| 摘要 |
Natural plant fibres, such as retted flax, hemp and china grass, are treated in an aqueous decolorizing bath comprising a dilute aqueous solution of any two of the substances sodium carbonate, sodium bicarbonate and sodium hydroxide. The decolorized fibres are washed, treated in an aqueous oiling bath containing formic acid and an emulsified fatty oil, again washed and then dried at an elevated temperature or in the open air. The decolorizing bath may contain about 1 gram per litre of sodium bicarbonate and about 3 grams per litre of sodium carbonate, or 1 gram per litre of sodium carbonate and 10 litres of an aqueous solution of caustic soda having a specific gravity of 36 DEG Be1 per 1000 litres of decolorizing solution. The decolorized fibres may thereafter be treated in an aqueous bleaching bath containing, per 1000 litres of bath, 1 Kg of soft soap, 1. 5 litres of a concentrated aqueous solution of sodium silicate of 36 to 38 DEG Be1 gravity and 5 litres of 130 vol. hydrogen peroxide, added as soon as the decolorizing solution has been heated to the boiling point. In either case the decolorized, or decolorized and bleached fibres are thereafter washed with water and treated in the oiling bath, which may contain about 400 mil. of formic acid and 1 litre of Traminol B (an emulsifying agent) for each 100 Kg. of fibres. The weight of the oiling bath may be about 20 times the weight of the fibres being treated The treatment of the invention may be applied to green flax obtained directly from the white crop when the seeds are separated from the stalks and conventionally cleaned by stripping to separate the straw from the flax fibres, which are then subdivided longitudinally and opened in a machine, the product being flax waste and a continuous material in the form of an untwisted cord. |
