Printing engineers and bulk buyers face core pain points: slow drying, high VOC emissions, frequent clogging, poor adhesion on non-porous substrates, and non-compliance with environmental regulations. This authoritative guide focuses on UV ink and professional flexo printing ink formulations, providing technical data, compliance standards, and selection criteria to boost production efficiency and print quality.

What Are UV Ink & Flexo Printing Ink? Definitions & Core Properties

UV ink is a zero-VOC, photo-curable printing ink that polymerizes instantly under UV light (365–395nm). It contains reactive oligomers, monomers, photoinitiators, and pigments, with 100% solids content—no evaporation, minimal waste, and exceptional durability.

Flexo printing ink is a fast-drying, low-viscosity ink designed for flexographic (flexo) presses. It transfers via anilox rolls, works on porous/non-porous substrates, and comes in UV, water-based, or solvent-based formulations. UV flexo ink dominates modern lines for instant curing and eco-compliance.

Classifications & Global Industry Compliance Standards

1. UV Ink Classifications

• By curing type: Free-radical UV (fast cure, LED/mercury compatible); Cationic UV (low shrinkage, deep cure)
• By application: UV flexo ink, UV inkjet ink, UV screen ink, UV offset ink
• By substrate: Hard UV ink (metal/glass); Flexible UV ink (PVC/leather/textile)

2. Flexo Printing Ink Classifications

• UV flexo ink: Instant cure, zero VOC, high gloss, outdoor durability
• Water-based flexo ink: Low odor, eco-friendly, for paper/corrugated
• Solvent-based flexo ink: Fast dry, strong adhesion for plastic films (high VOC)

3. Global Compliance Certifications

• REACH (EU): Restriction of hazardous substances
• RoHS: Heavy metal-free (Pb/Cd <100ppm)
• EN 71-3: Toy safety standard (heavy metal migration)
• GREENGUARD Gold: Low VOC for indoor use
• ASTM D3359: Adhesion test standard

Technical Parameters & Verified Test Data

Parameter	UVINK UV Ink (Flexo Grade)	Standard Flexo Printing Ink (UV Type)
Curing Speed	Instant (<1 sec, 395nm LED)	Instant (<1 sec, 365–395nm)
VOC Content	0 g/L (zero VOC)	<10 g/L (low VOC)
Viscosity (25°C)	80–150 mPa·s	50–200 mPa·s
Particle Size	≤100 nm (anti-clog)	≤120 nm
Adhesion Grade	4B–5B (excellent)	3B–4B
Outdoor Durability	24–36 months (anti-UV)	18–24 months
Compatible Substrates	PVC, PP, PET, paper, metal, glass	Paper, corrugated, BOPP, PVC
Shelf Life	18 months (5–25°C, sealed)	12–18 months

Data Source: UVINK R&D Test Report 2026; REACH, RoHS, ASTM D3359 Standards

Industrial Application Scenarios

UV ink and flexo printing ink (UV type) serve as mainstream consumables for high-speed, eco-friendly industrial printing:

• Packaging: Food/medicine labels, flexible packaging, cartons, corrugated boxes
• Labels & Tags: Self-adhesive labels, barcode tags, luxury product labels
• Commercial Printing: Brochures, posters, catalogs, high-gloss magazines
• Flexible Materials: PVC banners, vinyl stickers, textile printing, leather decoration
• Industrial Marking: Electronic parts, automotive interiors, plastic components
• Outdoor Graphics: Billboards, light boxes, building decoration materials

Professional Step-by-Step Selection Guide

1. Confirm press type: Flexo (anilox roll), inkjet, screen, or offset
2. Select ink type: UV ink (zero VOC) or traditional flexo ink (water/solvent-based)
3. Verify substrate compatibility: Paper, plastic, metal, glass, or composite materials
4. Check curing system: LED-UV (low energy) or mercury lamp (high power)
5. Confirm compliance: REACH, RoHS, EN 71-3, GREENGUARD Gold for target markets
6. Test key performance: Adhesion, curing speed, color fastness, scratch resistance
7. Assess production scale: Bulk supply stability, batch consistency, technical support

Frequently Asked Questions (FAQ)

Conclusion & Contact UVINK

UV ink and flexo printing ink (UV grade) represent the future of industrial printing—delivering instant curing, zero VOC emissions, exceptional adhesion, and long-term durability. They solve critical pain points of traditional inks while meeting strict global environmental and safety standards.

UVINK is a leading manufacturer of premium UV ink and flexo printing ink. We offer full CMYK color series, customized formulations, bulk wholesale supply, complete certifications, and dedicated technical support for printing enterprises worldwide.