A new application for a long-established technology platform
The first step was determining the ideal performance requirements for selecting the material properties we wanted each layer to have. We knew the outer layer needed to resist staining, scratching and discoloration. The inner layers needed to provide mechanical durability such as cracking and tearing resistance, force persistence, flexibility and ultimately, resilience.
Proprietary blend of materials deliver a synergistic effect greater than any single material we could develop.
Clarity Aligners Flex and 3M™ Clarity™ Aligners Force (the new name for our original material) form a system with different properties to address a range of needs for orthodontists. While developing the Clarity Aligners Flex part of the system, we received input from orthodontists to address these issues:
Force persistence that lasts for weeks.
Durability to resist cracking.
Resistance to staining and discoloration.
Make the aligner easy for patients to insert and remove.
Good engagement with attachments
From a materials standpoint, the properties needed to address these issues are somewhat at odds. For example, it’s challenging to combine the flexibility needed for easy insertion and removal with the durability needed for force persistence and cracking resistance. Meeting these disparate requirements collectively is not straightforward, but we were up for the challenge.
Working with an existing technology doesn’t mean there are no challenges when applied in a new way. For one thing, we had come up with a way to combine materials that had very different properties and discovered that we had to break all the rules set for multilayer coextrusion. We called on our multi-layer optical film technology group, and they designed a new manufacturing process for combining these supposedly un-combinable materials. There are not many companies that know polymer science well enough to be able to adapt in this way and develop the five-layer film solution used in Clarity Aligners Flex.