| Choosing the proper coating is an essential step in | | | | including options such as metallized flakes or |
| designing and producing quality packaging. Why are | | | | pearlized pigments. Although UV coating can be |
| coatings important? For some of the same | | | | applied either in-line or off-line, in-line UV coating |
| reasons that packaging is important. While | | | | offers comparable finish quality plus the |
| packaging protects and enhances the beauty of | | | | advantages of increased speed and reduced cost |
| what's inside, coatings help protect and enhance | | | | compared to the off-line UV coating process. |
| the appearance of the package itself. Because | | | | Both UV and aqueous coatings offer the |
| coatings are dually decorative and protective, | | | | convenience of in-line application and rapid drying, |
| they are an economical way to extend both the | | | | allowing for instant work and turn. In fact, either |
| appearance and the lifespan of the package. | | | | type of coating can be used with little or no spray |
| One of the goals of packaging is to catch the | | | | powder, improving smoothness and creating a |
| consumer's eye, encouraging them to examine | | | | cleaner work environment. In addition, both |
| and explore the package and its contents. A | | | | coatings can be applied as an overall or "flood |
| quality coating further increases shelf appeal by | | | | coating", or as a spot covering to highlight a |
| imparting additional tactile elements and adding | | | | particular image or area. |
| snap to printed graphics. The most common | | | | Aqueous coatings generally cost less up front, but |
| types of coatings used today are UV and | | | | the quality advantages and productivity gains of a |
| aqueous. Both are available in a range of finishes | | | | UV coating usually outweigh the higher unit costs. |
| from matte through satin to gloss, expanding | | | | When comparing costs it's helpful to think of UV |
| design flexibility beyond the choice of inks. | | | | as conferring all of the benefits of aqueous |
| A coating also protects the package from the | | | | coating, but to a greater degree. For example: |
| rigors of assembly, fulfillment, shipping and | | | | Aqueous dries fast -- UV dries faster |
| distribution, safeguarding it from fingerprints, | | | | Aqueous can be glossy -- UV is glossier |
| abrasion and scuffing. UV and aqueous coatings | | | | Aqueous provides protection -- UV provides more |
| both demonstrate excellent abrasion and block | | | | protection |
| resistance; in some cases, effectively eliminating | | | | UV coatings are particularly well suited for: |
| the need for shrinkwrap or other protective | | | | Applications requiring the ultimate in gloss |
| layers. | | | | Applications requiring the ultimate in hardness |
| Which is the best coating for a job? That depends | | | | Non-absorbent print surfaces (e.g. plastic, Tyvek |
| as much on the job as it does on the coating. | | | | ®, etc.) |
| Expectations of performance, appearance, quality | | | | POS displays |
| and cost are variables to weigh when making a | | | | Spot coating |
| decision. Other factors to consider include | | | | Appropriate applications for aqueous coatings |
| operator experience, job latitude (tolerance), | | | | include: |
| storage conditions and performance requirements. | | | | Food packaging (for direct food contact) |
| We'll begin with a comparison of UV and aqueous | | | | In-line heat seal blister packaging |
| coatings, and then discuss the most appropriate | | | | Primer / seal coating (to enhance gluing or |
| applications of each. | | | | subsequent UVvarnish over conventional inks) |
| Aqueous coatings are approximately 60% water | | | | Items that will be written on (e.g. mailers, |
| and 40% solids. During the drying process, the | | | | postcards, etc.) |
| liquids evaporate or are absorbed by the | | | | When you choose a coating you make an |
| substrate, leaving the solids to form a thin film. | | | | investment in the lifespan and performance of the |
| Aqueous coatings are clear and odorless when | | | | package, and ultimately of the product inside. The |
| dried, and are also available in FDA-approved | | | | more closely the package will interact with |
| formulations for use in food packaging. | | | | consumers or end users, the stronger the case |
| UV coatings are 100% solids, and finish by | | | | for incorporating the coating into the overall |
| light-curing rather than heat-drying. The solids | | | | design. |
| cross link to form a durable plastic film that | | | | Copyright ©2005 by Dennis Bacchetta. All |
| provides unparalleled gloss and hardness. UV | | | | rights reserved. |
| offers a broader range of finishes than aqueous, | | | | |