High-gum-content raw hemp fiber degumming method

Abstract

The invention discloses a high-gum-content raw hemp fiber degumming method. The method comprises a mechanical decortication and chemical immersion pre-degumming step, a steam explosion degumming step, a lignin oxidation degumming step and an ethanol boiling step. In the invention, based on the prior art, an independent lignin catalytic oxidation step is adopted, and chemical formula and technological conditions of a lignin catalytic oxidizer are improved to control the degradation degree of lignin, so that the lignin is partially degraded into non-water-soluble polyphenol substances, thus skillfully solving the problem that the lignin is sufficiently degraded into water-soluble monophenol and enters production wastewater. The polyphenol substances obtained after the degradation of the lignin are extracted through the subsequent ethanol boiling step, i.e. the polyphenol substances enter an ethanol solution and are subjected to simple distillation and purification to produce useful industrial byproducts. According to the invention, the method has the characteristics of favorable degumming effect, mild process, small fiber damage and the like; and the obtained fiber has high strength, favorable whiteness and high comprehensive quality.

Description

technical field [0001] The invention relates to a processing method of raw hemp fiber, in particular to a degumming method of raw hemp fiber with high colloid content, and belongs to the technical field of textile industry. Background technique [0002] Hemp plants are an important raw material source for textile fibers. Hemp plant raw materials have gradually become the main source of fiber resources due to their renewability and easy recovery of cellulose. The most important thing in the preparation process of hemp fiber is the fiber separation technology, that is, the degumming technology. [0003] Except for ramie, other hemp plants generally have high content of colloidal components and lignin components. It is precisely because of the high content of lignin components that the difficulty of degumming such raw hemp fibers is exacerbated. [0004] In the prior art, a combined method of chemical degumming and steam flash degumming is commonly used to degumming raw hemp ...

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Problems solved by technology

[0006] However, this flash explosion-high temperature cooking combined degumming process method has the following disadvantages: first, the temperature of the prepreg step is low (less than 50 ° C), and the degumming effect on the hemp fiber is limited, which limits the subsequent lignin removal; Second, in order to completely remove the lignin components, the conditions of the overall degumming method are relatively severe, which causes the hydrolysis of the cellulose and reduces the strength of the final fiber

[0012] Conventional presoaking + steam explosion + sodium hydroxide treatment, presoaking at room temperature can hardly remove lignin components, and subsequent sodium hydroxide combined with steam explosion treatment, sodium hydroxide will first interact with hemicellulose and pectin in the sample After most of the hemicellulose and pectin are removed, sodium hydroxide will be consumed in large quantities and the concentration will decrease. When it reacts with lignin, the removal effect of sodium hydroxide on lignin is low. This method cannot effectively remove lignin. Although the subsequent high-temperature lye cooking can remove lignin, the conditions are relatively severe (temperature 150-160°C, time 1-2h), and cellulose will inevitably be produced under long-term high-temperature conditions. Alkali hydrolysis, the strength is partially reduced, and the final fiber quality is affected

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