Dyneema® Ultra High Molecular Weight Polyethylene (UHMWPE) fabric is a gel-spun, multi-filament fiber produced from ultra-high molecular weight polyethylene. Dyneema UHMWPE fabric is available in three strength ranges and several linear densities. Dyneema UHMWPE fabric consists of a 175µm thick fiber weave. A diagram depicting Dyneema UHMWPE fabric is shown in Figure 1.
Dyneema UHMWPE fabric has high strength, low weight, low elongation at break and is chemically resistant. The non-contact nature of laser processing allows applications to be processed with small features and fine geometry which might be difficult to achieve with traditional mechanical methods. Dyneema UHMWPE fabric is only suitable for laser cutting which produces consistent laser processed edges and minimal heat affected zones. Other laser processes are not suggested as they are not conducive to the intended use of this material. Technology developed by Universal Laser Systems makes it simple to consistently and repeatedly process this material to a high degree of dimensional accuracy because the non-contact nature of laser processing eliminates material deformation during processing.
Laser Processing Notes
Dyneema UHMWPE fabric was tested to assess laser processing compatibility and determine the best configuration of laser peak power and wavelength. Testing revealed that both the 9.3µm and 10.6µm wavelengths of CO2 laser energy are absorbed efficiently by the UHMWPE material. A microscopy image taken at 300x magnification of the processed edge of Dyneema UHMWPE fabric is shown in Figure 2. The 3D image in Figure 3 depicts how the processed edge of the epoxy adhesive responds to processing with the system configuration of a single 75 watt 9.3µm laser.
Figure 2. Microscopy image (300x) of the laser processed edge of Dyneema UHMWPE fabric. The heat-affected zone measures 100µm.
Figure 3. 3D rendered microscopy image (300x) of the laser-processed edge of the Dyneema UHMWPE fabric.
Dyneema UHMWPE fabric weave was also using both a 9.3 and 10.6µm laser source. The results of these tests were compared by analyzing the heat effects, quality of the processed edge, 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. Both system configurations appear viable with some slight differences in quality of the results as stated in the comparison.
Table 1. System Configuration Comparison
System Configuration
Heat-Affected Zone
Process Characteristics
Post-Processing Requirements
9.3µm
Minimal heat-affected zone of approximately 100µm
This configuration produces a full ablation along the processed edge with no fraying or discoloration and minimal heat effects
No post-processing required
10.6µm
Minimal heat-affected zone of approximately 120µm
This configuration produces a full ablation along the processed edge with no fraying or discoloration and minimal heat effects
Figure 4. Comparison microscopy images (300x) of the processed edge resulting from 9.3µm processing (left) and 10.6µm processing (right).
Processing Example
Dyneema UHMWPE fabric applications requiring fine geometry and intricate detail without degrading the physical properties of the material can be accomplished with technology from Universal Laser Systems. An example demonstrating the results of laser processing Dyneema UHMWPE fabric using the recommended system configuration is shown in Figure 5.
Figure 5. Example of the geometry possible with laser processing of Dyneema UHMWPE fabric.
Conclusion
Dyneema UHMWPE fabric is suitable for laser processing and was extensively tested to determine the optimal processing configuration. Through this testing it was determined that laser processing is viable with this material and using a 75 watt 9.3µm or 10.6µm CO2 laser source is the best system configuration for the processing of this material. Dyneema UHMWPE fabric efficiently absorbs the 9.3µm and 10.6µm wavelengths of laser energy to produce a processed edge that has minimal heat-affected zone and discoloration.
