New Plant Growth Regulators for Fibre Flax

Tests of new natural non-polluting regulators of growth Verva （vegetative terpenoids from Abies sibirica） and Larixin （vegetative flavonoids from Larix） on growth, development and productivity of fibre flax are conducted. The level of phytohormones in vegetating plants （IAA, ABA, zeatine and zeatinriboside） is studied. Preparations stimulate germination of seeds and growth of plants. Field experiment fixed yield increase of flax straw and the seeds of flax-fibre with the use of growth regulators. Industrial experiment represents VERVA product effectiveness on yields increase of flax straw, seeds and flax fiber output.

Setting kinetics and mechanical properties of flax fibre reinforced glass ionomer restorative materials

Regardless of the excellent properties of glass ionomer cements,their poor mechanical properties limit their applications to non-load bearing areas.This study aimed to investigate the effect of incorporated short,chopped and randomly distributed flax fibers（0,0.5,1,2.5,5 and 25 wt%） on setting reaction kinetics,and mechanical and morphological properties of glass ionomer cements.Addition of flax fibers did not significantly affect the setting reaction extent.According to their content,flax fibers increased the compressive（from 148 to 250 MPa） and flexure strength（from 20 to 42 MPa）.They also changed the brittle behavior of glass ionomer cements to a plastic one.They significantly reduced the compressive（from 3 to 1.3 GPa） and flexure modulus（from 19 to 14 GPa）.Accordingly,flax fiber-modified glass ionomer cements could be potentially used in high-stress bearing areas.

Microwave Drying of Flax Fibre at Controlled Temperatures

Drying is essential for the production of fibre after retting process. Flax fibre was subjected to microwave drying at controlled temperatures to study the change in drying rate and qualities. The rate of drying was then compared with conventional hot air drying. The product temperature was maintained at 40 ℃, 60 ℃or 80 ℃ for both microwave and hot air drying. The initial moisture content of flax fibre was about 60% （wet basis）. The microwave drying was conducted in a microwave apparatus which recorded mass, product temperature, incident microwave power, reflected microwave power and inlet/outlet air temperature. The final moisture content was set to 9% （wet basis）. Microwave-convective drying ensured about 30% to 70% reduction of drying time for drying flax fibre as compared to hot air drying. Curve fitting with different mathematical models were carried out. While a significant difference in colorimeter-assessed co/our existed between microwave-convective dried flax fibre and hot air dried flax fibre. The tensile strength of flax fibre, measured with an Instron apparatus, increased with an increase in the processing temperature of both processes. Hot air dried flax fibre showed the greatest tensile strength and modulus of elasticity at processing temperatures of 60 ℃ and 80 ℃.

Characterisation of mechanical and thermal properties in flax fabric reinforced geopolymer composites

This paper presents the mechanical and thermal properties of flax fabric reinforced fly ash based geopolymer composites.Geopolymer composites reinforced with 2.4,3.0 and 4.1 wt%woven flax fabric in various layers were fabricated using a hand lay-up technique and tested for mechanical properties such as flexural strength,flexural modulus,compressive strength,hardness,and fracture toughness.All mechanical properties were improved by increasing the flax fibre contents,and showed superior mechanical properties over a pure geopolymer matrix.Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)studies were carried out to evaluate the composition and fracture surfaces of geopolymer and geopolymer/flax composites.The thermal behaviour of composites was studied by thermogravimetric analysis(TGA)and the results showed significant degradation of flax fibres at 300℃.