| 摘要 |
<p>The present invention provides a process for the preparation of cellulose fibres from pine, which are of the mediumviscosity to high-viscosity type, wherein the cellulose fibres obtained from pulping pine in sulphite cookers are treated, when required with a quantity of chlorine, which corresponds to between 0.01 and 20% by weight of the quantity of chlorine used in classical bleaching procedures applied to sulphite process cellulose fibres from pine, and/or wherein said cellulose fibres from pine, which have not been delignified further or only to a very limited extent in this treatment with chlorine, are pretreated, when required in an acidic medium, whereupon said cellulose fibres from pine are refined with alkali at an elevated temperature, and thereafter delignified in an alkaline, aqueous medium with peroxide compounds, and then bleached by applying conventional single-stage or multi-stage bleaching procedures.</p> |
