Mechanical qualities of adhesive bonds reinforced with biological fabric treated by plasma
Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences in Prague, Kamýcká 129, CZ165 21, Prague, Czech Republic
The paper deals with the utilization of a biological reinforcement in the area of an adhesive layer at structural adhesive bonds. A significant disadvantage of adhesive bonds is uneven layer of an adhesive, which can be eliminated by various technological procedures. One possibility is to use a reinforcing even layer. The primary aim of this paper was to experimentally investigate an influence of the surface plasma treatment of natural fabrics (flax, cotton) at different intervals of plasma affecting (0 to 90 seconds and power 350 W) on mechanical properties of the adhesive bond. There were positive results from reinforcing the adhesive bond by a layer of linen and cotton. Strength characteristics of reinforced adhesive bond were increased compared to non–reinforced adhesive bonds. When the linen was used, the strength was increased by 43.2% and when the cotton then 15.5% strength increase could be seen. When modifying the surface by plasma, next adhesive bond’s strength increase was seen. Using the linen there was approx. 47% strength increase, using the cotton the strength increase was approx. 38% compared to non–reinforced adhesive bonds (without reinforcing phase). It is obvious from the results that plasma modifying showed better results when the cotton was used as the reinforcing material. SEM analysis proved that adhesion was improved with plasma surface modification of biological fibres. In other words the distance between the warp and the resin was significantly decreased for 87.1% when using the cotton and by 46.5% when the linen was used.