Let's share more informations about Flexible Packaging

The requirements for PU resin are different in less demanding medium-performance packaging applications such as confectionery and condiments, or even standard performance lamination packaging applications such as snack bags. The prime considerations for a PU resin are compatibility with nitrocellulose, bond strengths and cost of the resin. Compatibility with nitrocellulose is key because of its widespread use. It has great pigment grinding ability and is widely used, but it doesn’t have the flexibility and adhesion of PU resin. Oftentimes, these PU resins are also used for surface print applications where they are required to provide resistance properties and adhesion to the substrate.

Regardless of the packaging application, when it comes to white inks, the ability to achieve maximum opacity and bond strengths is crucial. The addition of other resins can lower bond strengths and opacity. As a result, a PU resin with the ability to grind the inorganic pigment without another resin, such as nitrocellulose or polyvinyl butyral, helps achieve both higher bond strengths and higher opacity.

As the printing and packaging industry evolves, new requirements and challenges will arise and PU resin technology will need to evolve too. Two key trends that will influence the adoption of PU resins are increased use of solventless adhesives in the lamination process and the emergence of high speed presses. Solventless adhesives help eliminate VOC emissions and don’t require energy to dry, unlike solvent-based adhesive laminations. However, the chemistry of the solventless adhesives introduces the challenge of smearing the print. PU resin that provide greater resistance to solventless adhesives will make for a more robust ink system.

The other key trend is the emergence of high speed printing presses capable of printing at speeds greater than 2,000 feet per minute. It is common knowledge that while PU resin provide numerous benefits, they are also prone to stringing or cobwebbing at high speeds.

Other improvements that can be expected in the future are PU resin that provide enhanced pigment grind ability, especially with organic pigments.

There is no denying that the use of PU resin is only going to increase with the growth in flexible packaging being driven by certain food categories. The extent of adoption, however, is dependent on the ability of PU resin to enable this transition.

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