MTM 45-1 composite material product

MTM 45-1 is a toughened epoxy prepreg system from Syensqo, formerly marketed by Advanced Composites Group, Cytec and Solvay, for composite parts that are cured without an autoclave. In the composite materials category it is a prepreg, that is, reinforcement pre-impregnated with a B-staged epoxy matrix, supplied as unidirectional tape and as fabric.

The out-of-autoclave capability is the main point for a manufacturer. The material is cured under vacuum bag pressure in an oven, so the tooling, the investment in pressure vessels and the size limit of an autoclave do not apply. This helps with large or low-volume structures and with lower tooling cost. The glass transition temperature is 180 degrees C, which defines the upper service temperature range that the cured laminate can be used for, and which designers compare against the maximum operating temperature of the part.

The system is a lower-temperature curing prepreg. The maker's cure options are described in trade literature as 85 degrees C for 20 hours or 180 degrees C for 2 hours, which lets a manufacturer choose between lower-temperature tooling and a shorter cycle. The final laminate properties depend on the selected fibre, the layup, the cure cycle and the processing conditions, and engineers should work from the maker's technical data sheet and the qualification data of the chosen form.

Forms qualified in the NCAMP programme include carbon unidirectional tape on IM7, AS4 and HTS fibres, carbon plain-weave fabric, and glass fabrics such as 7781 E-glass and 6781 S-2 glass. Resin content for the IM7 tape is 32 percent on average with a fibre areal weight of 145 g/m2. Companion materials include the MTA241 adhesive for low-temperature cure and the MTF316 surface film, which is compatible with the out-of-autoclave prepreg range.

Integration into production requires cold storage and controlled out-time for the prepreg, a vacuum-bag and breather layup, and an oven that holds the chosen cure cycle. Typical applications are aerospace structures such as airframe panels, fairings, control surfaces and other secondary or primary components of UAS and eVTOL aircraft.