Van Wees can offer three different machines for the impregnation of fibers and fabrics.
- Dispersion impregnation.
- Thermoset impregnation by reverse roller coater.
- Thermoplastic resin impregnation with inline extruder.
The dispersion impregnation machine is used for the production of UD prepregs for the technical textiles (for example ballistics) industry. The process is very stable and the impregnation level is high due to the easy penetration of the resin in the fibers. The Van Wees unit has a post spreading device making the uniformity even better. The resin content in the UD tape can be adjusted by tuning the solid content of the dispersion. Speed of impregnation is up to 20 meters/minute.
The thermoset prepregs are made as a one step process. The resin is applied on the carrier (silicone coated paper) by the reverse roller coater. The spread fibers are applied on the resin film and by heating the material the impregnation takes place. For further impregnation, calibration and consolidation, one – two or three calendar units can be integrated in the machine. UD tapes as well as fabrics can be impregnated on this machines. Speed of impregnation is in the 3–10 meter/minute range.
For impregnation of thermoplastic resins, Van Wees has developed a process in which the resin film is made by melting the polymer in an extruder and metering the film thickness on the impregnation roller. The spread fibers are impregnated up to a certain level on the impregnation roller and post impregnation takes place before final consolidation and being cooled. Speed of impregnation is in the 3–15 meter/minute range.
The UD tapes or prepreg fabric can be wound on double winders. In that case the impregnation process is not interrupted and the material is stored in a compensator unit during rolls change.