Packaging / Advertising & Office

New Trends in International Trade! Paper packaging, pulp molding, paper film and other products produced with fluorine-free waterproof and oil resistant agents are the first choice for export to Europe, the United States, and Japan.

With the rapid development of the economy and the enhancement of environmental awareness, China's plastic ban and restriction order will be fully implemented in January 2021, as well as the European Commission's guidelines on disposable plastic products and the upcoming revision of the packaging and packaging waste directive, which will focus more on paper packaging of plant fiber substrates, including pulp molded product packaging. Paper packaging has become the largest packaging material used in fields such as catering and food packaging.

1. The drawbacks of PE coated paper and silicone oil paper

Due to the need to come into contact with food containing oil, fat, and water, paper packaging must have the ability to be waterproof, oil resistant, and impermeable. In order to achieve the effect of waterproofing and oil prevention, most food packaging paper is currently PE coated paper, which is coated with a thin layer of polyethylene plastic on the paper. Some water-based coating materials are polyacrylate, polyvinyl alcohol, carboxymethyl cellulose, etc., forming a continuous and dense organic polymer film, preventing oil and water from passing through the protective layer, thus achieving the goal of waterproofing and oil prevention. Some high-end products are also packaged with silicone paper, which has a three-layer structure. The first layer is the base paper, the second layer is the coating, and the third layer is silicone oil.

This type of polymer film itself is not oil resistant, and fats can still be spread on the surface of the film. Some contain bisphenol a fats, which may release harmful substances when in contact with high-temperature food. Moreover, this type of polymer material cannot degrade or degrades very slowly in nature, making it difficult to recycle and reuse, with high recycling costs and environmental pollution issues.

2. The drawbacks of fluorinated waterproof and oil repellent agents

In addition to film coating, nowadays a small amount of waterproof and oil repellent is added to the paper making process or a layer of waterproof and oil repellent coating is applied to the paper surface to reduce the surface tension of the paper, which can endow the paper substrate with waterproof and oil repellent properties without affecting the recycling of paper products. Although the waterproof and oil proof effect is excellent, these types of waterproof and oil proof agents usually use long-chain perfluoroalkyl monomers with a carbon atom number greater than 6, usually C8-PFCs with 8 carbon atoms (including 8 carbon perfluorocarbons). The longer the chain of carbon atoms in perfluoroalkyl, the better its waterproof and oil proof performance. This is because fluoropolymers can form a thin film on paper fibers, The long side chains containing fluorine in the film layer can extend and be arranged in a directional manner at the interface. This film layer can significantly reduce the surface energy of the substrate, which is smaller than that of ordinary liquids, so it has waterproof and oil resistant properties.

However, in recent years, research has found that these long-chain fluoroalkyl compounds can produce perfluorooctanoic acid ammonium/perfluorooctane sulfonates (PFOA/S) that are harmful to the environment and human body during use. Low doses of these substances have bioaccumulation, especially in long-term contact with food, which has strong toxicity to the human body and may cause genetic, reproductive, developmental, liver, and cardiovascular diseases to organisms.

Therefore, the European Union, Canadian environmental organizations, and the National Environmental Protection Agency of the United States have already restricted the use of PFOA/S, and long-chain fluoroalkyl compounds (with carbon atoms greater than 6) have also been restricted from being used in waterproof and oil proof agents for paper products. C8-PFCs are gradually being withdrawn from the market.

3. China's requirements for fluorinated additives

The new version of China's national standard GB 9685-2016 "Standard for the Use of Additives for Food Contact Materials and Products", compared to the old version GB 9685-2008, deleted two perfluorinated compounds: diethanolamine monophosphate (1H, 1H, 2H, 2H perfluoroalkyl) phosphate and bis (1H, 1H, 2H, 2H perfluoroalkyl) phosphate, perfluoroalkyl acrylate copolymer (perfluoroalkyl acrylate copolymer).

At present, the toxicological data on C6-PFCs is still limited, and research has shown that they do not have the same bioaccumulation and potential systemic and developmental toxicity as C8 substances. Animal and epidemiological studies have shown that C6-PFCs do not accumulate in organisms due to their rapid excretion. Therefore, currently in China, the use of short chain C6-PFCs as food contact materials is still allowed.

According to China's standards such as GB 9685-2016 Standard for the Use of Additives for Food Contact Materials and Products, GB 4806.6-2016 Plastic Resins for Food Contact, and GB 4806.10-2016 Coatings and Coatings for Food Contact, certain fluorinated small molecules or polymers can be used for food contact materials and products under certain restrictions. Polymers such as tetrafluoroethylene or copolymers of tetrafluoroethylene with other fluorinated monomers (such as hexafluoropropylene, perfluoropropyl vinyl ether, etc.) can be used in plastic products or coatings, but must meet the migration limits of fluorinated compounds such as tetrafluoroethylene, hexafluoropropylene, or perfluoropropyl vinyl ether (0.05 mg/kg, 0.01 mg/kg, and 0.05 mg/kg, respectively). Fluorine containing compounds such as difluoromethane, 2,2-ethylidene bis (4,6-di-tert-butylphenyl) fluorophosphazene, and bis [ethyl (perfluorooctane) sulfonamide ethyl] ammonium phosphate can be used as additives in food contact with plastic or paper products.

4. Fluorine free waterproof and oil resistant agent

In January 2015, the US FDA announced that food contact substances (FCSs) containing monoethanolamine and diethanolamine, pentanoic anhydride, and perfluoroalkyl substituted phosphonic acid were prohibited from being used as waterproof and oil resistant agents for paper and paperboard, and for food in contact with water and oil. In January 2021, the US FDA announced a requirement for manufacturers to voluntarily phase out the use of food contact packaging materials containing PFAS/PFOA within three years, with mandatory implementation starting from January 2024. As of July 2022, 26 states in the United States have introduced legislation restricting the use of PFAS/PFOA, and 11 states have implemented it.

The restrictions on PFAS within the EU are gradually expanding. In Denmark, the ban on the use of paper and cardboard food contact materials containing perfluorinated and polyfluoroalkyl compounds came into full effect in July 2020. The Netherlands, Germany, Norway, Denmark, and Sweden are proposing amendments to the REACH regulations to comprehensively restrict the manufacturing and use of PFAS/PFOA.

New Trends in International Trade! Fluorine free waterproof and oil repellent agents have become a research hotspot in the industry, making them safer and more environmentally friendly. The paper packaging, pulp molding, and paper film products produced with them are the first choice for international trade exports to Europe, the United States, and Japan. Although surface treatments such as film coating and spray coating can achieve the same waterproof and oil resistant performance as fluorinated products, their high equipment investment and processing costs are bound to be unable to be used on a large scale. The advantage of adding fluorine-free waterproof and oil repellent agents to the slurry is that there is no need for equipment investment and the cost is controllable. However, the disadvantage is that the oil repellent performance cannot meet the effect of fluorine-based products. However, there are different opinions in the industry regarding the anti oil effect testing of fluorine free additives. For example, the previous testing standard for 95 ℃ hot oil 30 minute impermeability of pulp molded products was considered by the industry and the end consumer market to greatly exceed the actual usage scenarios. At present, the European and American markets are more rational in accepting physical test results, or selecting a certain temperature (30 ℃, 40 ℃, 70 ℃) hot oil 30 minute impermeability test standard based on end use scenarios and customer needs. After all, the solution that can be widely accepted in the international trade market must be a feasible and cost-effective solution on the production side.