Tag Archives: mechanical properties

xxx L. Chladek, V. Plachy, P. Vaculik and P. Brany
Evaluation of nutritional and physical values of pellets based on pea and lupine with added yeast in chickens fattening
Abstract |
Full text PDF (699 kB)

Evaluation of nutritional and physical values of pellets based on pea and lupine with added yeast in chickens fattening

L. Chladek¹*, V. Plachy², P. Vaculik¹ and P. Brany¹

¹Czech University of Life Sciences Prague (CULS), Faculty of Engineering, Kamýcká 129, CZ165 21 Prague - Suchdol, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Kamýcká 129, CZ165 21 Prague - Suchdol, Czech Republic
*Correspondence: chladekl@tf.czu.cz

Abstract:

The article is focused on the development of the new type of broiler chicken feed, based on pea (Pisum sativum L.) and blue lupine (Lupinus angustifolius L), enriched with used dried brewer´s yeast. This composition eliminates use of soybean meal (PES) that was yet a traditional component in chicken feed. The main reason for its elimination was the using of genetically modified varieties of soybean and its relatively high price around 0.5 €uro kg-1 in Czech Republic. For milling of pea or blue lupine was used vertical (hammer) mill type Taurus, supplied by company TAURUS, for drying of used brewer´s yeast had been used drier Memmert UFE 800, final dry matter of the yeast was 88%. For pellets production were used two devices, press type JGE 120-6110 and Testmer. For the determination of physical properties of manufactured pellets (the weight of 1,000 pieces, bulk density, abrasiveness and pellet durability index PDI) were used following laboratory devices, Pellet Tester Holmen NHP and Testmer 200. Experimental activities had shown that the best results were reached using pellets manufactured on base blue lupine enriched by dried brewer´s yeast (6%).

Key words:

, , , , , , , , , , ,




1116–1122 P. Valášek
Study on impact strength of sisal fibers reinforced epoxy composites using experimental methods
Abstract |
Full text PDF (460 kB)

Study on impact strength of sisal fibers reinforced epoxy composites using experimental methods

P. Valášek

Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Kamýcká 129, CZ 165 21 Prague; e-mail: valasekp@tf.czu.cz

Abstract:

 Among the advantages of composite materials is their ability to exploit the properties of partial phases that creates the composite. Common materials used as matrix materials include polymeric composites. The properties of these matrices can be optimized by using synthetic or also natural fibers. Natural fibers are inexpensive, ranks among renewable resources and when respecting their biological nature, they can replace synthetic fibers in many applications. This paper describes the impact strength of epoxy resins filled with unordered short sisal fibers with a length of 2–6 mm. From the experimental results it is evident that the presence of fibers of sisal examined as epoxy resins, increases the impact strength, up to 143%. SEM (scanning electron microscopy) was used to assess the failure of mechanism of these composites.

Key words:

, , ,




639-653 H. Kallakas, M.A. Shamim, T. Olutubo, T. Poltimäe, T.M. Süld, A. Krumme and J. Kers
Effect of chemical modification of wood flour on the mechanical properties of wood-plastic composites
Abstract |

Effect of chemical modification of wood flour on the mechanical properties of wood-plastic composites

H. Kallakas*, M.A. Shamim, T. Olutubo, T. Poltimäe, T.M. Süld, A. Krumme and J. Kers

Department of Polymer Materials, Tallinn University of Technology, Ehitajate tee 5, EE19086 Tallinn, Estonia;
*Correspondence: heikko.kallakas@ttu.ee

Abstract:

The poor compatibility between the highly hydrophilic wood fibres and the hydrophobic polymers is associated with a loss of mechanical properties. Therefore, to improve the interfacial adhesion between the polymer matrix and wood flour (WF), a chemical modification of WF is an appropriate solution. This study analyzes the influence of different chemical modifications of WF on the mechanical properties of wood-plastic composites (WPCs). WPC test samples were prepared from birch (Betula) WF with a mesh size of 0.⁶³ mm as the filler material and polypropylene (PP) as the matrix material. WF was chemically modified by six different methods to increase its adhesion to, and compatibility with, the polymer matrix. The six chemical methods used were: alkaline (NaOH) modification, polyvinyl alcohol (PVA) modification, silane treatment with ³-aminopropyltriethoxysilane (APTES), acetylation with acetic anhydride, cyanoethylation, and wood fibre esterification. The composites were produced using a twin-screw extruder and the test samples were prepared by injection moulding. The composites’ mechanical properties (three-point bending test), Charpy impact strength and thermal properties were tested. In addition, SEM micrographs of WPC surfaces were generated. WF as a filler material enhanced the flexural properties, while impact strength decreased, making the material more rigid and brittle. The test results revealed that the chemical modifications of WF improved the mechanical properties and crystallinity of WPC materials, while the melting temperature decreased. However, the influence of the chemical modification on the mechanical and thermal properties of WPC varied by method.

Key words:

, , , ,




291-298 P. Valášek and M. Müller
EPDM rubber material utilization in epoxy composite systems
Abstract |
Full text PDF (429 kB)

EPDM rubber material utilization in epoxy composite systems

P. Valášek* and M. Müller

¹Department of Material Science and Manufacturing Technology, Faculty of Engineering, Czech University of Life Sciences Prague, Kamýcká 129, Prague; *Correspondence: valasekp@tf.czu.cz

Abstract:

Observing of possibilities for secondary raw materials utilization should rank among the key interests of the society. Nowadays, there are a lot of modern workplaces which are devoted to the possibilities of collecting, processing and using rubber materials. EPDM waste rubber in the form of particles is one of the many products of these workplaces. One of the possibilities for recycling this waste particles material is their interaction with another polymeric material. A reactoplastic which is filled with these particles comes into consideration. This way of utilization of the material is inexpensive and simple. The paper focuses on chosen mechanical qualities of the Epoxy/EPDM waste rubber composite. The waste rubber was gained as one of the outputs of a recycling line of the firm Gumoeko, Ltd., the reactoplastic was represented by a two-component epoxy resin. Distraction of rubber particles in the epoxy matrix was achieved by mechanical mixing without using the technology of vacuum. In the paper, the porosity, tensile strength and shear strength of the composites with various concentrations of EPDM are described. The resulting composite systems may find their application in the field of agriculture – especially during joining and sealing materials of larger units where high quality connections are not required.

Key words:

, , ,