Epoxy Tooling System (Low CTE, High-Temperature Composite Mold)

Epoxy Tooling System is a specialized high-performance epoxy resin system designed for fabricating composite molds (tools) used in aerospace and automotive autoclave curing of composite parts at temperatures up to 180-200°C. The system is engineered for minimum coefficient of thermal expansion (CTE 25-35 µm/m/°C, approaching carbon fiber composite values) and high Tg (180-220°C) to maintain dimensional stability during repeated autoclave cure cycles.

The low CTE is achieved through combination of multi-functional epoxy components (epoxy novolac content) and high-modulus filler systems (aluminum trihydrate, silica, or hollow glass microspheres depending on application). The system is formulated for hand lay-up, vacuum bagging, and spray application over master models (Ureol foam, aluminum, fiberglass) to build up tool laminate sections.

Tool performance requirements include: surface finish reproduction <0.5 µm Ra (for Class A automotive surface tools), dimensional accuracy within ±0.1mm over the tool surface, autoclave pressure resistance up to 7 bar, and operational life of >500 autoclave cycles. Post-cure protocol for maximum dimensional stability requires staged cure from 60°C to 200°C with controlled heating rates to minimize residual thermal stress. Applications: aerospace autoclave carbon fiber molds, automotive press-forming tools, wind blade molds, and high-temperature test fixtures.