Master Bond has introduced MasterSil 323, a two component, addition cured system for bonding, sealing and potting applications.
This product has a convenient to use 1:1 mix ratio and can be packaged in double barrel cartridges for dispensing from a gun applicator. It can be applied in thin and thick sections. This silicone has excellent flexibility, with an elongation of 150% - 250% at room temperature, a Shore A hardness of 35 – 45 and a low tensile modulus of 100 psi – 175 psi at 75°F for stress relief. It is capable of withstanding rigorous thermal cycling and shock without cracking or exerting stress on components. Additionally, MasterSil 323 has a low dielectric constant of 2.8 at 75°F, 1MHz.
“MasterSil 323 is a speciality compound which not only offers strain relief upon cure, but also provides decent bond strength to a variety of substrates, especially considering that it is a silicone,” says senior product engineer Rohit Ramnath. “The lap shear strength for an aluminium to aluminium bond joint is around 200 psi – 250 psi at 75°F. Moreover, MasterSil is optically clear in thinner sections and has a refractive index of 1.44 at 589Nm. It has a wide service temperature range of -65°F – 400°F.”
The optimal cure schedule for MasterSil is overnight at room temperature followed by 2 – 4 hours at 135°F - 165°F. The material will fully cure without exposure to air or humidity. The working life of a mixed 100g batch is approximately 2 – 3 hours. It also has extremely low shrinkage upon curing. MasterSil is available for use in ½ pint, pint, quart, gallon kit containers, 30cc syringe kits, and 50cc double barrel cartridges for gun dispensers. Shelf life in original, unopened containers at 75°F is six months.
Becca is the latest member to join our team and is eager to get stuck into the world of fasteners. She brings an enthusiastic and fresh outlook on what we do editorially and will be leading our social media activity – including sourcing material, editing articles and posting online.
