Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.

The Influence of Saturated Steam on Moso Bamboo Quasi-static Micromechanical Properties: Nano-Scale Evaluation

In this paper, in order to analyze the quasi-static properties of Moso bamboo, a new, environmentally friendly and eco-friendly method was used for bamboo thermal modification under the effect of saturated steam. Under saturated steam heat treatment, the chemical composition in bamboo decreased, and the bamboo cell wall shrunk slightly. The increased crystallinity index of cellulose and decreased intensity of peaks belong to hemicellulose were confirmed by XRD and Fourier transform infrared (FTIR) spectroscopy. In addition, the highest modulus of elastic and hardness of treated bamboo were 22.5GPa and 1.1GPa at 180℃/10 min. These conclusions confirmed the micro-mechanical properties of the bamboo cell wall were enhanced by saturated steam heat treatment. The E'r of differently treated bamboo increased with increasing temperature and time, while the E''r and tan δ negatively as a function of increasing frequency. Furthermore, this thermal modification can be regarded as a useful, environmental-friendly and eco-friendly treatment to outdoor use of bamboo-based materials.

Multi-scale evaluation of the effect of saturated steam on the micromechanical properties of Moso bamboo

The changes in chemical composition and micro-mechanical properties of Moso Bamboo fiber cells were evaluated by applying saturated steam heat treatment at 160, 170, and 180 °C for periods of 4, 6, and 8 min, and subsequent analysis by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopic, and nanoindentation methods. The hemicellulose and cellulose content decreased as expected, while the relative lignin content showed an upward trend. Significant changes in the bamboo micro-structure were detected by scanning electron microscope under the action of high-temperature and saturated steam. Both temperature and time were shown to affect micromechanical properties of the bamboo cell wall. In addition, higher cell wall elastic modulus and hardness were observed (a rise from 16.1 to 19.2 GPa and from 0.6 to 0.8 GPa, respectively), as compared with those of the untreated sample. Meanwhile, the creep ratio decreased after saturated steam heat treatment.

Intensifying sustainable solar water production by steam heat internal circulation

A strategy of steam heat internal circulation was designed for enhancing the efficiency of sustainable water production during solar evaporation.