Laser Processing of Isovolta VOLTAFLEX® F 6642 Flexible Film

Introduction

VOLTAFLEX® F 6642 flexible film is part of a product line of paper and film laminates produced by Isovolta. Three-ply VOLTAFLEX F 6642 is comprised of a PET film layer laminated between two layers of PET-fleece, impregnated with high grade, temperature-resistant resin. Each of the three layers are 50µm thick totaling150µm in thickness. A diagram depicting VOLTAFLEX F 6642 is shown in Figure 1.
Isovolta VOLTAFLEX F 6642 Flexible Film Layers

Figure 1. VOLTAFLEX F 6642 diagram showing the PET-fleece layers (50µm each)
on top and bottom of the PET layer (50µm).

VOLTAFLEX F 6642 has excellent electrical and mechanical properties and is used as slot, layer, and phase insulation for low voltage machines or as interlayer insulation for transformers. VOLTAFLEX F 6642 is suitable for laser cutting. The non-contact nature of laser processing enables applications with small features and fine geometry to be processed with virtually no material deformation or discoloration. VOLTAFLEX F 6642 is suitable for laser cutting; however other laser processes are not suggested as they are not conducive to the intended uses of this material. Universal Laser Systems technology makes it possible to consistently and repeatedly process this material to a high degree of dimensional accuracy, with consistent edges and minimal heat-affected zones.

Laser Processing Notes

VOLTAFLEX F 6642 was tested to assess laser cutting compatibility and to determine the best configuration of laser peak power and wavelength. The film laminate VOLTAFLEX F 6642 appears to absorb both the 9.3µm and 10.6µm CO2 laser wavelengths efficiently with slight differences in processing results. A microscopy image taken at 300x magnification of the edge of VOLTAFLEX F 6642 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.
Isovolta VOLTAFLEX F 6642 Flexible Film Figure 2

Figure 2. Microscopy image (300x) of the edge after laser cutting VOLTAFLEX F 6642. The heat-affected zone measures 40µm.

Isovolta VOLTAFLEX F 6642 Flexible Film Figure 3

Figure 3. 3D-rendered microscopy image (300x) of the edge of the VOLTAFLEX F 6642 after laser cutting.

VOLTAFLEX F 6642 was tested with both 9.3µm and 10.6µm CO2 laser wavelengths. The results of these tests were compared by analyzing the heat effects, edge quality, and post-processing requirements. The comparison of these two system configurations is 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 40µm This configuration results in a smooth edge that exhibits minimal heat effects and discoloration No post-processing is required
10.6µmMinimal heat-affected zone of approximately 70µmThis configuration results in a smooth edge that exhibits increased heat effects and minimal discoloration
Isovolta VOLTAFLEX F 6642 Flexible Film Figure 4

Figure 4. Microscopy images (300x) of the edge resulting from laser cutting with the 9.3µm wavelength (left) and 10.6µm wavelength (right).

Processing Example

VOLTAFLEX F 6642 applications requiring fine geometry and intricate detail with no degradation of the physical properties of the material can be accomplished with Universal Laser Systems technology. An example demonstrating the results of laser cutting VOLTAFLEX F 6642 using the recommended system configuration is shown in Figure 5.
Isovolta VOLTAFLEX F 6642 Flexible Film Figure 5

Figure 5. Example of the geometry possible when laser cutting VOLTAFLEX F 6642.

Conclusion

VOLTAFLEX F 6642 flexible film 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 viable with this material and that a 75 watt 9.3µm CO2 laser source is the recommended configuration. VOLTAFLEX F 6642 efficiently absorbs the 9.3 µm wavelength to produce an edge that has a minimal heat-affected zone and nominal discoloration.