Miroslav Müller

Thermoset Composite on Basis of Recycled Rubber

The paper describes the mechanical qualities of thermoset – epoxy resin filled with recycled rubber in the form of micro-particles. Such an application of waste can be regarded as material usage which should be preferred to other ways of waste handling. Micro-particles of recycled rubber affect the mechanical qualities of polymer in which they are dispersed. The paper quantifies cohesive and adhesive properties of the filled epoxy resin. Filling polymers – thermosets with waste fillers saves costs, it does not burden the environment, and it is inexpensive. The results described in this paper can lead to enlarging the application areas of recycled rubbers. As the filler, recycled rubber gained by the process of an ecological disposal of tyres by Gumoeko, s.r.o. (private limited company) was used.

Mechanical Behavior of Ensete ventricosum Fiber Under Tension Loading

ABSTRACT The mechanical behavior of Ensete ventricosum fibers, expressed as the dependency of tension force in relation to the elongation, was determined for fibers with gauge length 50 mm and transformed into general linear mathematical model describing dependency of tension stress and strain. The average rupture force (10.88 ± 1.11) N, rupture stress (390.33 ± 21.96) MPa, rupture strain (0.021 ± 2 · 10–5), and volume energy (3.39 ± 0.22) J m−3 were also determined at this conducted study. Using image analyses, it was determined that the cross section of Ensete ventricosum fiber has circle shape and its dimension was specified. From the study, it implies that Ensete ventricosum fiber, with respect to its mechanical behavior under tension loading having regard to its density and to the fact that it is environmentally friendly, biodegradable and recyclable, could be used as a perspective construction material of the future. Determined model of mechanical behavior could be applied as background for further research focused on the Ensete fiber application.

Mechanical properties of adhesive bonds reinforced with biological fabric

Abstract The paper deals with the utilization of a biological reinforcement in an area of an adhesive layer. An advantage of the biological reinforcement application is a simplification of following recyclation of adhesive bonds comparing to those with carbon and glass fibre based reinforcements. Biocomposites combining the biological reinforcement with an inorganic adhesive can be used in the area of connecting materials by means of the adhesive bonding technology. This study was focused on the analysis of an adhesive bond strength when the bonds were reinforced with biological fabric such as jute, flax and cotton. It evaluates the quality of the adhesive layer by means of SEM. The aim of this experiment was to describe an influence of the biological reinforcement in the form of fabric on the adhesive bond strength loaded with various loading speeds from 0.5 to 300 mm/min. The experimental part is devoted to the research on the influence of added fabrics of the natural origin on the shear strength of the adhesive bond which is prepared with the polymer adhesive. The experiment results proved a benefit of the reinforcing biological fabric in the layer of the adhesive. The reinforcement of the adhesive bond with the layer of the flax and the cotton showed in the positive way with the increase of the adhesive bond strength up of ca. 50%. The biological reinforcement was not fully wetted with the resin which did not considerably influence the adhesive bond strength.

Recikliranje čestica korunda - abrazivno trošenje između dva tijela od polimernih kompozita na temelju otpada

Original scientific paper Recycling of all materials should be supported by modern society. Material recycling is one of the most important ways of dealing with waste. One of material recycling possibilities is an inclusion of waste into primary matrices. A suitable ratio and a combination of waste particles influence in a positive way mechanical properties of the material in which they are dispersed and they decrease its price. An example of the mentioned material recycling is a dispersion of corundum waste particles in the polymeric matrix. The combination of these types of matrix and filler gives birth to new polymeric particles composite creates a qualitatively brand new material. As most important characteristics of the polymeric particle composites, one often lists resistance to abrasive wear, hardness, impact resistance and strength and, last but not least, their cost. This article deals mostly with the two-body abrasive wear resistance and hardness of polymeric particle composites with the waste Al2O3 as filler and two-component epoxy matrix.

Using Recycled Rubber Particles as Filler of Polymers

One of a way of a material utilization of a rubber waste originated at a recyclation of tyres is its inclusion into polymeric materials. The paper describes chosen mechanical properties of an epoxy adhesive and polyurethane filled with the waste rubber. The waste rubber was gained as one of outputs of a recycling line of a firm Gumoeko, Ltd. The filler presence influences resultant mechanical properties and decreases a price of gained materials. Defining of mechanical properties enables to specify possible application areas.

Degradation Process in Area of Connecting Metal Sheets by Adhesive Bonding Technology in Agrocomplex

From the production essence point of view the necessity to create constructional bonds comes into being. In the sphere of connecting thin metal sheets it is suitable to apply the adhesive bonding technology. A significant branch is an agricultural production which is distinguished for many very degradable environments. The aim of experiment is to study and experimentally verify the degradation processes influence running in the adhesive bonds. The interval of the exposition of the adhesive bonds to the degradation environment was 0, 2, 4, 8, 16 and 32 weeks. Secondarily, the influence of various contaminants on a rise of the corrosion at the constructional carbon steel S235J0 was evaluated. Another aim is to determine by means of statistical methods ANOVA an influence agreement of single liquid contaminants types based on industrial and mineral fertilizers (Ammonium sulphate, NPK, DAM and Slurry).

Effect of active rubber powder on structural two-component epoxy resin and its mechanical properties

Abstract The aim of the research was to investigate a possibility to use active rubber powder (ARP) from a process of tyres recyclation in an area of a filler into a reactoplastics matrix applied in structural adhesive bonds. This study focuses on an analysis of a tensile strength, a shear impact strength and a hardness of the composite mixture itself and further on the interaction with an adhesive bonded material, i.e. it evaluates an influence of different ratio of ARP on the adhesive bond strength. Effects of the cyclic degradation environment combining the decreased temperature −40 °C and the increased temperature 90 °C at the simultaneous acting of the increased moisture up 90% is a part of the research. The tensile strength and the hardness were decreased by adding ARP. The experiment results proved a positive effect of ARP in the area of adhesive bonds exposed to the cyclic degradation at increased and decreased temperatures. Elastic ARP is able to absorb an inner tension in the layer of the adhesive bond.

Effect of Length of False Banana Fibre (Ensete ventricosum) on Mechanical Behaviour under Tensile Loading

Abstract The effect of gauge length of false banana fibre (Ensete ventricosum) on the tensile strength, volume energy, and modulus of elasticity under tensile loading was examined. Fibres of gauge length L0 (mm) 10, 20, 40, 80, 160, and 320 mm were prepared and tested until rupture point at strain rate of 0.05 min−1. Mathematical models describing the mechanical behaviour of the varying gauge lengths were presented. With the increasing gauge length of fibre, the tensile strength and volume energy decreased while the values of modulus of elasticity increased. The theoretical model describing the mechanical behaviour of Ensete fibre under tensile loading presented herein provides useful information for the fibres application in industry. The determined models could be used as a background for further research focused on Ensete fibre application.

Mechanical properties of composite material reinforced with textile waste from the process of tyres recycling

Müller M. (2016): Mechanical properties of composite material reinforced with textile waste from the process of tyres recycling. Res. Agr. Eng., 62: 99–105. The paper deals with the polymeric fibre composite with the reinforcement on the basis of the waste from the process of the tyres recycling. The aim of the research was the use of the material of cleaned textile waste from the process of the tyres recycling. The secondary waste raw material was used as filler in the composite. The subject of performed experiments was the polymeric composite, whose continuous phase was in a form of a two-component epoxy adhesive (GlueEpox Rapid) and a discontinuous phase in a form of microfibers from the process of tyres recycling. The experiments results proved that the composite materials based on the textile waste from the process of the tyres recycling reached an increase of an impact strength, a tensile lap-shear strength and an elongation of the adhesive bond (to 2.5% vol.). The textile microfiller has a negative influence on the tensile strength and elongation of adhesives.

Recycling of Polyamide from Scrap Tyres as Polymeric Composites

Muller M., Žarnovský J., Drlicka R. (2015): Recycling of polyamide from scrap tyres as polymeric compos ites. Res. Agr. Eng., 61 (Special Issue): S79–S83. Rubber granulate, metal waste and textile waste (polyamide fibres) come into the mechanical process of waste tyres recycling. The pollution and degradation processes are problematic in using of secondary raw material. The matrix was in the form of three various adhesives in testing – two-component epoxy adhesives and a polyester adhesive. The filler was in the form of textile waste (polyamide fibres) from the process of tyres recycling containing approximately 10–12% of rubber granulate. The filler was added in app. 15% of weight ratio into the matrix. The aim of the research was to determine a possible utilisation of unsorted textile waste from the process of tyres recycling in the area of poly meric composite systems.