GB706699A - Improvements in and relating to the degumming of fibrous plant material - Google Patents

Abstract

Fibrous plant material, before degumming in known manner with an aqueous solution or emulsion of a sulphated fatty oil or fat containing a water-soluble phosphate, is heated in a dilute aqueous solution of a salt of an alkali metal or of an alkaline-earth metal, which salt is substantially neutral to phenolphthalein. The solution or emulsion of sulphated material is preferably used at raised temperature, e.g. at its boiling point at atmospheric pressure or at a pressure of 0.5-1 atmosphere higher. The sulphated material may be prepared from a purified fish oil or castor oil. The free fatty acid content of the oil or fat sulphated should preferably not exceed 1.5 per cent. The plant material is pre-treated with the salt solution preferably by boiling, e.g. at a super-atmospheric pressure of 0.5-1 atmosphere. The salt is preferably magnesium sulphate or a bicarbonate of an alkali metal, e.g. sodium bicarbonate. The sulphated degumming agent solution or emulsion may be rendered feebly alkaline before use by the addition of an alkali-metal compound alkaline to phenolphthalein, such as sodium hydroxide or sodium silicate. In an example, ramie or ramie refuse is boiled for 2.5 hours in a 5 per cent. aqueous solution of sodium bicarbonate or magnesium sulphate, separated and washed with water. It is then boiled for 2.5 hours under a super-atmospheric pressure of 0.75 atmosphere in an emulsion prepared in a described manner by sulphating castor oil or purified fish oil, adding sodium glycero-phosphate and then sodium hydroxide and water. In another example, flax refuse is treated in a similar manner. The process reduces the time required for the degumming of the plant fibres, and the consumption of sulphated degumming agent. It is particularly applicable to the treatment of plant refuse. Specifications 526,629, 569,333 and 706,702 are referred to.