a b s t r a c tSynthetic amorphous silica (SAS) like NM-200 is used in a wide variety of technological applications and consumer products. Although SAS has been widely investigated the available reproductive toxicity studies are old and do not cover all requirements of current OECD Guidelines. As part of a CEFIC-LRI project, NM-200 was tested in a two-generation reproduction toxicity study according to OECD guideline 416. Male and female rats were treated by oral gavage with NM-200 at dose levels of 0, 100, 300 and 1000 mg/kg bw/day for two generations. Body weight and food consumption were measured throughout the study. Reproductive and developmental parameters were measured and at sacrifice (reproductive) organs and tissues were sampled for histopathological analysis. Oral administration of NM-200 up to 1000 mg/kg bw/day had no adverse effects on the reproductive performance of rats or on the growth and development of the offspring into adulthood for two consecutive generations. The NOAEL was 1000 mg/kg body weight per day.

A new type of fiber reinforced filament materials for Fused Deposition Modeling applications has been developed. Polylactic acid (PLA), compounded with two types of plasticizer, is reinforced with bamboo and flax fibers. The fiber fractions are characterized by measuring their length (l) over diameter (d) before and after compounding so that the effect of the l/d on the final filament properties can be systematically studied. The pre‐processing and processing activities, to produce filaments with a diameter of 3 mm, are described. The porosities and the orientation of the fibers in the filament are assessed to predict the theoretical stiffness of the filament via short fiber mechanics which is compared to the experimental results. Reinforcing the PLA filament with short bamboo fibers (l/d = 4–5) increases the modulus with 91–230%, whereas the dust‐like fractions only show an increase up till 39%. The glass transition temperature of the produced filaments is also determined to investigate the suitability of the filaments and finally a demonstrator part was printed. POLYM. COMPOS., 40:1951–1963, 2019. © 2018 Society of Plastics Engineers

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Temperature management is crucial in Fused Filament Fabrication (FFF). This paper presents an infrared based setup able to record spatial and temporal variations during printing of an FFF part, with a field of view of 22×15 (mm) at spatial resolution of 30.2 μm. The system is experimentally verified and the captured temperature profiles are compared to numerical data, obtained via an own-developed FFF numerical model. This work is a first step towards a combined experimental-numerical approach for in-process monitoring of FFF, with implications for filament developers, machine builders and (end-) users, ultimately demanding high quality (certified) parts.

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