Additive manufacturing is trending toward functional applications beyond the scope of rapid prototyping. This requires the development of high‐performance, lightweight, and complex structures resulting from additive manufacturing. One of the biggest challenges for fulfilling these requirements is the limitation of material properties. The introduction of reinforcement allows for the expansion of current polymer‐based 3D printing technologies to achieve increased material properties while maintaining complex geometries. Commercial 3D printers able to print thermoplastic composites have recently been demonstrated with good repeatability. However, limitations of these thermoplastic composites include low fiber volume fraction and susceptibility to high temperatures. In contrast, thermoset‐based composites offer greater thermal stability and higher mechanical performance due to the cross‐linked structure of the polymer. Moreover, using continuous reinforcement instead of short fiber reinforcement offers higher performance opportunities. Therefore, the challenge of 3D printing with continuous fiber‐reinforced thermoset composite is addressed in this study. A 3D printer capable of printing a UV curable resin system reinforced with continuous carbon fiber was constructed. Variations of printed composites' mechanical properties depending on the fiber tow characteristic were investigated. Two different carbon fiber types and their associated tow twist count and sizing were evaluated in this study. Burn‐off tests were used to determine the printed composites' final fiber volume fraction. Using a rule of mixtures approach, strength and modulus were predicted for each composite and compared against their experimental values. Predicted modulus values were found within 2%–5% of experimental, while strength values were significantly less than predicted.

Wheat bran, abundant but underutilized, was investigated for its potential as a reinforcement in biocomposites through different pretreatment methods. Pretreatment methods included were dilute sodium hydroxide (NaOH), dilute sulfuric acid (H2SO4), liquid hot water (LHW), calcium hydroxide (CaOH), organosolv such as aqueous ethanol (EtOH), and methyl isobutyl ketone (MIBK). Changes in chemical composition and fiber characteristics of the treated bran were studied using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Cellulose content increased to 35.1% and 29.6% in brans treated with H2SO4 and NaOH, respectively. The SEM micrographs showed surface cleaning of treated bran while maintaining sufficient surface roughness for the H2SO4, NaOH, and MIBK treated brans. Crystallinity index increased slightly for all treatments except H2SO4. NaOH and H2SO4 pretreated brans achieved important fiber characteristics, which could be useful for making thermoplastic biocomposites. Innovative use of bran in thermoplastic will create more opportunities for growers while enhancing biodegradability.

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