ABOUT หัวเจียรเหล็ก

The English chemist Joseph Priestley gave it the title rubber in 1770 when he identified it may be accustomed to rub out pencil marks. Its significant industrial achievement arrived only following the vulcanization method was invented by Charles Goodyear in 1839.· Because it is crystallized with GC and polycrystalline porous abrasive grains, it pr