The staid process of pultrusion is getting a substantial facelift with a new approach from KraussMaffei that includes aspects of injection molding.
Traditional pultrusion is a form of extrusion in which reinforced reactive plastics are pulled (rather than pushed) through a die to form a constant cross section. Think ladder rails, one of the main applications for the process, which dates to the 1950s.
In the new iPul system by KraussMaffei, fibers are encapsulated in a closed “injection” box, which it says permits use of fast-reacting systems of epoxy, polyurethane, and polyamide 6. Production speeds rise from the usual 0.5 to 1.5 meters per minute to approximately 3 meters per minute, approaching extrusion speeds of thermoplastic PVC profiles, according to KrassMaffei.
Visitors had an opportunity to view the system in operation at KraussMaffei’s headquarters in Munich, Germany on July 13. Four of the ten largest global pultruders attended as did manufacturers of sporting goods, windows and automakers.
Development partners for the technology include Covestro (polyurethane matrix resins), Evonik (pultruded glass fiber reinforcement in construction), Huntsman (wind power applications), and Thomas Technik (curved pultrusions).