WTP

WTP, also known as three-dimensional curved surface coating and immersion transfer, is a decorative process that transfers printed patterns onto the surfaces of various three-dimensional objects. This technique involves placing a patterned film on the surface of water, then immersing the object into the water so that the design or pattern adheres tightly to the object's surface.

• Humidity: 45%-65%
• Temperature: 18-25℃
• Store in a cool, dry place, away from high temperatures and direct sunlight
• Keep flat to avoid folding and pressure
• After use, repackage completely and ensure moisture-proof and heat-insulated protection. Avoid excessive contact with the film by hands

• Water transfer film
• Special activator (transfer agent)
• Primer, base coat, and top coat
• Fixtures and jigs for transfer
• Spray gun and air compressor
• Water transfer tank
• Cleaning equipment
• Drying oven
• Environmentally friendly water recycling and drainage system

Water transfer printing is suitable for ABS plastic materials. For other materials such as metal, ceramic, other engineering plastics, and glass, an adhesion primer is required to modify the surface properties of the substrate so that the ink can properly adhere and achieve good transfer results.

• Helps the ink expand and soften, making the film more flexible and improving its stretchability, which allows better wrapping of the object during the transfer process
• Helps prevent bubbles and wrinkles, ensuring the pattern remains smooth and clear
• Contains solvents, so it does not dry during the transfer process and maintains the integrity of the printed pattern
• Improves the adhesion between the ink pattern and the surface of the object, preventing peeling during processing and ensuring stable attachment

Under-application:

• The ink on the film is not fully softened and remains too hard, which may cause pinholes
• The pattern may not adhere firmly and can easily peel off
• Bubbles or wrinkles may occur during the transfer process, affecting the final result
• The pattern or color may become uneven, blurred, or unclear

Over-application:

• The ink may be overly dissolved, causing uneven liquid flow, which can distort the pattern and create bubbles, resulting in poor transfer quality
• The surface may become overly sticky, affecting both texture and appearance
• Requires longer drying time, affecting the production schedule and process flow

The patterns on water transfer printed parts are generally quite durable, but their longevity depends on various factors, including the material type, surface treatment, and environmental conditions. When high-quality water transfer printing is used along with proper clear coats or top coats (such as UV-resistant and impact-resistant coatings) or protective layers, the durability of the pattern will be significantly improved. It is recommended to avoid excessive friction during use or cleaning to maintain the integrity of the pattern.

The main component of water transfer film is polyvinyl alcohol (PVA). PVA is a water-soluble material with good adhesion and stretchability. Before the transfer process, an activator is sprayed onto the film surface to soften the ink layer, ensuring that the pattern can effectively adhere to the workpiece.

The recommended temperature range is 25–35°C. This helps prevent the film from dissolving too early and improves the fluidity of the ink. When the film is spread on the water surface, it can closely adhere to the object, enhancing pattern clarity and detail. Temperatures that are too high or too low may negatively affect the final result.

Water transfer printing (Hydrographics) is a technique that allows complex patterns to be transferred onto three-dimensional objects. The quality of surface preparation directly affects the final appearance and durability. Key points of surface preparation include:

• Improving adhesion: Proper surface preparation ensures that the water transfer film adheres evenly to the object. If the surface is rough or contaminated with oil, dust, or other impurities, the film may not fully adhere, resulting in uneven patterns or peeling.
• Preventing adverse reactions: Poor surface preparation may cause unwanted reactions with the transfer film or activator, such as chemical reactions that damage the surface and affect the final result. Ensuring material compatibility is important.
• Pre-treatment for different materials: For plastics, metals, wood, glass, ceramics, etc., a suitable primer or base coat must be applied before water transfer printing to ensure proper adhesion.
• Providing a uniform base: Primers or base colors help enhance color accuracy and ensure the pattern appears clear and consistent.
• Ensuring film quality: A smooth and clean surface helps maintain pattern clarity and precision. Poor surface preparation may lead to distortion, blurring, or bubbles.
• Enhancing durability: Good surface preparation improves the durability of the transfer, making it less likely to peel or be damaged, especially for objects exposed to friction or physical stress.

Surface preparation typically includes cleaning, sanding, and priming. Each step directly affects the final water transfer result, making proper surface preparation essential before processing.

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• Film diffusion: During water transfer printing, the film expands and softens in water. If the immersion time is too short, the film may not fully spread; if it is too long, the film may over-diffuse. Both situations can cause pattern distortion or uneven transfer, affecting the final result on the workpiece surface.
• Pattern clarity: Excessive immersion time may affect the clarity and detail of the pattern. An appropriate immersion time helps maintain sharp and vibrant designs.
• Adhesion of the film: If the film is soaked for too long, its adhesion may decrease, making it difficult for the film to evenly adhere to the surface during the transfer process, thereby affecting the final outcome.
• Film stability: Excessive immersion time can make the film unstable in water and increase processing difficulty. A recommended immersion time is typically 30–60 seconds (depending on film type and water temperature), which helps maintain optimal film condition and improves process stability and results.

The immersion time of the film plays an important role in the final result of the hydrographic process. It should be adjusted according to actual conditions and product requirements to ensure the best transfer quality.