Multi-Layer Barrier Films
Building on Sigma's technologies for depositing functional nanolayers in vacuum, Sigma barrier films benefit from various multi-layer architectures that include a) polymer nanolayers applied before, after, or before and after deposition of the active barrier layer, and b) the applications of nanoparticle sealing layers creating both a torturous path for moisture, as well as a trap for moisture that enters the multi-layer structure. The result is vastly superior barrier properties, better durability, and enhanced printability.
One Layer Is Better Than None - MonoLayer Barrier Films
Application of a single, protective, coating onto any inorganic barrier layer, using SigMaterials VaporPhase deposition technology, results in drastically improved barrier properties. Sigma MonoLayer barrier films consist of a single metallized layer followed by a functional protective layer for increased barrier performance ideal for most food and electronics packaging applications.
More Layers Are Better Than Few - Multi-Layer Barrier Films
Sigma MultiLayer barrier films consist of a multitude of inorganic and organic layers to produce truly groundbreaking barrier performance for industrial applications such as flexible displays and photovoltaics.
Planarization of Micro-Rough Surfaces: Expand/Collapse
Binding Layers for Difficult-to-Metallize Substrates: Expand/Collapse
The ability to deposit thin, functional, polymer layers prior to metallization is also useful in creating interfacial binding layers that serve to establish a better bond of the barrier layer to the substrate. Additionally, such layers can work to seal the substrate surface, which in some cases can corrode the barrier layer over time. This effect can be observed in compostable barrier films, such as metallized polylactic acid, where the metallized barrier layer must be separated from the PLA surface to prevent corrosion and breakdown in barrier performance.
Barrier Layer Protection: Expand/Collapse
Most film surfaces are rough. Some films types are worse than others; however, even small micro-features on a film surface can result in poor barrier performance due to the inability of the thin barrier layer to cover the entire surface of the film. Introduction of a polymer "leveling" layer, just prior to barrier layer deposition, allows for the barrier layer to completely, and conformally, coat the substrate surface.
Formulated Top-Coats for Better Printing: Expand/Collapse
One of the advantages to Sigma's DryFab coating technology is the ability to deposit specially formulated protective top coats for better printing. This means no corona treatment, which can lead to pin-holes and degradation of barrier performance.
Permanent High Surface Energy
In cases where all that is needed for ink bonding is a surface with a high surface energy, coatings can be applied that range in surface energy from 40 dynes/cm2 to as high as 70 dynes/cm2.
Custom Coating Formulations
High surface energy is not always the answer when it comes to ink bonding. Certain ink systems require certain functional groups to be present to the substrate surface in order for sufficient bonding to occur. In cases such as these, protective top coats can be formulated to meet the needs of the specific ink system.
FDA Compliance: Expand/Collapse
SSM, for products used in food packaging applications, only uses monomers that have been cleared by the FDA for either direct, or indirect, food contact. Extractables testing is conducted to confirm that all SSM products meat FDA ppm requirements. See product data sheets for additional information.
Most film surfaces are rough. Some films types are worse than others; however, even small micro-features on a film surface can result in poor barrier performance due to the inability of the thin barrier layer to cover the entire surface of the film. Introduction of a polymer "leveling" layer, just prior to barrier layer deposition, allows for the barrier layer to completely, and conformally, coat the substrate surface.
Dealing with Particulates and Surface Contaminates
Particulates, or surface contaminates, present on the substrate surface, either from the film manufacturing process or subsequent handling, can contribute to poor barrier performance - especially if the dimensions of the contaminate exceed the thickness of the barrier layer, which is usually the case.
Sigma barrier films deal with surface contaminates in two ways; first, by plasma pre-treating the substrate surface prior to barrier layer deposition, which aids in the removal of small particulates; and second, by conformally coating, or "sealing," residual contaminates with a vacuum deposited polymer layer.