International Scientific Conference PRO-TECH-MA ’16PROGRESSIVE TECHNOLOGIES AND MATERIALS

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WHEAT BRAN-FILLED POLYETHYLENE: EXAMINATION OF SELECTED MECHANICAL AND PROCESSING PROPERTIES

Łukasz MAJEWSKI1

In the literature relating to the processing and applications of polymeric materials

can be distinguished the underscoring trend, which involves the use of natural resources as a component of polymer mixtures used in various industries. The type of filler is usu -ally dictated by the geographical location and the widespread occurrence of certain plant species in a given geographical area. In addition, preparation of the filler is often related directly to the production of food or clothes, but also other goods. The processing at in -dustrial scale different types of grains, vegetables, fruits, spices, wood or fiber plants re-sults in large quantities of natural waste in the form of shells, husks, kernels, bran, natural fibers, wood dust, bark dust etc. For example, the major producers of rice in the world are India and China, it is not surprising that the scientific work in which the rice bran and rice husks are used as a filler of polymer composites, come from that region. Works using banana powder as a filler most commonly arise in research centers located in South America and Malaysia, while corn flour and shells are used mostly in North America. Ex-amples abound, because every geographic region of the world has specific types of culti -vations. The use of each type of filler has a specific purpose. Frequently natural fillers are added in order to reduce production costs (bran, grain flour), improvement of biodegrad -ability (bran, natural fibers), increase of hardness (minced nut shells) or to give resistance to odors (vanilla, citrus straw). In Poland, one of the most popular cultivation is wheat. It is used primarily for the production of white wheat flour. After the milling process re -mains a lot of waste in the form of crushed grain husks (bran). Following paper is the re -sult of an attempt to use this waste as a component of the polymer mixture.

This paper reports the results of research on the selected mechanical and process -ing properties of low-density polyethylene filled with fine wheat bran (WB). The LDPE/WB compounds were prepared by twin-screw direct extrusion process, with a dif-ferent particle sizes and the filler content ranging between 0wt% and 10wt%. Ready-made pellets were injection molded and the resulting molded pieces were subjected to tests in order to determine density, melt flow index, abrasiveness, Young modulus, ten-sile strength, hardness, water absorption, etc.

1 l.majewski@pollub.plLublin University of Technology, Poland

International Scientific Conference PRO-TECH-MA ’16PROGRESSIVE TECHNOLOGIES AND MATERIALS

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Fig. 1. Appearance of the polymer powder (a) and the separated fractions of bran (b – 0,8-0,6mm; c – 0,6-0,4mm; d – <0,4mm)

Bran were minced and separated by a sieve. Obtained three fractions of different

particle size (0,8-0,6mm, 0,6-0,4mm; <0.4 mm). The individual fractions were mixed mechanically with the powdered material. The examined composites were prepared in co-rotation twin-screw extrusion process. Extruded strands were pelletized after being cooled in water. Composite pellets were injection molded to produce samples for further research.