Effect of hemp fibre length on the properties of polypropylene composites

P.F. Alao*, H. Kallakas, T. Poltimäe and J. Kers

Laboratory of Wood Technology, Department of Materials and Environmental Technology, Tallinn University of technology, Ehitajate tee 5, EE19086 Tallinn, Estonia
*Correspondence: percy.alao@taltech.ee

Abstract:

Hemp fibre (HF) is a natural fibre that has gained increased application in interior material for automobile industries (Sanjay, et al., 2016). However, good interfacial bonding between fibre/matrix is necessary to enhance the mechanical properties of the composite (Pickering, et al., 2007). This study focuses on the effect of fibre length, alkali and silane treatments on the mechanical and physical properties of hemp fibre reinforced polypropylene composites. Compression moulding technique was used to produce the composite, fibre lengths of 50, 100 and 150 mm were selected and combined with polypropylene powder at a fibre/PP ratio of 60/40%, a pressure of 1.67 MPa and temperature between 160–200 °C. The results obtained show that longer fibres enhanced mechanical strength. The tensile test result, for instance, shows a 21% increase in flexural strength at 150 mm compared to the fibre length of 50 mm. The modification resulted in a 46% decrease in strength, especially for 150 mm long fibres. This may have been as a result of fibre damage, inadequate modification, less quality fibre or higher initial moisture content in the modified fibres as observed from FTIR spectroscopy. Further investigation of these factors is required to be able to conclusively determine if they may have affected the mechanical performance (Alao, 2018).

Key words:

fibre length, hemp fibre, interfacial bonding, mechanical properties, modification, moisture content., polymer composite, polypropylene

Conceptual ‘Cradle to Gate’ analysis of GHG emissions from wood, agricultural plant and synthetic fibres

V. Kazulis*, I. Muižniece and D. Blumberga

Riga Technical University, Faculty of Power and Electrical Engineering, Institute of
Energy Systems and Environment, Azenes iela 12/1, LV-1048 Riga, Latvia
*Correspondence: valters.kazulis@rtu.lv

Abstract:

Industrialization and fossil resource use has brought unprecedented anthropogenic carbon dioxide emissions. Use of synthetic fibre materials and unsustainable plant cultivation practices contribute to greenhouse gas emissions. The global market share of polyester fibre (synthetic fibre made from fossil resources) exceeded the share of cotton fibre (natural fibre) for the first time in 2000 and since then polyester has remained the most popular fibre. The demand for textiles keeps increasing. In Northern Europe locally made fibres from wood, hemp and flax could substitute fossil based fibres decreasing the global GHG emissions and helping local economies to prosper. Multi-criteria analysis method TOPSIS was used to carry out a conceptual research evaluating GHG emissions from wood, agricultural plant and synthetic fibre acquisition under two scenarios: fossil fuels are used as energy sources & industrial fertilizers are used; and renewable energy sources are used & industrial fertilizers are not used. Results show that wood and plant fibres have smaller GHG emissions than synthetic fibres in both scenarios. Factors affecting emission performance are analysed.

Key words: