Cooking cellulose material using high alkali concentrations and/or high ph near the end of the cook

Abstract From the Canadian patent

Chemical (typically kraft) pulp having enhanced intrinsic fiber strength and bleachability compared to pulp produced using conventional or modified kraft cooking is produced by using high alkali and/or pH cooking preferably by , adding, the vast majority of cooking liquor (such as kraft white liquor) after the first, removal of liquid from the digester so that the effective alkali concentration is, high near the end of the cook. That is during at least the last minute (preferably, at least the last 15 minutes and most preferably at least the last 30 minutes) before the cook is terminated the effective alkali concentration is between 15- 50, g/l, more preferably between about 18-40 g/l …