Most of the materials that meet UL-94 specification melt quite a bit when laser cut, especially when working with thicknesses above 1/16". In my experience, PTFE has given better results than nylon, polypropylene, and polyethylene, but this material is very expensive. Thinner sheets (for all of the materials listed) are expected to melt less than the thicker sheets since less heat is required to cut the material.
If you'd like, you can submit a quote request to test PTFE or other materials. Please note that we cannot cut any materials that contain chlorine, such as PVC, and we do not stock any of the materials listed above but you can have the material sent to us (it would also be helpful to send extra in case we run into any trouble while cutting).
Feel free to contact us if you have any questions!