Laser Processing of Rogers Corporation™ BISCO® BF-1000
Laser Processing of Rogers Corporation™ BISCO® BF-1000
Introduction
Rogers Corporation™ BISCO® BF-1000 is a soft, cellular silicone foam with high compressibility and durability. The material is UL certified for flame resistance without the use of added chemicals, making it an environmentally friendly alternative material. BISCO BF-1000 is available in a variety of thicknesses ranging from 1.60 millimeters to 25.40 millimeters at a density of 208kg/m3. The 1.60 millimeter thick BISCO BF-1000 cellular silicone was selected for laser testing. A diagram depicting the BISCO BF-1000 material is shown in Figure 1.
Figure 1. BISCO BF-1000 diagram showing the consistent nature of the 1.60mm thick foam.
BISCO BF-1000 can maintain its physical and mechanical properties over a wide range of pressures and temperatures, particularly high temperatures, making it compatible with, and a desirable material for, laser processing. The non-contact nature of laser processing provides a method of cutting BISCO BF-1000 cellular silicone without mechanically deforming the material. Universal Laser Systems makes it simple to consistently and repeatedly process this material with a high degree of dimensional accuracy, as the non-contact nature of laser processing eliminates material deformation during processing.
Laser Processing Notes
BISCO BF-1000 cellular silicone was tested to assess laser processing compatibility and to determine the best configuration of peak laser power and wavelength. For laser cutting, BISCO BF-1000 cellular silicone absorbs 9.3µm CO2 energy more efficiently than other wavelengths, producing an edge with minimal heat effects. Utilizing a higher peak power laser allows for a faster motion system travel speed, which reduces the amount of laser dwell time while laser cutting the material, further reducing the heat-affected zone. With the configuration of 150 watts of 9.3 µm CO2 laser energy, laser cutting BISCO BF-1000 cellular silicone produces a straight and consistent edge and requires minimal post-processing. Laser cutting BISCO BF-1000 cellular silicone produces a small amount of debris that accumulates along the processed edge, which can be easily removed in post-processing with light abrasion. Due to the cellular nature of this product, the edge is not completely smooth as air pockets at the edge create a wavy contour. A microscopy image taken at 300x of the edge is shown in Figure 2.
Figure 2. A top-down microscopy image (300x) of the edge after laser cutting BISCO BF-1000. The heat-affected zone of the edge measures 90µm.
BISCO BF-1000 was tested with both 9.3µm and 10.6µm laser wavelengths. The results of these tests were compared by analyzing the heat effects, quality of the processed edge, and post-processing requirements. The comparison of these two system configurations is listed in tabular form in Table 1 and shown photographically in Figure 3. The 9.3µm configuration produces a noticeably better edge when cutting this material and is the recommended configuration.
Table 1. System Configuration Comparison
Process Configuration
Heat-Affected Zone
Process Characteristics
Post-Process Requirements
9.3µm (Recommended)
Minimal heat-affected zone of approximately 90µm
The 9.3µm laser energy has the advantage of better absorption by the material, resulting in a consistent edge along the processed path, with a reduced heat-affected zone
Post-processing requirements include the removal of slight deposition from the surface using light abrasion
10.6µm
Increased heat-affected zone of approximately 125µm
This configuration results in an increased heat-affected zone and produces a rough edge along the processed path
Figure 3. Microscopy images (300x) of the processed edge resulting from the 9.3µm (left) and 10.6µm (right) wavelengths.
Processing Example
BISCO BF-1000 cellular silicone applications requiring fine geometry and intricate detail without degrading the physical properties of the material can be accomplished with Universal Laser Systems technology. An example demonstrating the results of laser cutting BISCO BF-1000 material is shown in Figure 4.
Figure 4. Example of the geometry possible laser cutting BISCO BF-1000.
Conclusion
BISCO BF-1000 is suitable for laser processing and was extensively tested to determine the best processing configuration. Through this testing it was determined that laser cutting is viable with this material and a 150 watt 9.3µm CO2 laser source is the recommended configuration. The BISCO BF-1000 efficiently absorbs the 9.3 µm wavelength laser energy to produce a processed edge that has minimal heat-affected zone and discoloration.
