MasterSil 323Med

Master Bond MasterSil 323Med is a two component silicone for high performance bonding, sealing, and encapsulating. It does not require air when polymerizing and does not outgas while curing. It has a forgiving one to one mix ratio by weight. Although higher in viscosity, it is easily mixed and has good flow properties. It is a low exothermic material with a long open time of about 2-3 hours. It cures at ambient temperatures in 48-72 hours or in 2-4 hours at 135-165°F. The optimum cure is overnight at room temperature followed by 2-4 hours at 135-165°F. This silicone contains no solvents or diluents and has very low shrinkage upon curing.

MasterSil 323Med bonds well to a wide variety of substrates including metal, glass, plastics and ceramics, as well as to silicone rubber. It can withstand the most rigorous kinds of thermal shock and cycling without cracking or exerting stress on components. It can be used on disposable and reusable medical devices and it will resist various forms of sterilization including dry heat, UV and gamma radiation, EtO, glutaraldehyde, and other chemical sterilants. It has a Shore A hardness of 35 to 45. The combination of high viscosity but flowability prior to curing, and especially good bond strength after curing, is noteworthy. The service temperature range is from -65°F to +400°F. Other notable features are its optical clarity, especially in thinner sections, and its superior electrical insulation profile. MasterSil 323Med is a good candidate for disposable and reusable medical device manufacturing where a high viscosity silicone with a good strength profile is required.

Product Advantages

• Addition cured, no by-products released during cure
• Flowable, with long open time
• Optically clear, especially in thin sections
• Good bond strength
• Low dielectric constant
• Well suited for potting and encapsulation