Multi-component mixing and metering equipment with online stoichiometry control
The invention describes an advanced mixing and metering technology with online analytics for a supply of formulated liquid thermosetting resins into an open or closed mold. The application addresses where a precise control of the composition of formulated components is required. Composite structures used in primary and secondary structural aerospace applications manufactured in Infusion or RTM processes are possible examples.
1. An apparatus for supplying a liquid or molten liquid thermosetting composition comprising
one or more resins and one or more curing agents mixed in a mixing unit before curing in a mold,
an online analytical tool comprising an analytical method to measure inline the correct mixing ratio of the one or more resins and the one or more curing agents before and/or after mixing, and
material lines upstream of the mixing unit comprising inline measurement probes installed therein,
wherein the online analytical tool is based on irradiation of the liquid thermosetting composition.
2. The apparatus of claim 1 , wherein the analytical method is based on refractive index difference, or UV, or Visible, or Infra-red wavelength.
3. The apparatus of claim 2 , wherein the analytical method is based on Infra-red (IR) or Near Infra-red (NIR).
4. The apparatus of claim 1 , further comprising a valve after the analytical tool, wherein the valve regulates the thermosetting composition to be injected in a mold or to be directed to a waste drum.
5. The apparatus of claim 1 wherein the analytical method of the analytical tool is modeled to process the thermosetting composition comprising a mixture of epoxy resins, in liquid or molten phase, and at least one curing agent for epoxy resins, in liquid or molten phase to be blended in the mixing unit.
6. The apparatus of claim 1 wherein the analytical method of the analytical tool is modeled to process the liquid thermosetting composition comprising an epoxy resin that is a liquid at room temperature or higher with an epoxy equivalent of 80 to 250 g/equivalent and the curing agent comprises a low viscosity liquid or a solid with a melting point lower than 160°.
7. The apparatus of claim 6 wherein the epoxy resin is a liquid at room temperature or higher and with an epoxy equivalent of 80 to 200 g/equivalent and the curing agent is either a low viscosity liquid or a solid with a melting point lower than 160° C.
8. The apparatus of claim 1 wherein the curing agent comprising amine derivatives in liquid form in the material lines before the mixing unit or acid derivatives in a liquid form in the material lines before the mixing unit.
9. The apparatus of claim 1 , wherein the mixing unit comprises a static or dynamic mixing device.
10. The apparatus of claim 1 , further comprising a pump and further comprising a reservoir or recycling chain disposed after the mixing device.