Like any cutting tool, you need to keep sharp for quicker, easier & better results. Why waste the material and just toss them when they can be used for years. Having a few sharpened scrapers around is also nice when you have a lot of scraping.
A plexi-scraper works best when it’s edge is straight and smooth and the corners are sharp without burrs or jagged areas. Very much like wood, plastic can be cut and formed with a variety of methods and tools to achieve desired results:
1) A dedicated scraper sharpening guide with a file, ceramic cutters or a carbide blade.
2) Setting up a 90° dedicated or multi-angled side edge guide with a panzer or very coarse file.
3) A large, flat or panzer file secured to a bench or in a bench vise
4) Power tools: belt sander, jointer, router table, etc
5) Coarse sandpaper or drywall screen on flat surface
6) Securing a plexi-scraper in a bench vise and quickly scraping edge with sharp metal scraper