Purpose

Dyeing process is usually to blame negatively for deteriorating the environment. Eco-friendly silk fibers are able to exercising their commercial values well followed by eco-friendly processing. One of the supporting examples is the process of changing the colors of silk fabrics. This would include the dyeing process used to change the colors of silk fabric. The intention of the study is to reach the goal of creating an eco-friendly finishing process using a local natural plant-based indigo dyeing process that would complement an eco-friendly degumming process. Currently, most dye houses use sodium hydrosulfite (Na₂S₂O₄) and alkali (NaOH) as the substances for providing hydrogen as a reducing agent. Since the sodium hydroxide by-products are acidic, they may damage equipment in the dye houses, generate air pollution in working environment. The other problems associated with the use of sodium hydrosulfite are the cost and instability with low storage.

Design/methodology/approach

This paper is based on continuing improvements to the commercialization of the raw materials via the innovative degumming process elaborated in the author’s previous study: “Degumming of Silk Fibers by CO₂ Supercritical Fluid.” The initial study has already proved that it was possible to remove sericin from raw silk fiber by using an organic acid pretreatment and CO₂ supercritical fluid over the heavy processes the industry currently deploys. The sericin removed from this innovative and eco-friendly processing of silk fiber will be remained in a clean state, not in the form of waste via the existing technologies in use. Clean sericin, rich in silk protein with high market values, can be a potentially perfect substitute of collagen the medical and cosmetic industries widely use. The continued research is focused on the other by-product coming out from this eco-friendly degumming process the silk fibers post degumming. Dyeing process is usually to blame negatively for deteriorating the environment. Eco-friendly silk fibers are able to exercising their commercial values well followed by eco-friendly processing. One of the supporting examples is the process of changing the colors of silk fabrics. This would include the dyeing process used to change the colors of silk fabric. The intention of the study is to reach the goal of creating an eco-friendly finishing process using a local natural plant-based indigo dyeing process that would complement an eco-friendly degumming process.

Findings

Degumming is an important stage in the silk manufacturing. Due to removing sericin from silk fibers, when subjected the degumming process, these silk fibers acquire the properties, which are of high consumer and commercial values, those include gloss, perfect color, soft handle and texture, elegant drape. Another purpose for the silk fabric degumming is preparing for the next step in processing, such as dyeing or printing. The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO₂ degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment. The implications or potential applications of the findings: as it is clearly seen from Table 1, the effectiveness of the degumming process can be improved by at least 38% applying scCO₂. Moreover, implementation of the scCO₂ silk degumming process into the textile industry may help manufactures to consume less water and energy resources (Elmaaty and Abd El-Aziz, 2017), as well as to obtain pure sericin as a valuable end-product that can be used in the medical and cosmetic industries.

Research limitations/implications

The innovation and novel aspects of research: degumming is an important stage in the silk manufacturing. Due to removing sericin from silk fibers, when subjected the degumming process, these silk fibers acquire the properties, which are of high consumer and commercial values, those include gloss, perfect color, soft handle and texture, elegant drape. Another purpose for the silk fabric degumming is preparing for the next step in processing, such as dyeing or printing. The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO₂ degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment.

Practical implications

The author has developed a new approach to the degumming process exploiting a supercritical fluid carbon dioxide and found it as a good alternative to the conventional methods that are currently used in industry. Silk fabrics treated by the scCO₂ degumming process are characterized by improved dyeing ability or color strength, while this process does not adversely affect the environment.

Social implications

As it is clearly seen from Table 1, the effectiveness of the degumming process can be improved by at least 38% applying scCO₂. Moreover, implementation of the scCO₂ silk degumming process into the textile industry may help manufacturers to consume less water and energy resources (Elmaaty and Abd El-Aziz, 2017), as well as to obtain pure sericin as a valuable end-product that can be used in the medical and cosmetic industries.

Originality/value

To make the silk manufacturing more green, the author has developed a technology for obtaining a plant-based indigo dye applying only locally grown agricultural products. The author has found that banana paste and banana peel paste have a sufficiently enough reduction potential for converting the indigo dye into indigo white, which is an important stage in the dyeing processes. The investigation performed showed that both these pastes can serve as a green alternative to sodium hydrosulfite, widely used in industry as a reducing agent. The main result of this study is the demonstration that natural, recyclable and easily biodegradable resources can be exploited to produce the semi-products for the textile industry and the final dyed silk fabrics as well. Summarizing the above, it can be concluded that we have got the results, which show promising alternative green processes for the textile industry in silk treatment (both degumming and dyeing). Their implementation may turn the silk textile production into a sustainable green circle and economically viable manufacturer.

中文翻译：

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CO2超临界流体对蚕丝脱胶及其对靛蓝的染色能力。

目的

染色过程通常会给环境恶化带来负面影响。环保的蚕丝纤维能够很好地行使其商业价值，随后进行环保的加工。支持示例之一是更改真丝织物颜色的过程。这将包括用于改变真丝织物颜色的染色过程。该研究的目的是要达到使用本地天然植物靛蓝染色工艺创建生态友好型整理工艺的目标，该工艺将对生态友好型脱胶工艺进行补充。当前，大多数染厂使用的是亚硫酸氢钠（Na ₂ S ₂ O ₄）和碱（NaOH）作为提供氢作为还原剂的物质。由于氢氧化钠副产物是酸性的，它们可能会损坏染房中的设备，并在工作环境中产生空气污染。与使用亚硫酸氢钠有关的其他问题是成本低，储存量低时的不稳定性。

设计/方法/方法

本文基于作者先前研究中阐述的创新脱胶工艺对原料商业化的持续改进：“用CO ₂超临界流体对丝绸纤维进行脱胶”。初步研究已经证明，通过使用有机酸预处理和CO ₂可以从生丝纤维中去除丝胶。超临界流体在行业当前部署的繁重过程中。从这种创新的，生态友好的丝纤维加工过程中除去的丝胶将保持清洁状态，而不是通过使用中的现有技术以废物的形式出现。清洁的丝胶蛋白，富含丝蛋白，具有很高的市场价值，可以成为医学和化妆品工业广泛使用的胶原蛋白的理想替代品。继续的研究集中在这种生态脱胶过程中，丝绸纤维脱胶后产生的其他副产品上。染色过程通常会给环境恶化带来负面影响。环保的蚕丝纤维能够很好地行使其商业价值，随后进行环保的加工。支持示例之一是改变真丝织物颜色的过程。这将包括用于改变真丝织物颜色的染色过程。该研究的目的是要达到使用本地天然植物靛蓝染色工艺创建生态友好型整理工艺的目标，该工艺将对生态友好型脱胶工艺进行补充。

发现

脱胶是丝绸制造中的重要阶段。由于从蚕丝纤维中去除了丝胶，因此在进行脱胶处理时，这些蚕丝纤维具有很高的消费和商业价值，包括光泽，完美的色彩，柔软的手感和质感，优雅的悬垂性。真丝织物脱胶的另一个目的是为下一步加工做准备，例如染色或印花。作者开发了一种利用超临界流体二氧化碳进行脱胶工艺的新方法，并发现它是工业上目前使用的常规方法的良好替代品。scCO ₂处理过的真丝织物脱胶过程的特点是提高了染色能力或色强度，而该过程不会对环境造成不利影响。研究结果的含义或潜在应用：从表1可以清楚地看出，使用scCO ₂可以使脱胶过程的效率提高至少38％。此外，将scCO ₂真丝脱胶工艺应用于纺织业可能有助于制造商减少水和能源的消耗（Elmaaty和Abd El-Aziz，2017年），以及获得纯的丝胶蛋白作为有价值的最终产品，用于医疗和化妆品行业。

研究局限/意义

研究的创新和新颖方面：脱胶是丝绸制造中的重要阶段。由于从蚕丝纤维中去除了丝胶，因此在进行脱胶处理时，这些蚕丝纤维具有很高的消费和商业价值，包括光泽，完美的色彩，柔软的手感和质感，优雅的悬垂性。真丝织物脱胶的另一个目的是为下一步加工做准备，例如染色或印花。作者开发了一种利用超临界流体二氧化碳进行脱胶工艺的新方法，并发现它是工业上目前使用的常规方法的良好替代品。scCO ₂处理过的真丝织物 脱胶过程的特点是提高了染色能力或色强度，而该过程不会对环境造成不利影响。

实际影响

作者开发了一种利用超临界流体二氧化碳进行脱胶工艺的新方法，并发现它是工业上目前使用的常规方法的良好替代品。经过scCO ₂脱胶处理的真丝织物的特点是染色能力或色强度得到改善，而该过程不会对环境造成不利影响。

社会影响

从表1可以清楚地看到，使用scCO ₂至少可以提高脱胶过程的效率38％。此外，将scCO ₂真丝脱胶工艺应用于纺织业可能会帮助制造商减少水和能源的消耗（Elmaaty和Abd El-Aziz，2017），以及获得纯的丝胶蛋白作为有价值的最终产品，可以用于医疗和化妆品行业。

创意/价值

为了使丝绸制造更加绿色，作者开发了一种技术，该技术用于获取仅使用本地种植的农产品制成的基于植物的靛蓝染料。作者发现，香蕉糊和香蕉皮糊具有足够的还原潜力，可以将靛蓝染料转化为靛蓝白，这是染色过程中的重要阶段。进行的研究表明，这两种糊剂都可以作为亚硫酸氢钠的绿色替代品，后者在工业上广泛用作还原剂。这项研究的主要结果是证明了可以利用天然，可循环利用和易于生物降解的资源来生产纺织工业的半成品以及最终的染色真丝织物。综上所述，可以得出结论，我们得到了结果，该图显示了在丝绸处理（脱胶和染色）方面纺织工业有希望的替代绿色工艺。它们的实施可以使丝绸纺织品生产成为可持续的绿色圈子和经济上可行的制造商。