Pad printing Process Control Through Additives

Using hardener and thinner is not just about modifying ink properties — it’s about controlling the entire pad printing process. These additives help you stabilize key variables and achieve consistent, predictable results, even when working in changing production conditions.

 

🔁 Finding the right balance between hardener and thinner is essential for stable print quality, especially in high-volume, pharmaceutical, and medical applications.

 

🔬 Why Use Hardener in Pad Printing?

Hardener plays a critical role in enhancing the durability, adhesion, and chemical resistance of pad-printed images. This becomes especially important when printing on demanding surfaces or components used in medical, pharmaceutical, or industrial environments.

 

🔐 Key Functions of Hardener in the Process:

1. Improved Adhesion
   Hardener chemically bonds with both the ink and the substrate, improving adhesion on difficult materials such as polypropylene, silicone, or metal — where regular inks may fail to stick.
2. Resistance to Sterilization & Cleaning
   Once cured, the ink becomes resistant to:
   • Autoclaving
   • Alcohol-based or acidic cleaning agents
   • Ultrasonic washing
     This is vital for medical devices and labware that undergo harsh sterilization.
3. Abrasion and Scratch Resistance
   Adding hardener increases the mechanical strength of the printed layer — important for applications like control buttons, enclosures, and measuring instruments.
4. Chemical Resistance
   Hardened ink can withstand oils, solvents, and other aggressive chemicals, making it suitable for industrial environments or contact with pharmaceutical substances.

 

⚠️ Key Considerations:

• Pot Life: Once mixed with hardener, the ink begins to cure chemically and must be used within a limited time (typically 6–8 hours).
• Dosage: Too much hardener may reduce open time and increase viscosity quickly. Too little may lead to poor durability. The typical dosage range is 5–20%, depending on substrate and ink type.
• Environmental Factors: Higher temperatures and low humidity can accelerate the curing process. Adjusting the hardener content helps maintain process stability.

 

And good news:

Our popular Hardener TO H is now available in a new 200 ml tube —
✅ Less waste
✅ Easier dosing
✅ Same trusted performance
✅ Better for the environment

Check out all the inks and additives we have available