Sunflower leaf dyeing and setting process

Abstract

The present application provides a sunflower leaf dyeing and setting process. The process comprises the steps of: (1) removing petiole and retaining only leaf blade; (2) separating each leaf blade and hanging on a support; (3) adding dye to heated water and stirring to dissolve and obtain dye liquor; (4) after heating the dye liquor, immersing the fixed leaf blade vertically in the dye liquor and continuing to cook for a certain time; (5) removing the dyed leaf blade and cooling and soaking in water; (6) after setting, airing under natural sunlight and carrying out double-sided clip ironing. Each leaf blade is hung on a support, the leaf blades are separated and fully contact with the dye liquor to realize uniform dyeing. High-temperature cooking of sunflower leaf causes the sunflower leaf to swell by absorbing water, and the dye solution penetrates into the sunflower leaf to enhance the brightness of the sunflower leaf and improve the dye adsorption rate. The oil and wax on the surface of the sunflower leaf are separated from the sunflower leaf and float on the liquid surface during high-temperature cooking. Double-sided clip ironing not only can fix the color of the dyed sunflower leaf, but also can set the sunflower leaf to maintain the oil and bright gloss of the sunflower leaf.

Description

Technical Field

[0001] This invention relates to the field of dyeing technology, and more particularly to a sunflower leaf dyeing process, and even more particularly to a sunflower leaf dyeing and setting process. Background Technology

[0002] Palm leaf art refers to art products made from palm leaves. Xinhui palm leaf art is a general term for palm leaf products produced in the Xinhui region of Guangdong. Together with ivory carving and embroidery from Guangzhou, paper cutting and pottery from Foshan, Duan inkstones from Zhaoqing, lacquerware from Yangjiang, and Maolong brushes from Xinhui, it forms the eight major traditional folk crafts of Guangdong, and was included in the second batch of China's "National Intangible Cultural Heritage List" in 2008. Xinhui palm leaf art products were once indispensable daily necessities for the people of Xinhui.

[0003] Xinhui palm leaf crafts boast a wide variety, nearly 500 types, which can be broadly categorized into three types based on their function: palm leaf fans, palm leaf containers, and palm leaf mats. Early palm leaf crafts used minimal color decoration; raw materials and finished products were generally undyed, mostly using the natural color of dried palm leaves, resulting in pale yellow, yellowish-white, and other colors, showcasing a rustic charm. However, as people's pursuit of vibrant colors grew, they were no longer satisfied with the pale yellow and yellowish-white natural colors, desiring palm leaf crafts with more colors. Thus, a small number of dyed products appeared in the 1980s, but the processing technology was immature, resulting in products lacking luster. Later, other materials such as nylon and fabric were added to the crafts to enhance their color. Furthermore, the natural wax layer on the surface of palm leaves makes it difficult for dyes to adhere, hindering the production of vibrant colors. In addition, if the palm leaves are not properly treated after dyeing, they will become soft and lose their luster, making it difficult to maintain the glossy sheen of the palm leaves. Therefore, the resulting palm woven products will not have a good visual effect. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a process that can not only dye palm leaves to include a rich variety of colors, but also shape palm leaves to maintain their glossy sheen.

[0005] To achieve the above objectives, the present invention provides a sunflower leaf dyeing and fixing process, comprising the following steps:

[0006] (1) Pretreatment of sunflower leaves

[0007] Remove the petioles from the palm leaves, leaving only the leaf blades;

[0008] (2) Fixing with palm leaves

[0009] The blades are separated into individual pieces and suspended on a bracket;

[0010] (3) Prepare the dye solution

[0011] Add dye to heated water and stir to dissolve it to obtain a dye solution;

[0012] (4) Staining

[0013] After heating the dye solution, the fixed leaf is vertically immersed in the dye solution and boiled for a certain period of time.

[0014] (5) Fixing color

[0015] The dyed leaves were removed and cooled and soaked in water;

[0016] (6) Finalization

[0017] After the color-fixed leaves are dried in natural sunlight, they are then ironed on both sides.

[0018] In this invention, the hard petioles are removed, leaving the soft leaves for dyeing. Each leaf is suspended on a support and then vertically immersed in the dye solution for a specific time. This ensures the leaves are fully exposed and in complete contact with the dye, resulting in even dyeing and preventing color spots. During the boiling process, the high temperature causes the palm leaves to absorb water and swell, allowing the dye solution to penetrate and enhance the color vibrancy, thus increasing the dye adsorption rate. The wax on the palm leaf surface detaches from the leaves and floats to the surface during boiling. Finally, cooling, soaking, and double-sided ironing completely remove the wax from the leaves, thus fixing the color. Double-sided ironing not only maintains the color after dyeing but also shapes the leaves, preserving their glossy sheen.

[0019] As a technical solution of the present invention, in step (3), the dye is added after the water is heated to 35-55°C.

[0020] As one technical solution of the present invention, the leaves are immersed in the dye solution when it is heated to 70-85°C.

[0021] As one technical solution of the present invention, the certain time is 1 to 3 minutes.

[0022] As a technical solution of the present invention, the sunflower leaf is torn open and the petiole is removed to obtain individual strip-shaped leaves.

[0023] As a technical solution of the present invention, the bracket suspends a plurality of spaced and evenly arranged first clips, each first clip clamping one end of each blade, and the opposite end of each blade is provided with a second clip.

[0024] As one technical solution of the present invention, the dye is a basic dye, the weight ratio of the dye to water is 1:400-600, and the ratio of the dye to the leaves is 5g / 80-120 leaves.

[0025] As a technical solution of the present invention, the water temperature in step (5) is 20-28°C.

[0026] As a technical solution of the present invention, the double-sided ironing is performed using a high-temperature ironing plate clamp at 170-250°C.

[0027] As a technical solution of the present invention, the double-sided ironing moves from one end of the blade to the opposite end and irons back and forth two or three times. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the scaffold used in the sunflower leaf dyeing and shaping process of the present invention.

[0029] Figure 2 This is a schematic diagram of the support used in the sunflower leaf dyeing and shaping process of the present invention after the sunflower leaf is clamped.

[0030] Figure 3 This is a schematic diagram of the high-temperature hot ironing clamp used in the sunflower leaf dyeing and setting process of the present invention.

[0031] Component Symbol Explanation

[0032] 10-Support; 11-Support body; 13-First clamp; 30-High-temperature heating plate clamp; 31-First clamping plate; 33-Second clamping plate; 50-Blade Detailed Implementation

[0033] The palm leaf dyeing and shaping process of the present invention not only allows palm leaves to be dyed to include a rich variety of colors, but also shapes the palm leaves to maintain their glossy sheen. This ensures both the original ecological nature of palm-woven products and the diversity of colors, thereby promoting the widespread use of palm-woven products.

[0034] The sunflower leaf dyeing and fixing process of the present invention includes the following steps: (1) sunflower leaf pretreatment, (2) sunflower leaf fixation, (3) preparation of dye solution, (4) dyeing, (5) color fixing and (6) fixing.

[0035] Step (1) pretreatment of sunflower leaves includes removing the petioles from the sunflower leaves, leaving only the leaf blades. The petioles of sunflower leaves are relatively hard, which is not conducive to subsequent dyeing and weaving of products, so they are removed and only the soft leaf blades are retained. Specifically, the sunflower leaves are torn apart and the petioles are removed to obtain individual strip-shaped leaf blades.

[0036] Step (2) securing the palm leaves involves separating the leaves into individual pieces and hanging them separately on a support. The support used can be as follows: Figure 1As shown, the support 10 includes a support body 11 and a plurality of first clips 13 suspended below the support body 11 and spaced apart and evenly arranged, each first clip 13 clamping the root of each leaf 50. The support 10 needs to be specially made so that it will not deform due to temperature during high-temperature boiling and will not react with the dye. The force of the first clips 13 needs to be appropriate, enough to hold the leaves 50 in place during high-temperature boiling, but not too strong to avoid damaging the fibers on the palm leaves. By using the support 10 of this invention to fix the leaves 50, a certain distance can be maintained between each leaf 50 to prevent mutual interference and avoid uneven dyeing due to overlapping of leaves, which would eventually lead to color spots. A second clip (not shown in the figure) is provided at the opposite end of each leaf. The second clip (i.e., the second clip clamps the other end of the leaf) increases the weight of the leaf, preventing it from floating in the dye solution due to buoyancy, thus avoiding uneven dyeing. The second clip can be the same shape and material as the first clip, or they can be different.

[0037] Step (3) preparing the dye solution involves adding the dye to heated water and stirring to dissolve it. Further, the dye is added after the water is heated to 35–55°C, which accelerates the dissolution of the dye. For example, the heating temperature can be, but is not limited to, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, and 55°C. Preferably, the heating temperature is 40°C. Further, during stirring, any undissolved suspended matter is removed with a spoon to prevent the suspension from adhering to the leaf surface and affecting the uniform coloring of the leaves.

[0038] The dyes are basic dyes, which are salts formed by aromatic bases and acids (organic acids and inorganic acids), that is, colored organic base salts. Specifically, the dyes can be basic brilliant green (green 1), basic magenta green (green 4), basic rose violet B (10), basic magenta blue, basic violet 5BN (violet 3), basic orange block (orange 2), basic magenta red (violet 14), basic light yellow O (yellow 2), basic brown G (brown 1), basic brilliant blue BO (blue 7), basic blue G (blue 1), basic blue B (blue 5), basic lake blue BB (blue 9), basic scarlet (basic national flag red), basic black, basic dark green, basic brilliant blue, etc. The weight ratio of dye to water is 1:400 to 600. For example, the weight ratio can be, but is not limited to, 1:400, 1:420, 1:440, 1:460, 1:480, 1:500, 1:520, 1:540, 1:560, 1:580, or 1:600. Preferably, the weight ratio of dye to water is 1:500. The ratio of dye to leaves is 5g / 80 to 120 leaves, meaning that 5g of dye can dye 80 to 120 palm leaves. For example, the ratio can be, but is not limited to, 5g / 80 leaves, 5g / 85 leaves, 5g / 90 leaves, 5g / 95 leaves, 5g / 100 leaves, 5g / 105 leaves, 5g / 110 leaves, 5g / 115 leaves, or 5g / 120 leaves. Preferably, the ratio of dye to leaves is 5g / 100 leaves.

[0039] Step (4) dyeing involves heating the dye solution, then vertically immersing a fixed leaf in the dye solution and continuing to boil it for a certain period of time. For example... Figure 2As shown, the leaves 50, fixed by the first clip 13, are vertically immersed in the dye solution. Because they are fixed together by the separated clips, they do not overlap. Further, the leaves are immersed in the dye solution when it is heated to 70-85°C. Heating the dye solution first, and then immersing the leaves, causes the leaves to absorb water and swell after immersion. This allows the dye solution to penetrate the leaves, enhancing their color vibrancy and increasing dye adsorption rate. For example, the dye solution heating temperature can be, but is not limited to, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, and 85°C. Vertical immersion in the dye solution prevents the leaves from overlapping when tilted, which would affect the uniformity of coloring. The leaves are then boiled for a certain period after vertical immersion in the dye solution. During this process, boiling is not recommended; the temperature should not exceed 100°C to prevent the leaves from shifting and overlapping due to air pressure during boiling. Meanwhile, during the high-temperature boiling process, the wax on the surface of the palm leaves detaches from the leaves and floats to the surface. After cooling, soaking, and double-sided ironing, the wax completely detaches from the leaves, thus fixing the color. The boiling time is 1-3 minutes; for example, the time can be, but is not limited to, 1, 2, or 3 minutes. The boiling time should not be too long, otherwise it will damage the fibers on the palm leaves, which is detrimental to the later production of handicrafts. During dyeing, all leaves can be soaked in one dye solution, or the leaves can be divided into multiple groups and soaked in different dye solutions respectively, thus obtaining palm-leaf woven products with different colors.

[0040] Step (5) color fixation involves removing the stained leaves and immersing them in water at a temperature of 20–28°C. For example, the water temperature can be, but is not limited to, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, or 28°C. In other words, the stained leaves can be immersed in room temperature water to fix the color.

[0041] Step (6) Shaping involves drying the color-fixed leaves in natural sunlight and then ironing them on both sides. The ironing is performed using a high-temperature ironing plate at 170–250°C. For example, the ironing temperature can be, but is not limited to, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, or 250°C. Preferably, the ironing temperature is 200±5°C. The ironing is performed by moving the iron from one end of the leaf to the opposite end and repeating the process two to three times. Preferably, the ironing is repeated twice. Figure 3 The high-temperature hot ironing clamp 30 shown includes a first clamping plate 31 and a second clamping plate 33. Both the first clamping plate 31 and the second clamping plate 33 can be heated. It is also equipped with a cotton cloth to clean the dye that gets on the clamping plate due to the high temperature, so as to ensure that different colored palm leaves will not be stained.

[0042] To better illustrate the purpose, technical solution, and beneficial effects of this invention, the invention will be further described below with reference to specific embodiments. It should be noted that the methods described below are further explanations of this invention and should not be construed as limiting it.

[0043] Example 1

[0044] This embodiment describes a sunflower leaf dyeing and setting process, including the following steps:

[0045] (1) Pretreatment of sunflower leaves

[0046] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0047] (2) Fixing with palm leaves

[0048] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0049] (3) Prepare the dye solution

[0050] Add the dye to water heated to 40°C and stir to dissolve it to obtain a dye solution. The dye is basic bright green (green 1), the weight ratio of dye to water is 1:500, and the ratio of dye to leaves is 5g / 100 leaves.

[0051] (4) Staining

[0052] After heating the dye solution to 80°C, take a fixed leaf and vertically immerse it in the dye solution and continue boiling for 2 minutes.

[0053] (5) Fixing color

[0054] Remove the stained leaves and cool them in water at room temperature.

[0055] (6) Finalization

[0056] After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing board at 200℃. The ironing process involves moving the iron from one end of the leaf to the opposite end and repeating the process twice.

[0057] Example 2

[0058] This embodiment describes a sunflower leaf dyeing and setting process, including the following steps:

[0059] (1) Pretreatment of sunflower leaves

[0060] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0061] (2) Fixing with palm leaves

[0062] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0063] (3) Prepare the dye solution

[0064] Add the dye to water heated to 45°C and stir to dissolve it to obtain a dye solution. The dye is basic light yellow O (yellow 2), the weight ratio of dye to water is 1:550, and the ratio of dye to leaves is 5g / 120 leaves.

[0065] (4) Staining

[0066] After heating the dye solution to 75°C, take a fixed leaf and vertically immerse it in the dye solution and continue boiling for 3 minutes.

[0067] (5) Fixing color

[0068] Remove the stained leaves and cool them in water at room temperature.

[0069] (6) Finalization

[0070] After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing board at 200℃. The ironing process involves moving the ironing board from one end of the leaf to the opposite end and repeating the process three times.

[0071] Example 3

[0072] This embodiment describes a sunflower leaf dyeing and setting process, including the following steps:

[0073] (1) Pretreatment of sunflower leaves

[0074] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0075] (2) Fixing with palm leaves

[0076] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0077] (3) Prepare the dye solution

[0078] Add the dye to water heated to 50°C and stir to dissolve it to obtain a dye solution. The dye is basic scarlet (basic national flag red). The weight ratio of dye to water is 1:550, and the ratio of dye to leaves is 5g / 90 leaves.

[0079] (4) Staining

[0080] After heating the dye solution to 85°C, take a fixed leaf and vertically immerse it in the dye solution and continue boiling for 1 minute.

[0081] (5) Fixing color

[0082] Remove the stained leaves and cool them in water at room temperature.

[0083] (6) Finalization

[0084] After the leaves have been dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing clamp at 220℃. The ironing process involves moving the clamp from one end of the leaf to the opposite end and repeating the process twice.

[0085] Example 4

[0086] This embodiment describes a sunflower leaf dyeing and setting process, including the following steps:

[0087] (1) Pretreatment of sunflower leaves

[0088] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0089] (2) Fixing with palm leaves

[0090] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0091] (3) Prepare the dye solution

[0092] Add the dye to water heated to 55°C and stir to dissolve it to obtain a dye solution. The dye is basic bright green (green 1), the weight ratio of dye to water is 1:475, and the ratio of dye to leaves is 5g / 95 leaves.

[0093] (4) Staining

[0094] After heating the dye solution to 85°C, take a fixed leaf and immerse it vertically in the dye solution and continue boiling for 2 minutes.

[0095] (5) Fixing color

[0096] Remove the stained leaves and cool them in water at room temperature.

[0097] (6) Finalization

[0098] After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing board at 230℃. The ironing process involves moving the iron from one end of the leaf to the opposite end and ironing back and forth twice.

[0099] Comparative Example 1

[0100] This comparative example illustrates a sunflower leaf dyeing and setting process, including the following steps:

[0101] (1) Pretreatment of sunflower leaves

[0102] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0103] (2) Prepare the dye solution

[0104] Add the dye to water heated to 40°C and stir to dissolve it to obtain a dye solution. The dye is basic bright green (green 1), the weight ratio of dye to water is 1:500, and the ratio of dye to leaves is 5g / 100 leaves.

[0105] (3) Staining

[0106] After heating the dye solution to 80°C, take the leaves and place them vertically into the dye solution and continue boiling for 2 minutes.

[0107] (4) Fixing color

[0108] Remove the stained leaves and cool them in water at room temperature.

[0109] (5) Finalization

[0110] After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing board at 200℃. The ironing process involves moving the iron from one end of the leaf to the opposite end and repeating the process twice.

[0111] Comparative Example 2

[0112] This comparative example illustrates a sunflower leaf dyeing and setting process, including the following steps:

[0113] (1) Pretreatment of sunflower leaves

[0114] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0115] (2) Fixing with palm leaves

[0116] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0117] (3) Prepare the dye solution

[0118] Add the dye to water heated to 40°C and stir to dissolve it to obtain a dye solution. The dye is basic bright green (green 1), the weight ratio of dye to water is 1:500, and the ratio of dye to leaves is 5g / 100 leaves.

[0119] (4) Staining

[0120] After heating the dye solution to 80°C, take a fixed leaf and vertically immerse it in the dye solution and continue boiling for 2 minutes.

[0121] (5) Finalization

[0122] After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing board at 200℃. The ironing process involves moving the iron from one end of the leaf to the opposite end and repeating the process twice.

[0123] Comparative Example 3

[0124] This embodiment describes a sunflower leaf dyeing and setting process, including the following steps:

[0125] (1) Pretreatment of sunflower leaves

[0126] Tear the palm leaves apart and remove the petioles to obtain individual strip-shaped leaflets;

[0127] (2) Fixing with palm leaves

[0128] Take a support, and hang multiple spaced and evenly arranged first clips on the support. Each first clip clamps the root of each leaf, and its tail is clamped by a second clip.

[0129] (3) Prepare the dye solution

[0130] Add the dye to water heated to 40°C and stir to dissolve it to obtain a dye solution. The dye is basic bright green (green 1), the weight ratio of dye to water is 1:500, and the ratio of dye to leaves is 5g / 100 leaves.

[0131] (4) Staining

[0132] After heating the dye solution to 80°C, take a fixed leaf and vertically immerse it in the dye solution and continue boiling for 2 minutes.

[0133] (5) Fixing color

[0134] Remove the stained leaves and cool them in water at room temperature.

[0135] The surface color uniformity of the dyed palm leaves prepared in Examples 1-4 and Comparative Examples 1-3 was observed, and the rubbing fastness of the dyed palm leaves prepared in Examples 1-4 and Comparative Examples 1-3 was tested under the following conditions. The test results are shown in Table 1.

[0136] Rubbing fastness test: The dyed palm leaves prepared in Examples 1-4 and Comparative Examples 1-3 were tested according to the standard "GB-T3920-1997 Textiles - Tests for Color Fastness to Rubbing". Ten samples of each type of dyed palm leaf were randomly prepared, and the average value of the ten data points was calculated. After rubbing the dyed palm leaves prepared in Examples 1-4 and Comparative Examples 1-3 continuously for 2 hours, the rubbing fastness test was performed again using the above method. The average value of the ten data points was then calculated.

[0137] Table 1. Properties of the dyed sunflower leaves obtained in Examples 1-4 and Comparative Examples 1-3

[0138]

[0139] As shown in Table 1, the sunflower leaf dyeing and shaping process of the present invention, based on the use of a support for fixation, and supplemented by water cooling and soaking and double-sided ironing, can produce dyed sunflower leaves with a glossy sheen and uniform color.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A dyeing and setting process for sunflower leaves, characterized in that, Including the following steps: (1) Pretreatment of sunflower leaves Remove the petioles from the palm leaves, leaving only the leaf blades; tear the palm leaves and remove the petioles to obtain individual strip-shaped leaf blades. (2) Fixing with palm leaves The blades are separated into individual pieces and suspended on a bracket; (3) Prepare the dye solution A dye solution is obtained by adding dye to heated water and stirring to dissolve it; the dye is a basic dye. (4) Staining After heating the dye solution to 70~85℃, take the fixed leaf and vertically immerse it in the dye solution and continue boiling for 1~3 minutes; (5) Fixing color The dyed leaves were removed and cooled and soaked in water; (6) Finalization After the leaves are dried in natural sunlight, they are then ironed on both sides using a high-temperature ironing plate clamp at 170~250℃.

2. The sunflower leaf dyeing and setting process according to claim 1, characterized in that, In step (3), the dye is added after the water is heated to 35~55℃.

3. The sunflower leaf dyeing and setting process according to claim 1, characterized in that, The bracket suspends multiple spaced and evenly arranged first clips, each first clip clamping one end of each blade, and each blade has a second clip at the opposite end.

4. The sunflower leaf dyeing and setting process according to claim 1, characterized in that, The weight ratio of the dye to water is 1:400~600, and the ratio of the dye to the leaves is 5g / 80~120 leaves.

5. The sunflower leaf dyeing and setting process according to claim 1, characterized in that, The water temperature in step (5) is 20~28℃.

6. The sunflower leaf dyeing and setting process according to claim 1, characterized in that, The double-sided ironing process involves moving the iron from one end of the blade to the opposite end and repeating the ironing process two to three times.

Images