In the world of food and consumer packaging, performance is paramount. From anti-fog to slip & release properties, these functionalities ensure product integrity, consumer satisfaction, and manufacturing efficiency. However, achieving these properties can be approached in two main ways: through topical coatings or in-resin/masterbatch additives. This blog will explore why topical coatings often outperform in-resin additives, providing examples that highlight the practical advantages.
What Are Topical Coatings?
Topical coatings are surface-applied formulations that impart specific functionalities to packaging substrates. These coatings are applied post-extrusion or pre-thermoforming, developing a thin, uniform layer that interacts directly with the surface of the substrate. Examples include anti-fog coatings to prevent condensation, anti-stat coatings to reduce static electricity, and tactile coatings to enhance the sensory appeal of packaging.
What Are In-Resin/Masterbatch Additives?
In-resin or masterbatch additives are integrated into the polymer matrix during the manufacturing process. These additives are mixed into the resin before or during extrusion, with the aim of distributing functional properties throughout the bulk material.
Topical Coatings vs. In-Resin Additives: Key Benefits
- Enhanced Surface Performance
- Topical coatings are directly applied to the surface where functionality is needed, ensuring maximum effectiveness. For example, anti-fog coatings prevent moisture condensation by modifying surface tension, creating a clear and clean appearance for food packaging. In contrast, in-resin anti-fog additives must migrate to the surface over time, which can lead to inconsistent performance.
- Avoiding Blooming Issues
- A common issue with in-resin additives is “blooming,” where excess additive migrates to the surface. This phenomenon often occurs during storage, leaving a powdery or oily residue that can be visually unappealing and lead to product rejections. For example, masterbatch anti-fogs may eventually leave a white powdery film on packaging surfaces, impacting clarity and causing hygiene concerns and even rejections.
- Topical coatings, being applied directly to the surface, eliminate the risk of blooming. The coating stays intact, providing a consistent appearance and functionality over the product’s shelf life.
- Cost Efficiency and Targeted Application
- Topical coatings allow for precise application only where needed, reducing waste and optimizing costs. In contrast, in-resin additives are dispersed throughout the extrudate, even in areas where their functionality is not required. This is often difficult to control as % added can fluctuate greatly depending on extrusion equipment capabilities. This leads to higher material costs and inefficiencies as the gauge/thickness of the substrate increases. The in-resin additives can also impact the integrity of substrate, interacting with the polymers and inhibiting the formation of a proper resin matrix.
- Customizable and Versatile Solutions
- With topical coatings, customization is straightforward. Formulations can be tailored to meet specific performance requirements for different packaging applications. For instance, a barrier coating can be designed to enhance oxygen or moisture resistance, while a tactile coating can provide a premium, soft-touch feel. Additionally, multiple functionalities can be combined within a single coating, such as anti-fog properties integrated with slip characteristics, offering versatile solutions for complex packaging needs. In-resin additives, however, are limited by their integration into the bulk material and often lack the flexibility to address evolving needs.
- Eco-Friendly Advantages
- Many topical coatings are water-based, reducing the environmental impact compared to some masterbatch additives that require complex chemistries. Additionally, targeted application minimizes excess use of materials, contributing to sustainability goals. Topical coatings also support recyclability and integration into closed-loop systems, as they can be designed to align with substrate recycling processes and reduce contamination, enabling a circular economy for packaging materials.
Real-World Applications
- Anti-Fog Coatings for Fresh Produce Packaging
- Clear visibility is crucial for consumer appeal in fresh produce packaging. Topical anti-fog coatings ensure a consistent, fog-free appearance without the residue issues caused by in-resin anti-fogs
- Slip Coatings for Conveyor Efficiency
- Slip coatings applied to the surface of packaging films facilitate smooth movement on production lines, reducing downtime and improving operational efficiency. In-resin slip additives often lose effectiveness over time due to migration.
- Barrier Coatings for Extended Shelf Life
- In food packaging, oxygen and moisture barriers are critical for preserving freshness. Topical barrier coatings provide superior, uniform protection directly on the surface, outperforming the inconsistent barriers formed by in-resin additives.
Conclusion
Topical coatings offer unparalleled advantages in packaging applications, delivering consistent performance, cost efficiency, and customization options that in-resin/masterbatch additives struggle to match. By addressing common challenges such as blooming and waste, topical coatings ensure packaging meets the high standards demanded by today’s market.
At ACC Coatings, we specialize in advanced topical solutions designed to optimize your packaging performance. Contact us today to learn more about how our innovative coatings can elevate your products!