Study on the mechanism and law of temperature,humidity and moisture content on the mechanical properties of molded fiber products

The change of temperature, humidity and moisture content (MC) will lead to the change of mechanical properties of molded fiber products (MFP). However, it is difficult to decouple the effects of temperature, humidity and MC on the mechanical properties of MFP, and predict the mechanical properties of MFP during the use. In this study, the laws and mechanism of mechanical properties of MFP with ambient temperature, humidity and MC were studied. The results showed that the direct effect of temperature (20−70 °C) on mechanical properties of MFP was insignificant, and the mechanical properties of MFP were mainly changed by MC. The MC was related to ambient temperature and humidity, and the relationship between the three could be described by the modified Guggenheim-Anderson-de Boer (GAB) model (20−70 °C and 30 %–90 % relative humidity). With the increase of MC, the elastic modulus and fracture strain was increased and decreased linearly, the yield strength and failure strength were presented GaussAmp laws, and the failure strain was presented asymptotic regressed distribution law. Two fracture modes of MFP, brittle fracture and ductile fracture, were revealed by the scanning electron microscopy of the mesoscopic fiber structure of sugarcane bagasse molded fiber products. The mathematical models and the changes of fiber structure were verified by wheat straw molded fiber products and waste paper molded fiber products. This study was contributed to understand the effects and mechanism of the change of temperature, humidity and MC on the mechanical properties of MFP.

Molded fiber and pulp products as green and sustainable alternatives to plastics:A mini review

There are significant incentives/pressures on decreasing the use of plastics and their related prod-ucts in the packaging industry,correspondingly,strong demands are emerging for clean,renew-able,recyclable/biodegradable packaging products.In this context,molded fiber/pulp products have attracted increasing attention,due to their green/sustainable advantages,simply because the raw materials used are plant-based and/or recycled fibers.Many companies have switched their packing practices from plastics to more environmentally friendly products,such as molded fiber products,which already have had and will continue to have obvious effect on packaging industries.This paper initially provides an overview on the general concept of molded pulp prod-ucts,and further summarizes the different types of molded fiber products in terms of natural fiber sources,manufacturing processes,current and emerging applications as well as the environmental sustainability of molded products.

Effect of Processing and Aging on Particle Size of Explosives

Influence of such processes as molding powder production, pellets pressing and aging under different conditions on particle size of TATB ( 1,3,5-triamino- 2,4,6-trinitrobenzene) and HMX (cyclotetramethylenetetranitramine) was experimentally studied. The results showed that particle size of these explosives was greatly changed before and after molding powder production, but for different size grade of explosive this change was not the same; pressing process had also great effect on explosive particle size, but before and after ageing process explosive particle size did not change seriously.