Brief Overview of Application Techniques for Mirror Ink in Screen Printing
2025-07-30 15:41
Brief Overview of Application Techniques for Mirror Ink in Screen Printing
Mirror ink printing is applied on transparent plastic sheets such as PC, PET, PVC, and PMMA, printed on the backside of these transparent substrates. When viewed from the front of the transparent substrate, it presents a smooth effect similar to a mirror surface or hot stamping, hence it is called mirror ink. Mirror ink is widely used for operation panels of washing machines, refrigerators, and microwave ovens. Currently, mirror ink is also applied in IMD technology for manufacturing items such as mobile phones, automotive instrument panels, and various decorative instrument panels and panels. This shows that mirror ink has penetrated multiple industries, adding luster to these products. However, compared to ordinary screen printing inks, mirror screen printing ink requires higher printing technology and must be printed by personnel with certain printing experience and skills according to the process parameters of mirror ink to achieve satisfactory mirror effects after screen printing. The following are recommendations for how to properly screen print mirror ink:
I. Characteristics of Mirror Ink:
1. Mirror ink is formulated from special metal powder and resin as basic materials. After screen printing, it achieves a metallic mirror effect. Due to the need to maintain maximum ink flowability, this ink contains a large amount of special solvents, making the viscosity of mirror ink very low, as thin as water. Therefore, screen printing is quite difficult and requires high-level printing skills. Otherwise, (1) when not printing, the mirror ink will leak through the screen mesh and contaminate the substrate. (2) During the printing process, mirror ink dries easily, which not only easily clogs the mesh but also causes dried mirror ink to accumulate on the mesh, forming "silver slag" and reducing the mirror effect of the printed product.
2. Mirror ink utilizes the smooth surface properties of the substrate material, allowing the metal powder pigment in the printed ink to align parallelly on the smooth substrate surface to achieve a mirror effect. Due to this property of mirror ink, (1) materials with poor surface smoothness of transparent substrates (transparent sheets) cannot achieve mirror effects. (2) If transparent substrate materials cannot withstand the solvents in mirror ink, good mirror effects cannot be obtained. (3) The mirror effect after mirror ink screen printing is related to the drying method. (4) Screen printing operation skills affect the mirror effect.
II. Types of Japanese Seiko Mirror Ink and Applicable Material Range:
1. Mirror Silver B, only suitable for printing PET sheets.
2. Mirror Silver No.2, can print PET, PC, PVC, PMMA.
3. Mirror Silver No.2BS is No.2 with 30% solvent reduced.
4. Colored Mirror Ink No.3, includes medium gold, red gold, and blue gold, which are high-viscosity colored mirror inks that can print PET, PC, PVC, PMMA.
III. Screen Printing Techniques for Mirror Ink:
1. First, understand that mirror ink is thin as water, and printing technique is crucial. When printing speed is slow, on one hand, the water-thin mirror ink will leak through the screen stencil, and on the other hand, mirror ink easily absorbs moisture from the air, resulting in poor mirror effects after printing. Therefore, during printing, after pouring mirror ink onto the screen stencil, continuous rapid printing must be performed to ensure successful printing. Even checking workpieces while printing will affect the printing effect, such as clogging the mesh, inability to print ink, and formation of sludge on the screen stencil.
2. Environmental temperature and humidity are very important when printing mirror ink. Since this ink dries easily on the screen stencil, screen printing cannot be done in environments with high air circulation, otherwise it is very prone to mesh clogging and becoming jelly-like. Additionally, when air humidity is high, the mirror effect is poor. Therefore, during screen printing, air flow and humidity should be avoided as much as possible, and the screen printing environment should be treated with dehumidification. If mirror ink is stored at 20°C and screen printed at 20°C, the printing adaptability will be better.
3. Since this ink is thin as water, high mesh count screens should be selected. Moreover, the squeegee hardness should be relatively hard, above 80.
4. Mirror ink must be thoroughly stirred before use to ensure the metal powder and resin are fully mixed evenly to ensure the appearance of mirror effects. Otherwise, it will affect the generation of mirror effects.
5. The screen tension should be slightly lower, the screen distance should be adjusted closer, and the squeegee pressure should be appropriately reduced to enable the generation of mirror effects.
6. When machine printing, the flood bar cannot be made of hard aluminum or stainless steel, but should use a rubber flood bar to ensure uniform coating of the screen-printed mirror ink and consistent mirror effects.
7. The mirror effect of mirror ink is related to the drying method. In terms of mirror effect, natural drying is not as good as heated drying. Note that the heating temperature and drying time should be consistent, otherwise the mirror properties and color saturation will also differ.
Mirror ink printing is applied on transparent plastic sheets such as PC, PET, PVC, and PMMA, printed on the backside of these transparent substrates. When viewed from the front of the transparent substrate, it presents a smooth effect similar to a mirror surface or hot stamping, hence it is called mirror ink. Mirror ink is widely used for operation panels of washing machines, refrigerators, and microwave ovens. Currently, mirror ink is also applied in IMD technology for manufacturing items such as mobile phones, automotive instrument panels, and various decorative instrument panels and panels. This shows that mirror ink has penetrated multiple industries, adding luster to these products. However, compared to ordinary screen printing inks, mirror screen printing ink requires higher printing technology and must be printed by personnel with certain printing experience and skills according to the process parameters of mirror ink to achieve satisfactory mirror effects after screen printing. The following are recommendations for how to properly screen print mirror ink:
I. Characteristics of Mirror Ink:
1. Mirror ink is formulated from special metal powder and resin as basic materials. After screen printing, it achieves a metallic mirror effect. Due to the need to maintain maximum ink flowability, this ink contains a large amount of special solvents, making the viscosity of mirror ink very low, as thin as water. Therefore, screen printing is quite difficult and requires high-level printing skills. Otherwise, (1) when not printing, the mirror ink will leak through the screen mesh and contaminate the substrate. (2) During the printing process, mirror ink dries easily, which not only easily clogs the mesh but also causes dried mirror ink to accumulate on the mesh, forming "silver slag" and reducing the mirror effect of the printed product.
2. Mirror ink utilizes the smooth surface properties of the substrate material, allowing the metal powder pigment in the printed ink to align parallelly on the smooth substrate surface to achieve a mirror effect. Due to this property of mirror ink, (1) materials with poor surface smoothness of transparent substrates (transparent sheets) cannot achieve mirror effects. (2) If transparent substrate materials cannot withstand the solvents in mirror ink, good mirror effects cannot be obtained. (3) The mirror effect after mirror ink screen printing is related to the drying method. (4) Screen printing operation skills affect the mirror effect.
II. Types of Japanese Seiko Mirror Ink and Applicable Material Range:
1. Mirror Silver B, only suitable for printing PET sheets.
2. Mirror Silver No.2, can print PET, PC, PVC, PMMA.
3. Mirror Silver No.2BS is No.2 with 30% solvent reduced.
4. Colored Mirror Ink No.3, includes medium gold, red gold, and blue gold, which are high-viscosity colored mirror inks that can print PET, PC, PVC, PMMA.
III. Screen Printing Techniques for Mirror Ink:
1. First, understand that mirror ink is thin as water, and printing technique is crucial. When printing speed is slow, on one hand, the water-thin mirror ink will leak through the screen stencil, and on the other hand, mirror ink easily absorbs moisture from the air, resulting in poor mirror effects after printing. Therefore, during printing, after pouring mirror ink onto the screen stencil, continuous rapid printing must be performed to ensure successful printing. Even checking workpieces while printing will affect the printing effect, such as clogging the mesh, inability to print ink, and formation of sludge on the screen stencil.
2. Environmental temperature and humidity are very important when printing mirror ink. Since this ink dries easily on the screen stencil, screen printing cannot be done in environments with high air circulation, otherwise it is very prone to mesh clogging and becoming jelly-like. Additionally, when air humidity is high, the mirror effect is poor. Therefore, during screen printing, air flow and humidity should be avoided as much as possible, and the screen printing environment should be treated with dehumidification. If mirror ink is stored at 20°C and screen printed at 20°C, the printing adaptability will be better.
3. Since this ink is thin as water, high mesh count screens should be selected. Moreover, the squeegee hardness should be relatively hard, above 80.
4. Mirror ink must be thoroughly stirred before use to ensure the metal powder and resin are fully mixed evenly to ensure the appearance of mirror effects. Otherwise, it will affect the generation of mirror effects.
5. The screen tension should be slightly lower, the screen distance should be adjusted closer, and the squeegee pressure should be appropriately reduced to enable the generation of mirror effects.
6. When machine printing, the flood bar cannot be made of hard aluminum or stainless steel, but should use a rubber flood bar to ensure uniform coating of the screen-printed mirror ink and consistent mirror effects.
7. The mirror effect of mirror ink is related to the drying method. In terms of mirror effect, natural drying is not as good as heated drying. Note that the heating temperature and drying time should be consistent, otherwise the mirror properties and color saturation will also differ.