With the implementation of the "National Food Safety Standard for Inks Used in Food Contact Materials and Articles" (GB 4806.14-2023), the development of migration-resistant inks has become a crucial task in the food packaging industry. The core objective of migration-resistant inks is to ensure that chemical components in the ink do not migrate into food during contact, thereby ensuring food safety.
Key Points in Development and National Standard Requirements
- Raw Material Selection
The selection of raw materials for migration-resistant inks must be stringent. For inks that directly contact food, additives and base materials must comply with the "National Food Safety Standard for the Use of Food Additives" (GB 2760) and related announcements. For inks that indirectly contact food, coloring agents must not contain elements or compounds such as lead, mercury, cadmium, chromium (VI), arsenic, antimony, or selenium. Additionally, heavy metal residue levels must meet the following requirements: lead ≤ 10 mg/kg, mercury ≤ 10 mg/kg, cadmium ≤ 5 mg/kg, chromium ≤ 25 mg/kg, and arsenic ≤ 5 mg/kg.
- Migration Limit Control
Migration limits are a key indicator in ink development. According to GB 4806.14-2023, the total migration from the ink layer in direct contact with food must not exceed 10 mg/dm², and the potassium permanganate consumption must not exceed 10 mg/kg. Furthermore, the total migration of aromatic primary amines must not be detectable (detection limit: 0.01 mg/kg).
- Optimization of Physical Properties
Inks must possess good physical properties during use to ensure printing quality and food safety. Specific requirements include: - Adhesion:The ink must adhere firmly to the printing substrate under standard test conditions.
- Wear Resistance:After friction testing, the printed pattern should not show significant wear.
- Heat Resistance: The ink must withstand high temperatures during processing and
Solutions
- Strict Testing and Verification
During the development process, the migration levels of inks must be strictly tested to ensure compliance with GB 4806.14-2023. For example, the total migration is tested by soaking in simulated food liquids (such as 10% ethanol solution or 3% acetic acid solution) and measuring the total migration of substances in the migration liquid within 24 hours.
- Formulation Optimization
By adjusting the ink formulation, such as selecting high-purity pigments and food-safe resins, and reducing the use of harmful substances, the migration resistance of the ink can be significantly improved. Additionally, optimizing the dispersion of pigments and the curing degree can enhance the ink's performance.
- Process Improvement
Advanced curing technologies (such as UV curing) can reduce volatile compounds in the ink, thereby lowering migration risks. Furthermore, optimizing the production process, such as improving printing accuracy and curing efficiency, can also effectively enhance ink performance.
- Interdisciplinary Collaboration
The development of migration-resistant inks requires collaboration across multiple disciplines, including materials science, chemical engineering, and printing technology. Interdisciplinary research can help identify new material combinations and processing techniques to improve ink performance.
Summary
The development of migration-resistant inks is an essential measure for the food packaging industry to address food safety challenges. By optimizing raw materials, strictly controlling migration limits, enhancing physical properties, and combining rigorous testing and verification, the migration risks of inks can be effectively reduced to meet the requirements of GB 4806.14-2023. In the future, with continuous technological advancements, migration-resistant inks will provide safer and more environmentally friendly solutions for the food packaging industry.