General perception for using plastic scrapers is for removing hardened or soft sealant, caulking, stickers, decals, paint, other things needing scraping. Ultimately the end user makes the choice in which plastic/resin scraper works for their task.
Scraper plastic types included:
Our stiffest resin, it is more chemically resistant, and generally used for removing hardened sealant soaked in solvents
(This material is abrasive; do not use on alclad or unpainted surfaces as it can scratch)
Acrylic blend (blue)
Our hardest resin, generally used for removing soft and leathery sealant, stickers/decals
(Not chemically resistant, chips easier, can scratch; do not use on alclad, unpainted surfaces as it can score surfaces)
Our softest resin, more chemically resistant, Boeing requires for use on alclad surfaces.
(This material requires more work at scraping due to softness, it is the best option when wanting to avoid scratching surfaces)