Carbon Fiber and Fiberglass Epoxy Prepreg Products with 350 °F (177 °C) Cure for Aerospace Applications: Type 35, Class 1, Grade 191
AMS6891/1
This WIP is part of an open WIP to the base specification for AMS6891. In order to increase the work life requirement in the base specification, AMS6891/1 will be updated to increase the specification limit of HPLC P4/P1 located in Section 3.2.1, Table 1.
Rationale: CMA has conducted a study and analyzed the physical, chemical, and mechanical properties of material T800SC-24K-10E/3900-2C, also known as P2362W-19L and controlled by AMS6891/1, after 5.5 years freezer storage time and up to 70 days of room temperature exposure. Results of this study show that P2362W-19L does not fail the requirements of AMS6891/1 after 5.5 years of shelf life and that the prepreg work life may be increased to 28 days at that time. Also, conducted a study and analyzed the physical, chemical, and mechanical properties of material T830HB-6K-PW/3900-2D, also known as FM6673G-37KL and controlled by AMS6891/2, after 5.5 years freezer storage time and up to 70 days of room temperature exposure. Results of this study show that FM6673G-37KL does not fail the requirements of AMS6891/2 after 5.5 years of shelf life and that the prepreg work life may be increased to 28 days at that time. This standard AM6891 that controls the shelf life and handling has been requested by industry to provide new requirements for extending shelf life and handling of the existing AMS6891 material. The new standard will mitigate and facilitate new storage and handling strategies for material up to 5.5 years shelf life.