ASSESSMENT OF RUBBER BLENDS USING MULTI-CRITERIA ANALYSIS

Abstract

The intensive technology development, as well as the increase in the number of inhabitants, results in a significant consumption of natural and energy resources, as well as the daily generation of increasing amounts of waste. Because of that the significant efforts are being made in finding new ways of materials recovery from waste, as well as the application of secondary raw materials in the production of products and for alternative purposes. The rubber blend consists of different components: elastomers (rubber - natural or synthetic); fillers; vulcanization activators; accelerators of vulcanization; antioxidants, etc. Most of these components are obtained from non-renewable resources. Given that rubber is a material from which a large number of products (primarily tires) are produced, replacing some of the components with recycled materials would contribute to the preservation of natural resources, as well as the environmental protection. A large number of researches are carried out with the aim of using secondary raw materials (recycled rubber, polyurethane waste powder, waste powdered glass, waste laser toners etc.) is as a filler in rubber blends. These materials can be used as substitutes for certain components of rubber blends due to their similar chemical composition. The reason why these materials were taken into consideration lies in their availability, as well as their impact on the environment. The aim of this work is to evaluate different rubber blends filled with recycled materials using multicriteria analysis, i.e., the Analytic Hierarchy Process (AHP) method. Four different types of rubber blends were taken in to consideration: virgin rubber filled with 20% of recycled rubber powder, virgin rubber filled with 20% of polyurethane waste powder from electrical and electronic waste equipment, virgin rubber filled with 20% of waste powdered glass with an average particle size smaller than 63 μm, and virgin rubber filled with 20% of waste laser toner. Criteria used for rubber blends assessment are: availability of raw materials, mechanical properties of rubber blends, environmental impact of raw materials, and raw materials price. The used procedure of the AHP method implies the formation of a hierarchical structure, pair-wise comparison, determination of weighting factors, and alternatives ranking. The obtained results show that rubber blend filled with 20% of recycled rubber is best ranked with ranking priority of 52.7%, because of the best mechanical properties of rubber blend. In order to examine the impact of the criteria weighting, a sensitivity analysis was performed, which confirmed the obtained results that in every case the Rubber blend 1 is the best ranked.