Single line injection

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Single Line Injection (SLI) is a patented process for the production of fiber composite components . The patent holder is the German Aerospace Center (DLR), Institute for Composite Structures and Adaptronics (formerly: Institute for Structural Mechanics).

Infusion technology

The infusion process and differential pressure resin transfer molding (DP-RTM) offer the best compromise between tool costs and reproducible component quality. In contrast to Resin Transfer Molding (RTM), a solid tool (mold) can be dispensed with, as the process pressure is achieved via an “increase in ambient pressure” within an autoclave (compressed air oven).

The dry preform is expanded in the tool with infusion channels and suction channels. This structure is then hermetically enclosed with a vacuum film and evacuated. This achieves precompacting and prevents defects from occurring in the component due to air inclusions.

With the infusion process (also: injection process), the structure is always evacuated first and then the epoxy resin is sucked into the dry fiber material with the help of the negative pressure generated. A special feature of the SLI procedure is that evacuation and subsequent infusion are carried out through the same ("single") line. Switching between the vacuum pump and the resin supply is done by a valve after suction, because it is important to ensure that no epoxy resin gets into the vacuum pump . The injected structure is then cured at the appropriate pressure and temperature over the specified period of time.

See also

Web links

Institute for Composite Structures and Adaptronics

Individual evidence

  1. Patent: [1]