UV inks for direct food contact

Date: Mar 14 2025 From: Star Color Views:

We can regard the inks used for printing food packaging as inks that can come into direct contact with food. This type of ink has extremely high safety requirements, needing to be 100% non-toxic and free of heavy metals, benzene-based solvents, polycyclic aromatic hydrocarbons (PAHs), plasticizers, etc., to prevent food contamination.

Additionally, this ink is a low-migration ink, meaning that even when in direct contact with food, no components of the ink will migrate into the food. Usually, such food-contact printing inks require certain safety tests, such as the EU's EC 1935/2004, the US FDA's food contact materials standards, and China's GB 4806.10 National Food Safety Standard - Inks for Food Contact. The Zhongzhixing UV flexographic ink we will discuss below is a food-contact ink that fully meets the above requirements.

I. Technical Specifications of Food-Grade UV Inks

Regulatory Framework and Safety Requirements
In the global food packaging safety standards system, the US FDA 21 CFR Part 175.300 and the EU Regulation 10/2011 constitute the core guidelines for food contact materials. Taking Zhongzhixing UV flexographic inks certified by the FDA as an example, their components must strictly adhere to the Food Contact Notification (FCN) list, with a comprehensive ban on high-risk substances such as benzene solvents and phthalate plasticizers. The residual monomer content after ink curing must not exceed 0.5%, and the total heavy metal content (lead, cadmium, mercury, arsenic) must be less than 1 ppm, ensuring no risk of toxic residues.
Flexographic Printing Adaptability Design
Tailored for the precise cell structure of laser-engraved flexible plates, Zhongzhixing food-grade UV inks have a viscosity precisely controlled within the range of 300-800 cP at 25°C to achieve uniform ink transfer. Under LED-UV light sources (395 nm), an energy density of 80-120 mJ/cm² ensures complete curing of the ink at high printing speeds of up to 200 m/min. It meets the ASTM D3359 5B adhesion standard in the cross-hatch test and passes a 100°C/30-minute boiling water test without peeling, demonstrating its stability in complex environments.

II. Core Advantages of UV Curing Technology

Safety and Low Migration Characteristics
UV inks form a high-molecular cross-linked network (molecular weight > 500 Da) through photopolymerization, significantly inhibiting the migration of small molecules. Compared to traditional solvent-based inks (migration of 15-25 mg/dm²), UV ink migration can be reduced to 3-8 mg/dm². Using a low-migration photoinitiator, Genocure EPD, the residual content is below 0.1 ppm as detected by HPLC.
Flexographic Printing Adaptability Innovation
With a solid content of over 95%, UV inks have an ink layer thickness of only 1.5-2.5 μm, reducing material costs by 30% compared to water-based inks. Their broad substrate compatibility covers PE, PP, PET, and paper-based composites, making them particularly suitable for direct contact applications such as yogurt cup lids and candy liners. Additionally, their zero VOC emissions reduce energy consumption by 60% compared to traditional hot-air drying, aligning with environmental trends.

III. Key Points of FDA Testing and Certification

To obtain FDA certification, three rounds of testing are required: first, GC-MS screening for over 1800 restricted substances; second, migration testing through boiling at 121°C for 2 hours and soaking in 10% ethanol/n-heptane; and finally, toxicological assessment using the QSAR model. Zhongzhixing UV flexographic inks, which have passed this certification, perform excellently in food packaging: using a CI flexographic press with an 800 LPI anilox roll, after curing at an energy of 100 mJ/cm², the Tabor abrasion tester retention rate after 500 cycles is over 98%, no migration was detected in a palm oil soak test (40°C/10 days) (GC detection limit 0.01 mg/kg), and it passed the ISO 13301 olfactory test without odor.

uv ink FDA Test report

Zhongzhixing food-grade UV flexographic inks leverage light-curing technology and formulation innovation to revolutionize printing efficiency while ensuring food safety. With the refinement of international certification systems such as the FDA, and the maturity of technologies like low-temperature curing and biobased materials, this field will continue to evolve towards higher safety, lower energy consumption, and sustainability.

In the field of food packaging printing, Zhongzhixing food-grade UV flexographic inks have become an industry-leading solution due to their exceptional technical performance and rigorous compliance management.

This product has passed the FDA food contact safety certification, adopts a low-migration formula design to ensure a total migration of less than 5 mg/dm², photoinitiator residuals below 0.05 ppm, and a curing system that achieves rapid curing under LED-UV 395 nm light sources at a printing speed of 150 m/min, combining high adhesion and extreme environment resistance.

For a complete FDA test report, please contact: eva@starcolor-ink.com