When I took apart my Alienware 17R4 laptop to switch out the fans, I noticed cloth-like tape over the fan and heatsink fins. I know it has to take a lot of heat, so I did some research and found the closes technology to it is call Tesa Triple A 51036 PET Tape. Here’s a link to the product information page: https://www.tesa.com/en-us/industry/tesa...
It comes in various sizes, but 19mm (3/4 in) is the closes width to the original tape.
This is a Germany based company, so look for genuine branded Tesa made in Germany. Some are made in China or Mexico which some Customers says aren’t genuine, but it’s possible that Tesa may be allowing those countries to manufacture for them.
UPDATE: I installed two new fans using the Tesa tape I ordered to cover up the gap between the fins and edge of fan. Here’s some pictures:
A bare fan with no tape after replacing the fan.
Adding the Tesa 51036 tape.
Overall all look of the finished job, you can see the old tape I replaced.
Close-up of the old tape vs. the new tape.