About their work together, Frans Haafkens, managing director at RESIN notes, “As a company philosophy, RESIN always opts for the safest and most environmentally sustainable solution we can find for our custom compounds and masterbatches. With our new halogen- and antimony-free, ECO-compliant flame retardant recipes for polypropylene, we have achieved the difficult balance of good processing and mechanical properties at an attractive cost. Although it was a lot of work, these new thermoplastic formulations are well positioned to serve demanding market segments such as automotive, consumer electronics, composite pallets and other materials-handling components, as well as roof-mounted solar PV systems.”
Meanwhile, recognizing that the solar panel module system would need excellent outdoor weathering for several decades in addition to meeting required mechanical and FR requirements, Stassen also partnered with QolorTech B.V. (Vaassen, The Netherlands), a supplier of custom-color masterbatches, to develop a series of unique colorant packages for the new LFT-PP compounds that would not interfere with the efficiency of the reinforcements. The goal here was to develop three “industrial” colors (grey, green, and blue).
Like basic automotive black and unpigmented natural/off-white grades, these new colors would need to look good long term despite exposure to heat, ultraviolet (UV) radiation from sunlight, and other forms of weathering that can affect aesthetics and, more importantly, lead to a deterioration of performance. In the automotive industry, nearly all of the glass-reinforced LFT applications are black or neutral (unpigmented), but as LFT moves into non-automotive markets, it will be necessary to offer a better and broader color palette.
“Colorant packages need to be formulated as carefully as other components of the compound because they can inadvertently contribute to a loss of mechanical properties and service life,” explained QolorTech’s managing director, Michiel De Jong.
“We put our pigment know-how to work in helping formulate unique color masterbatches for these new FR-LFT grades and that knowledge produced materials with good aesthetics and excellent long-term UV protection that do not cause property loss. Of course, having a broader color palette will attract customers from a wider range of industries.”
Once a thermoplastic compound was developed and tested on small-scale equipment, it was necessary to identify a commercial molder who could evaluate the compound on production-scale compounding equipment to ensure it processed properly and, once the final formulation work was completed, who would be able to produce the large panel structures commercially for TULiPPS. For this work, voestalpine Plastics Solutions (Roosendaal and Putte, The Netherlands – formerly Polynorm Van Niftrik), the largest automotive LFT molder in the Netherlands, was chosen as the fourth development partner. Not only was the company highly experienced at working with both pelletized LFT and inline compounded (ILC) direct-LFT (D-LFT), but it also had an excellent reputation for quality, and used the latest inline compounding as well as injection and compression molding technologies.
Speaking about their involvement in the project, Huibjan Braafhart, sales director of voestalpine Plastics Solutions noted, “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. Based on the excellent mechanical properties that we measured, this obviously was not a problem with these materials.
