Optimal process and reliability analysis of fiber-ammonium lignosulphonate-PLA wood composites .

In order to investigate the effect of biomass resources on interfacial and comprehensive properties, composites of wood fiber-ammonium lignosulphonate-PLA (polylactic acid) were manufactured. We used a flat platen press technology to analyze and discuss the effect of patterns of additional amounts of PLA, oxidation modified ammonium lignosulphonate (MIL), as well as the duration of hot-pressing on the physical and chemical properties of these wood composites. The production technology can be optimized by evaluating a number of indicators from a reliability analysis of models. These models are quadratic regression models developed by response surface methodology (RSM). The results reveal that technological factors have a great effect on the physical and chemical properties of the composites. In our single factor experiment, these properties showed a significant improvement with 20-25% MIL, 30% PLA and 7 to 9 min hot-pressing time. The responses of the modulus of rupture (MOR) , internal bonding strength (IB) and 24 h thickness swelling (TS) in a third order power regression model were all significant at the 0.01 level, confirming that such models could be used to analyze and predict the properties of composites accurately and reliably. The integrated optimal production technology was as follows: 25% MIL, 33% PLA and 7.5 min time for the hot-pressing; rates of deviation between test and predicted values of the composites properties were less than 5%. The physical and chemical properties of the composites met the requirements for ordinary medium density fiberboard under damp conditions defined by the standards of GB/T 11718—2009 MDF of China.