While investigating the smoke/fire damage to the dry storage cabinet used to store the finished SI fibers I also noticed an excessive amount of soot on most of the fibers caused by overheating the fibers at the end of the pulling process. The amount of soot would likely have render the fibers unusable due the the soot coating the fibers. During the pulling process it is necessary to shut the laser down within 1 second of completing the pulling cycle or a concentrated heat load occurs that emits a white soot that covers the end of the fiber which also rains down the fiber and under cuts the fiber. We use a vacuum system to pull the fumes away during this process that also showed excessive amount of soot in the clear vacuum hose. We need to be more aware of this during the next run. I will reiterate this on the next run and possible automate a laser kill switched.
Image 2799 shows the soot from both sources, white from over heated fiber and black from dry cabinet smoke.
Image 2806 fiber coated with white soot and ring where the fiber was under cut.
Image 2810 ring groove
Image 2811 assembly with clamp block, fibers and angle stiffeners.
Image 2820 is the dry storage cabinet showing the soot from the fried power supply in the desiccant regenerating box. Cause is under investigation, possible power surge(?)