C-204 Basics of Vacuum Web Coating
This tutorial is intended for roll coater machine operators, maintenance personnel, technicians, engineers, scientists, supervisors, and others who would benefit from an introduction to issues related to roll-to-roll vacuum coating onto polymer substrates. This tutorial will emphasize practical aspects of the topics, and the treatment will be descriptive with little mathematics used. The tutorial focuses strongly on coatings made by resistance evaporation but touches on e-beam and induction evaporation and sputter coating. If your primary interest is sputtering onto webs, please see our other offering, “Sputter Deposition onto Flexible Substrates” (C-211).
- Markets for coated web products
- Vacuum technology for web coating
- Substrate characteristics
- Web handling and web winding systems
- Coating techniques and web cooling issues
- Process and product monitoring methods
- System maintenance issues
- Sources of information about web coating
This tutorial is intended for roll coater machine operators, maintenance personnel, technicians, engineers, scientists, supervisors, and others who would benefit from an introduction to issues related to roll-to-roll vacuum coating onto polymer substrates. This tutorial will emphasize practical aspects of the topics, and the treatment will be descriptive with little mathematics used. The tutorial focuses strongly on coatings made by resistance evaporation but provides introductions to e-beam evaporation, induction evaporation and sputter coating.
This tutorial provides the participant with a solid introduction to the following topics.
Materials for coated web products. It is valuable to understand the breadth of the markets for this technology area because the quite different technical solutions are often defined by these markets. Evaporative coating of aluminum is done at very high volumes and relatively low margins; by contrast sputtering is done at lower volumes and higher margins.
Vacuum technology for web coating. We need to pump down the coater and provide adequate vacuum for the coating processes. We discuss the adequacy of the vacuum in terms of the mean free path (to insure efficient coating) and the surface impingement rate (to insure high purity coatings). High rate evaporation processes can tolerate quite high pressures without compromising the coating quality. We also often need to understand how we can isolate multiple processes from one another within the coater.
Substrate characteristics. Success is often dependent on an informed choice of the substrate and possibly by the pretreatments that can are used.
Web handling and web winding systems. Good coatings can easily be ruined by wrinkles induced by bad winding. We touch on winding systems to develop an understanding of current state-of-the-art capabilities and less advanced systems (as may be used in development and pilot systems).
Web cooling issues. Heat related web distortion issues are often speed limiting. The important features of web cooling are well understood but not obvious to the newcomer.
Coating techniques. We spend the bulk of the afternoon talking about the most widely used web coating technique: resistance evaporation. We also describe other evaporation techniques and sputtering.
Process and product monitoring methods. Monitoring methods can range widely depending on the needs of the process. Fully automated systems for large volume application like resistance evaporation of aluminum are readily available. Smaller volume applications often demand partially or fully custom solutions.
System maintenance issues. We briefly describe the normal maintenance issues needed to maintain a machine in good working order.
Sources of information about web coating. This tutorial includes an extensive set of notes but can’t cover it all, so we tell you where the rest of the details can be found.Instructor: Donald J. McClure, Acuity Consulting and Training
This course is currently available via:
On Location Education Program