What are the key advantages of low-migration inks for food packaging?

Low-migration inks offer three critical benefits for food packaging: 1) Safety Assurance – migrating substances like heavy metals and volatile organic compounds (VOCs) are reduced by over 80% compared to traditional inks, with aniline migration often below 0.01mg/kg (meeting EU 10/2011 standards); 2) Regulatory Compliance – they pass strict certifications such as FDA 21 CFR 175.300 and China GB 9685-2016, minimizing recall risks; 3) Performance Stability – maintaining adhesion ≥3.5N/cm on low-energy substrates like PET/PP (3M tape test) and resisting high-temperature migration in microwave or frozen storage scenarios.

Why choose Zhongzhixing low-migration inks for pharmaceutical packaging?

Zhongzhixing low-migration inks stand out for pharmaceutical packaging due to: 1) Medical-Grade Safety – achieving photoinitiator residues <0.002ppm (10x stricter than China Pharmacopoeia requirements) and passing 121℃ steam sterilization without migration; 2) Enhanced Durability*– retaining 4B adhesion (ASTM D3359) after γ-ray sterilization (25kGy) and resisting drug-induced chemical corrosion; 3) Global Compliance – certified by both FDA and EU REACH, providing traceable migration data for regulatory submissions, ensuring safety for critical applications like vaccine and insulin packaging.

Analysis of Low Migration Ink Technology

Date: Apr 18 2025 From: Star Color Views:

In the fields of food packaging, pharmaceutical labeling, and high-end consumer goods printing, the safety and stability of inks are non-negotiable requirements. As a core solution to address chemical migration risks, low-migration inks have gained favor in the printing industry. This article combines international standards and cutting-edge technologies to provide a comprehensive analysis of the core principles and applications of low-migration inks.

I. Migration Mechanisms of Low-Migration Inks

1.1 The Essence of Migration: Three Penetration Pathways

When printed materials come into contact with food or drugs, chemical substances in the ink migrate through three primary pathways:

Direct Migration: Follows Fick's law of diffusion, where small molecules such as solvents and additives penetrate the substrate through the contact interface. The migration rate correlates with the concentration gradient and ink film thickness.
Gas-Phase Migration: In high-humidity or sealed environments, volatile components (e.g., residual solvents) spread through the air, particularly prone to contaminating liquid foods like beverages and sauces.
Contact Transfer: Mechanical friction or pressure causes substances on the ink film surface to directly transfer to the contacted material, commonly observed in frequently opened packaging for infant food.

1.2 Comparison of Global Migration Limit Standards

Test Item	EU (EU 10/2011)	US FDA 21 CFR 175.300	China GB 9685-2016
Total Migration Limit	≤10mg/dm²	Non-volatile matter≤0.1mg	≤5mg/dm²
Aniline Migration	≤0.01mg/kg	Not detectable	≤0.02mg/kg
Photoinitiator Residue	List system (76 allowed)	Unspecified list	Refer to EU standards

Technological Breakthrough: New-generation low-migration inks use high-molecular-weight prepolymers (e.g., cross-linked polyurethane) with a molecular weight ≥1000Da, reducing small-molecule migration to 1/50th that of traditional inks.

II. Source Control: Building a "White List" of Safe Substances

2.1 Raw Material Screening: Safe Substance Curation

Monomer Safety Library: Exclusively uses substances from the EFSA (European Food Safety Authority) Positive List, such as isobornyl acrylate (IBOA) and trimethylolpropane triacrylate (TMPTA), eliminating potential migration risks at the source.
Photoinitiator Innovation:
- Traditional UV inks often use benzophenone (BP), with migration levels reaching 0.5mg/kg under high temperature—50 times the EU limit.
- Low-migration solutions adopt ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate (TPO-L), which shows <0.005mg/kg migration in SGS tests, complying with FDA direct food contact standards.

Principle: Higher energy density promotes full monomer polymerization, while a nitrogen environment suppresses oxidative byproducts. Post-curing eliminates free small molecules, forming a dense ink film with pore sizes ≤5Å.

Low Migration Ink

III. Key Application Scenarios with Tested Data

3.1 Food Packaging: Setting the Bar for Infant Food Safety

Case: Infant Formula Can Label Printing (Zhongzhixing Water-Based Low-Migration Ink)

Test Conditions: Storage at 40℃ and 75% relative humidity for 10 days (simulating an 18-month shelf life).
Results:
- Nonylphenol migration: 0.003ppm (EU limit: 0.01ppm).
- Di(2-ethylhexyl) phthalate (DEHP): Not detected (detection limit: 0.001mg/kg).
Technical Highlights: Uses water-based polyurethane resin and nanoscale titanium dioxide dispersion, controlling ink film thickness at 3-5μm while achieving high gloss (60° gloss ≥85) and low migration.

3.2 Pharmaceutical Labeling: Sterilization Resistance and Adhesion Excellence

Blister Packaging Aluminum Foil Printing Parameters

Sterilization Resistance: After 121℃/30min steam sterilization, photoinitiator migration <0.001mg/kg (China Pharmacopoeia 2025 edition requirement: <0.01mg/kg).
Adhesion: Passes 3M tape peel test at 4B grade (highest level in ASTM D3359) after γ-ray sterilization (25kGy).
Application Value: Ensures no substance migration in packaging for biopharmaceuticals like insulin and vaccines during harsh sterilization, preventing efficacy loss.

3.3 Consumer Electronics: Weather Resistance and Regulatory Compliance

Mobile Phone Case Direct Printing Performance

Environmental Certification: Passes RoHS 2.0 ten heavy metal tests (lead, cadmium, etc. <10ppm).
Sweat Resistance Test: Migration <0.005mg/dm² after 24-hour immersion in artificial sweat (pH=5.5), exceeding EU electronic packaging standards.
Process Innovation: Uses water-based acrylic resin modification to achieve 3.5N/cm adhesion on PC/ABS composite substrates (traditional water-based inks: ~2.5N/cm).

IV. Zhongzhixing Low-Migration Inks: Technological to Product Advantages

As a leading Chinese enterprise in high-end eco-friendly inks, Zhongzhixing has established three core advantages in low-migration technology:

4.1 Full-Scenario Compliance Certification

Food-Grade Certification: Passes FDA 21 CFR 176.170 (paper packaging) and 177.1210 (plastic film) certifications, with migration test values 1/10th of standard limits.
Pharmaceutical-Grade Standards: Complies with China’s Regulations on Pharmaceutical Packaging Materials and Containers, with photoinitiator residues <0.002ppm (detection method: LC-MS/MS).

4.2 Solutions for Special Scenarios

Low-Temperature Frozen Packaging: No ink film embrittlement and unchanged migration after -20℃ storage for 72 hours, suitable for ice cream and frozen seafood packaging.
Microwave Food Containers: Passes 120℃ microwave heating test with weight loss <0.1% (traditional inks: ~1.5%), eliminating harmful substance release at high temperatures.

4.3 Digital Detection Support

Operates a CNAS-certified laboratory equipped with Agilent 7890B gas chromatographs, capable of detecting migration substances at the 0.001ppm level.
Provides customized migration risk assessment reports covering different substrates (paper/plastic/foil) and printing processes (flexo/gravure).

The technological breakthrough of low-migration inks represents an interdisciplinary innovation in materials science, printing engineering, and safety toxicology. From molecular-level raw material screening to industrial process control, every step requires precise balance between safety and functionality. As global regulations move toward "zero migration," enterprises like Zhongzhixing are driving low-migration inks from a "compliance option" to a "preferred solution" through continuous R&D, building a technical moat for packaging safety in food, building a technical moat for packaging safety in food, pharmaceuticals, and other daily life sectors.