Discharge Agent is the activation component for discharge printing. This agent can only be used in combination with a finished Discharge Ink like Discharge Base, Discharge White, or Ryo Charge in order for discharging to take place. Discharge Agent comes in a crystalline powder form and is sold and shipped by the pound. To activate a discharge ink, mix discharge agent into the final ink at about 4-6% of the final weight.
Example: When mixing 350 grams of a discharge color, your discharge base may only be around 300 grams of the total formula. Yet you measure out the discharge activator, based on the total final weight of 350 grams.
Activator should always be the last item added, after the ink and ink components have been blended together. When mixing, blend the agent slowly into the ink until it is beginning to dissolve, then continue to mix well at higher speeds for up to 1 minute. Let the ink sit for 5-10 minutes before testing or going into production to ensure full dispersion of the crystals into your ink.
We strongly recommend using a gram scale for optimal mixing performance.
How Discharge Works and Proper Cure
Discharge agent is a compound molecule. That compound is Zinc Formaldehyde Sulfoxylate. The discharge process begins from high heat, either during flashing or curing, breaking apart the activator molecule. Once the activator is in its separate components, the formaldehyde attaches to the fabric dye and breaks the dye molecule. It's this process which removes the color from the garment you are printing on. However, not all dyes react well and are considered “nondischargeable”. So check with your garment manufacturer for a dischargeability rating chart.
After the garment dye is removed (this process happens at 250°F) you need to continue to heat up the ink layer and get a FULL cure of your entire ink layer. Water-based ink cures once the entire ink layer is at “cure temp” and it holds at that temp. 320°F is the target temperature here in the U.S. At this temp you need to hold at or above 320°F for 20-30 seconds. If this means that you need to keep the garment in the dryer for 3 minutes to reach 320° and hold at or above that temp for 20-30 seconds, then that is how long you need to keep your shirt in the dryer to achieve a durable print.
At the end of the discharge process and during cure, the formaldehyde combines with the sulfur to create an inert molecule. As always, make sure you vent all air from the dryer to the outside. Some people have an itchy or swelling reaction when handling the discharge agent, what they are reacting to is the Sulfur in the activator. About 3% of the population have a sulfur allergy.
If you are unable to keep your shirt at those cure parameters, you can add Warp Drive to your ink. When you do this, you need to make sure that a FULL discharge of the garment happens. A full discharge of the garment only happens after you have removed all of the water in the ink and the ink reaches 250°F. So this is a great indicator that you have met all the parameters needed for the Warp Drive to activate.
As always, test before running production.
SCREEN PREPARATION
Screens must be coated with a water Resistant emulsion, we recommend using a water-resistant emulsion like
Baselayr Complete emulsion. For extended screen life and long print runs it is recommended to post expose the screens and/or use an emulsion hardener like
Baselayr emulsion hardener.
For all Ink Applications, Print Parameters, Cure and ink Clean Up Procedures: See the relevant ink type section:
Discharge BaseDischarge WhiteRyoCharge
United States