Vacuum infusion is how we turn dry stacks into precise, light, repeatable parts. The resin infusion process pulls low-viscosity resin through carbon and Kevlar® under full vacuum, setting a reliable fiber-to-resin ratio with minimal porosity.
At AMC Composites, we vacuum infuse components daily. When an application calls for tight cosmetics or thin sections, vacuum bag infusion and well-planned flow paths keep the laminate consistent; for larger spans, carbon fiber vacuum infusion scales cleanly with the right tooling and cure.
Dry fabric is laid into a mold, sealed in a bag, and evacuated. Under vacuum, resin is introduced from controlled inlets and travels through the flow media until the stack is fully wet-out. The laminate is then post-cured in an oven; for higher performance or tighter porosity/tolerance, we move to an autoclave. The fundamentals of flow control and scale-up are well covered in Design and Performance – useful context when you’re mapping gates, vents, and cycle time.
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Infusion loads the laminate in the right order: compact first, then wet out. With the stack under full vacuum, fibers are already aligned and consolidated before resin arrives. Low-viscosity epoxies then flow cleanly through corners and radii, raising fiber volume and lowering voids. The outcome is higher, more repeatable stiffness and strength at the same weight.
In large parts, strength comes from discipline as much as materials. We document leak-down, verify lines and catch pots, and stage infusion so the resin front stays uniform. Holding a vacuum through gel stabilizes fiber volume and surface class. Post-cure ensures application temperature requirements are met.
The same workflow scales from thin carbon laminates to deep sections; the benefits (reduced porosity, predictable cure, controlled operator exposure) are well recognized in production programs, where flow control and pre-checks are emphasized before, during, and after infusion.
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If you need end-to-end support – from laminate kit to cure plan and finish – our Composite manufacturing services cover design, molds, infusion, trimming, and finishing.
Tool selection follows the vacuum infusion process and the part’s duty cycle.
This workflow is the backbone of vacuum infusion carbon fiber programs at AMC – clean wet-out, controlled fiber-to-resin ratio, and consistent mechanicals part to part.
Infusion-specific epoxies – chosen for low viscosity and the required temperature service – let the resin front wet out evenly under vacuum. We hold vacuum through gel to lock fiber volume, then move to an elevated-temperature oven cure; for tighter porosity or tolerance we shift to autoclave. The result is consistent laminate density and surfaces that are easy to bring to final finish. This is the core advantage of carbon fiber resin infusion on production panels and shells.
Repeatability comes from keeping the variables small. We kit fabrics in the weights we run every day, route vacuum paths the same way part to part, and match tooling to the cure window – aluminum for cost-stable heat cycles, steel for long life, composite shells for large panels. Post-cure, we verify dimensions and thickness before finishing, so the next run behaves like the last.
Infusion sits between wet layup and prepreg in terms of control and cost. Compared with hand wet layup, the closed vacuum infusion process reduces trapped air and stabilizes the fiber-to-resin ratio, which translates to lighter, stronger parts with less variance across a build. Versus prepreg, infusion removes freezer logistics and gives more flexibility on large envelopes, while still delivering predictable mechanicals after oven or autoclave cure. That’s why resin infusion carbon fiber is our default for most laminates.
Material choice follows the use case. Epoxy is our standard for stiffness and temperature service; we move to vinyl ester where corrosion or frequent flexing dominates. Across routes, the same rule applies: pair the fabric architecture to the geometry and the resin to the environment, then keep the flow path simple. Infusion makes that balance practical at scale.
What is vacuum infusion?
It’s a closed-mold process where dry reinforcement is bagged, evacuated, and then saturated as resin is pulled through under vacuum. We use it daily on carbon and Kevlar laminates for predictable fiber-to-resin control.
Which resins do you run?
Epoxy is our standard, and we use low-viscosity systems tuned to temperature requirements. We switch to vinyl ester for corrosive environments or parts that see frequent flexing.
What fabrics and weights are typical?
We infuse carbon fiber and Kevlar in the 5-6 oz/yd² range – 3K/6K plain or 2x2 twill, with biax/triax and UD where needed. Fiberglass typically runs 8-12 oz/yd². We match weave and architecture to the part’s geometry and load path.
How do you cure infused parts?
After infusion, parts move to an elevated-temperature oven cure. For tighter porosity and dimensional control, as well as maximum temperature resistance we use autoclaving.
What tooling materials do you use for the vacuum infusion process?
6061-T6 aluminum for cost-effective heat stability, steel for long life under compression, tooling board for fast machining of infusion molds, and composite tooling for large body-panel-type skins. High-density foam plugs are also machined and gel-coated to create molds for our largest projects.
Do you infuse carbon fiber and Kevlar regularly?
Yes. We vacuum infuse carbon fiber and Kevlar daily, then post-cure as required for the application.
Vacuum infusion keeps variables small and properties consistent. Epoxy systems deliver clean wet-out and stable service temperatures; vinyl ester supports corrosive or flex-heavy duty. Pairing 5-6 oz/yd² carbon or Kevlar with the right tool and cure route yields strong, repeatable parts without unnecessary mass. If you want to scope materials, cure windows, and kit plans for your geometry and volumes, we will help you with your project.
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