Construction And Parameter Optimization Of Combined Degumming Preparation Of Spinnable Fiber Of Poacynum Hendersonii

Poacynum hendersonii is a wild plant.The bast is rich in cellulose,and it is an environmentally friendly plant fiber textile raw materials.There are many healthy functions in its fiber textiles such as air permeability,radiation resistance,antibacterial and so on.It is known as the"king of wild fibers".At present,due to the distribution location and its own characteristics,the popularity of Poacynum hendersonii textiles are not widespread enough.In order to realize sustainable utilization of Poacynum hendersonii resources in textile industry,it is necessary to construct a green preparation system of Poacynum hendersonii fiber based on biotechnology.The degumming process of bast fiber is the key step to obtain spinnable fiber,which has an important influence on the subsequent spinning process.Degumming is the process of removing non-cellulose from bast to obtain fiber.The chemical degumming method has high speed,low fiber residual gum rate and meets the needs of industrial production.However,the use of chemicals is much,and a lot of wastewater is discharged,which pollutes the environment and is not conducive to environmental protection.The microbiological degumming conditions are mild and the energy consumption is small,but the fiber residual gum content is high,which is not conducive to the subsequent spinning.It is a subject that needs to be further studied.The gum content of Poacynum hendersonii is higher than other fibrilias,and it is difficult to achieve the spinnability requirement by single degumming method,so it is an important choice to integrate the advantages of multiple methods to solve related problems.For this purpose,starting from the concept of sustainable development of the green cleaning,a chemical and microbiological degumming system was established for the preparation of spinnable fibers of Poacynum hendersonii distributed in Xinjiang,China.The purpose is to reduce the use of chemicals,improve the degumming effect,meet the requirements of textile industry for the spinnability of Poacynum hendersonii fiber and provide support for sustainable development of Poacynum hendersonii fibers.The combined degumming is divided into three processes:pretreatment,microbiological degumming,bleaching and refining stage.Orthogonal tests were used to determine the degumming effect of ultrasonic,sodium hydroxide and hydrogen peroxide pretreatment alone,and response surface test was used to determine the degumming effect of the combination of the three pretreatment methods.With weight loss rate as index,the optimal conditions were as follows:ultrasonic alkali bath 55°C,3 g/L,1:25,15 min;hydrogen peroxide 65°C,3 g/L,1:20,15 min.The weight loss rate was 22.19%.Degumming tests of single and mixed strains showed that the mixture degumming of Bacillus Circulans-DZ002 and Bacillus subtilis-DZ001 was the best.The average pectinase and xylanase activities were increased by 14.39%and 16.47%,respectively.Microbiological degumming is optimized by single factor and response surface tests.With the weight loss rate as index,the optimal conditions were as follows:bath ratio 1:50,inoculation amount 9%,initial p H=8.6,37°C,180 rpm,4.6 d;The weight loss rate was 45.26%under the optimal pretreatment and microbiological degumming conditions.Through single factor and orthogonal tests and with the weight loss rate index,the optimal bleaching conditions were H₂O₂ 9g/L,75 min,90°C,Na₂Si O₃ 5 g/L,Na₂CO₃ 3 g/L,Na₂SO₃ 1 g/L,JFC 3 g/L and bath ratio 1:20.The weight loss rate is 13.42%.The fibers obtained by chemical,combined and microbiological degumming methods were characterized and analyzed.In appearance,chemical and combined degummed fibers are loose,soft and shiny,while microbiological degummed fibers still have a lot of gum.The uniformity is not enough.IR spectra showed that there was no change in the structure of fibers before and after degumming,and the content of each component was different.Chemical composition showed that the combined degumming basically achieved the same degumming effect as chemical degumming.The average production rate,whiteness,fineness and moisture regain of the combined degumming were 46.63%,55.73%,0.3886 tex and 6.19%,respectively.According to calculation,for every 1 t of refined dried-jute,the amount of chemicals used in and chemical wastewater treated by combined degumming were reduced by 51.77%and 56.23%,respectively,which can reduce environmental pollution clearly.The wastewater used in microbiological degumming process accounts for 49.50%,and the wastewater rich in organic matter can be used for farm irrigation after reaching the standard of harmless treatment.