<p>ISO 5269-3:2008 specifies two procedures for preparing a closed water system which is in retention equilibrium, to be used for the preparation of laboratory sheets from pulps with a high fines content. One procedure is applicable to the preparation of laboratory sheets using the conventional sheet former and the other using the Rapid-K'then sheet former. The sheets prepared prior to attaining retention equilibrium are discarded.</p>
<p>ISO 5269-3:2008 is especially applicable to mechanical and chemimechanical pulps, as well as to pulps prepared from recycled fibres, i.e. pulps with a high fines content for which retention of fines is poor when using the open water system as described in ISO 5269-1 or ISO 5269-2. ISO 5269-3:2008 is<b> </b>not applicable to some very long-fibred pulps, such as those from unshortened cotton, flax and similar materials.</p>
<p>After retention equilibrium is attained, the preparation of laboratory sheets for testing the physical properties follows the procedures described in ISO 5269-1 (conventional sheet former) or ISO 5269-2 (Rapid-K'then sheet former), whichever is relevant.</p>
<p>ISO 5269-3:2008 is generally not applicable for the preparation of laboratory sheets from chemical pulps for which ISO 5269-1 or ISO 5269-2 are used.</p>
<p>ISO 5269-3:2008 is not applicable for the preparation of laboratory sheets for measuring ISO brightness. These sheets can be prepared in accordance with ISO 3688.</p>
Registration number (WIID)
42775
Scope
<p>ISO 5269-3:2008 specifies two procedures for preparing a closed water system which is in retention equilibrium, to be used for the preparation of laboratory sheets from pulps with a high fines content. One procedure is applicable to the preparation of laboratory sheets using the conventional sheet former and the other using the Rapid-K'then sheet former. The sheets prepared prior to attaining retention equilibrium are discarded.</p>
<p>ISO 5269-3:2008 is especially applicable to mechanical and chemimechanical pulps, as well as to pulps prepared from recycled fibres, i.e. pulps with a high fines content for which retention of fines is poor when using the open water system as described in ISO 5269-1 or ISO 5269-2. ISO 5269-3:2008 is<b> </b>not applicable to some very long-fibred pulps, such as those from unshortened cotton, flax and similar materials.</p>
<p>After retention equilibrium is attained, the preparation of laboratory sheets for testing the physical properties follows the procedures described in ISO 5269-1 (conventional sheet former) or ISO 5269-2 (Rapid-K'then sheet former), whichever is relevant.</p>
<p>ISO 5269-3:2008 is generally not applicable for the preparation of laboratory sheets from chemical pulps for which ISO 5269-1 or ISO 5269-2 are used.</p>
<p>ISO 5269-3:2008 is not applicable for the preparation of laboratory sheets for measuring ISO brightness. These sheets can be prepared in accordance with ISO 3688.</p>
