Laser Welding of Clear-to-Clear Resin
Additive-Free Direct Welding of Transparent Resin
——No absorbers. Welded, while remaining transparent.
Direct welding of transparent resins to each other — once considered impossible with lasers. This is a process technology that achieves a strong, optically clear bond using only the physical properties of light, with no additives or adhesives of any kind.
Challenge: Constraints Inherent to Transparency
Laser welding relies on the principle that materials absorb light and generate heat. Because transparent resins transmit most of the light, joining two transparent pieces traditionally required applying an absorber (e.g., black pigment) to one surface, or using an adhesive.
However, these approaches introduced contamination risk and loss of optical clarity — issues critical in medical devices and optical components.
Solution: Selective Interface Heating
While transparent resins transmit the fundamental wavelength (1064 nm), they absorb mid-infrared light (~2 µm). By leveraging our process control and integration capabilities, we established a process that concentrates energy absorption at the interface — enabling welding without any absorbers.
Benefits
- Design freedom: Enables fully transparent product designs.
- Clean bonding: Eliminates outgassing from adhesives and application process variability.
- Medical & bio-compatible: Ideal for medical devices, microfluidic channels, and sensor components where optical clarity is essential.
