Does Flexo UV Ink Have a Strong Odor?

Date: Mar 31 2025 From: Star Color Views:

Ⅰ. Primary Sources of Flexo UV Ink Odor

Volatilization of Ink Components
Monomer diluents (e.g., low-molecular-weight acrylates), low-molecular photoinitiators (e.g., initiator 907), and resin in UV ink may slowly release irritating odors during printing. Monofunctional monomers like IBOA are prone to emitting malodors at room temperature, while poor-quality raw materials may retain unreacted "acrylic acid," causing a sour smell.
Chemical Reactions During Curing
When UV ink cures under UV light, photoinitiators and resins decompose to produce aldehydes, sulfur compounds, and other irritating gases. Incomplete curing can exacerbate odor issues. Additionally, short-wave UV radiation (below 275nm) from curing equipment reacts with oxygen to form ozone, which pollutes the air and adheres to printed surfaces, creating persistent odors.
Impact of Substrates and Cleaners
High temperatures and intense UV light may trigger chemical releases from substrates (e.g., plastic films, metal foils). Stacked printed materials trap heat, worsening odor retention. UV cleaners with high-boiling solvents, if not fully evaporated, can mix with ink to generate off-odors.

Ⅱ. Odor Components in Flexo UV Ink

The odor of flexo UV ink primarily stems from unreacted photoinitiators and residual monomers. Their composition and release patterns are as follows:

Component	Odor Characteristics	Release Phase	Example Substances
Photoinitiators (e.g., ITX, TPO)	Pungent sourness	Slow evaporation post-curing	Isopropyl thioxanthone (ITX)
Reactive monomers (e.g., HDDA)	Sweet, cloying smell	During printing/curing	Hexanediol diacrylate (HDDA)
Oligomers	Subtle resin-like odor	Long-term storage	Epoxy acrylate
Additives (e.g., leveling agents)	Solvent-like smell	During printing	Propylene glycol methyl ether acetate (PMA)

Ⅲ. Strategies to Reduce Flexo UV Ink Odor

Select High-Quality Ink Materials
Prioritize low-molecular-weight, high-purity monomers and resins. Avoid volatile monofunctional monomers. Replace traditional initiators (e.g., 907, BP) with efficient alternatives (e.g., 369, EHA, TPO). Zhongzhixing UV ink reduces odor by 60% through formulation improvements.

Optimize Curing Processes
Ensure UV equipment parameters (wavelength, energy) match the ink. Improve ventilation to expel ozone and volatiles. Extend post-printing resting time for gas diffusion.

Parameter	Traditional Mercury Lamp	LED-UV
Wavelength range	200-450nm	365-405nm
Ozone production	High (requires exhaust)	Negligible (no extra exhaust)
Energy consumption	3kW/m	1.2kW/m

Control Substrates and Cleaners
Choose stable substrates and test their light/heat resistance. Use fast-evaporating cleaners (e.g., ethanol, ethyl acetate) to minimize residue.
Enhance Production Environment Management
Maintain good ventilation and install air purification systems (e.g., ozone decomposers). Regularly clean equipment to prevent ink/cleaner buildup.

As a leading eco-friendly ink manufacturer in China, Zhognzhixing’s UV flexo ink stands out with solvent-free formulas and UV-LED curing technology, offering:

Environmental Safety: Zero VOCs, minimal odor, certified by EN71, FDA, etc., ideal for food/pharmaceutical packaging.
Rapid Curing: Compatible with UV-LED, reducing energy consumption by 50% and boosting productivity.
Wide Substrate Compatibility: Works on plastics, metal foils, papers, with strong adhesion and post-processing flexibility (e.g., hot stamping, laminating).
Innovative Bio-Based Series: Uses high-bio-content resins to reduce carbon footprint.

Zhongzhixing addresses traditional UV ink odor challenges through low-odor formulation and efficient curing, while maintaining gloss, weather resistance, and reliability.