摘要 |
<p>A fibrous sound absorbing mass mode of fibers having a biologically degradable composition, comprises components (I) in % by weight, wherein the sum of calcium oxide and magnesium oxide is in a range of 26.1 to 30.1 % by weight and the sum of sodium oxide and potassium oxide is in a range of 3.5 to 6.5 % by weight.</p> |