Does fabric require pre-treatment in the garment sublimation roll-to-roll process?

In the garment sublimation roll-to-roll process, fabric typically requires pre-treatment, especially in the following situations:

✅ Strongly recommended pre-treatment cases:

1. Natural fibers or blended fabrics (cotton, linen, silk, polyester-cotton blends, etc.):

Pre-treatment is mandatory! Sublimation ink can only vaporize at high temperatures and directly bond with polyester fibers. Natural fibers do not possess this property.

Function of the pre-treatment solution: A special polymer coating (pre-treatment solution/paste) is applied to the fabric surface. This coating captures the gaseous sublimation dye during high-temperature transfer and fixes it to the fiber surface, enabling pattern coloration and fixation on non-polyester fabrics. Without it, the pattern either fails to color or washes off easily.

2. Fabrics requiring specific high-performance standards (even 100% polyester):

High colorfastness/high clarity/special effects: Even for pure polyester fabrics, pre-treatment (such as sizing) helps:

Control ink penetration: Prevent ink from overly penetrating into the fiber interior or spreading, resulting in sharper, clearer pattern edges and improved precision.

Increase color yield and vibrancy: The pre-treatment layer allows more dye to remain on the fiber surface, resulting in richer, more vibrant colors.

Enhance certain fastness properties: Such as abrasion fastness, wash fastness, etc.

Achieve special effects: Such as a whiter base color (if the pre-treatment solution contains whitening agents), waterproof functionality, etc.

🤔 Situations where pre-treatment may not be necessary (requires careful assessment):

1. 100% polyester fabric + low requirements for pattern precision and vibrancy + high-quality fabric:

Pure polyester is an ideal substrate for sublimation printing, as dyes can directly bond with the fibers.

If the fabric is tightly woven, has a smooth surface, and moderate ink absorbency, and the produced items do not require extremely high color vibrancy or precision (e.g., low-end promotional shirts, internal use items), the pre-treatment step can sometimes be omitted, and printing can be performed directly on the fabric. This simplifies the process and reduces costs.

📌 Special considerations for pre-treatment in roll-to-roll (R2R) processes:

Online vs. offline: Pre-treatment can be performed online on R2R equipment (coating and drying immediately before printing) or offline (the entire roll of fabric is pre-treated by the fabric supplier or a specialized coating plant before printing).

Advantages of online pre-treatment:

Simplifies the process and reduces handling of semi-finished products.

More suitable for small-batch, quick-response production.

The coating is fresher, potentially resulting in more stable effects.

Advantages of offline pre-treatment:

Can be outsourced to a specialized coating factory, potentially resulting in more stable quality.

The printing factory does not need to invest in pre-treatment equipment.

Suitable for large-scale standardized production.

📣 Summary and recommendations:

1. Non-polyester fabrics (cotton, linen, silk, blends): Pre-treatment is mandatory! Otherwise, effective transfer and color fixation cannot be achieved.

2. 100% polyester fabrics:

Strongly recommended to perform pre-treatment: This is the standard practice for achieving optimal color performance, clarity, colorfastness, and stability, especially for high-quality garments and intricate patterns.

Pre-treatment may be omitted: Only consider this cautiously when the fabric itself has excellent performance (e.g., high-density, smooth polyester satin, certain sports fabrics) and there are no stringent requirements for the final product's appearance and durability. Conduct small-scale testing to confirm that printing results and colorfastness meet requirements.

3. Roll-to-roll process selection: Choose between online or offline pre-treatment methods based on your equipment configuration, order characteristics (batch size, delivery time, quality requirements), and cost considerations.

📌 Best Practices: Regardless of fabric composition, conduct rigorous pre-treatment process sample testing prior to large-scale roll-to-roll sublimation production to determine the optimal pre-treatment formulation (if required), coating quantity, drying parameters, and final printing and transfer parameters to ensure compliance with required color, clarity, and durability standards. Skipping pre-treatment testing poses significant risks and may result in substantial waste. 💪