Carestream’s precision, multi-layer solution coating processes are ideally suited for the casting of a variety of polymers to create standalone films such as polycarbonate, polyurethane and polyvinyl alcohol. We can produce several million square meters of film each year for large applications and we can also economically produce small batches for niche applications, as flexibility and service are paramount.

Our latest casting advancements include the development of a new Carestream cast polycarbonate film, available in thicknesses from 6 to 40 micron. In addition to being well suited for medical and optical applications, the new cast polycarbonate film is an ideal replacement for films made by LOFO, which ceased production last year.

Our process for solution casting polymers dissolved in a solvent onto a temporary substrate delivers many advantages versus melt extrusion including:

• Ability to cast polymers susceptible to heat degradation or those not easily melted
• Tighter thickness uniformity
• Filtration to avoid gels and other point defects
• Improved optical properties
• Ability to de-aerate to avoid bubbles
• Option to add functional layers during the film casting process to eliminate the cost of secondary coating steps

Carestream’s scale-up and manufacturing expertise consists of rigorous benchwork, pilot testing and full-scale production trials that lead to process accreditation.

The following list details the various steps Carestream employs to help customers deliver high-performance solution cast films featuring uniform thickness distribution, high dimensional stability and optical purity.

1. Gather customer needs and wants.
2. Screen resin types and grades.
3. Identify appropriate solvent and optimize percentage of solids required for good coating and drying process windows.
4. Identify the appropriate casting substrate.
5. Create prototype sheets via bench-scale casting.
6. Run roll-to-roll trials to further optimize the process and test film quality versus product specifications.
7. Slit and strip from the substrate to create a standalone film.
8. Replicate trials for final qualification.

For a more detailed overview of Carestream’s solution casting process, read our “Working with a Manufacturer to Create Solution Cast Films” article series. Part I of the series, “Designing Optimal Coating Formulations and Methods,” outlines Carestream’s robust process for scaling-up a solution cast film from benchwork, through pilot coating and full-scale production trials to final process and product accreditation. In addition to delivering an optimized process, the development process described in Part I results in a well-understood range of production process conditions.

Part II, “The Importance of In-Line Control and Inspection,” details how process control and inspection ensure that conditions accredited during the qualification process are maintained during production, and that any defects generated during casting can be removed before film is made into a final product.

For additional information on our solution casting capabilities or to learn more about our polycarbonate or other film options to replace films previously made by LOFO, contact Todd Arndorfer at 907-304-4683.