Optically clear, low viscosity epoxy system offers high flexibility

12-06-2019 | Masterbond | Subs & Systems

Master Bond EP88FL is a two-component epoxy, highly flexible, optically clear compound formulated for bonding, sealing, coating, potting and encapsulation. It is straightforward to use, with a mixing ratio of one to one by weight or volume.


The epoxy resists thermal cycling and shock. It is excellent in applications where stress relief is required with a tensile modulus ranging from 10,000psi to 20,000psi. This system offers an elongation of 30-50% and bonds well to a broad assortment of substrates such as ceramics, metals, plastics and glass. Notwithstanding curing with an ample degree of flexibility, it cannot be considered soft since it has a Shore D hardness between 45-55 at 75F. The refractive index is 1.51 at 589nm, making the system suitable for applications in optics, optoelectronics, aerospace and OEM.


The mixed viscosity of the epoxy is 800-1,200cps at room temperature, and its working life is 20-30 minutes for a 100g batch. The epoxy can be cured at room temperature or elevated temperatures. The optimal cure is overnight at 75F plus one to two hours at 150-200F. The epoxy is offered in standard packaging ranging from half a pint to five-gallon containers as well as speciality packaging including FlexiPaks, syringes and gun dispensers.

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