Papers by Keyword: Plastic

Abstract: Sawdust and used plastic materials are generally considered as waste and due to the inability of the later to degrade, it constitutes a lot of hazard to the environment and ecosystem. This research aimed at evaluating the performance and quality of the extrudates produced from a single screw wood-plastic composite extruder. The machine performance was evaluated using shredded Poly ethylene, terephthalate (PET) and high-density polyethylene (HDPE) to produce wood-plastic composites. The composite comprising of six samples of different mix ratios (plastic to stone dust mix ratio of 60:40, 70:30 and 80:20 and plastic to sawdust mix ratio of 60:40, 70:30 and 80:20) of the materials. Temperature range of 200°C to 300°C was adopted throughout the evaluation. The plastic composite was shredded into smaller bits and then inserted into the plastic chamber for melting at a determined temperature. The functional efficiency, throughput capacity, specific energy consumption, and selected physical properties were evaluated. Data collected were analyzed using Microsoft Excel package. It was discovered that the extruder work optimally when the mixing ratio of plastic to sawdust and plastic to stone dust content were in the ratio 80% and 20% which gave the functional efficiency of 73% and 84% respectively. However, it was observed that the throughput capacity of the machine has the highest at the 70% and 30% mixing ratio of plastic to stone dust of 7.2 kg/hr and plastic to sawdust of 9.38 kg/hr respectively. Also, the specific energy consumption has its highest value at 60% and 40% mixing ratio of the plastic to stone dust and saw dust of 5.67 KWh/Kg and 1.7 KWh/Kg respectively. A linear trend on the effect of the percentage of wood and stone content on the unit density of the products was also observed. It was observed that the higher the wood or stone dust content in the composite the denser the products. There are no changes in the physical composition in terms of size (length and thickness ) and mass such as water absorption, thickness swelling and linear expansion. It was observed that the extruder performed optimally when the percentage of plastic & wood and plastic & stone dust were in the mix ratio of 80 and 20 respectively. These products can be use for internal and external applications in buildings and other structures.

Abstract: This study proposes an alternative formwork system using recycled plastic to reduce the use of wood in the construction of tie columns and tie beams in San Pedro Sula, Honduras. The main objective is to develop a more sustainable and efficient solution to reduce wood consumption and the high costs that these formworks represent in projects. A geometric design was developed using reinforced recycled plastic boards, tailored to meet the structural needs of secondary concrete elements. The study applied a comparative methodology, evaluating the proposed system against traditional wooden formwork based on parameters such as assembly time, reuse potential, resistance, and material reduction. Results showed a 20% to 30% decrease in formwork assembly and disassembly time, along with an over 80% reduction in wood consumption. The recycled plastic formwork demonstrated greater durability and resistance to moisture compared to wood, offering improved performance in terms of lifespan and reusability. In conclusion, the proposed system proved to be a functional, cost-effective, and environmentally friendly alternative for the construction sector in Honduras. It also promotes the reuse of plastic waste in the development of modern, sustainable construction technologies.

Abstract: Additive technology (3D printing) is a method of manufacturing plastics that allows you to create sophisticated shaped parts at relatively low costs and in a short time. This method is particularly useful for rapid manufacturing, including engineering applications such as rapid prototyping. The most common commercially used Fused Filament Fabrication (FFF) method consists in dispensing the filament from a heated nozzle located in three moving axes, which solidifies after exiting the nozzle. This technology has gained significant popularity due to its versatility in producing custom parts and prototypes efficiently. Moreover, it enables designers to experiment with complex geometries that would be difficult or costly to achieve with traditional manufacturing techniques. This article presents research focused on the mechanical properties (tensile strength and elongation) of FFF printed parts made of polyethylene terephthalate glycol (PETG) in three infill density patterns: 100% rectilinear, 50% gyroid, and 50% Hilbert curve. The article describes the strengths and weaknesses of the material used and compares the mechanical properties of individual infill printing patterns.

Abstract: Plastic waste is an environmental problem that is widely discussed in the era of globalization. Catalytic reforming can be applied to improve the quality of plastic waste oil. This study aims to improve the properties of liquid fuel from pyrolysis oil using natural diatomaceous earth (NDE) with independent variables, namely catalytic reforming temperature and catalyst mass. The NDE (100 mesh) catalyst was washed with distilled water and then dried in the oven for 24 hours. The characteristics of liquid fuels were investigated using gas chromatography (GC-MS), while the catalyst was analyzed using a scanning electron microscope (SEM) to better understand the particle size and surface topography. The catalytic pyrolysis process is carried out in a fixed-bed reactor at 300-500 °C with a catalyst mass of 4-6%. The surface morphology of NDE appears to have a microporous structure with a honeycomb shape and 5 μm average size. Liquid products consist of hydrocarbons in the gasoline range, based on GC-MS analysis. This process shows that increasing the temperature and catalyst mass results in higher product yields of 52.12% at 300 °C and 4% catalyst mass. NDE could be applied to the conversion of pyrolysis PP into gasoline. According to the findings, NDE will eventually be one of the options for completing the conversion of PP plastic.

Abstract: This study aims to obtain an alternative fuel from plastic pyrolytic oil (PPO) that has similar properties to gasoline and diesel fuel. The process carried out is distillation, which is heating the PPO at a certain temperature so that light and heavy molecules will evaporate and turn into distillate plastic oil (DPO). The effect of temperature on the quality of the DPO was observed based on the color of the obtained DPO. Temperatures ranging from 120 to 350 °C were examined in this study. The cleaner DPO was produced at a temperature of about 120 °C, which indicated a light molecule of hydrocarbon similar to gasoline, while a little dark color was produced when the temperature was increased to 350 °C, which indicated heavy molecules of hydrocarbon similar to diesel. This research shows that distillation can produce alternative fuels with different grades depending on the applied operating temperature.

Abstract: In this study eggshells and low density polyethylene plastic (LDPE) wastes were reused to produce tiles. The eggshells were ground in a laboratory scale jar mill into the particle size of fine sand. The optimum grinding parameters were determined to be the setting that produced the highest mass of eggshell powder that was within the desired particle diameter size range of 0.425 mm (No. 40) and 0.075 mm (No. 200). A two to the three factorial design of experiment was used with variables of Time, Speed, and Ball Filling Ratio. The high and low values used in this study were 20 minutes and 10 minutes for the time, 250 rpm and 100 rpm for the speed, and 35% and 20% for the ball filling ratio. There were eight settings made with 3 trials per setting and one validation for the optimal setting produced. The eggshell powder produced by the optimal setting of the jar mill was used to create the LDPE-eggshell tiles. Four tiles were made for the three trials and for the validation part. The tiles were tested for its relative strength using the Compression Testing Machine. The researchers determined that eggshells and LDPE plastics may be formed into tiles and that the strength of the tiles that were produced by these materials exceeded the standard value set for this type of product.

Abstract: Plastic waste disposal is among the most challenging problems of the current era. Therefore, new methods and applications for the utilization of waste plastics are increasingly needed. To find them, it is essential to research and develop the material properties of recycled plastics. The effect of different ultraviolet light (UV) stabilizers on the color stability, melt properties and tensile properties of mixed waste plastics blends was studied in this paper. The mixed waste plastics collected from two different waste sources were prepared as specimens by injection molding, and studied with two different types and loading amounts of UV stabilizers. UV absorbers (UVAs) and hindered amine light stabilizers (HALS) were used as UV stabilizers. A specimen produced without the addition of a UV stabilizer was used as a reference specimen of both the blends. After the accelerated weathering, the addition of a UVA provided an improved, smaller change in color than the addition of HALS. Among the tensile properties, the addition of UV stabilizers clearly improved the tensile strength and tensile modulus for almost all the studied specimens. Additionally, the melt properties of both the studied plastic blends were found to be increased by the addition of UV stabilizers.

Abstract: A material testing apparatus for measuring the biaxial deformation behavior of a polymer tube has been developed to quantitatively evaluate the deformation behavior of polymeric materials. The testing apparatus can apply axial force and internal pressure to a tubular specimen. A noncontact strain measurement system was also developed, and the biaxial strain components and the radius of curvature in the axial direction of the bulging specimen are continuously measured to control the stress path applied to the specimen. Polyethylene tube with an outer diameter of 17 mm and a thickness of 2 mm are used as a test sample. The tubular specimens were subjected to linear stress paths with stress ratios of σ_Φ:σ_θ =1:0, 4:1, 2:1, 4:3, 1:1, 3:4, 1:2, 1:4, and 0:1, where σ_Φ and σ_θ are the axial and circumferential stress components, respectively, applied to the central area of the bulging specimen. Loading and unloading tests were performed to determine the biaxial true stress-logarithmic plastic strain curves. The strain rate was 1×10^-3s^-1. From these test results, contours of plastic work and the directions of the plastic strain rates were measured to identify a proper material model for the test sample using the Yld2000-2d yield function (Barlat et al., 2003).

Abstract: The paper analyzes the impact of personal protective equipment used by the population as a result of the COVID-19 pandemic on the environment. The scale of the additional amount of waste generated as a result of the use of protective face masks, etc. is noted. The globality of the existing problem and its multiparametric impact on the components of the environment are indicated. The short-term effect of a number of disposable protective face masks on the condition of soil by chemical component has been studied. The dependence of leaching of heavy metals from masks on soil acidity was experimentally analyzed, the dynamics of mobile phosphorus and potassium in soil samples was studied. It is shown that the presence of masks in the soil leads to exceeding the standard for zinc content, while for copper content and manganese content exceeding the standard is not observed in the study period, for lead there are fluctuations in content beyond standard value. The need for long-term research on the impact of face masks on the environment, and in particular soils, was noted.

Abstract: In this paper, the selected properties of lightweight composites based on the different kinds of binder and recycled waste plastics aggregate were studied. Plastic waste e.g. foamed polystyrene, polypropylene, polyurethane foam or ethyl vinyl acetate (EVA) as an aggregate in these composites was used. Cement CEM II B/S 32.5 R and an organic-based adhesive with the business name Conipur 360 were used as a binder. The cement composites consisted of constant water to cement ratio 0.50 and dose of cement 175 kg/m³. Mixtures of adhesive composites were prepared with constant dose of adhesive 100 kg/m³. The kind of recycled waste aggregate was only changed. The physical properties, such as bulk density, compressive strength and thermo-technical properties were verified. The application of organic-based adhesive resulted in a significant decreasing values of the bulk density (100 kg/m³ - 230 kg/m³) and the thermal conductivity coefficient (0.0511 W/m.K - 0.0686 W/m.K) of lightweight composites. The negative impact of this type of binder resulted to a decreasing value of the compressive strength (0.15 MPa - 0.32 MPa). Use of cement binder caused to an increasing of bulk density (290 kg/m³ - 375 kg/m³) and worsening of the thermal conductivity coefficient of these composites (0.0660 W/m.K - 0.0799 W/m.K). The compressive strength values of cement composites ranged from 0.24 MPa to 0.50 MPa.