Typical wound dressings are an assembly of composite components, combining different types of materials: a backing film for comfort and integrity, an hydrophilic absorbent for managing exudates and an adhesive layer that is designed to guarantee soft adhesion to skin, while remaining elastic and permeable. Soft silicone adhesives combined with polyurethane films are materials of choice for this adhesive layer because they are highly breathable, biocompatible and flexible.
However, existing soft silicone adhesives available in the market bond poorly with polyurethane substrates. To avoid any risk of residue left on the skin, manufacturers use a priming solution or a physical treatment like plasma or Corona to increase bonding strength. This is a complex and often costly process. Additionally, it’s important to apply stringent quality controls after the coating has been done to ensure that the adhesive layer will leave no residue when used on skin.