Tired Research Articles

Thinking Green on 3D Printing: Sustainable Polymer Compositions of Post-Consumer Polypropylene and Tire Rubber Crumbs Intended for Industrial Applications

Year by year, more and more plastic is used worldwide. A large part of post-consumer waste is still stored in landfills instead of being reused. The solution to this problem may be recycled materials (recyclates) or biodegradable materials. The method of 3D printing, regarded as a clean processing technology, can significantly contribute to addressing global plastic pollution by utilizing post-consumer recycled polymers to create new components and parts. Therefore, this study focuses on the assessment of various properties and characteristics of 3D-printed compositions based on post-consumer polypropylene (PP) and rubber crumbs, recycled from packages foils and car tires, respectively. Moreover, within this study, we compared the mechanical performance of the injection molding material with the one obtained from 3D printing. A characterization was made considering the thermal and mechanical properties as well as the “print quality” through the microscopic and tomographic analysis of subsequent print passes, the number of free spaces, and imperfections in the polymer melt. Samples obtained using the FDM and injection methods exhibited comparable melting temperatures, while the samples obtained by injection molding exhibited slightly better mechanical performance, higher hardness, and impact strength.

How relationship shapes the market: an ethnographic study of French tire industry

Based on a two-year autoethnographic research in the car tire trade, this study of market exchanges examines how merchants’ relationships with customers enable and sustain exchange by shaping market arrangements. Referring to these relationships as an attachment process at work in the market, this study demonstrates the relational influence wielded by merchants through the ideational, practical, and emotional ties they cultivated with customers. These framed, patterned, and emotionally meaningful relationships show that market embeddedness is endogenously produced and exerts an impact upon customers, competition, demand, and supply. Complementing the conventional economic transactional view of market, our findings contribute to a relational perspective and understanding of market dynamics.

Soil: forensic interpretation some cases study

While investigating a crime scene related to murder, hit-and-run accidents, road accident analysis, vehicles collisions, rapes and burglaries, forensic soil examination is used for linking the suspect or an object to the crime scene. Comparison of soil provide information about location and place where from picked up by an automobile tire (location) with the soil sample taken from the crime site may help to prove that the suspect automobile may have been used in crime (place of happening). Similarly, soil or mud found adhering to clothing or shoes of a person may provide the clue that can link a suspect to a particular crime site. In the present study we reported the importance of soil and their interpretation as forensic evinces. The study has been reported with the help of cases study to provide exemplary explanation.

Early Childhood Education: Listening to A Child’s Voices Through A/R/Tographic Journey

This inquiry explores the impact of child-led perspectives in art education, using the methodologies of a/r/tography and autoethnography to explore the intersection of artistic practice, personal reflection, and educational theory. The research was inspired by a transformative experience with a 7-year-old child at a spring camp, whose imaginative storytelling of a “tire kingdom”, where car tires live secret lives, reversed traditional adult-child dynamics. The child’s insights redefined my roles as an artist-researcher-teacher/learner, placing him in the role of teacher and myself as the learner. This reversal opened up new pathways for reflection and creativity, as his imaginative exploration became a catalyst for my own artistic practice. I created a series of illustrations based on our stories, which evolved into a picture book that amplifies children’s voices, illustrating the importance of recognizing children’s contributions to educational discourse. Through a/r/tography, which integrates art-making, research, and teaching, alongside autoethnography’s focus on personal and cultural reflection, this inquiry underscores the value of interdisciplinary approaches in understanding the fluid relationships between adult and child, teacher and student. It also highlights the importance of listening to and incorporating children’s imaginative inquiries as a means of enriching educational and artistic practices. By engaging in this child’s world, I not only deepened my own creative and educational practice but also discovered the potential of child-led inquiry to reverse-shape adult learning, fostering reciprocal, inter-generational dialogue and new forms of creative collaboration.

Investigating Tire Ground Contact Mechanics Under Partial Hydroplaning Conditions: A Multivariate Analysis Approach

Tire hydroplaning is one of the main causes of traffic accidents on slippery roads. In order to study the ground contact mechanical characteristics of tires under partial hydroplaning conditions, 205/55the R16 passenger car tire was taken as the research object, a tire hydroplaning CEL simulation model was established, and the test plan was created using the orthogonal experimental design method. Through range analysis, partial correlation analysis and multivariate linear regression analysis, a tire side slip UA model suitable for different working conditions on slippery roads was established. Comparative analysis shows that the model can accurately predict the tire ground contact mechanical characteristics on slippery roads, and provide a theoretical reference for studying the tire multi-condition hydroplaning performance.

ISO test track influence on the EU tyre label noise value

In 2009, the European Union (EU) introduced a directive governing the labelling of tyres, which underwent revision in 2020. This labelling system encompasses three key parameters related to tyre performance: wet grip (safety), rolling resistance (energy consumption), and external rolling noise (environmental impact). These label values serve as crucial information for customers seeking to purchase replacement tyres for their vehicles.However, the accuracy and reliability of noise measurements have been a concern. Testing conducted across various ISO-standardized tracks has revealed significant inconsistencies in noise levels, with variations of 4–5 dB between tracks. Such discrepancies directly impact the labelling process, introducing uncertainty.This paper presents results of tyre noise measurements conducted on a limited number of ISO test tracks and proposes a methodology to mitigate track-to-track variability. The study exclusively focuses on passenger car tyres. By addressing these inconsistencies, this research aims to enhance the accuracy and reliability of tyre noise labelling, thereby facilitating informed consumer decision-making and promoting environmental sustainability.

Measurement of tyre-based microplastics using traditional and quantum cascade laser-based infrared spectrometry

BackgroundDespite the potential environmental impact of TWPs (tyre wear particles), there is a lack of reliable analytical methodologies suitable for their routineidentification and characterization. The number of papers dealing with this topic is, so far, very reduced and, therefore, there is a need for addressing it, mostly because traditional transmittance-based IR techniques are suboptimal due to scattering caused by black carbon in tyres. ResultsThis study aims to evaluate the most appropriate infrared (IR) spectrometric technique for monitoring TWPs. Macro attenuated total reflectance (ATR), reflectance microscopy, and quantum cascade laser-based micro transflectance (QCL-LDIR) were employed to analyse samples from used car and truck tyres in two sample configurations: small tyre fragments (∼1 cm2) and TWPs (< 1 mm). ATR yielded well-defined spectra with good signal-to-noise ratios, allowing for a straightforward interpretation of the major functional moieties. Despite reflectance measurements on tyre fragments provided good results, those on TWPs offered limited information due to noise and scattering. Transflectance offered clear peaks and enhanced resolution in the fingerprint region –compared to the other techniques-, much faster analysis times and the ability to effectively measure particles down to 20–10 µm, thus, emerging as the most effective technique for TWPs analysis. However, spectral interpretation is not immediate. Further, a proof-of-concept study was done to evaluate whether the analytical techniques contain information to differentiate types of tyres. An unsupervised pattern recognition and a supervised classification technique (principal components analysis and classification trees, CART) were used, which were able to differentiate among the tyres, notably the truck tyre from the cars tyres. SignificanceThe study presents first time the use of micro transflectance IR to study tyre particles down to 20 µm. Traditional total attenuated reflectance is demonstrated as a suitable way to analyse bigger microplastics. These two options open pathways to monitor this important emerging contaminant in environmental matrices

Energy harvesting by car-tire using piezoelectric polymer films blended with carbon-nanotubes

Energy harvesting through harnessing mobile cars is possible by combining mechanicals systems with advanced materials. Piezoelectric polymer blends with excellent mechanical properties facilitate energy harvesting using the car-tire as a source. Furthermore, by adding simplicity of preparation to the blends with multi-walled carbon nanotubes (MWCNT), an increase of energy conversion can lead to improved existing polyvinylidene fluoride/polymethylmethacrylate (PVDF/PMMA), films. This work focuses on investigating the best concentration of MWCNT to achieve car-tire energy harvesting as a sustainable and renewable energy option. The results show that 0.05 wt% of MWCNT is the best concentration among several values. A test set-up applying normal stress, simulating car-tire deformation indicated enhanced voltage generation. Compared to the energy consumption of combustion cars, the enriched films generate up to 4.3kWh. This energy is harvested over a car trip of 100 km. A higher nanotube concentration caused saturation of the blend film and poor output. The novel enriched polymer must be tested for resisting cyclic loads to encourage sustainable energy harvesting using car tires.

Effects of tire wear particle on growth, extracellular polymeric substance production and oxidation stress of algae Chlorella vulgaris: Performance and mechanism

Tire wear particles (TWP) represent a distinctive form of microplastics (MPs) that are widely distributed in aquatic ecosystems. However, the toxicity of various types of TWP on phytoplankton remain to be further explored. Thus, three different TWPs originating from replaced bicycle, car, and electro-mobile tire (marked as BTWP, CTWP, and ETWP) were selected and their long-term biological influences on Chlorella vulgaris were investigated. Results demonstrated TWPs showed a concentration-dependent growth promotion of Chlorella vulgaris, with a maximum promotion rate reached to 40.51 % (10 mg/L, 10 d), 23.5 % (80 mg/L, 12 d), and 28.7 % (20 mg/L, 12 d) in the presence of BTWP, CTWP and ETWP, respectively. Meanwhile, TWPs could stimulate the secretion of EPS and induce oxidative stress. EPS analysis revealed the increase of polysaccharides could protect the cell from the direct contact with TWP particles. Moreover, the increased concentration of EPS also helps to induce the settlement of TWP and reduce the leachate release. The release of TWP into the environment could act as an accelerator for the growth of Chlorella vulgaris, which might further change the normal physicochemical behaviors of algae colony in aquatic system. Our findings provide new insights into the toxicity mechanism of TWPs on freshwater algae and valuable data on environmental risk assessment of TWPs.

Stripping down sustainability assessments for easier comparison of innovative recycling options

In this short communication we propose a screening approach for assessing the sustainability of new recycling options. Before performing a full comparative LCA it is useful to perform a simplified LCA because of the lower data intensity. The impact categories are limited to greenhouse gas emissions and land use. As an example car tire recycling is shown. This screening approach is already useful for decision makers and can be used by stakeholders to compare innovative with the baseline technology.

P-Phenylenediamines and p-phenylenediamine quinone derivatives in rubber consumer products and typical urban dust: Sources, transformation profiles, and health risks

N,N′-Substituted p-phenylenediamines (PPDs) are widely used as antioxidants in the rubber industry and are released into the environment in large quantities during the production and use of rubber products. We quantified PPDs and PPD quinone derivatives (PPD-Qs) in rubber consumer products, including car tires, rubber belts, rubber gloves, rubber cables, and rubber hoses, to obtain information on the degree of weathering over time during their use. Additionally, we investigated the occurrences and sources of PPDs and PPD-Qs in dust samples collected from four typical urban environments (roads, parking lots, automotive repair shops, and residences). The detected compounds included the highly toxic N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine quinone, which can cause acute mortality of coho salmon (Oncorhynchus kisutch). Concentrations of PPDs in the automotive repair shops reached 56.0 μg/g, and were much higher than in the other environments, while the residential samples had the lowest contaminant concentrations. In road and residential samples, N,N′-di-2-naphthyl-p-phenylenediamine accounted for 17 %–30 % of the PPDs, and may have originated from different sources. We preliminarily identified 32 transformation products, and 11 of these were N,N′-di-2-naphthyl-p-phenylenediamine transformation products. The average daily intakes of PPDs and PPD-Qs were calculated to assess the health risks of dust exposure in each environment. Workers had high total intakes of PPD [60.3 ng/(kg day)] and PPD-Qs [20.1 ng/(kg day)], and were at some risk of occupational exposure. These results improve our understanding of the environmental occurrences, sources, transformation, and health risks of PPDs and PPD-Qs.

Fracture mechanism and ductility performances of fiber reinforced shotcrete under flexural loading insights from digital image correlation (DIC)

This paper investigates the fracture mechanism and ductility performance of fiber-reinforced shotcrete (FRS) under flexural loading through digital image correlation (DIC) analysis. The focus is on determining the optimal mix design, utilizing recycled and manufactured fibers in shotcrete through four-point bending tests. These tests reveal significant improvements in flexural strength and ductility, as well as crack resistance, attributed to the synergistic effect of both types of fiber in hybrid fiber reinforcement. Notably, the inclusion of recycled fibers from automobile tires enhances mechanical characteristics and impact resistance, contributing to environmental sustainability and cost reduction. DIC analysis offers crucial insights into crack initiation and propagation in shotcrete, highlighting the impact of fiber reinforcement on crack patterns. Manufactured fibers delay crack onset effectively, while hybridization enhances fracture characteristics, offering improved crack control and flexural strength. The study underscores the potential of hybrid fiber mixes for enhancing structural performance in tunnel support applications, emphasizing the synergistic effect of hybrid of different fiber types. Overall, the research contributes to advancing understanding of fracture behavior in fiber-reinforced shotcrete and provides practical insights for optimizing mix designs to achieve superior mechanical properties and durability.

Comparative study of grass pyrolysis over regenerated catalysts: Tyre ash, zeolite, and nickel-supported ash and zeolite

This paper presents investigations on catalytic and non-catalytic grass pyrolysis conducted at 500 °C using two reactor scales: a micro-scale reactor and a laboratory fixed-bed reactor. Four catalysts were employed in the catalytic pyrolysis process: car tyre ash, commercial zeolite mordenite-sodium, nickel supported on ash, and nickel supported on zeolite. The use of catalysts reduced the production of oxygenates and promoted the formation of gaseous compounds, with the most pronounced effect observed for nickel supported on zeolite. Catalytic pyrolysis produced chars with yields that were higher than those of the non-catalytic process. The coking behaviour of the spent catalysts was evaluated by analysing carbon content, with the highest content (3 wt% C) obtained for ash after the first cycle. In the second cycle, the deposited carbon content decreased for all catalysts. Furthermore, the employment of catalysts was shown to promote the production of hydrogen, methane, and other hydrocarbons in pyrolysis gas. The higher heating value of the pyrolysis gas was the highest at 21.1 MJ/m³ when the ash catalyst was first used for pyrolysis. Reusing the pyrolysis catalysts slightly reduced the heating value of the gas to 20.3 MJ/m³ over ash and 20.6 MJ/m³ over zeolite.

Comparing the effects of pristine and UV–VIS aged microplastics: Behavioural response of model terrestrial and freshwater crustaceans

Physico-chemical properties of microplastics (MPs) change during weathering in the environment. There is a lack of knowledge about the effects of such environmentally relevant MPs on organisms. We investigated: 1) the physico-chemical changes of MPs due to UV–VIS weathering, and 2) compared the effect of pristine and aged MPs on the behaviour of the water flea Daphnia magna and terrestrial crustacean Porcellio scaber. Dry powders of MPs were produced from widely used polymer types: disposable three-layer polypropylene (PP) medical masks (inner, middle and outer), polyester textile fibres, car tires and low-density polyethylene (LDPE) bags and were subjected to accelerated ultraviolet–visible (UV–VIS) ageing. Our results show that the extent of transformation depends on the type of polymer, with PP showing the most changes, followed by LDPE, textile fibres and tire particles. Obvious fragmentation was observed in PP and textile fibres. In the case of PP, but not polyester textile fibres, changes in FTIR spectra and surface properties were observed. Tire particles and LDPE did not change in size, but clear changes were observed in their FTIR spectra. Most MPs, aged and pristine, did not affect the swimming of daphnids. The only effect observed was a significant increase in path length and swimming speed for the pristine tire particles when the recording was done with particles remaining in the wells. After transfer to a clean medium, this effect was no longer present, suggesting a physical rather than chemical effect. Similarly, woodlice showed no significant avoidance response to the MPs tested, although there was a noticeable trend to avoid soils contaminated with pristine polyester textile fibers and preference towards the soils contaminated with aged MP of the middle mask layer. Overall, the apparent changes in physico-chemical properties of MPs after accelerated ageing were not reflected in their effects on woodlice and daphnids.

Air conversion of pyrolysis products of hydrocarbon raw materials into synthesis gas (H2+CO) for the production of electrical energy using solid oxide fuel cells

The article discusses the technology of combined production of electrical and thermal energy using preliminary air conversion of the pyrolysis liquid of automobile tires into synthesis gas, with its subsequent supply to the battery of an electrochemical generator. The electrical power of the installation is 100 kW, the network heater is 126 kW. The main energy characteristics of the installation were determined using the methods of physicochemical modeling and compilation of energy balances. It has been shown that the specific consumption of pyrolysis liquid for the production of electrical energy is 108 g/kW∙h (169 g r.f./(kW∙h)), and the heat consumption is 30 kg/GJ (196 kg r.f./Gcal). The specific consumption of natural and conventional fuels is compared with the specific fuel consumption at power plants operating on hydrocarbon natural fuels. They are slightly inferior to them, with the exception of the specific electricity generation from external heat consumption. Fuel utilization rate 46.4%. Recommendations are given for the use of pyrolysis liquid to generate electrical and thermal energy using a high-temperature fuel cell based on SOFC.

Comparative study on rolling resistance force in tire-ice interaction with a variation of tread rubber compound

Abstract The complex phenomenon involved in the tire-ice interaction can be better understood by studying the tire and ice properties. A significant force at the contact patch is the rolling resistance force. To study the effect of tire characteristics on rolling resistance forces, data collected from a free-rolling tire can be used as there is no tractive or braking torque applied to the wheel and thus the data representing the longitudinal forces is only related to resistive forces viz. friction and rolling resistance force. Although a lot of research and literature has been developed for tire-ice interaction over the years, there is a significant lack of work in the subsection of free-rolling tires specifically to study the effect of ice parameters on rolling resistance forces. To fulfill the aim of this study, several sets of experiments for 16 winter tires of 8 different rubber compounds in free-rolling conditions were conducted. The experimental data was compared with predictions of 4 well-known formulations from the literature. Based on the findings and the relative error between the predicted and measured values, it was proposed that the high error percentage could be due to the variation in the viscoelastic properties of the tread rubber. The longitudinal force generated during those tests would thus be a combination of frictional forces due to adhesion between the tread rubber and its viscoelastic nature in addition to the contribution from the remaining sections of the tire. The data collected from the experiments and results from implementing the existing models to obtain frictional force will further help in analyzing the relation between the rolling resistance force with variation in normal load, inflation pressure, and change in camber angle once a generic formulation considering the rubber compound effects is incorporated. Another significant finding of this work is that formulations in literature used for finding the rolling resistance coefficient of radial passenger car tires were found to highly underestimate the coefficient when compared to the equivalent coefficient of friction found from experimental results. The future scope may include the development of a model which will incorporate the viscoelastic properties, especially the loss moduli and loss tangent to evaluate the coefficient of friction and rolling resistance force in the free-rolling condition of a winter tire on ice as the rolling resistance losses are found to be highly correlated to these two properties.

Noncovalent Interactions Define Global Properties of HTPB Isomers.

Commercially available hydroxyl-terminated polybutadiene (HTPB) variants [containing various percentages of its isomers (cis, trans, and vinyl) and utilized in numerous applications ranging from rocket propellant binders to automobile tires] exhibit differences in their thermomechanical properties. Observed thermomechanical response variation between two isomers of HTPB (based upon simulation work at the molecular dynamic level) has been shown to be associated with noncovalent interaction between the isomers. Even though the study has been presented for a specific polymeric system, it could be of interest to the broader polymer chemistry community concerned with the reasons behind the property variation of different isomers of a specific molecule.

High-resolution mapping of urban Aedes aegypti immature abundance through breeding site detection based on satellite and street view imagery

Identification of Aedes aegypti breeding hotspots is essential for the implementation of targeted vector control strategies and thus the prevention of several mosquito-borne diseases worldwide. Training computer vision models on satellite and street view imagery in the municipality of Rio de Janeiro, we analyzed the correlation between the density of common breeding grounds and Aedes aegypti infestation measured by ovitraps on a monthly basis between 2019 and 2022. Our findings emphasized the significance (p ≤ 0.05) of micro-habitat proxies generated through object detection, allowing to explain high spatial variance in urban abundance of Aedes aegypti immatures. Water tanks, non-mounted car tires, plastic bags, potted plants, and storm drains positively correlated with Aedes aegypti egg and larva counts considering a 1000 m mosquito flight range buffer around 2700 ovitrap locations, while dumpsters, small trash bins, and large trash bins exhibited a negative association. This complementary application of satellite and street view imagery opens the pathway for high-resolution interpolation of entomological surveillance data and has the potential to optimize vector control strategies. Consequently it supports the mitigation of emerging infectious diseases transmitted by Aedes aegypti, such as dengue, chikungunya, and Zika, which cause thousands of deaths each year.

Materials and Products Development Based on a Novelty Approach to Quality and Life Cycle Assessment (QLCA).

The development of materials and the products made from them should respond to new challenges posed by market changes and also by climate change. Therefore, the objective of this investigation was to develop a method that supports the sustainable development of materials and the products made from them based on an aggregated indicator of quality and environmental load in the life cycle (QLCA). The testing and illustration of the QLCA method included a passenger car tyre and nine prototypes. These prototypes were described using eight quality criteria: season, class, size of the load index, speed index, rolling, adhesion, and external noise. Then, customer expectations regarding the importance of the criteria and satisfaction with the indicators in the current and modified states were obtained. Based on the customer assessment, the quality indicators of the prototypes were assessed. This assessment was supported by the weighted sum model (WSM) and the entropy method. Then, life cycle assessment for the reference tyre was performed using the Ecoinvent database in the OpenLCA program. LCA indicators were modelled for other prototypes, taking into account quality changes. As a result of the verification of the method, an aggregated QLCA indicator was estimated, based on which it was possible to select the most favourable (qualitatively and environmentally) prototype out of nine. This was the P4 prototype (QLCA = 0.57). The next position in the ranking was taken by P7 (QLCA = 0.43). The QLCA method can be used to determine the direction of development of materials and products in terms of their sustainable development.

Influence of Carbonated Pyrolysis Oil Recycled from Scrap Tires on Metallurgical Efficiency of Coal Flotation

This research assesses the effect of carbonated pyrolysis oil (CPO) derived from scrap car tires on the metallurgical efficiency of coal flotation as a flotation additive. Using a statistical experimental design, the influence of various operational variables, including solid percent of feed pulp and dosages of reagents, i.e., CPO as an additive, diesel oil as a collector, and pine oil as a frother, on the ash content and yield of the final concentrate were investigated. Experimental data vary significantly based on operational conditions, ranging from 6.6% ash content with a 15% yield to 19.1% ash content with a 76.8% yield. The composition of the pyrolysis oil was identified by using Fourier transform infrared spectroscopy (FTIR). The analysis of variance (ANOVA) of experimental results demonstrated that almost all variables had a substantial effect on the flotation responses, positive or negative, depending on the variable or variable interaction. It was discovered that the usage of CPO intensified the total yield and ash content of concentrate in a nonlinear fashion in a range of 15% and 4%, respectively. The results revealed a non-selective interaction effect between CPO and pine oil, as well as competitive adsorption between diesel oil and CPO, which contributed to the curved behavior of flotation measurements. The detrimental effect of CPO on the flotation response of the studied coal sample was also related to the interaction of the hydrophilic groups in the CPO structure and the oxide groups of ash material in coal particles. This work shows the potential of carbonated pyrolysis oil to enhance coal flotation performance and sheds light on the underlying mechanisms.