I agree on the “feed faster”, which is like the universal answer in soft plastics.
I would also add to plunge faster, it’s easy to overlook the plunge rate, and any melting that happens during plunge can be enough to end up with plastic hairs
I’ve had good results with v-bits in pickguard material…
EDIT: If that is the bit you used in the pic I would definitely up the feed rate, you should be able to get pretty clean results with that.
What router are you using? Check runout as well. Mine cut best around 16000-17000 rpms…
I haven’t tried that brand, but, checking the website description, it says they are 2-flute, is that true? They look like single flute to me. Not that it needs to be either of those, just more interested in an accurate description, inaccuracies concerning something as fundamental as the number of flutes would tell me a lot about the company…
Either way, I assume your stock is about 2.35mm (~0.093") thick 3-ply pvc, correct? The success I have had with this is being more conservative with the stepdown, I would do a 0.5mm stepdown (two 0.5 steps for a depth of 1.0mm), and then do a finishing pass at final depth with higher rpms (about 3.1 on the Makita dial).
The first stepdown will show you if you are getting re-welding/hairs so you can adjust if you aren’t liking the finish.
Afterwards you can use some 320-grit sandpaper (or an x-acto knife) to clean up any rough spots (like inside the corners). Use a fine-bristle paintbrush, soft toothbrush, or a make-up brush to clean the piece without scratching it.
If your results still aren’t ideal, try using plain uncoated carbide or high-speed steel, the coating makes the edge less sharp. Alternatively, you could try a narrow point carving bit (0.25mm radius ball-nose) as well. I have had good results in 3-ply pvc with both carving and v-bits…