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Lub qhov rooj saib hluav taws
Thaum qhov kub nce mus txog 180 ℃ hauv hluav taws, lub plawv intumescent sab hauv ntawm lub qhov rooj saib yuav nthuav dav sai sai kom puv qhov chaw sib tshuam kom tiv thaiv hluav taws, pa luam yeeb lossis roj thoob plaws.