A consortium of four companies has developed a new family of long-fibre reinforced thermoplastic (LFT) polypropylene compounds for solar roof frames, which could find wider applications due to the high performance of the materials.
Dutch company TULiPPS Solar was set up two years ago by Paul Stassen to develop solar photovoltaic modules from LFTs to replace standard aluminium frames. The company’s system is designed for rapid assembly and disassembly, which reduces installation costs and time. Weight reduction makes the units suitable for flat roofs and is achieved through use of LFTs, plus a thin-glass PV laminate and a roof anchor system which eliminates the need for ballast.
The design requirements placed large demands on the compounds. The system needed to be flame retardant, lightweight and thin, so the materials had to have high stiffness and strength plus excellent long-term durability – properties that can be affected by the non-halogenated FR additives that TULiPPS wanted to use.
Stassen’s background is in automotive polymer additives and compounding (he has previously worked for Dutch additive producer Addcomp), so he was able to bring his knowledge and contacts to the selection of the consortium partners: RESIN (Products & Technology), QolorTech (both based in the
Stassen said: “What we are trying to make LFT-PP polymers do for the TULiPPS module is a breakthrough that has never been done before – not even in the demanding automotive industry where these materials got their start.”
The PP compounds use proprietary non-halogenated flame retardants, are 30% glass reinforced, and provide a 25-year service life to the solar modules. RESIN has started selling the compounds, available in natural, black, green, grey and blue, under the trade name Eco-Forte.
Huibjan Braafhart, sales director of Voestalpine Plastics Solutions, said: “We were impressed by how well these formulations processed, with good flow, no discoloration, and achieving excellent wetout of glass, which can be a problem with FR compounds.”