ViscoTec expands its portfolio with the static-dynamic mixer vipro-DUOMIX for the aerospace industry
The static-dynamic mixer vipro-DUOMIX is perfectly suited for two-component materials with very different viscosities, extreme mixing ratios and high-pressure sensitivity. The 2-component dispenser was launched at the ILA 2018 in Berlin.
Technology for compressible fluids & pastes
Like all products in our portfolio, the vipro-DUOMIX also relies on the technology of the endless piston principle. However, the 2-component dispenser extends the existing technology by allowing the mixing helix to rotate in both directions – without valves inside the mixing head. The dynamic mixing allows a reduction of the mixing section and the resulting back pressure by approximately one half. The individual components to be metered are dosed volumetrically into the mixing tube.
The compact design of the vipro-DUOMIX, in which both individual dispensers are arranged in parallel, makes it easy to integrate the dispenser into automated applications. Nozzle adaptation is also flexible due to the bayonet. We design and construct individual nozzles according to our customer’s specifications – making use of our high fluidic know-how.
Application example vipro-DUOMIX: Sealing compounds based on polysulfide
Compressible materials, such as polysulfide-based sealants, present four special challenges for a dosing system:
- To guarantee the correct mixing ratio, since pressurization can result in compression of the dosed volume in one component (usually base mass).
- To achieve an adequate mixing quality (homogeneous mixing) at extreme mixing ratios.
- To counteract the relaxation of the material: Due to the previous compression of the fluid (even if only minimally) a relaxation occurs after leaving the nozzle. This causes uncontrollable pressing of the dosed materials.
- To avoid destruction of the hollow spheres contained in the fluid.
The vipro-DUOMIX is particularly suitable for compressible materials where the back pressure must be kept as low as possible. We offer a dosing system that provides the optimal solution:
- Flow- and counter-pressure-optimized product channels prevent fluid compression. This ensures that the mixing ratio is maintained.
- By increasing the speed of the mixing spiral, direct influence can be exerted on the mixing process. The mixing quality can thus be dynamically adjusted.
- Compression is already largely prevented by low back pressures in the system. The (residual) expansion of the material is compensated or absorbed by the possibility of rotating the filament in the opposite direction.
- The progressive cavity pump technology ensures shear-sensitive and low-pressure fluid handling. The density remains unchanged during the entire dosing process.
The correct mixing ratio, homogeneous mixing and non-destructive dosing of the hollow spheres were evaluated by the material manufacturer Chemetall using the MC-780-B material as an example and found to be good.
The vipro-DUOMIX can be used for dot dosing, bead application and potting applications. Various 2-component materials based on e.g. polyether, epoxy resin, silicone or polyurethane can be dosed.