A red and yellow natural dye based on pomegranate peel, and a preparation method and application thereof

Abstract

This invention discloses a natural red and yellow dye material based on pomegranate peel, its preparation method, and its application. The natural dye material formula, by dry weight percentage, consists of the following components: Core component A: pomegranate peel, 20%-90%; Auxiliary component B: one or more of wild chrysanthemum, foxtail grass, purslane, gentian, de-thorned cocklebur, and sow thistle, 10%-80%. Its significant advantages are: using pomegranate peel as the core dye material, combined with common, inconspicuous wild plants found in forests and rural areas as auxiliary dye materials, and through specific compounding and extraction processes, multi-tone red and yellow dyeing can be achieved without adding any chemical auxiliaries. It offers excellent color fixation, extremely low cost, convenient availability, and strong feasibility. Simultaneously, it provides corresponding application methods, is compatible with various natural fibers, and can be directly used in industrial production.

Description

Technical Field

[0001] This invention relates to the field of dye preparation technology from natural raw materials, specifically to a red and yellow natural dye material based on pomegranate peel, its preparation method, and its application. Background Technology

[0002] Natural plant dyeing, as a traditional and environmentally friendly dyeing process, has been widely promoted in recent years in the fields of textiles, clothing, and home furnishings due to its natural, non-toxic, soft colors, and environmental friendliness. Among them, red and yellow are the most demanded classic color schemes, and their application scenarios cover clothing, home textiles, cultural and creative products, etc.

[0003] Currently, natural dyes for red and yellow colors mainly rely on artificially cultivated plants (such as madder, gardenia, turmeric, and safflower). These dyes have significant drawbacks: First, the planting cost is high, requiring arable land resources and having a long cultivation cycle, which is not conducive to large-scale, low-cost application. Second, the distribution range of some dyes (such as safflower and madder) is limited, and they are greatly restricted by region and climate, making it difficult to achieve convenient access nationwide. Third, most existing natural dyes are single-raw material dyes, which have problems such as limited color, poor color fixation, and insufficient color fastness, requiring the use of mordants, which further increases the dyeing cost and process complexity.

[0004] Meanwhile, a large number of inconspicuous wild plants (such as wild chrysanthemum, foxtail grass, and purslane) are distributed in forests and rural areas of my country. These plants do not require artificial cultivation, grow vigorously, are easy to collect, and are extremely inexpensive. In fact, some of these plants have even become so overgrown that they affect the ecosystem and are currently mostly cleared as weeds, resulting in extremely low resource utilization. Currently, there are no existing technologies that combine these common rural wild plants with pomegranate peel to develop red and yellow natural dyes, nor have they solved the technical bottlenecks of achieving "low cost, easy access, rich colors, and good colorfastness" in red and yellow dyes.

[0005] Pomegranate peel, as a fruit processing waste, is produced in huge quantities. The flavonoids and tannins it contains have certain dyeing properties. However, current technologies only use pomegranate peel as a single dye material, resulting in a limited dyeing effect, low color fixation rate, and failure to combine it with wild plants in rural areas to expand the color spectrum. This fails to meet the demand for multiple colors in the red and yellow series and also fails to realize the resource utilization of waste and wild weeds.

[0006] Therefore, it is necessary to develop an exclusive red and yellow natural dye formula that uses pomegranate peel as the core, combined with common and inconspicuous wild plants found in forests and rural areas, which is extremely low in cost, easy to obtain, rich in color, has good color fixation effect, is highly feasible, and can realize the resource utilization of waste and wild resources, thus solving the problems of high cost, difficulty in obtaining, single color, and poor color fixation of existing dyes. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a natural red and yellow dye material based on pomegranate peel, its preparation method, and its application. Using pomegranate peel as the core dye material, it combines wild chrysanthemum, foxtail grass, purslane, kochia, burdock (with thorns removed), and sow thistle as auxiliary dye materials. Through specific proportions of compounding and extraction processes, it achieves multi-tone red and yellow dyeing without the need for any chemical auxiliaries. It boasts excellent color-fixing effect, extremely low cost, convenient availability, and strong feasibility. Furthermore, through corresponding application methods, it can be adapted to various natural fibers and can be directly used in industrial production.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a red and yellow natural dye material based on pomegranate peel, the key feature of which is that it comprises the following components by dry weight percentage: The core ingredient is pomegranate peel, accounting for 20%-90%. The auxiliary components consist of one or more of the following: wild chrysanthemum, foxtail grass, purslane, ground worm, cocklebur, and sow thistle, ranging from 10% to 80%.

[0009] Furthermore, when the natural dye is scarlet, it contains the following components by dry weight percentage: 45-65% pomegranate peel, 25-40% wild chrysanthemum, and 10-20% purslane.

[0010] Furthermore, when the natural dye is brick red, it contains the following components by dry weight percentage: 65-75% pomegranate peel, 15-25% cocklebur, and 5-15% bitter lettuce.

[0011] Furthermore, when the natural dye is scarlet, it contains the following components by dry weight percentage: 45-65% pomegranate peel, 25-40% wild chrysanthemum, and 10-20% purslane.

[0012] Furthermore, when the natural dye has a dark red hue, it contains the following components by dry weight percentage: 70-90% pomegranate peel, 10-20% kochia scoparia, and 5-10% foxtail grass.

[0013] Furthermore, when the natural dye is turmeric yellow, it contains the following components by dry weight percentage: 25-50% pomegranate peel, 40-50% foxtail grass, and 10-20% purslane.

[0014] Furthermore, when the natural dye material is yellowish-brown, it contains the following components by dry weight percentage: 50-70% pomegranate peel, 20-40% kochia scoparia, and 5-20% bitter lettuce.

[0015] Furthermore, when the natural dye is pale yellow, it contains the following components by dry weight percentage: 20-40% pomegranate peel, 45-60% wild chrysanthemum, and 10-20% cocklebur.

[0016] Secondly, the present invention proposes a method for preparing a red and yellow natural dye material based on pomegranate peel as described in the first aspect, comprising the following steps: Preparation: According to the formula ratio of the corresponding color tone above, accurately weigh the crushed parts of each dyeing material component, mix them evenly, and put them into a stainless steel cooking pot; at the same time, prepare deionized water, with the mass-volume ratio of dyeing material to deionized water being 1:20. Pre-soaking: Add deionized water to a saucepan to submerge the dye material and soak for 30 minutes; Decoction extraction: Add an ethanol aqueous solution with a volume concentration of 60%-70% at a material-to-liquid ratio of 1:20. Turn on the heater and raise the water temperature to 90-95℃. Maintain a gentle boil and continue to decoct for 60 minutes, stirring once every 15 minutes during the process. Filtration: After boiling, turn off the heat and let it cool naturally to 40-50℃. Filter with an 80-mesh filter and collect the first filtrate. Add the filtered residue to 10L of deionized water and repeat step 3. Filter and collect the second filtrate. Combine the two filtrates to obtain the crude dye solution. Concentration: Place the combined crude dye solution into a concentration pot, control the temperature at 60-70℃, and concentrate under reduced pressure until the dye solution concentration is 0.05g / mL; Clarification: Add 0.5% natural clarifying agent to the concentrated dye solution, stir well, let stand for 20 minutes, and filter with a 100-mesh filter to obtain a clear and uniform dye solution; Storage: After clarifying the dye solution, put it into a sealed stainless steel container and store it in a cool, ventilated, and dark place.

[0017] Thirdly, the present invention proposes a method for dyeing fabrics containing natural fibers using red and yellow natural dyes as described in the first aspect, comprising the following steps: Fabric pretreatment: Cut the natural fiber fabric to the required size and soak it in deionized water for 20-30 minutes; Dyeing treatment: The pretreated fabric is placed in a clear dye liquor made from red and yellow natural dyes for dyeing. The liquor ratio is controlled at 1:25. The dyeing temperature and dyeing time are adjusted according to the fiber type and the desired color depth. Natural color fixation: After dyeing, take out the fabric, squeeze out the water, and hang it in a cool, ventilated, and dark place to fix the color naturally for 24 hours. Post-treatment: After natural color fixing, rinse the fabric in deionized water 2-3 times to remove unfixed pigments on the surface, and then air dry to obtain the finished product.

[0018] The significant effects of this invention are: 1. Reduce dyeing costs and make it easy to obtain dye materials: This invention uses pomegranate peels (a waste product from fruit processing) and common wild plants from forests and rural areas as dye materials, which completely solves the problems of high cost and limited availability of existing red and yellow natural dye materials, significantly reducing the cost of dyeing raw materials. At the same time, it realizes the resource utilization of "waste + wild weeds", without the need for additional investment in cultivation and procurement costs. It is suitable for industrial mass production and small and medium-sized workshops, and is highly feasible.

[0019] 2. Enriching the red and yellow color palette to meet diverse dyeing needs: Through the scientific blending of pomegranate peel with various wild rural plants, six specific color formulas—crimson, brick red, dark red, ginger yellow, earth yellow, and goose yellow—are precisely designed. This allows for the adjustment of multiple color levels and textures within the red and yellow color system, overcoming the shortcomings of existing dye materials with their single color intensity. It adapts to the dyeing needs of different scenarios such as clothing, home textiles, and cultural and creative products, enhancing product added value and broadening the application range of natural dye materials.

[0020] 3. Environmentally friendly and non-toxic with excellent color-fixing effect, in line with the concept of green development: No heavy metal mordants or chemical color-fixing agents are required. Natural color fixation is achieved only through the synergistic effect of the dye material's own flavonoids, tannins and other components. Dyeing wastewater has no harmful residues, is environmentally friendly and non-toxic, and fits the core concept of "green and healthy" natural plant dyes. At the same time, the color fastness reaches level 4 or above, which is significantly better than existing technologies, solving the problem of poor color-fixing effect of existing natural dyes and the need to rely on harmful chemical auxiliaries.

[0021] 4. Improved dye liquor stability, suitable for industrial storage and production: By optimizing the dye formulation ratio, material-to-liquid ratio, extraction temperature, concentration and other extraction process parameters, the dye liquor can be stably stored for 2-3 months under normal temperature, cool and dark conditions, without obvious stratification or precipitation, and the dyeing effect retention rate reaches more than 94%. This solves the problems of poor stability and short storage time of existing dye liquors, meets the needs of industrial batch storage and continuous production, and improves production efficiency.

[0022] 5. Expanding the application range of dyeing materials and protecting the original characteristics of fibers: The dyeing materials and dyeing process of this invention can be adapted to four natural fibers: cotton, linen, silk, and wool. Differentiated dyeing parameters are designed for different fiber characteristics. The dyeing process does not damage the fibers and can maintain the softness, smoothness, and natural luster of silk and wool fabrics, as well as the breathability and skin-friendly properties of cotton and linen fabrics. This invention solves the problems of the narrow application range and easy damage to fibers of existing dyeing materials, making it highly practical.

[0023] 6. Promote resource recycling and support the development of low-carbon industries: Achieve efficient utilization of pomegranate peel waste and reduce waste from fruit processing; at the same time, explore the dyeing value of common wild plants in rural areas, improve the utilization rate of wild weed resources, avoid the ecological pressure caused by weed overgrowth, realize "turning waste into treasure", promote the development of environmentally friendly, low-carbon, and resource-based plant dyeing industry, and conform to the national green development strategy and sustainable development concept.

[0024] 7. The process is simple and easy to implement, reducing the production threshold: The extraction process adopts the conventional decoction method, which does not require complicated equipment; the dyeing process adopts an integrated process of "immersion dyeing - natural color fixing - post-treatment", which is easy to operate and can be mastered without professional technicians. This not only reduces the equipment investment and technical threshold for industrial production, but also makes it suitable for small and medium-sized workshops and individual practitioners, which is conducive to the promotion and popularization of the technology.

[0025] 8. Improve pigment extraction efficiency and increase dye material utilization: By optimizing extraction process parameters, the pigment extraction rate reaches 82-88%, which is significantly higher than the extraction rate of single dye materials (the extraction rate of single pomegranate peel is only 72.5%, and the extraction rate of single wild plant is 60-68%). This effectively improves the utilization rate of dye materials, reduces resource waste, and further reduces dyeing costs. Attached Figure Description

[0026] Figure 1 This is a flowchart of the preparation method described in this invention; Figure 2 This is a flowchart of the staining method described in this invention. Detailed Implementation

[0027] The specific embodiments and working principles of the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] As can be seen from the background art, the present invention aims to solve the following technical problems: 1. To address the issues of high cost and limited availability of existing red and yellow natural dyes, this paper utilizes pomegranate peels and common, inconspicuous wild plants found in forests and rural areas as dyes, achieving low-cost, readily available, and resource-efficient use of dyes without the need for artificial cultivation, thereby reducing dyeing costs.

[0029] 2. To solve the problem of the limited color range of existing dye materials, a scientific blend of pomegranate peel and various wild rural plants is used to achieve precise adjustment of multiple shades within the red and yellow family, including scarlet, brick red, dark red, ginger yellow, earth yellow, and goose yellow, thus meeting diverse dyeing needs.

[0030] 3. This invention addresses the problems of poor color fixation and insufficient color fastness of existing natural dyes, which require reliance on heavy metals or chemical fixing agents. By leveraging the synergistic effect of the dye's own components, it improves color fixation rate and color fastness without the need for any harmful mordants or fixing agents, ensuring environmental friendliness and non-toxicity.

[0031] 4. To address the issues of poor stability and short storage time of existing dye liquors, optimize dye formulations and extraction processes to improve dye liquor stability and meet the needs of industrial-scale batch storage and use.

[0032] 5. Solve the problems of narrow applicability and easy damage to fibers of existing dyeing materials, and realize that the dyeing materials are compatible with four natural fibers: cotton, linen, silk and wool. The dyeing process does not damage the fibers and maintains the original hand feel and luster of the fabric.

[0033] 6. To address the problems of low utilization rates of forest and rural wild weed resources and waste of pomegranate peels, and to achieve "turning waste into treasure," thereby promoting the development of the environmentally friendly, low-carbon, and resource-oriented plant dyeing industry.

[0034] Therefore, this invention provides a red and yellow natural dye formula based on pomegranate peel and common rural plants. It uses pomegranate peel as the core dye, combined with common, unassuming wild plants from forests and rural areas such as wild chrysanthemum, foxtail grass, purslane, kochia, burdock (with thorns removed), and sow thistle as auxiliary dyes. Through specific compounding and extraction processes, it achieves multi-tone red and yellow dyeing without the need for any chemical auxiliaries. It boasts excellent colorfastness, extremely low cost, easy availability, and strong feasibility. It also provides corresponding application methods, is compatible with various natural fibers, and can be directly used in industrial production. The specific implementation method is as follows: Example: The red and yellow natural dye material based on pomegranate peel proposed in this embodiment consists of the following components by dry weight percentage: Core component A: Pomegranate peel, 20%-90%; Auxiliary component B: one or more of the following: wild chrysanthemum, foxtail grass, purslane, ground worm, de-thorned cocklebur, and sow thistle, 10%-80%.

[0035] In practice, if the dyeing material is suitable for red-toned cotton, linen, silk, or wool, the natural dyeing material shall consist of the following components: Core component A: Pomegranate peel, 40%-90%; Auxiliary component B: one or more of the following: wild chrysanthemum, foxtail grass, purslane, ground worm, de-thorned cocklebur, and sow thistle, 10%-60%.

[0036] The specific preferred embodiments are shown in the table below:

[0037] If the dyeing material is a yellow-toned material suitable for cotton, linen, silk, and wool, then the natural dyeing material consists of the following components: Core component A: Pomegranate peel, 20%-80%; Auxiliary component B: one or more of the following: wild chrysanthemum, foxtail grass, purslane, ground worm, de-thorned cocklebur, and sow thistle, 20%-80%.

[0038] The specific preferred embodiments are shown in the table below:

[0039] In practice, the natural dyes must also meet the following requirements: 1. All dyeing materials are dry products. After collection, they are naturally air-dried at a temperature of 25±5℃, in a well-ventilated and dark place for 3-5 days. They are then crushed to 60-80 mesh to remove impurities such as pebbles and withered leaves before use. 2. Pomegranate peel is made from dried peels of ripe pomegranates and other fruit processing waste. After removing any pulp residue, it is naturally dried and then crushed. No additional processing is required, and the cost is 0. 3. All the wild plants in rural areas are common varieties and can be collected for free in most parts of my country. No artificial cultivation is required. The best time to collect them is from July to October each year when the plants are in their vigorous growth period and have the highest pigment content. 4. The allowable error range for the weight percentage of each component in the formula is ±5%, which will not affect the dyeing effect.

[0040] 5. To ensure consistent dyeing effects across different batches and origins of dye materials, the wild plants must undergo standardized processing after collection. This involves determining the content of their marker components (e.g., flavonoids in wild chrysanthemum and betalains in purslane) using high-performance liquid chromatography (HPLC) or ultraviolet spectrophotometry. Different batches of raw materials are then physically mixed and blended to control the fluctuation of active ingredient content within ±5% before further pulverization and subsequent processing.

[0041] In practical implementation, the natural dyes described in this application may also have the following alternative formulations: 1. Core Dye Material Substitution: The core dye material, pomegranate peel, can be replaced by other common fruit processing wastes, including apple peel, pear peel, and orange peel. These wastes are also rich in flavonoids and tannins, have zero cost, and are readily available. When combined with existing wild rural plants, they can achieve multi-tone dyeing in red and yellow hues. The pigment extraction rate and color fastness are basically the same as the original scheme (extraction rate 80-86%, color fastness grade 4 and above), with only slight differences in hue (apple and pear peels lean towards warm yellow, orange peel towards orange-red), which does not affect the achievement of the invention's purpose. Using apple peel instead of pomegranate peel, and compounding according to the original scarlet ratio, the pigment extraction rate is 81.5%, and the color fastness after dyeing reaches grade 4. The hue is not significantly different from the pomegranate peel formula.

[0042] 2. Substitution of Auxiliary Dyeing Materials: Wild plants such as wild chrysanthemum, foxtail grass, purslane, kochia scoparia, burdock root (without thorns), and sow thistle in the original scheme can be replaced with other similar, readily available, and distributed rural wild plants. The specific substitution relationships are as follows: wild chrysanthemum can be replaced with dandelion (containing chrysanthemum xanthophyll, brightening the color); foxtail grass can be replaced with bermudagrass (containing carotenoids, providing a yellow base); purslane can be replaced with dandelion (containing betalains, enhancing red saturation); kochia scoparia can be replaced with lambsquarters (containing components similar to kochia fruit, adjusting color dullness); burdock root (without thorns) can be replaced with velvetleaf (containing components similar to xanthophyll, deepening the tone); and sow thistle can be replaced with sow thistle (containing chlorophyll derivatives, adjusting color uniformity). The formula ratios after substitution can be slightly adjusted (error ±3%), while the dyeing effect and color-fixing performance remain consistent with the original scheme, still achieving the goal of resource utilization of "waste + wild weeds" and cost reduction.

[0043] 3. Formula ratio substitution: The dry weight percentage error of each component in the original scheme is allowed to be ±2%, which can be further optimized to ±3%. At the same time, it can be finely adjusted within the range of 40%-85% of the core dye material (pomegranate peel or its substitute) and 15%-60% of the auxiliary dye material according to the target hue depth. The same dyeing effect can be achieved without changing the types of components, adapting to the hue requirements of different scenarios, and still achieving the purpose of the invention.

[0044] This embodiment also proposes a preparation method for the above-mentioned natural dyes, namely, an extraction process, such as... Figure 1 As shown, it includes the following steps: 1. Preparation: According to the formula ratio of the corresponding color tone above, accurately weigh each dry component of the dye material that has been pulverized to 60-80 mesh, mix them evenly, and put them into a stainless steel cooking pot; at the same time, prepare deionized water, with the mass-volume ratio of dye material to deionized water being 1:20, that is, 1000g of dry dye material is added to 20L of deionized water. 2. Pre-soaking: Add deionized water to a pot to submerge the dye material and soak for 30 minutes to allow the dye material to fully absorb water, which facilitates pigment dissolution and improves the extraction rate; 3. Decoction extraction: Add an ethanol aqueous solution with a volume concentration of 60%-70% at a material-to-liquid ratio of 1:20. Turn on the heater and raise the water temperature to 90-95℃. Maintain a gentle boil and continue decocting for 60 minutes, stirring every 15 minutes to ensure that the dye pigment is fully dissolved. During the decoction process, add a small amount of deionized water to maintain a constant liquid level and prevent the dye solution from concentrating too quickly. 4. Filtration: After decoction, turn off the heat and let it cool naturally to 40-50℃. Filter with an 80-mesh filter and collect the first filtrate. Add the filtered residue to 10L of deionized water and repeat the gentle boiling decoction in step 3 for 30 minutes. Filter and collect the second filtrate. Combine the two filtrates to obtain the crude dye solution. 5. Concentration: Place the combined crude dye liquor into a concentration pot, control the temperature at 60-70℃, and concentrate under reduced pressure until the dye liquor concentration is 0.05g / mL, that is, each 1mL of dye liquor contains 0.05g of dry dye material extract. Stir during the concentration process to avoid local overheating that could cause pigment deterioration. 6. Clarification: Add 0.5% of natural clarifying agent - chitosan to the concentrated dye solution, stir well, let stand for 20 minutes, filter with a 100-mesh filter to remove impurities and precipitates, and obtain a clear and uniform red and yellow natural dye solution, which can be used directly for dyeing. 7. Storage: After clarifying the dye solution, put it into a sealed stainless steel container and store it in a cool, ventilated, and dark place. It can be stored stably at room temperature for 2-3 months without separation, precipitation, or odor, and the dyeing effect will not be significantly reduced.

[0045] As can be seen, the preparation method proposed in this embodiment is simple, requires no complex equipment, can be carried out using conventional decoction methods, and is suitable for industrial mass production and small and medium-sized workshops.

[0046] The key process parameters for the above process are explained below: 1. Extraction temperature: 90-95℃. This temperature ensures that the pigment is fully dissolved while avoiding pigment decomposition caused by high temperature. The pigment extraction rate can reach 82-88%. 2. Material-to-liquid ratio: 1:20. This ratio can balance the pigment extraction rate and the amount of dye solution used, avoiding water waste and excessively low dye solution concentration. 3. Concentration: 0.05 g / mL. This concentration ensures the staining effect while avoiding uneven staining caused by an overly thick dye solution.

[0047] In practical implementation, the preparation method described in this embodiment also has the following alternatives: 1. Alternative Extraction Method: The original method uses conventional decoction to extract pigments, which can be replaced by ultrasonic-assisted extraction. The specific parameters are adjusted as follows: the dye material is crushed to 80-100 mesh, the material-to-liquid ratio is 1:18, the ultrasonic power is 300W, the extraction temperature is 60-70℃, and the extraction time is 30 minutes. No pre-soaking step is required, the filter residue does not need to be decocted again, and the pigment extraction rate can reach 83-89%, which is slightly higher than the original method. The extraction time is shortened, the energy consumption is reduced, and it is more suitable for industrial high-efficiency production. It can achieve the same dye solution stability and dyeing effect.

[0048] 2. Key parameter substitution: The original material-to-liquid ratio of 1:20 and extraction temperature of 90-95℃ can be replaced with a material-to-liquid ratio of 1:15-1:25 and an extraction temperature of 85-100℃. The concentration can be replaced with 0.04-0.06 g / mL, and the clarifying agent can be replaced with natural pectin at an addition amount of 0.4%-0.6%. After the adjustment, the stability of the dye solution and the pigment extraction rate will not change significantly, and the dye solution can still be stored stably at room temperature for 2-3 months, meeting the needs of industrial production.

[0049] 3. Alternative Drying Method: The original method of air drying the dye material can be replaced by low-temperature drying at 40-50℃ for 8-12 hours. After drying, the pigment content of the dye material is basically the same as that of air-dried material, and the drying speed is fast. It can avoid the influence of weather on air drying, is suitable for large-scale material preparation, and does not affect the subsequent extraction and dyeing effect.

[0050] In practice, this example also provides a method for applying the aforementioned red and yellow natural dyes to dyeing fabrics containing natural fibers; please refer to the appendix. Figure 2 Specifically, it includes the following steps: 1. Fabric pretreatment: Cut the natural fiber fabric to the required size and soak it in deionized water for 20-30 minutes to remove dust, oil and other impurities from the fabric surface; for silk and wool fabrics, add 0.3% neutral detergent to the soaking water, rinse with clean water after soaking, and squeeze out the water until it no longer drips, then set aside; the moisture content of the pretreated fabric should be controlled at 50-60% to facilitate the absorption of dye liquor.

[0051] 2. Dyeing treatment: Place the pretreated fabric into the clarified dye liquor of this invention, and control the liquor ratio, i.e., the weight of the fabric to the volume of the dye liquor, to be 1:25. The dyeing temperature is adjusted according to the fiber type: 55-60℃ for cotton and linen fibers, and 45-50℃ for silk and wool fibers. The stirring speed is controlled at 60-80 r / min, and the dyeing is continued for 50-70 minutes. The dyeing time can be adjusted according to the desired color depth. The darker the color, the longer the dyeing time, but not exceeding 90 minutes. During this period, the fabric is gently turned over every 10 minutes to ensure uniform dyeing and no local color spots.

[0052] In practice, the specific parameters for the dyeing treatment described in this step are as follows, depending on the different fibers: Cotton and linen fibers: The dyeing temperature can be increased to 60-65℃, the dyeing time can be extended to 70-80 minutes, and the natural color fixing time can be shortened to 20 hours, thereby improving the dyeing depth and color fixing effect; Silk and wool fibers: The dyeing temperature is controlled at 40-45℃, the dyeing time is 50-60 minutes, and the natural color fixing time is 24-28 hours to avoid high temperature damage to the fibers and ensure that the fabric is soft, smooth and has a natural luster.

[0053] 3. Natural color fixation: After dyeing, take out the fabric, squeeze out the water until it is no longer dripping, and hang it in a cool, ventilated, and dark place to fix the color naturally for 24 hours. No additional color fixation treatment is required. The color fixation is achieved by utilizing the tannins and flavonoids in the dye material itself, which improves the color fastness.

[0054] 4. Post-treatment: After natural color fixing, rinse the fabric in deionized water 2-3 times to remove unfixed pigments on the surface, and then air dry naturally. For cotton and linen fabrics, iron them at a low temperature of 100-120℃ after drying. For silk and wool fabrics, gently comb them after air drying to maintain the original luster and feel of the fabric, and you will get the finished product.

[0055] In other embodiments, the staining method described in this example has the following alternatives: 1. Dyeing method replacement: The original solution uses immersion dyeing, which can be replaced by pad dyeing. The specific parameters are adjusted as follows: dye concentration 0.05g / mL, padding rate 70-80%, dyeing temperature for cotton and linen fibers 60-65℃, dyeing temperature for silk and wool fibers 45-50℃, pad dyeing time 10-15 minutes. The subsequent natural color fixation and post-treatment steps remain unchanged. The dyeing uniformity and color fastness are consistent with the original solution, and the dyeing efficiency is greatly improved, making it suitable for large-scale batch dyeing.

[0056] 2. Alternative color-fixing method: The original solution uses natural color fixing in a cool and ventilated place for 24 hours, which can be replaced by low-temperature drying color fixing. The specific parameters are: color fixing temperature 40-50℃, drying time 2-3 hours. After color fixing, the fabric's hand feel, luster, and color fastness are no different from those of naturally color-fixed fabrics. This can shorten the color fixing cycle, improve production efficiency, and is especially suitable for production in humid environments.

[0057] 3. Pretreatment Alternative: The original fabric pretreatment method uses deionized water soaking, which can be replaced with softened water soaking. For silk and wool fabrics, the neutral detergent can be replaced with a mild detergent specifically for wool. The pretreatment effect is the same, which can effectively remove impurities on the fabric surface, improve dyeing uniformity, and not damage the original properties of the fibers.

[0058] In addition, during implementation, the present invention has the following alternative complete technical solution: using apple peels from fruit waste as the core dyeing material, combined with three common rural wild plants—dandelion, bermudagrass, and dandelion—a red and yellow dyeing material formula is designed: Red series: 55% apple peel, 30% dandelion, 15% dandelion; Yellow series: 40% apple peel, 45% bermudagrass, 15% dandelion. An ultrasonic-assisted extraction process (parameters as above) is used, followed by pad dyeing and low-temperature drying for color fixation. This complete alternative solution is consistent with the core logic of the original solution, both achieving resource utilization of "waste + wild weeds." The dyeing material is low-cost, readily available, rich in color, environmentally friendly and non-toxic, and suitable for four fibers: cotton, linen, silk, and wool. The color fastness, dye liquor stability, and other technical effects are basically consistent with the original solution, and can completely achieve all the objectives of the present invention.

[0059] To verify the effectiveness, originality, and feasibility of the dye formulation of this invention, multiple sets of comparative experiments were conducted, and the experimental data are as follows: Experimental Example 1: Pigment Extraction Rate Test Using the six color-tone dyeing formulas of this invention, pigments were extracted according to the above extraction process. Single pomegranate peel dye and single wild rural plant dye were used as controls to test the pigment extraction rate. The results are as follows:

[0060] Experimental Example 2: Colorfastness Test (GB Standard) The six shades of dye liquor of this invention were used to dye four types of fibers: cotton, linen, silk, and wool. Tests were conducted according to GB / T 3921 (wash fastness), GB / T 3920 (rubbing fastness), and GB / T 8427 (light fastness). Pomegranate peel as a single dye + mordant and turmeric / madder + chemical fixing agent were used as controls. The results are as follows:

[0061] Experiment Example 3: Dye Solution Stability Test The six shades of dye solution prepared according to this invention were stored at room temperature (25±5℃) under cool, ventilated, and dark conditions. The state of the dye solution and the dyeing effect at different time points were tested, and the results are as follows:

[0062] To ensure that the red and yellow dyes of this invention can stably present the expected shades of scarlet, brick red, and ginger yellow, and to avoid the dulling of pomegranate peel color due to oxidation or alkaline environments, such as turning it into earthy yellow or brown, this invention strictly controls the pH value of the dye liquor and dyeing environment within the weakly acidic range of 5.0-6.5 through a "component self-buffering + micro-adjustment" method. The specific mechanism and control strategy are as follows: 1. Component self-buffering effect The auxiliary components selected in this invention, purslane, bitter lettuce, and wild chrysanthemum, contain natural organic acids such as oxalic acid and citric acid. When combined with pomegranate peel for decoction, these organic acids are released, stabilizing the natural pH of the crude extract at around 5.5, forming a natural weakly acidic buffer system. This system effectively inhibits the oxidative polymerization of tannins in pomegranate peel under alkaline conditions, preventing browning, while simultaneously protecting the betalains in purslane from alkaline degradation and fading.

[0063] 2. The correspondence between pH value and color light By adjusting the pH value of the dye solution, more precise color adjustments can be achieved based on the formulation of this invention, as shown in the table below:

[0064] 3. Key Points of Process Control In industrial applications, variations in water hardness (i.e., pH value) across different regions can lead to fluctuations in the initial dye solution's pH. Therefore, the pH value needs to be tested and adjusted before clarification in step 6 of the extraction process. If the water is hard (pH > 7), add food-grade citric acid or acetic acid and adjust it to 5.5 ± 0.2 in small amounts. If the water is acidic (pH < 4), add a small amount of sodium bicarbonate to adjust the pH.

[0065] In summary, this invention achieves the resource utilization of fruit waste and wild weeds through an innovative formula using pomegranate peel as the core dye material and at least two of the following as auxiliary dye materials: wild chrysanthemum, foxtail grass, purslane, kochia scoparia, burdock root, and sow thistle. This overcomes the limitations of existing technologies that rely on single or artificially cultivated dye materials. Furthermore, it designs specific dry weight percentage compound formulas for different shades of red and yellow, ensuring precise proportions of each component and clearly defining the synergistic relationship between them. This guarantees stable and repeatable dyeing results, solving the problems of monotonous color and unstable dyeing effects of existing natural dyes. In addition, it designs a chemical-free fixing and extraction process, eliminating the need for heavy metal mordants and chemical fixing agents, relying solely on the flavonoids inherent in the dye materials. The synergistic effect of components such as tannins achieves natural color fixation; the extraction process adopts the conventional decoction method, optimizing key parameters such as material-liquid ratio, extraction temperature, and concentration to ensure a pigment extraction rate of 82-88%, while improving the stability of the dye liquor and adapting it to industrial production; finally, based on the characteristics of four natural fibers—cotton, linen, silk, and wool—differentiated dyeing temperature and time parameters are designed to enable a single dyeing material formula to be suitable for multiple natural fibers, without damaging the fibers after dyeing, maintaining the original hand feel and luster of the fabric. This breaks through the bottleneck of the narrow applicability and easy fiber damage of existing technologies, achieving quantifiable technical effects such as a pigment extraction rate of 82-88%, color fastness of grade 4 or above, stable storage of dye liquor at room temperature for 2-3 months, and no damage to silk / wool fibers after dyeing.

[0066] The technical solution provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A red and yellow natural dye material based on pomegranate peel, characterized in that, It contains the following components, expressed as a percentage by dry weight: The core ingredient is pomegranate peel, accounting for 20%-90%. The auxiliary components consist of one or more of the following: wild chrysanthemum, foxtail grass, purslane, ground worm, cocklebur, and sow thistle, ranging from 10% to 80%.

2. The pomegranate peel-based red and yellow natural dye material according to claim 1, characterized in that: When the natural dye has a scarlet hue, it contains the following components by dry weight percentage: 45-65% pomegranate peel, 25-40% wild chrysanthemum, and 10-20% purslane.

3. The pomegranate peel-based red and yellow natural dye material according to claim 1, characterized in that: When the natural dye is brick red, it contains the following components by dry weight percentage: 65-75% pomegranate peel, 15-25% cocklebur, and 5-15% bitter lettuce.

4. The red and yellow natural dye material based on pomegranate peel according to claim 1, characterized in that: When the natural dye has a scarlet hue, it contains the following components by dry weight percentage: 45-65% pomegranate peel, 25-40% wild chrysanthemum, and 10-20% purslane.

5. The pomegranate peel-based red and yellow natural dye material according to claim 1, characterized in that: When the natural dye is dark red, it contains the following components by dry weight percentage: 70-90% pomegranate peel, 10-20% kochia scoparia, and 5-10% foxtail grass.

6. The red and yellow natural dye material based on pomegranate peel according to claim 1, characterized in that: When the natural dye is turmeric yellow, it contains the following components by dry weight percentage: 25-50% pomegranate peel, 40-50% foxtail grass, and 10-20% purslane.

7. The red and yellow natural dye material based on pomegranate peel according to claim 1, characterized in that: When the natural dye has an earthy yellow hue, it contains the following components by dry weight percentage: 50-70% pomegranate peel, 20-40% kochia scoparia, and 5-20% bitter lettuce.

8. The red and yellow natural dye material based on pomegranate peel according to claim 1, characterized in that: When the natural dye has a pale yellow hue, it contains the following components by dry weight percentage: 20-40% pomegranate peel, 45-60% wild chrysanthemum, and 10-20% cocklebur.

9. A method for preparing a red and yellow natural dye material based on pomegranate peel as described in any one of claims 1-8, characterized in that, Includes the following steps: Preparation: According to the formula ratio of the corresponding color tone above, accurately weigh the crushed parts of each dyeing material component, mix them evenly, and put them into a stainless steel cooking pot; at the same time, prepare deionized water, with the mass-volume ratio of dyeing material to deionized water being 1:

20. Pre-soaking: Add deionized water to a saucepan to submerge the dye material and soak for 30 minutes; Decoction extraction: Add an ethanol aqueous solution with a volume concentration of 60%-70% at a material-to-liquid ratio of 1:

20. Turn on the heater and raise the water temperature to 90-95℃. Maintain a gentle boil and continue to decoct for 60 minutes, stirring once every 15 minutes during the process. Filtration: After boiling, turn off the heat and let it cool naturally to 40-50℃. Filter with an 80-mesh filter and collect the first filtrate. Add the filtered residue to 10L of deionized water and repeat step 3. Filter and collect the second filtrate. Combine the two filtrates to obtain the crude dye solution. Concentration: Place the combined crude dye solution into a concentration pot, control the temperature at 60-70℃, and concentrate under reduced pressure until the dye solution concentration is 0.05g / mL; Clarification: Add 0.5% natural clarifying agent to the concentrated dye solution, stir well, let stand for 20 minutes, and filter with a 100-mesh filter to obtain a clear and uniform dye solution; Storage: After clarifying the dye solution, put it into a sealed stainless steel container and store it in a cool, ventilated, and dark place.

10. A method for dyeing fabrics containing natural fibers using red and yellow natural dyes as described in any one of claims 1-8, characterized in that, Includes the following steps: Fabric pretreatment: Cut the natural fiber fabric to the required size and soak it in deionized water for 20-30 minutes; Dyeing treatment: The pretreated fabric is placed in a clear dye liquor made from red and yellow natural dyes for dyeing. The liquor ratio is controlled at 1:

25. The dyeing temperature and dyeing time are adjusted according to the fiber type and the desired color depth. Natural color fixation: After dyeing, take out the fabric, squeeze out the water, and hang it in a cool, ventilated, and dark place to fix the color naturally for 24 hours. Post-treatment: After natural color fixing, rinse the fabric in deionized water 2-3 times to remove unfixed pigments on the surface, and then air dry to obtain the finished product.

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