What are the coloring processes for silicone products? Silicone products are widely used in daily life and industrial production due to their softness, durability, and environmental friendliness. In order to meet the diverse needs of different customers for product appearance, the coloring process of silicone products is particularly important. Appropriate coloring techniques can not only enhance the aesthetic appeal of products, but also strengthen their market competitiveness.
Common coloring techniques for silicone products
1. Screen printing process
Screen printing is a commonly used technique for coloring silicone products. It uses silk screen as the printing base and is made into a silk screen printing plate with graphics and text by photosensitive plate making method. During printing, a scraper is used to press and transfer ink through the mesh holes of the graphic and text parts to the surface of the silicone product, thereby forming the same graphic and text as the original. The advantage of screen printing technology is that it can achieve high-precision pattern printing, with bright and full colors, and can print a variety of complex patterns and text. However, the silk screen printing process has a relatively weak effect on the layering and three-dimensional sense of the pattern, and there may be uneven color distribution when coloring on a large area.
2. Spray coating process
The spraying process is a coating method that uses a spray gun or disc atomizer to disperse the coating into uniform and fine droplets under pressure or centrifugal force, and apply them to the surface of silicone products. This process can achieve uniform coloring over a large area and quickly cover the entire surface of silicone products, resulting in good color consistency of the product. The spraying process can also create a smooth and delicate surface effect, enhancing the texture of the product. But it also has some shortcomings, such as relatively low utilization rate of coatings, which may result in some waste of coatings; Moreover, during the spraying process, improper operation can easily lead to defects such as sagging and orange peel.
3. Transfer printing process
Pad printing is an indirect concave adhesive head printing technology. First, etch the designed pattern onto a printing plate, apply ink to the etching plate, and then transfer most of the ink onto the surface of the silicone product through a silicone head. The advantage of transfer printing technology is that it can print on the surface of irregularly shaped silicone products, with strong adaptability, and can print fine patterns and text, especially suitable for products with curved or uneven surfaces. However, the production efficiency of transfer printing technology is relatively low, and for multi-color printing, multiple transfer prints are required, which may affect the accuracy of pattern registration.
4. Immersion dyeing process
The immersion dyeing process involves immersing silicone products in a solution containing dyes, allowing the dyes to gradually penetrate into the interior of the silicone, thereby achieving the purpose of coloring. This process has uniform coloring, and the color can penetrate deep into the interior of silicone products, which is not easy to fade and has good washing and friction resistance. The immersion dyeing process is commonly used for some silicone products that require high color durability, such as silicone bracelets, silicone keychains, etc. However, the color selection of immersion dyeing process is relatively limited, mainly suitable for some dark colors, and it is difficult to achieve complex patterns and texts through immersion dyeing process.
Preparation before coloring silicone products
1. Surface treatment of silicone products
Before coloring, it is necessary to clean the surface of silicone products to remove oil stains, dust, impurities, etc., to ensure that ink or paint can adhere well to the silicone surface. You can use specialized cleaning agents for cleaning, then rinse with clean water and air dry. For some silicone products with rough or rough surfaces, polishing treatment is also needed to make the surface smooth and flat.
2. Ink or coating selection
Choose the appropriate ink or coating based on the selected coloring process and the requirements for the use of silicone products. Consider factors such as ink or coating adhesion, weather resistance, wear resistance, and environmental friendliness. For example, for silicone products used outdoors, it is necessary to choose inks or coatings with good weather resistance to ensure that they do not fade easily after prolonged exposure to sunlight. At the same time, it is important to ensure that the selected ink or coating is compatible with silicone material and does not undergo chemical reactions.
3. Color adjustment
According to the color samples or color cards provided by the customer, use color matching equipment to mix ink or paint into the desired color. During the color mixing process, it is necessary to accurately control the proportion of various pigments, and through multiple color tests and adjustments, ensure that the blended color is consistent with the target color. After color matching is completed, the ink or coating should be stirred evenly to ensure color consistency.
Coloring process for silicone products
1. Positioning and fixation
Place the silicone product to be colored on the workbench of the coloring equipment, and accurately position and fix it to ensure that the silicone product does not move during printing or spraying, thereby ensuring the accuracy and quality of coloring. Special fixtures or positioning devices can be used to fix silicone products.
2. oloring operation
Screen printing: Install the prepared screen printing plate on the screen printing machine and adjust the distance and angle between the plate and the silicone product. Pour the prepared ink into the ink tank of the screen printing machine, start the screen printing machine, and transfer the ink through the mesh to the surface of the silicone product through the squeezing of the scraper. After printing is completed, take out the silicone product for inspection and reprint if necessary.
Spraying: Connect the spray gun to the air compressor, adjust the spray amplitude, air pressure, and paint output of the spray gun. Pour the prepared coating into the coating cup of the spray gun, hold the spray gun in hand, maintain an appropriate distance and angle from the surface of the silicone product, and evenly spray the coating. During the spraying process, attention should be paid to the speed and direction of the moving spray gun to avoid uneven coating.
Pad printing: Install the etching plate on the pad printing machine, apply an appropriate amount of ink on the etching plate, and then use a scraper to scrape off excess ink, leaving only the graphic and text parts. Press the silicone head onto the etching plate to transfer ink onto the silicone head. Move the silicone head onto the surface of the silicone product and gently press to transfer the ink onto the silicone product.
Dip dyeing: Pour the prepared dye solution into the dip dyeing tank and control the temperature and concentration of the solution. Slowly place the silicone product into the immersion tank and soak for a period of time to allow the dye to fully penetrate into the interior of the silicone. After soaking, remove the silicone product and rinse it with clean water to remove excess dye on the surface.
3. Drying and curing
After coloring is completed, the silicone product needs to be dried and cured to firmly adhere the ink or coating to the surface of the silicone. The drying method can be selected based on the properties of the ink or coating, such as natural drying, hot air drying, or ultraviolet curing. Natural drying time is longer, but the cost is lower; Hot air drying can accelerate the drying speed, but it is necessary to control the temperature well to avoid deformation of silicone products caused by excessive temperature; UV curing is suitable for some UV curable inks, with fast curing speed and high efficiency.
