Long-Fiber PP Can Be Colored, FR and Tough

TULiPPS Solar B.V. in The Netherlands, is a start-up company developing rooftop solar panels based on PP long-fiber thermoplastic (LFT) composites. The composites must be lightweight, thin, and weatherable to last for 25 years or longer. They also need to be flame retardant (without halogenated additives) and colorable in gray, green, and blue. “We have seen from previous trials that using ordinary color masterbatches really kills the mechanical properties of LFT-PP,” says Paul Stassen, TULiPPS founder and managing director, who has a background in compounding and polymer additives. “The negative effect of green/gray/blue standard colors in LFT can be 50% to 70% loss of impact performance compared with standard automotive black LFT. And using halogen-free FR additives will further decrease impact and strength properties.”

With a consortium of Dutch companies, Stassen and his team developed colored FR formulations that matched or even exceeded the dart impact of standard automotive FR and non-FR black LFT-PP samples. Stiffness was also enhanced, a difficult balancing act. The LFT-PP formulations come in ready-to-use and masterbatch form from Resin (Products & Technology) B.V. They are made with color masterbatches from QolorTech B.V. The panels will be supplied by automotive LFT molder voestalpine Plastics Solutions. It found that the materials had good flow and were stable at a high molding temperature of 240 C/464 F, a challenge for non-halogen FR agents. Resin (Products & Technology) has a Detroit-area rep, Gary Johns (248-855-2005).