Ink hardeners are chemical additives or catalysts that are mixed into 2-component inks to trigger cross-linking and polymerization. Hardener, known as a cross-linker or catalyst, is an important in the pad printing process. This pad printing supply improves the final print’s durability, adhesion, abrasion resistance, and chemical durability properties.
Different inks use different hardeners; both ink and hardener must be chemically compatible. It is therefore very important to match screen- or pad-printing ink with the right ink hardener.
An ink hardener is a chemical additive used with certain two-component or multi-component industrial printing inks to initiate or accelerate curing and improve the final performance of the printed ink film.
Depending on the ink system, a hardener may improve properties such as adhesion, chemical resistance, abrasion resistance, and durability. The correct hardener and mixing ratio depend on the specific ink formulation and application.
The terms hardener, catalyst, and curing agent are sometimes used interchangeably, but they do not always describe the same chemical function.
A hardener may chemically react with an ink resin to create a cured film, while a catalyst typically accelerates a chemical reaction without necessarily becoming part of the final cured material. The terminology varies between ink technologies and manufacturers.
Always use the hardener or catalyst specifically recommended for the ink system you are using.
Hardeners are used to help certain ink systems achieve the performance characteristics required for demanding industrial applications. Depending on the formulation, adding the correct hardener can help improve:
The specific benefits depend on the ink and hardener combination.
Not all printing inks require a hardener. Hardeners are generally used with two-component (2K) or multi-component ink systems that require a chemical curing reaction.
Single-component inks may cure through other mechanisms, such as evaporation, oxidation, heat, UV exposure, or moisture. Always check the technical data sheet for your specific ink before adding a hardener.
The correct hardener depends on the specific ink series, resin chemistry, substrate, application, and required performance characteristics.
Use only the hardener recommended by the ink manufacturer for your specific ink system. Using an incompatible hardener or the wrong mixing ratio can negatively affect pot life, adhesion, curing, flexibility, appearance, or chemical resistance.
The recommended hardener ratio varies by ink system and application. Mixing ratios are typically specified by the manufacturer and may be provided by weight or volume.
Always follow the technical data sheet or product instructions for the exact ink and hardener combination. Do not assume that the same ratio applies across different ink series.
