Waste tires (granulate) and selected plastics from the automotive industry were evaluated by using the tertiary (pyrolysis) and quaternary (calorimetry) recovering. Pyrolysis is proving to be an environmentally friendly alternative to incineration and inefficient landfilling. Currently, the main challenges for pyrolysis of plastic waste are unavailability and inconsistent quality of feedstock, inefficient and hence costly sorting, and last but not least insufficient regulations around plastic waste management. Waste plastics and tire materials were characterized by TG/DTG analysis, Py-GC/MS analysis and calorimetry. TG analysis of the investigated materials gives the typical decomposition curves of synthetic polymers. The tested samples had the highest rate of weight loss process in the temperature range from 375 °C to 480 °C. Analytical pyrolysis of the tested polymers provided information on a wide variety of organic compounds that were released upon thermal loading of these materials without access to oxygen. Analytical pyrolysis offers valuable information on the spectrum of degradation products and their potential uses. Based on the results of calorimetry, it can be stated that the determined calorific value of selected plastic and rubber materials was ranging from 26.261 to 45.245 MJ/kg depending on the ash content and its composition.

Particleboards containing waste rubber (tires and mixtures of isolators and carpets) filler were evaluated from the point of view of its flammability. The assessment of the utilization of these composites in the construction industry was analyzed through the determination of their spontaneous ignition temperatures, mass burning rate and calorific value. Based on the results of spontaneous ignition temperatures, similar values between particleboards and particleboards containing 10%, 15% and 20% of waste tires were obtained. The average time was from 298 s to 309 s and the average temperature was from 428.1 °C to 431.7 °C. For the mass burning rate, there were similar results between particleboards and particleboards containing 10% of waste tires and waste rubber. The time to initiation was 34 s and the time to reaching a maximal burning rate was from 66 s to 68 s. The calorimetry results showed similar properties for the calorimetric value and ash content in particleboards and particleboards containing 10% of waste tires and waste rubber. The calorific value was from 18.4 MJ·kg⁻¹ to 19.7 MJ·kg⁻¹ and the ash content from 0.5% to 2.9%.

Open Access Agricultural Journals published by Institute of Agricultural Economics and Information

The article deals with the influence of irregular tooth pitch on energy consumption of cross-cutting wood. In this article, the effect was assessed of feeding velocity and parameters of saw blade on the cutting power Pc of spruce (Picea Abies), pine (Pinus Sylvestris) and beech (Fagus Silvatica) wood during sawing with a guided circular saw. For the research, two types of circular saw blades were used, one of them having irregular tooth pitch. The circular saw blades had sintered carbide inserts with a diameter of D = 350 mm and the same number of teeth. The feed velocities were vf = 4, 8,12 m∙min-1 and revolutions n = 3000 min-1. The results showed that the circular saw blades with irregular tooth pitch have higher energy consumption than the circular saw blades with regular tooth pitch. The highest cutting power Pc was shown in the case of beech. It was also shown that energy consumption is increasing linearly with increasing feed velocity.