvay Ajedium Film Ultem 1000-1000 Polyetherimide (PEI) Figure 4

Figure 4. Comparison microscopy images (300x) of the edge using the 9.3μm wavelength (left) and 10.6μm wavelength (right).

Processing Example

Solvay Polyetherimide applications requiring fine geometry and intricate detail without degrading the physical properties of the material can be accomplished with technology from ULS. An example demonstrating the results of laser cutting Solvay PEI is shown in Figure 5.
Solvay Ajedium Film Ultem 1000-1000 Polyetherimide (PEI) Figure 5

Figure 5. Example of geometry possible when laser cutting Solvay PEI.

Conclusion

Solvay PEI is suitable for laser processing and was extensively tested to determine the optimal processing configuration. Through this testing, it was determined that laser cutting is a viable process and a 75 watt 9.3μm or 10.6μm CO2 laser source is the best configuration for the processing of this material.