Exploration of Alkaline Degumming Printing Techniques for Silk Gauze Fabric: Alkaline Boiling, Alkaline Steaming, and Alkaline Gel

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This work is devoted to textile materials science, and specifically to the development of new more efficient methods of processing silk fabric. This work contains an impressive experimental part, interesting results and conclusions. All the Figures and Tables are well-designed. The work is of interest to readers.

However, the relevance and novelty of the work are unclear. The motivation for choosing a topic and object of research is unclear. In addition, I have a number of questions and comments: - The title does not fully reflect the essence of the work. - Abstract: The background section seems superfluous, it does not carry any useful information about the content and essence of the work, I recommend replacing it with the problem that the authors solve in this work. - 8 references in the introduction is very few, the authors do not provide an overview of the problem and existing solutions. The introduction is very sparsely written. - The authors do not formulate the problem that this work solves. It is unclear what the motivation of the research is and what exactly the task is. This should be indicated in the introduction. It is necessary to reflect the current state of the problem, the shortcomings of existing solutions, and then note what is good about the authors' solution. - What are the surface density and the bulk density of materials? What restrictions does this parameters impose on the usage of the discussed method? - FTIR is poorly discussed. The discussion should be supplemented by analyzing the ratio of peaks. A significant change in intensity is noticeable, especially in the region of 2000-1615. Also the comment on the change in the 700-1000 range are of the need.

Nevertheless, the article may be of a great interest after revision.

Author Response

Comments and Suggestions for Authors

 

This work is devoted to textile materials science, and specifically to the development of new more efficient methods of processing silk fabric. This work contains an impressive experimental part, interesting results and conclusions. All the Figures and Tables are well-designed. The work is of interest to readers.

However, the relevance and novelty of the work are unclear. The motivation for choosing a topic and object of research is unclear. In addition, I have a number of questions and comments:

1. The title does not fully reflect the essence of the work.
2. Abstract: The background section seems superfluous, it does not carry any useful information about the content and essence of the work, I recommend replacing it with the problem that the authors solve in this work.
3. references in the introduction is very few, the authors do not provide an overview of the problem and existing solutions. The introduction is very sparsely written. - The authors do not formulate the problem that this work solves. It is unclear what the motivation of the research is and what exactly the task is. This should be indicated in the introduction. It is necessary to reflect the current state of the problem, the shortcomings of existing solutions, and then note what is good about the authors' solution.
4. What are the surface density and the bulk density of materials? What restrictions does this parameters impose on the usage of the discussed method?
5. FTIR is poorly discussed. The discussion should be supplemented by analyzing the ratio of peaks. A significant change in intensity is noticeable, especially in the region of 2000-1615. Also the comment on the change in the 700-1000 range are of the need.

Nevertheless, the article may be of a great interest after revision.

 

Thank you for your comments and the suggestions are very considerable. We made changes in sequence as following:

 

1. We appreciate the reviewers’ comments regarding the precise positioning of the research topic. The discussed alkali boiling, alkali steaming, and alkali gel degumming processes in this study specifically focus on the printing technology for silk gauze fabrics. The original title lacked the keyword “printing,” which has now been revised from “Exploration of Alkaline Degumming Techniques for Silk Georgette Fabric: From Alkaline Boiling, Alkaline Steaming to Alkaline Gel” to “Exploration of Alkaline Degumming Printing Techniques for Silk Gauze Fabric: From Alkaline Boiling, Alkaline Steaming to Alkaline Gel”

 

2. The background section previously overemphasized the historical status of alkali printing in China while neglecting relevant technical information. This has been revised to: “As an important branch of ancient Chinese silk dyeing and printing technology, alkali degumming printing utilizes alkali agents to degum raw silk, creating differences in fiber water absorption, dye uptake, and optical characteristics between degummed and non-degummed areas to achieve localized pattern formation.”
3. In response to the reviewers’ suggestions regarding insufficient clarity in problem statement and solution rationale, we have strengthened the argumentation in the Introduction section by adding four additional references to enhance the overall understanding of research objectives. Added details as follows:

 

The silk fabric printing achieved by alkali degumming technology can be summarized through two key aspects: First, the substrate uses raw silk gauze fabric, which forms patterns by exploiting the differential properties between raw and degummed silk. Second, the degumming process relies on the combined effects of alkali, water, and heat to successfully remove sericin from raw silk, thereby creating degummed patterns[9]. To meet these requirements, various gel printing methods were explored, ultimately selecting sodium polyacrylate (PAAS) as the alkali carrier. Dissolving alkali agents in PAAS gel enables rapid and precise degumming within seconds through hot-pressing[10]. As a high-performance water-soluble polymer, PAAS is widely used in textile printing for paste formulation and process optimization[11]. According to Flory^,s polymer gelation theory[12], the carboxyl groups (-COOH) on PAAS chains undergo near-complete deprotonation to carboxylate anions (-COO^-) under alkaline conditions. This induces enhanced interchain electrostatic repulsion, resulting in extended molecular chains and pH/Na⁺-dependent crosslinking strength, ultimately forming a three-dimensional physical gel network that transitions from liquid to elastic gel state[13]. The resulting alkali gel retains sufficient water to trigger gel network relaxation under hot-pressing, enabling directional alkali penetration into silk fibers while maintaining the essential “alkali-water-heat” environment. This demonstrates exceptional alkali sustained-release capability and thermal responsiveness.

The study found that alkali boiling degumming tends to cause edge diffusion of patterns under liquid alkaline medium conduction, which is advantageous for achieving abstract patterns. Alkali steaming degumming relies on steam to provide moisture, enhancing the precision of figurative patterns but is constrained by equipment capacity and energy consumption intensity. Alkali gel degumming meets the “alkali-water-heat” environment required for silk degumming under hot-pressing conditions, demonstrating excellent degumming and printing performance for figurative patterns. This research compared the effects of alkali dosage, processing time, and hot-pressing temperature on the degumming and printing process of silk gauze fabrics using alkali boiling, alkali steaming, and alkali gel degumming methods. The fiber morphology and infrared spectroscopy of degummed samples were analyzed. The study aims to explore the degumming effects of alkali agents under different process conditions through scientific quantification, thereby expanding the artistic expression and application of traditional Chinese alkali degumming techniques in modern silk degumming and printing.

The references added are as follows:

[10] Bashir S, Hina M, Iqbal J, Rajpar AH, Mujtaba MA, Alghamdi NA, Wageh S, Ramesh K, Ramesh S. Fundamental Concepts of Hydrogels: Synthesis, Properties, and Their Applications. Polymers, 2020, 12, 2702.

[11] Batara, B.; Steven, S.; Mulyana, M.; Saputra, A.S.; Hutahaean, A.C.; Yemensia, E.V.; Soekotjo, E.S.A.; Abidin, A.Z.Graha, H.P.R. Recent Advances, Applications, and Challenges in Superabsorbent Polymers to Support Water Sustainability. J Appl Polym Sci, 2025, 142,11.

[12] Flory, P.J. Principles of Polymer Chemistry. Cornell University Press, 1953, Chapter IX Gels and Networks.

[13] Li, Y.; Qu, G.; Zhang, H.; Xie, L.Zhang, Y.-F. pH-Responsive removal of dyes from wastewater using MXene composited L-Cysteine-grafted HEMA hydrogel: Dynamics, selectivity, regeneration and mechanism. Chem Eng Sci, 2024, 300,120648.

 

4. All solid powder materials were measured using 100% mass fraction for solution preparation, while liquid solvents were quantified by volume (mL). The three alkali degumming methods employ unified preparation protocols to ensure measurement consistency. Current study doesn’t address material surface density and packing density, which will be considered in subsequent research.
5. Following the reviewers’ recommendation, we supplemented detailed analysis of FTIR peak ratios to quantify the effects of different alkali degumming methods on silk fibroin. The revised section now included as follows to support the quantitative comparisons:

The differences in silk light transmittance and absorption peaks observed among different degumming processes primarily stem from the impact of degumming on silk’s molecular structure. Silk-I crystalline structure, a metastable form formed by stacking α-conformation fibroin chains, can transition to Silk-II (β-sheet) through hydrothermal treatment or mechanical stress. The three degumming methods showed slightly varied degumming rates under different processing conditions: (b) alkali boiling 27%, (c) alkali steaming 25%, and (d) alkali gel 26%. Figure 6 reveals that compared with undegummed sample (a), all degummed samples exhibited characteristic absorption peaks at 3275 cm^-1 (N-H stretching vibration) and at 1615, 1509, 1221 cm^-1 (amide I, II, III bands from β-sheet structures). Quantitative analysis of characteristic peaks in the 2000-1615 cm^-1 region using 3275 cm^-1 peak as internal reference showed systematic enhancement of 1615 cm^-1 peak intensity (β-sheet, amide I) in degummed samples (b-d), with enhancement magnitude positively correlating with degumming rate, indicating increased β-sheet content. Notably, no distinct α-helix amide I peak was detected in 1700-1650 cm^-1 region, and deconvolution analysis confirmed significant reduction of α-helix components, supporting Silk-I to Silk-II conformational rearrangement.

All samples showed neither peak shifts nor new/absent peaks compared to control, confirming that degumming processes preserved the primary chemical structure without generating new molecular configurations or functional groups [25]. The intensified absorption peaks at 1615 cm^-1 (amide I), 1509 cm^-1 (amide II), and 1221 cm^-1 (amide III) in degummed samples correlated with degumming rates, attributable to preferential removal of water-soluble amorphous Silk-I (α-helix) components with sericin elimination, while stable water-insoluble Silk-II (β-sheet) proportion increased [26]. In 700-1000 cm^-1 region (amide IV-VI bands and amino acid side-chain vibrations), no peak shifts or new peaks emerged. Calculated peak area ratios between amide bands (e.g., 950 cm^-1) and reference peak (760 cm^-1) showed no significant variations, confirming that degumming processes caused no disturbance to local protein backbone conformations, thereby excluding chemical bond cleavage or side reactions.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper “Exploration of Alkaline Degumming Techniques for Silk Georgette Fabric: From Alkaline Boiling, Alkaline Steaming to Alkaline Gel” is very interesting. However, I have the following suggestions:

 

Introduction: perhaps an image of the degumming printing method of the Tang Dynasty would add value to the paper, as well as a scheme of the various uses of alkali agents.

Materials and methods: Add chemical formulas to most of the materials.

Please add images or schemes of your experimental process. This makes it much easier to follow the paper.

It was not clear how and why the temperatures were chosen.

Figure 6- the spectra is not clear. Please add full lines and not dotted lines.

Author Response

Comments and Suggestions for Authors

 

The paper “Exploration of Alkaline Degumming Techniques for Silk Georgette Fabric: From Alkaline Boiling, Alkaline Steaming to Alkaline Gel” is very interesting. However, I have the following suggestions:

 

1. Introduction: perhaps an image of the degumming printing method of the Tang Dynasty would add value to the paper, as well as a scheme of the various uses of alkali agents.
2. Materials and methods: Add chemical formulas to most of the materials.
3. Please add images or schemes of your experimental process. This makes it much easier to follow the paper.
4. It was not clear how and why the temperatures were chosen.

5.Figure 6- the spectra is not clear. Please add full lines and not dotted lines.

 

Thank you for your comments and the suggestions are very considerable. We made changes in sequence as following:

 

1. In response to the reviewer’s comments, we supplemented the application of alkali-degummed raw silk fabrics in the introduction:

The “alkali printing method” is exclusively applicable to raw silk fabrics made from undegummed silk. The resulting solid-color alkali-printed patterns can maintain lifelong permanence without disappearing due to dyeing or fading, finding extensive applications in ancient costumes, decorative items, and religious artifacts.

Additionally, Section 3.2 was expanded to include the process flow of alkali-gel printing as detailed below, enhancing the clarity of theme presentation.

 

2. In the Materials and Methods section, chemical formulas have been added for most materials as follows:

Main Reagents: Sodium hydroxide (NaOH, analytical grade, Shenzhen Xilong Scientific Co., Ltd.), Food-grade sodium polyacrylate ((C3H3NaO2)n, Zhejiang Eno Bio-Technology Co., Ltd.), Slaked lime (Ca(OH)₂, analytical grade, Shanghai Chemical Reagent Co., Ltd.), Wheat starch (food grade, Shanghai Baoding Brewing Co., Ltd.), Urea (CH4N2O, analytical grade, Shanghai Chemical Reagent Co., Ltd.), Distilled water (Suzhou Herishin Electromechanical Co., Ltd.)

 

3. In response to the reviewer’s comments, Section 3.2 has been expanded with a dedicated subsection titled “Alkali Gel Printing Process” to clarify the procedure for readers. The new subsection reads:

3.2 Alkali Gel Printing Process

Compared to the alkali-steaming method, which requires approximately 2 hours of steaming post-printing, the alkali gel degumming-printing process drastically reduces processing time to about 1 minute of hot pressing. As illustrated in Figure 1(a), the prepared alkali gel is screen-printed onto the raw silk organza fabric. The printed fabric is then subjected to hot pressing for roughly 1 minute using a heated platen press (Figure 1(b)). After removing residual gel through washing (Figure 1©), solid-color patterns emerge on the undyed fabric, which remain permanently intact without fading or disappearing over time. Subsequent dyeing (Figure 1(d)) exploits the differential dye uptake between degummed and raw silk areas: the printed regions exhibit soft, fluffy fibers with high luster, while unprinted areas retain stiffness, lightness, and transparency. By controlling the alkali gel printing parameters, the patterns achieve localized degumming with sharp, non-feathered edges, presenting new directions for reconstructing Tang Dynasty alkali-based textile printing techniques.

Figure 1. Alkali gel degumming and printing process (a) Coating alkali gel for printing (b) Heat pressing using a flatbed heat press machine (c) Plain-colored pattern after cleaning residual gel (d) Pattern after dyeing

 

4. The selection of temperature is based on the requirements of three different degumming methods for degumming rate. Normal silk contains approximately 25% sericin. By controlling the degumming rate, the patterns can exhibit color contrast between raw and degummed silk. Therefore, the degumming rate is typically controlled between 10% and 30%. Excessive degumming rates can damage the fabric.

 

5. Figure 6 has been revised to use solid lines for illustration, and we thank the reviewers for their reminder.

Author Response File: Author Response.docx