Soybean ink is a type of printing ink where the carrier (the liquid component that carries the pigment) is made primarily from soybean oil, as opposed to traditional petroleum based carriers. Traditional Inks use volatile organic compounds from petroleum as the carrier. These VOCs evaporate during drying, releasing harmful emissions into the air. Soybean Ink use refined soybean oil, a renewable resource. They have significantly lower levels of VOCs.
Soybean ink is compatible with both major printing processes for food packaging:
- Offset Lithography (Offset Printing): This is the most common application for soybean inks. They perform excellently in the offset process, providing vibrant colors and sharp details.
- Flexography (Flexo Printing): Soybean based inks are also widely available and used in flexographic printing for paper cups and other packaging.
- The manufacturing process remains exactly the same. The only difference is the ink in the press's fountains is made from soybean oil.
Key Advantages of Soybean Ink for food packaging:
1. Environmental Sustainability:
- Renewable Resource: Made from soybeans, a crop that can be replanted annually, unlike petroleum.
- Lower VOCs: Reduces air pollution and improves indoor air quality in printing facilities.
- Easier De-inking: In the paper recycling process, soybean-based inks are easier to remove from paper fibers. This results in less effort, fewer chemicals, and higher-quality recycled paper.
- Biodegradability: While the ink itself is a small part of the packaging, soybean oil is more biodegradable than petroleum, contributing to a less harmful product if it ends up in a landfill.
2. Performance and Quality:
- Vibrant Colors: Soybean ink provides excellent, rich color saturation. The colors can appear brighter and sharper because the soybean oil carrier is clearer than petroleum oil.
- Sharper Image: Because it doesn't soak into the paper as quickly as some petroleum-based inks, it spreads less, resulting in a sharper dot and a more accurate print.
Disadvantages:
1. Drying Time: Soybean ink can take slightly longer to dry than petroleum-based inks because it is not as volatile.
2. Cost: Historically, it was more expensive, but as demand has grown and technology improved, the price difference has narrowed.
Is the Cup Still Recyclable/Compostable?
- Recycling: Yes. The presence of soybean ink actually makes the food packaging easier to recycle.
- Industrial Composting: Yes, the ink is not a barrier. Soybean-based inks are a perfect fit for the requirement as they are derived from plants and are non-toxic.
A food packaging printed with soybean ink is a more sustainable choice than one printed with petroleum ink. However, the cup's overall recyclability or compostability depends much more on the inner liner than on the ink used.