Drainage method

The present invention relates to a drainage method comprising the steps of:-providing a drainage device wherein the drainage device comprises artificial vitreous fibres (MMVF) bonded with a cured aqueous binder composition free of phenol and formaldehyde; -positioning the drainage device in contact with the ground, wherein the drainage device absorbs water and releases the water to a receiving site; wherein the aqueous binder composition prior to curing comprises:-a component (i) in the form of one or more lignosulfonate-based lignin having a carboxylic acid group content of 0.03 mmol/g to 1.4 mmol/g, based on the dry weight of the lignosulfonate-based lignin; -a component (ii) in the form of one or more cross-linking agents. 本发明涉及一种排水方法，其包括以下步骤：-提供一种排水装置，其中所述排水装置包括与不含苯酚和甲醛的固化水性粘结剂组合物粘结的人造玻璃质纤维(MMVF)；-使所述排水装置位于与地面接触的位置，其中所述排水装置吸收水并将水释放到接收处；其中固化前的水性粘结剂组合物包含：-组分(i)，其为一种或一种以上木质素磺酸盐类木质素的形式，其基于所述木质素磺酸盐类木质素的干重具有0.03mmol/g至1.4mmol/g的羧酸基团含量；-组分(ii)，其为一种或一种以上交联剂的形式。