Rubber Manufacturing Research Articles

THE RELATIONSHIP BETWEEN SUSTAINABLE MANUFACTURING OPERATIONS AND ENVIRONMENTAL PERFORMANCE OF PLASTICS AND RUBBER MANUFACTURERS IN KENYA: THE MODERATING EFFECT OF ECO-INNOVATIONS

Objective: This study aimed to expose the effect of sustainable manufacturing operations on performance of plastics and rubber manufacturing firms in Kenya. Theoretical Framework: The main concepts and theories that support the research were conveyed. The study employed the natural resource-based view and ecological modernisation theory. Method: The study employed descriptive research survey that targeted all the 90 plastics and rubber manufacturing firms registered by the Kenya Association of manufacturers. A structured questionnaire as well as a data collection form were useful in collecting data. For data analysis descriptive and inferential statistics were used with the precise inclusion of partial least squares structural equation modeling method. Results and Discussion: There was a statistically significant influence of eco-innovations on the effect of sustainable manufacturing operations on environmental performance. However, the individual eco-innovations indicators namely eco-product innovations, eco-process innovations, green system innovations and material flow innovations yielded varied results. Research Implications: The findings confirm previous studies that indeed there are positive gains made from the moderating role of eco-innovations in the correlation between sustainable manufacturing operations and performance of the environment. Originality/Value: These results are expected to benefit stakeholders such as policy makers in government, plastic and rubber manufacturers and academia in augmenting the existing knowledge.

Study on high-temperature emission behaviors of crumb rubber modified asphalt: Experimental analysis and molecular simulation approach

The harmful emissions produced during the manufacturing and construction processes of crumb rubber modified asphalt (CRMA) significantly hinder its widespread application. Addressing this issue hinges on a thorough investigation into the mechanism governing its high-temperature emissions. This study employed microscale testing methods to analyze the microstructure and chemical property disparities between CRMA and base asphalt (BA). Subsequently, the impacts of varying crumb rubber (CR) content, experimental temperature, and sulfur stabilizer dosage on the high-temperature emissions of CRMA were investigated. Furthermore, comparative analyses of the molecular weight distribution, emission species, and CR crosslink density in asphalt after the fume experiment were conducted to further elucidate the high-temperature emission mechanisms. Finally, molecular simulation techniques were employed to analyze the interactions between CR and the four fraction molecules of asphalt at the microscale. The results indicated that the fume release volume of CRMA initially decreased and then increased with the addition of CR, while both the experimental temperature and sulfur stabilizer content exhibited a positive correlation with emission volume. CR reduced the volatilization of some small molecular hydrocarbons in the BA by absorbing light fractions. Meanwhile, excessive swelling caused the crosslinking density of CR to decrease by 77 %, which led to the release of toxic substances. At 20% CR content, the overall emissions of CRMA achieve their lowest level; however, the emission of toxic gases does not diminish. Molecular simulations have also confirmed the above results, showing that there is a strong interaction between CR and the light fractions. Compared with asphaltene molecules, rubber molecules had higher molecular polarity and stronger adsorption behavior for light fraction molecules.

Spatiotemporal Prediction of Greenhouse Gas Emissions from Rubber Wood Furniture Industry, Taking Hainan as the Case

The rubber wood furniture industry chain, including planting and manufacturing subsystems, emits significant greenhouse gases (GHGs), meanwhile, has huge carbon emission reduction potential. However, quite few studies have taken the whole industry chain GHGs into consideration, especially assessing and modelling those from rubber tree planting to furniture manufacturing. We took the rubber wood furniture of Hainan province as the case, explored its whole life cycle GHGs from cradle-to-gate and predicted the potential GHGs from 2031 to 2062. This study is fully based on field survey and sampling data, including that of the rubber tree planting (40-year cycle) and furniture manufacturing. The results reveal: (1) Whole industry chain of rubber wood furniture emits 3.27×106 kgCO2-eq GHGs per 20,000t rubber logs consuming, where the planting accounts the most (88.20%). Transport and electricity consumption are the main GHGs sources of planting and manufacturing subsystems respectively; (2) The whole life-cycle GHGs of rubber wood furniture in 2023 of Hainan is 2.07×107 kgCO2-eq, which mainly come from Danzhou (24.74%), Haikou (19.55%), and Qiongzhong (15.79%); (3) The total GHGs from the rubber wood furniture industry in Hainan from 2031 to 2062 are 210 MtCO2-eq and 129 MtCO2-eq respectively, without or with felling restriction. The changes of GHGs from 2051 to 2062 are caused by the regional center shift of planting gravity; (4) Improving energy use efficiency and optimizing the location of furniture factories would reduce GHGs. This study can provide empirical support for the low carbon sustainable transformation of the rubber wood furniture industry worldwide.

Optimization of the annulus space structure for hydrocyclone separation of rubber particles based on NSGA-II and GMDH

Rubber particles produced during industrial rubber manufacturing pose significant health and environmental risks. Due to their small size, these particles are difficult to efficiently separate and recover. Previous studies have shown that increasing the annular gap can reduce the circulation of small particles within the hydrocyclone. However, the optimal design of the annular gap structure has not been thoroughly investigated. This paper focuses on the structural optimization of the annular space, dividing it into three parts: annular width (w), insertion depth (L), and diameter (Dh). Single-factor analysis reveals that an increase in annular width lowers the internal pressure field; an increase in annular insertion depth causes vortex movement downward, reducing the separation zone; and an increase in annular diameter generates vortices within the annular gap. Multi-factor analysis using GMDH and NSGA-II shows that the GMDH model has excellent predictive capability, with R2 values of 94.23 % for separation efficiency and 92.77 % for pressure drop. The optimal structure obtained from NSGA-II is the C-type hydrocyclone (Dh: 7.45, L: 7.2, w: 3.96), with separation efficiency and pressure drop of 85.72 % and 0.1649 MPa, respectively. The optimized hydrocyclone shows improvements of 4.46 % in separation efficiency and 8.89 % in pressure drop compared to the non-optimized performance. This study applies genetic algorithms to the structural optimization of the annular gap, providing theoretical insights into the design of hydrocyclone annular gap structures.

Occurrence of tyre-derived particles in size-segregated aerosol in the urban area of Venice

Benzothiazoles (BTHs), commonly used in various industrial applications, have emerged as significant contaminants due to their widespread usage and potential adverse effects on ecosystems and human health. The aim of this study is to quantify and, for the first time, to characterize the particle size distribution of eight BTHs across twelve fractions of atmospheric aerosol representative of the urban boundary layer. Samples were collected from August to October 2023 in the urban area of Venice, located in the Po Valley, known for its poor air quality. Instrumental analysis was achieved via an UHPLC system coupled with a triple quadrupole mass spectrometer.All target compounds were present in the samples analyzed and most of them tended to distribute mainly in the fine fraction of aerosol (<1.8 μm). An exception is given by BTH-SO3H, which presents a bimodal distribution with maxima centered in the coarse fraction; this may imply a different source compared to other BTHs. BTH-SH is the most abundant benzothiazole derivative, suggesting tyre debris as the main source since it is the main compound used in vulcanizing accelerators in rubber manufacture. Given its mutagenic properties, its high relative abundance could be of concern for human health. Resultsof this work provide valuable insights into the distribution of BTHs in urban aerosols, laying the groundwork for future research aimed at better understanding their sources and environmental pathways, fate and impacts.

Utilization of spent bleaching earth as green filler and plasticizer in the manufacture of rubber compounds for solid tire production

This study utilized spent bleaching earth (SBE) as a single form of filler and plasticizer in the manufacture of rubber components for solid tire vulcanizate. SBE, an underutilized byproduct of vegetable oil purification, is abundantly available globally and can be used as a filler and plasticizer in rubber compounds. This aligns with environmental sustainability principles, reduces disposal costs, and lowers raw material expenses in rubber manufacturing. In this research, the SBE was applied for each formula from SBE-02 to SBE-05 at ratios of 15–30 per hundred rubber (phr). As a comparison, carbon black (CB) filler (65 phr), CaCO3 (35 phr), and plasticizer derived from petroleum in the form of paraffinic oil (PO) (6 phr) were used. Rubber components were produced by masticating natural and synthetic rubber in an open mill, followed by the addition of filler, plasticizer, accelerator, co-activator, anti-degradant, and vulcanization agent. The resulting compounds were vulcanized at 150 °C and 10 MPa for 17 minutes. The test results demonstrated that incorporating SBE at a ratio of 15 phr (SBE-02) significantly reduced the cure time (t90) to 8 minutes and 20 seconds, the shortest among all tested formulations. The mechanical properties of the SBE-02 vulcanizate rubber met the requirements for solid wheelchair tire applications, with a hardness of 70 Shore A. However, its abrasion resistance test result of 189.1 g/cm³ was the lowest among the formulations tested. Furthermore, the scorch time (ts2) of the SBE-02 was determined to be 2 minutes and 35 seconds. Results from a 1000x magnification scanning electron microscope (SEM) reveal air gaps on all sample surfaces of different sizes. The elements C, O, Zn, Si, Ca, and Pb dominate the SEM-EDX results for all rubber vulcanizate samples from all three spectra, in varying weight percentages. The identification of functional groups with FTIR on all rubber vulcanizate samples shows Si–O–Si bending at 2, 4, and 5 and Si–O–Al stretching at 3, 5 on the wave number spectrum of 680–413 cm−1 Si–O–Si on the wave number spectrum 1100–1050 cm−1 from the infrared spectrum.

Contrastive loss with dynamic margin for rubber-recipe physical-property prediction

Predicting the physical properties of rubber presents difficulties because of the intricate and nonlinear relationships between its constituent elements. The laborious nature of rubber manufacture results in restricted data sets, hence exacerbating this difficulty. To achieve successful training of a neural network with a smaller amount of data, it is crucial to use an appropriate weight initialization approach and carefully construct the network architecture to avoid overfitting. This study presents a novel approach to representation learning that uses a contrastive loss with dynamic margin loss function. The approach is specifically designed to capture semantic similarities in rubber material quantities and physical-property recipes. In addition, a novel neural network architecture is proposed that uses latent vectors for assigning initial weights. The proposed approach, validated using data from a rubber manufacturing company, showed a significant improvement of up to 30% in predictive accuracy for physical properties with a restricted amount of data.

REVIEW OF RUBBER RECYCLING PRACTICAL STUDIES AND TECHNOLOGICAL DEVELOPMENTS IN USING ASPHALTCONCRETE PAVEMENTS

This review paper examines the global situation of modifying asphalt binder using crumb rubber, offering a thorough summary of the progress achieved in this area till now. Utilizing a broad range of international experiences, the study explores the various procedures, strategies, and formulations used by researchers and practitioners throughout the globe. The examination covers significant advancements in the manufacture of crumb rubber, the modification procedures of binders, and the subsequent improvements in the performance of asphalt. The article analyzes case studies and research results from different nations, highlighting the intricate strategies used to enhance the integration of crumb rubber into asphalt binders. Moreover, the study examines the economic, environmental, and performance-related consequences linked to these alterations, emphasizing the sustainable and cost-efficient elements that have gained growing recognition within the global asphalt community. This paper seeks to provide significant insights into the current practices, problems, and possible future prospects in the field of modifying asphalt binder using crumb rubber by synthesizing and comparing data from various locations. This resource is very beneficial for academics, engineers, and politicians who want to use worldwide experiences to improve sustainable and resilient asphalt infrastructure.

Support medium development for 3D printing natural rubber latex via direct ink writing in the support bath technique

The direct manufacturing of rubber products from natural rubber latex through 3D printing, particularly extrusion in air, faces challenges in creating intricate shapes. Research suggests that utilizing 3D printing with extrusion in a support medium, known as direct ink writing (DIW), is effective for crafting complex-shaped rubber products. However, few studies have explored 3D printing natural rubber as a support medium. This study focuses on formulating a support medium for the DIW printing of natural rubber by incorporating triethanolamine (TEA) and alcohol in varying proportions. Key characteristics, such as viscosity, were assessed for each formulation, along with essential printing parameters, such as speed and flow rate. A suitable support liquid consisting of TEA (2.5 g), alcohol (160 g), Carbopol (1.5 g), and water (200 g) was determined for DIW printing natural rubber. The optimal settings were determined to be a nozzle size of 0.85 mm, a speed of 30 mm/s, and a flow rate of 30 mm3/s. Comparative results from the forming process indicate that 3D-printed rubber specimens exhibit poorer mechanical properties than traditionally molded specimens, owing to material uniformity. The vulcanized rubber system with the EV pattern exhibited superior mechanical characteristics. The developed support medium for DIW printing shows potential for use in intricate natural rubber products; however, further exploration of additional parameters is crucial for advancing complex-shaped natural rubber manufacturing using 3D printers.

Impact of sulfur compounds on motorbike wheel damper rubber manufacturing materials with 3 Phr, 4 Phr, and 6 Phr compositions

Rubber force is a simple but important thing for vehicles. This component is located in the rear wheel drum which is directly connected to the gear. Many factors influence the damage to this component. This research aims to determine how much influence stearic acid has on the hardness and tensile strength values of the lifting rubber compound. The materials used to make the compound are rubber smoked sheet (RSS) and synthetic rubber mixed with the chemicals stearic acid, black carbon white oil, ZnO, paraffin wax, MBTS, comaron resin and sulfur. These ingredients are mixed using two roll mixing until they combine and form a compound sheet. To determine the maturation time of rubber, a rheometer process is carried out. The next process is vulcanization of rubber using a mold that is pressed at a temperature of 1600C and a pressure of 150 psi. Tensile testing uses rubber testing equipment with SNI ISO 37: 2015 (IDT–2011) standards. Hardness testing uses a tool with a Shore A hardness tester scale with ISO 7619–1:2010 standards. Based on the results of the tests carried out, the addition of sulfur has a very significant effect on the hardness value and tensile strength value. For the hardness value of compound 3 with a sulfur composition of 6 phr, it has the highest hardness, namely 77 Shore A and the lowest value is composition 1 with a hardness value of 65.6 Shore A. The highest tensile strength value is 15,394 N/mm2 in composition 1 and the lowest value is in composition 3 with a value of 11.44 N/mm2

Well-Defined Supported ZnOx Species: Synthesis, Structure, and Catalytic Performance in Nonoxidative Dehydrogenation of C3-C4 Alkanes.

ConspectusZinc oxide (ZnO) is a multipurpose material and finds its applications in various fields such as rubber manufacturing, medicine, food additives, electronics, etc. It has also been intensively studied in photocatalysis due to its wide band gap and environmental compatibility. Recently, heterogeneous catalysts with supported ZnOx species have attracted more and more attention for the dehydrogenation of propane (PDH) and isobutane (iBDH) present in shale/natural gas. The olefins formed in these reactions are key building blocks of the chemical industry. These reactions are also of academic importance for understanding the fundamentals of the selective activation of C-H bonds. Differently structured ZnOx species supported on zeolites, SiO2, and Al2O3 have been reported to be active for nonoxidative dehydrogenation reactions. However, the structure-activity-selectivity relationships for these catalysts remain elusive. The main difficulty stems from the preparation of catalysts containing only one kind of well-defined ZnOx species.In this Account, we describe the studies on PDH and iBDH over differently structured ZnOx species and highlight our approaches to develop catalysts with controllable ZnOx speciation relevant to their performance. Several methods, including (i) the in situ reaction of gas-phase metallic Zn atoms with OH groups on the surface of supports, (ii) one-pot hydrothermal synthesis, and (iii) impregnation/anchoring methods, have been developed/used for the tailored preparation of supported ZnOx species. The first method allows precise control of the molecular structure of ZnOx through the nature of the defective OH groups on the supports. Using this method, a series of ZnOx species ranging from isolated, binuclear to nanosized ZnOx have been successfully generated on different SiO2-based or ZrO2-based supports as demonstrated by complementary ex/in situ characterization techniques. Based on kinetic studies and detailed characterization results, the intrinsic activity (Zn-related turnover frequency) of ZnOx was found to depend on its speciation. It increases with an increasing number of Zn atoms in a ZnmOn cluster from 1 to a few atoms (less than 10) and then decreases strongly for ZnOx nanoparticles. The latter promote the formation of undesired C1-C2 hydrocarbons and coke, resulting in lower propene selectivity in comparison with the catalysts containing only ZnOx species ranging from isolated to subnanometer ZnmOn clusters. In addition, the strategy for improving the thermal stability of ZnOx species and the consequences of mass-transport limitations for DH reactions were also elucidated. The results obtained allowed us to establish the fundamentals for the targeted preparation of well-structured ZnOx species and the relationships between their structures and the DH performance. This knowledge may inspire further studies in the field of C-H bond activation and other reactions, in which ZnOx species act as catalytically active sites or promoters, such as the dehydroaromatization of light alkanes and the hydrogenation of CO2 to methanol.

Uncovering the recycling potential of industrial waste in Sri Lanka.

The generation of industrial waste is mainly dependent on several factors, including the type of industry, production capacity, technology use and raw materials involved in the manufacturing processes. The present study is a cross-sectional study that was conducted with 580 industries under six industrial sectors in Sri Lanka in 2022. The main objective of this research was to investigate solid waste generation and estimate the recyclable fraction in the waste. Furthermore, this study calculated the prevailing recycling rate of each industrial sector and the waste generation per person employed in the sector. Industrial processes, the types and quantities of waste, waste disposal methods and management activities in terms of recycling and disposal were evaluated through a structured questionnaire and random field observations. The study identified that the composition of selected recyclable items was 16.7% of the total waste generated in the industrial sector. The prevailing rate of recycling in different sectors was as follows: manufacturing of food products (36.6%), manufacturing of beverages (82.3%), manufacturing of textiles (68.6%), manufacturing of chemical and chemical products (28.5%), manufacturing of rubber and plastic (46.5%) and manufacturing of metallic mineral products (17.8%) from the total generated recyclable material. The study further estimated the waste intensity (waste generation per unit of product output) of the industrial sectors as follows: 0.38 (manufacturing of food products), 0.36 (manufacturing of beverages), 0.27 (manufacturing of textiles), 0.26 (manufacturing of chemical and chemical products), 0.17 (manufacturing of rubber and plastic) and 0.16 (manufacturing of non-metallic mineral products).

Evaluation of Energy Performance Indicators and Energy Saving Opportunities for the Italian Rubber Manufacturing Industry

The objective of this work is the energy characterisation and evaluation of the energy efficiency potential of the rubber manufacturing industry in Italy, exploiting the detailed data included in energy audits by large and energy-intensive companies. This sector is divided into two sub-activities: the manufacture of rubber products and the production of tyres. Existing studies are focused mainly on tyre production, and there is a lack of quantitative evaluation of energy indicators that can provide guidance for improving process efficiency. In this work, updated global and specific energy performance indicators (EnPIs) related to the production process and to the auxiliary and general services are defined and evaluated. At the same time, targeted actions and interventions to improve the energy efficiency of the sector are analysed, showing the role of different intervention areas and their cost-effectiveness. The analysis is based on 100 Italian mandatory energy audits of the sector collected according to Art.8 EU Directive 27/2012. The applied methodology made it possible to calculate specific energy performance indicators by considering the overall and sub-process energy consumption of different production sites. Based on a detailed database containing real data from recent energy audits, this study provides an up-to-date and reliable benchmark for the rubber industry sector. In addition, the analysis of energy audits allows the identification of the most effective energy efficiency interventions for the rubber industry in terms of cost-effectiveness and payback time.

Study of BOD: COD Ratio as an Indicator for Wastewater of Rubber Industry Sector

When considering the rubber industry sector, the most significant challenge is the efficient wastewater treatment before discharging it into the natural environment. The rubber industry is considered to be highly chemical and water-intensive: and involves enormous quantitative s of waste production. The ratio between Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) is a widely used parameter in characterising wastewater and then the same was used in this study as an indication to measure the efficiency of wastewater treatment plant operated in the rubber industry sector. Data for the study was extracted from samples collected from 10 wastewater treatment plants of rubber industries in the Sabaragamuwa Province; two samples from each representing before and after treatment. The samples were tested in two replicated for BOD5, COD, pH, and conductivity. These selected rubber factories contain lagoon/pond type wastewater treatment systems or activated sludge wastewater treatment systems. The results showed that the treated wastewater samples were within the range of 0.1–0.4 of BOD5: COD and were below the BOD5: COD permissible level as per CEA standards. (General standards for rubber in inland surface waters; Latex-BOD 60, COD 400; Lanka rubber/crepe rubber–BOD 50, COD 400) comparing the BOD, COD, pH, and conductivity influent and effluent of the treatment process proves the effectiveness of each treatment plant of the relevant industry. Tested samples show a high BOD5: COD ratio in influent and effluent of wastewater treatment system indicate that wastewater of the industry is easily biodegradable. However, more research comparing the characteristics of different rubber manufacturing processes is needed to develop this approach further. &#x0D; Keywords: BOD, COD, BOD: COD ratio, Wastewater treatment plant

Determinants of efficient water use and conservation in the Colombian manufacturing industry using machine learning

Water is a fundamental aspect of achieving sustainable industries, and it is essential for firms to make efficient use of it. However, not all companies have sustainable water management practices in place. In this study, we aim to answer the research question: What factors influenced the efficient use and saving of water in the Colombian manufacturing industry in 2020? We used data from the Annual Manufacturing Survey and the Industrial Environmental Survey conducted by DANE to investigate this question. Our study grouped the variables into four categories: Environmental commitment, Risk mitigation, Innovation, and Location. We used two supervised learning machine-learning algorithms—decision tree and logit regression with LASSO regularization—to analyze the data. The results underscore those investments in wastewater treatment, total water consumption, and commitments to air and climate protection emerge as pivotal drivers for embracing sustainable practices. Moreover, the geographical location of companies significantly influences the likelihood of implementing water conservation initiatives. To enhance efficient water use and conservation in the Colombian manufacturing sector, several targeted public policies are recommended. These include offering fiscal and financial incentives to encourage investments in advanced wastewater treatment and reuse technologies. Additionally, advocating for specialized training and environmental education programs tailored for corporate personnel is crucial. Moreover, establishing initiatives for environmental certification and eco-labeling within the corporate sector can significantly promote sustainable water practices. Lastly, enforcing more stringent environmental regulations and standards, especially for industries like Textile, Metallurgy, and Manufacturing of rubber and plastic products, is essential to ensure responsible water management across the sector.

The Impact of Digital Transformation on New Product Development with the Mediating Role of Organizational Intelligence

Objective: This article aims to investigate the impact of digital transformation on new product development (NPD) with the mediating role of organizational intelligence. Methods and Materials: The research employs a descriptive-correlational design, utilizing questionnaires and field studies to collect data from 100 experts in the rubber manufacturing industry, specifically from Barez and Artavil Tire companies. Confirmatory factor analysis (CFA) was used to assess the validity of the questionnaire, with structural equation modeling (SEM) conducted using Smart PLS software to test the hypotheses. The reliability and validity of the constructs were evaluated through composite reliability (CR), average variance extracted (AVE), and discriminant validity measures. Findings: The study found that digital transformation significantly affects NPD performance (path coefficient = 0.586, t-value = 9.849), and organizational intelligence strongly mediates this relationship (path coefficient = 0.817, t-value = 12.838). Additionally, digital transformation directly enhances organizational intelligence (path coefficient = 0.296, t-value = 2.865). The R² value for NPD was 0.717, and for organizational intelligence, it was 0.688, indicating strong explanatory power. Conclusion: Digital transformation significantly impacts NPD success, particularly when supported by high levels of organizational intelligence. Companies that invest in digital infrastructure and knowledge management systems are better equipped to handle the complexities of NPD, leading to more innovative and competitive products. Organizational intelligence serves as a key enabler in leveraging digital tools for successful product development.

Manufacturing industry potential of the Kyrgyz Republic in Eurasian economic integration

The Kyrgyz Republic, as a developing country with a socialist past, has great opportunities for further economic development. An important factor to consider is the growth of the manufacturing industry, which highlights the significance of analyzing this sector within the country. This study centers on the potential contribution of the Eurasian Economic Union (EAEU), of which Kyrgyzstan is a constituent, towards the advancement of this industry. The research aimed to evaluate the current manufacturing capacity of the Kyrgyz Republic in the industrial sector and to comprehend the influence of the EAEU on industry growth. The main methods that were used during the writing of the research were analysis, forecasting, abstraction, and historical analysis. The work analyzed the industrial sector of Kyrgyzstan within the framework of its integration into the EAEU. The research assessed the historical background of Kyrgyzstan’s accession to the EAEU and the subsequent harmonization of national legislation with the provisions and requirements of the union. In addition, data comparing the industrial production and growth rates of Kyrgyzstan, Armenia, and Kazakhstan have been presented, highlighting notable trends and differences. The work examines specific components of the manufacturing industry of the Kyrgyz Republic, the manufacture of food, beverages, and tobacco products; rubber and plastic manufacture, and non-metallic mineral goods; manufacturing of basic metals and metal products (excluding machinery and equipment); and supply of electricity, gas, steam, and conditioned air. It also talks about the manufacturing sector's importance in Kyrgyzstan, current trends, and possible future improvements, and it enables the assessment of the country's involvement in the EAEU.

Effects of Ergonomic Interventions on Health Indicators in a Rubber Industry

Background: This study aimed to determine the impact of engineering, organizational, and individual ergonomic interventions on the percentage of workers complaining Musculoskeletal disorders, inappropriate work environment, exposure to manual handling, and the rate of sick-leave in workers of rubber industry.&#x0D; Methods: This was a descriptive-analytical and retrospective study conducted in the production department of a rubber manufacturing industry. Ergonomic interventions, which have been fully implemented and have been stable in the industry, were included in the study. Health indicators were determined by reviewing completed Nordic questionnaires, insurance documents, and the documents about different methods of ergonomic risk assessment before and after each intervention. Before and after comparing the indicators, paired t and Wilcoxon tests were done. Results: Ergonomic interventions included 114 engineering, 20 organizational, and 7 individual interventions. Engineering interventions had a significant effect on all the indicators such as reducing total MSDs) 66%). Organizational interventions led to the improvement of the index of MSDs (60%), inappropriate posture (55%) and pain intensity (30%). Individual interventions had a significant effect on MSDs (85.71%) and sick-leaves (100%) (P&lt;0.05).&#x0D; Conclusion: All the types of ergonomic interventions in the production sector of the rubber industry have been effective in reducing MSDs. Engineering interventions have had a significant impact on all the health indicators considered in this study; they are highly effective in the rubber industry, and it is better to implement them together with organizational or individual interventions for better results.

Study on the Biotoxicity, Microbial Degradation and Metabolism, and Solidification of Monoaromatic Hydrocarbons (MACHs)

Monoaromatic hydrocarbons (MACHs), also known as aromatic organic compounds, are a general term for benzene and its derivatives. In a broad sense, monoaromatic hydrocarbons include all aromatic compounds. It can be used as an organic solvent in building decoration materials and is also widely used in other industries such as dye manufacturing, rubber manufacturing, pharmaceutical industry, pesticide industry, etc. Therefore, monoaromatic hydrocarbons are common pollutants emitted by human activities and can be widely detected in human living and living environments. With the development of China's urban economy, the improvement of residents' living standards, and the rapid increase in the number of motor vehicles, the pollution of monoaromatic hydrocarbons has become increasingly severe. Monoaromatic hydrocarbons have strong carcinogenic effects and can directly harm human respiratory, hematopoietic, nervous, reproductive and other system organs. Monoaromatic hydrocarbons also have high photochemical reactivity and are closely related to the formation of photochemical smog and aerosols in the atmosphere. Moreover, monoaromatic hydrocarbons have the characteristics of wide pollution sources, long action time, high pollution concentration, and long release cycle. They have been prioritized by the United States Environmental Protection Agency (USEPA) as pollutants for control, and have also been included in China's "blacklist" of environmental priority pollutants.

Procurement Best Practices and Sustainable Supply Chain Performance of Plastic and Rubber Manufacturing Firms in Kenya

Purpose: The study aimed at assessing procurement best practices and sustainable supply chain performance of plastic and rubber manufacturing firms in Kenya.&#x0D; Methodology: Descriptive research design was adopted by the study. A total of 167 plastic and rubber manufacturing firms in Kenya was the target population, as indicated by KAM (2022) directory. This study used census, as a rule of thumb for population below 200. To gather data, structured questionnaires were used to collect data. Once collected, data was analyzed using descriptive and inferential statistics. Quantitative data was analysed using multiple regression analysis. The qualitative data generated was analyzed by use of the Statistical Package of Social Sciences (SPSS) version 21.&#x0D; Findings: In this study multivariate regression analysis was used to determine the significance of the relationship between the dependent variable and all the independent variables pooled together. Regression analysis was conducted to find the proportion in the dependent variable which can be predicted from the independent variables. The current study obtained an R2 of 64.7% and should therefore be expanded further in futhe ture in order to include other procurement best practices that may as well have a positive significance to the sustainable supply chain performance of plastic and rubber manufacturing firms.The findings of the study indicated that reverse logistics management, procurement outsourcing, e-procurement and green procurement have a positive relationship with sustainable supply chain performance of plastic and rubber manufacturing firms in Kenya.&#x0D; Unique contribution to theory, practice and policy: The study recommended that institutions should embrace procurement best practices so as to improve sustainable supply chain performance and further research should to be carried out in other institutions to find out if the same results can be obtained