Flint bets big on coating for packaging applications

Noel Marshall D’Cunha (NMD): Right at the outset, is there a knowledge-gap or tech-gap about coatings in the applicator ecosystem? Can this be addressed? 
Upal Roy (UR): Well, there is the risk of a slight set-off from the printed side of the substrate, to the non-printed side.  And so, to answer your question, the applicator must be educated about the proper drying and printing conditions to avoid this type of issue.  Furthermore, to achieve the desired properties, proper GSM of coating is recommended. Again, tech-knowledge about the process is a must.

NMD: The share of polymers in sustainable food packaging applications is expected to reduce by 50% over the next two decades. Meanwhile, fibre-based materials are projected to contribute to 40% of all materials in use for food packaging. How is this impacting your coating R&D?
UR: Even though there is a demand for more sustainable coating chemistry, there are no bio-based coatings currently on the market. However, there are coatings and primers available that can support recycling processes.

NMD: Do coatings offer barrier properties without harmful side effects?
UR: Yes, the Flint Group’s coatings, including our barrier coatings, are safe to use and do not have harmful side effects.

NMD: What is the product's chemistry? Is it acrylic, olefin-based, biobased?
UR: The Flint Group manufactures energy-curable, water-based and solvent-based coatings. For water-based, these coatings are based on acrylic and olefin chemistries; for solvent-based, we offer both nitrocellulose (NC) and polyurethane (PU) chemistries, and energy-curable coatings are based on cross-linking acrylates.

NMD: Is the coating compatible with all methods like gravure, flexo, offset, or screen?
UR: Flint Group’s water-based coatings are suitable for flexographic applications and our solvent-based coatings are suitable for both flexo and gravure applications. Our energy-curable coatings are suitable to be run through flexo and roller coaters.

NMD: What is the minimum gram of coat weight to achieve the desired results?
UR: We recommended three to five grams per square metre (GSM) for water-based coatings, 1.5-2.0 GSM for UV gloss and matt coatings and 1 to 2 GSM for solvent-based coatings. This depends on the end-use application, and we recommend contacting your technical representative for printing advice. Some special effect coatings, like UV tactile and sand effect coatings, require a higher coating weight.

NMD: Given the cost comparison, are there any superior benefits? For example, any value addition with a coating that lamination cannot achieve and similar limitations if any. In this sense, what is the right product-market fit for coatings?
UR: Yes – for example, for solvent-based applications, the Flint Group offers a single-pack gloss overprint varnish for wrap-around labels that can achieve desired COF properties.  Additionally, we offer a two-pack matt overprint varnish for PET and BOPP substrates.

NMD: What kind of certifications do you have for your product or what certification have you applied for?
UR: The Flint Group has water-based coatings for direct food contact which meets BIS 15495:2020 and EuPIA guidelines. For solvent-based, all coatings are suitable for indirect food contact applications and comply with EU Directive 94/62/EG, BIX 15495:2020, and EuPIA guidelines. Benzophenone Free UV Coatings are available that meet CONEG, EU 94/62/EC, EUPIA Guidelines and BIS 15495:2020.

NMD: Does it comply with the rules and regulations for the export market?
UR: Each region has its own set of regulations. The Flint Group’s coatings are suitable for use in multiple regions. Regulatory compliance data is available for all regulations on request.

NMD: One feedback we have received from converters is that controlling the viscosity of coatings and ensuring consistency is burdensome. Your view?
UR: I agree with this assessment.  Because of environmental conditions and the evaporation of ingredients in coatings, there are chances of the product thickening which can result in uneven coating weight and inconsistent results.