Sublimation is a fascinating process that has revolutionised the printing industry. It's a technique that has brought about an array of vibrant, durable, and high-resolution products, from customised mugs to personalised t-shirts. One of the key components in this process is the use of sublimation blanks. But what exactly are sublimation blanks? And how does the science behind sublimation work? Let’s delve into these intriguing questions.
Understanding Sublimation
Before we get into the specifics of sublimation blanks, it's essential to understand what sublimation is. In scientific terms, sublimation refers to the process where a substance transitions from a solid state directly to a gas state without passing through the liquid phase. This phenomenon is commonly observed in dry ice (solid carbon dioxide), which turns directly into carbon dioxide gas when exposed to room temperature.
In the world of printing and personalisation, however, sublimation takes on a slightly different meaning. Here, it refers to dye-sublimation printing — a method where heat is used to transfer dye onto various materials such as fabric, plastic, card or paper.
The Role of Sublimation Blanks
Sublimation blanks are essentially items that have been specially prepared for the dye-sublimation process. These items can range from clothing and ceramic mugs to metal sheets and phone cases. The common factor among all these products is that they are coated or made with materials that can accept and hold onto sublimated ink.
During the dye-sublimation process, heat converts solid ink particles into gas without going through a liquid phase. This gaseous ink then permeates the surface of the blank item and solidifies into its fibres or coating as it cools down. The result? A vibrant, permanent print that won’t peel, crack, or wash away.
The Science Behind Sublimation Printing
Now that we understand what sublimation and sublimation blanks are, let's delve into the science behind this process. The key to sublimation printing lies in the type of ink used and its interaction with heat and pressure.Sublimation inks contain certain types of dyes known as disperse dyes. When these dyes are heated, they transform into a gas and become highly active. The high temperature also causes the pores of the polymer-based coating on the blank item to open up. The gaseous dye molecules then penetrate these open pores.
Once the heat source is removed, the temperature drops, causing the dye molecules to revert to their solid state and the pores of the polymer coating to close up. This traps the dye within the material, resulting in a permanent and vibrant print.