DTF (Direct to Film) transfer is a specialized heat transfer technique that uses a DTF printer and associated consumables to print designs onto fabrics and other materials. Compared to traditional printing methods, DTF transfer stands out for its vibrant designs, durability, breathability, and ability to create complex patterns.

Today, we’ll explain one of the most common issues: Why does DTF transfer have oil backflow and bubbles? How can we effectively handle this problem?

Let’s first explore the reasons behind this: oil backflow, water condensation, and bubbling are all closely related to machine processes, materials, and environmental conditions.

1. DTF Transfer Machine Process Factors

To understand the issue, we need to look at how DTF drying works. After the dtf ink is printed, the DTF printer applies adhesive powder. At this stage, about 50-60% of the moisture is still trapped in the ink layer.

The PET DTF film is then passed into a drying chamber where temperatures between 135°C and 140°C melt the adhesive powder into a layer that seals the DTF ink. However, around 30-40% of the moisture remains trapped between the ink and the dtf hot melt powder layer.

Although the surface of the film may appear dry, this is only an illusion. When the trapped moisture condenses, it forms droplets, leading to oil backflow and condensation on the surface.

How to avoid this?
If manufacturers divide the drying process into three stages (referred to as three-stage drying), this issue can be significantly reduced.

Here’s how the three-stage drying process works:

• In the first stage, the DTF transfer enters the dryer at 110°C. At this point, the water in the ink begins to evaporate, but the adhesive powder does not melt significantly, allowing the moisture to evaporate effectively.
• In the second stage, the temperature rises to between 120°C and 130°C to dry the glycerin and oily substances in the ink.
• In the third stage, the temperature reaches 140°C to 150°C, quickly melting the adhesive powder, ensuring that it forms a solid layer, tightly bonding the design.

You can refer to our article on three-stage drying machines for more details.

2. DTF PET Film Factors

The quality of the materials used in DTF transfer greatly impacts the outcome. It affects the color accuracy, detail sharpness, durability, and even the feel of the final product.

The quality of the film’s ink absorption layer is critical. If the layer is uneven or of low quality, it can lead to poor ink absorption and result in oil backflow and condensation.

Additionally, using low-quality ink can also lead to these issues. Always ensure you are using high-quality materials for better results.

3. DTF PET Film Storage Conditions

Proper storage of printing films is essential. After each use, printing films should be returned to their original packaging and stored away from direct contact with the floor or walls. If the original packaging is unavailable, cover the film base and store it in a sealed, dry, and ventilated area.

4. Environmental Factors Of DTF Transfer

In humid environments, DTF printing films tend to absorb moisture, which can cause ink droplets to condense on the surface, leading to oil backflow. Humidity also increases the risk of clogged print heads, affecting print quality.

To maintain DTF transfer quality, it’s crucial to avoid operating the machine in humid conditions.

How to Effectively Prevent Oil Backflow in DTF Transfers?

Here are several practical ways to reduce the likelihood of oil backflow and bubbling during DTF transfers:

1. Ventilation
   Regularly ventilate your workspace to prevent moisture from accumulating indoors, which helps reduce the risk of film condensation.
2. Use a Dehumidifier
   In humid climates or seasons, using a dehumidifier can significantly lower indoor humidity, reducing the chance of moisture build-up in the transfer process.
3. Control Printing Temperature
   High printing temperatures can cause ink to evaporate too quickly, resulting in water droplets on the film surface and oil backflow. Be sure to manage the printing temperature carefully.
4. Avoid Overprinting
   Excessive ink on the film leads to too much moisture, increasing the chance of condensation and backflow. Always use the correct amount of ink to prevent this.
5. Clean the Print Heads Regularly
   Regular cleaning of the print heads will keep them in good working condition and prevent ink from clogging, reducing the risk of excess ink leading to oil backflow.
6. Store Transfer Films Properly
   Always store both raw and printed transfer films in dry, ventilated environments. Materials stored in damp areas (such as basements or bathrooms) are prone to absorbing moisture, leading to ink scattering and backflow issues.

Can Using DTF Paper Reduce Oil Backflow and Water Condensation?

Yes, using DTF paper can significantly reduce the occurrence of oil backflow and water condensation. Unlike PET film, which is commonly used in DTF transfers, DTF paper offers better ink absorption and drying performance due to its paper-based substrate.

Here are the key reasons why DTF paper performs better in preventing these issues:

1. Better Ink Absorption
   The paper substrate in DTF paper is more absorbent compared to PET film. This means that it can absorb more ink, reducing the chance of excess moisture being trapped between the ink and adhesive layers. By effectively managing ink absorption, DTF paper helps to minimize oil backflow during the transfer process.
2. Improved Drying Efficiency
   DTF paper dries faster and more thoroughly than PET film during the curing process. Because of the paper’s superior ink absorption, the residual moisture in the ink layer is lower. As a result, DTF paper is less likely to trap moisture, which could lead to water condensation and bubbles after the drying phase.
3. Enhanced Print Quality
   Since DTF paper absorbs ink more evenly, it helps produce cleaner, sharper designs without the risk of water droplets forming on the surface. This leads to higher-quality prints with fewer issues related to oil backflow.

So, switching to DTF paper can help reduce oil backflow and water condensation problems by enhancing ink absorption and drying efficiency. It’s an excellent alternative for anyone experiencing frequent issues with moisture and bubbling when using PET DTF film in DTF transfers.

Conclusion

Preventing oil backflow and bubbles in DTF transfers requires a multifaceted approach, including proper care of the machine, using quality materials, and controlling environmental factors. By following these tips, you can achieve excellent results with your DTF transfers.