- Sublimation Ink: The process begins with special sublimation inks that are formulated with dyes that have the ability to undergo sublimation. These inks are typically made up of a liquid suspension that contains tiny solid particles of dye.
- Heat Transfer: The sublimation ink is first printed onto a transfer paper using a sublimation printer. The printer uses heat to vaporize the solid dye particles in the ink, converting them directly into a gas form without passing through a liquid phase.
- Gas-to-Solid Transformation: The transfer paper with the printed sublimation ink is then placed in direct contact with the substrate, which is typically made of polyester or has a polyester coating. When heat and pressure are applied, the gaseous dye particles are forced to penetrate the surface of the substrate.
- Molecular Bonding: As the substrate cools down, the dye particles return to their solid state and become embedded within the polyester fibers or coating. This solidification process creates a permanent molecular bond between the dye and the substrate, ensuring excellent color fastness and durability.
The key scientific principle at work in sublimation printing is sublimation itself. Sublimation is the phase transition of a substance directly from a solid to a gas, bypassing the liquid state. By utilizing heat and pressure, the sublimation ink undergoes this phase transition, transforming into a gas without leaving any residue on the transfer paper.
The process is specifically effective with polyester or polyester-coated substrates because the polyester fibers have a high affinity for the dye gas molecules. This allows the dye to penetrate the surface and become a part of the substrate, resulting in vivid and permanent coloration.
It’s important to note that sublimation printing is not suitable for all materials. Since the process relies on the dye penetrating the substrate, it is primarily used on polyester fabrics, polyester-coated items like mugs or phone cases, and certain synthetic materials specifically designed for sublimation printing.
Understanding the science behind sublimation printing enables us to appreciate the intricacies of this unique printing process and its ability to produce high-quality, durable, and vibrant prints on a variety of substrates.