| 摘要 |
<p>A method for making kraft paper, wherein a sulphate pulp is subjected to HC refining only or to HC refining in combination with LC beating, the LC beating, if applicable, being carried out at a relatively low energy supply, and wherein a strengthening agent, especially a charged polymer, is subsequently added to the stock, preferably at two separate points in the process, in a total amount of at least 8 kg per tonne of paper. Kraft paper with a tensile energy absorption index of 2.5-3.5 J/g at a porosity (Gurley) of less than 10 seconds. A valve sack made of one or more layers of said kraft paper.</p> |
