When it comes to textile printing there are two main types of ink available: water based printer inks and Plastisol inks. Each type of printer ink has its own unique characteristics.
Water Based Printer Inks
A water based printer ink uses either pigments or dyes that are suspended in water. The water is used as the solvent. When the water evaporates the ink is cured or set. It can happen either by using a forced air drying system or the fabric can be left to dry at room temperature.
The method used to dry the material will usually be determined by the volume or speed of production.
Water based printer ink is usually used for printing yard goods either on the roll or in piece form.
Plastisol Printer Inks
Plastisol is usually used for printing finished goods such as tote bags, T-shirts, jackets, and sweatshirts. This type of ink is PVC based and essentially does not contain any solvents at all. It is a pure solid ink printing system.
This thermoplastic ink does require that the garments are dried by heating them to a temperature that is high enough to cause the PVC resin molecules to solidify or cure. Most Plastisol inks that are used for printing textiles cure in the 160 degree C to 200 degree C range.
In order to greatly reduce ink wastage it is necessary to keep Plastisol inks clean. You need to keep them from being contaminated by other colors or with dirt. One of the big benefits of using this type of process is that if any ink is left over and it is clean it can be returned to its original container for reuse and you will not find any degradation in quality.
And even if the ink does get contaminated with other colors it isn’t necessary to throw it out. Instead put it in a separate container where it can be used to create new colors. For example, contaminated colors can be over pigmented with other colors, such as black, to create a darker color.
Because Plastisol has little if any solvent it can be left on screens and any ink that’s left at job’s end can be returned to the original container without having any adverse affects. This can save a lot of money.
One of the challenges of using Plastisol is that if it is disposed of when it is not yet cured then you will need hazardous chemicals during the cleaning process. The biggest challenges to the environment come when it’s time to clean the screens and the equipment. At that point in time it is necessary to use a solvent that is environmentally hazardous.
After cleaning, the solvent needs to be properly disposed of in order to minimize its impact on the environment.
