How to Choose the right Silicone Adhesive in the Medical Field

Found in many medical devices, silicone is often used as a bonding material. Read on to find out how to optimize production by choosing the right silicone adhesive in your production. 

Why determine adhesive selection early? 

Determining specific adhesive requirements early in the development of a medical device can save time by avoiding unexpected adhesion/bonding problems that can affect the final manufacturing process. It is important to know what adhesives are available, how to handle them and how to prepare the surface. Most silicone adhesives are ideal for creating joints or bonding silicone to other silicones, metals, glass or certain plastics. They can also be custom-made to improve their physical properties or modify their adhesion to meet specific end-use requirements. If you are using silicones for professional purposes, you can turn to Elkem, a specialist silicone company that can both advise and supply you. You can also take a look on this blog post about pressure sensitive adhesive. It will give you a lot of information about this subject. 

Two types of silicone adhesives: one-component and two-component 

One-component, room-temperature, moisture-curing adhesives are the most commonly used silicone adhesives for medical devices. They are easily applied and require no mixing, but have a slower cure rate and can cause volume shrinkage. Cure rate depends on humidity, cure temperature, surface exposure to air and also the thickness of the applied adhesive layer. Two-component adhesives are among the most versatile silicone polymer compounds. They cure much faster than conventional one-component adhesives, either at room temperature or under heat, depending on their formulation. For room-temperature curable adhesives, the process begins after the two components are mixed and is not dependent on ambient humidity. For others, the process is accelerated by the application of heat. These adhesives can meet unique bonding requirements, such as creating bonds on interfaces with little or no exposure to air. Two-component adhesives cured at room temperature are ideal for heat-sensitive parts or assembly processes requiring relatively low temperatures. Heat-cured adhesives are used to meet the need for rapid curing to save time in device assembly and to bond parts that are not heat sensitive. 

What else is important to consider? 

Many physical, mechanical and chemical forces act against a bond. It is important to work with a supplier that can perform real-world testing to qualify adhesion, such as shear and peel strength. In addition, medical grade silicones must be biocompatible and comply with current regulations and ISO testing protocols. It is best to favor high-purity medical-grade silicone adhesives, which have broad regulatory support to facilitate submissions to regulatory agencies. This helps speed up the time to market for a medical device. Finally, medical grade silicones must be designed and manufactured to strict purity standards, with carefully selected raw materials and proven purification techniques. 

Remember that close collaboration is the best way to anticipate what the strict design and production parameters will be, while overcoming some of the obstacles that could affect the medical device manufacturing process.