Low-density Polyethylene Films Research Articles

Active Low-Density Polyethylene-Based Films by Incorporating α-Tocopherol in the Free State and Loaded in PLA Nanoparticles: A Comparative Study

In this work, alpha-tocopherol (α-TOC) was encapsulated in poly(lactic acid) nanoparticles (PLA NPs) and added to low-density polyethylene (LDPE) films with the aim of producing an active film for food packaging applications. PLA NPs loaded with α-TOC were produced through nanoprecipitation and dried using two methods (freeze-dryer and oven). LDPE-based films with final polymeric matrix concentrations of 10 and 20 g/kg were then produced through blow extrusion. The results showed that LDPE-based films loaded with α-TOC can be produced using blow extrusion, and a good distribution of PLA NPs can be obtained within the LDPE matrix as observed using scanning electron microscopy (SEM). The mechanical properties were affected by the incorporation of α-TOC and PLA NPs loaded with α-TOC, with the observation of a decrease in tensile strength and Young’s Modulus values and an increase in elongation at break. Regarding water vapor permeability, the films showed a reduction in the values with the addition of α-TOC and PLA NPs loaded with α-TOC compared to the LDPE film (control). Films with α-TOC in the free state and loaded in PLA NPs showed antioxidant activity, but their behavior was affected by the encapsulation process.

LLDPE film development surface with nucleating agents to reduce fat stains from food adherence on the film surface for easy rinsing before recycling

The purpose of this research was to enhance the surface of linear low-density polyethylene (LLDPE) film by using single and hybrid nucleating agents to reduce fat stains from food adherence on the film surface for easy rinsing before recycling, consequently reducing energy consumption before recycling. The process begins with the preparation of a high-concentration masterbatch of LLDPE with nucleating agents and polyethylene glycol (PEG), followed by blown film and test analysis. The results showed that both single and hybrid nucleating agents resulted in substantial modifications in the surface characteristics of the film. The altered surface texture of the film makes fat stains easy to remove. In addition, the use of hybrid nucleating agents resulted in considerable roughness on the film's surface. It can calculate the average roughness (Ra) from atomic force microscopy (AFM) images, which is very low at 4.7 nm, and the roughness is consistent. The contact angle was 99.17 degrees, and the percentage of crystallinity was clearly higher than that of a single nucleating agent. As a result, the fat stains on the film surface are easier to remove. The visual appearance, morphology, functional group, and mechanical properties of the films, on the other hand, were not significantly different. In summary, using a nucleating agent helped to rinse fat stains from the film easily.

Durable Surface Modification of Low-Density Polyethylene/Nano-Silica Composite Films with Bacterial Antifouling and Liquid-Repelling Properties for Food Hygiene and Safety.

The growing prevalence of antimicrobial resistance in bacterial strains has increased the demand for preventing biological deterioration on the surfaces of films used in applications involving food contact materials (FCMs). Herein, we prepared superhydrophobic film surfaces using a casting process that involved the combination of low-density polyethylene (LDPE) with solutions containing surface energy-reducing silica (SRS). The bacterial antifouling properties of the modified film surfaces were evaluated using Escherichia coli O157:H7 and Staphylococcus epidermidis via the dip-inoculation technique. The reduction in bacterial populations on the LDPE film embedded with SRS was confirmed to be more than 2 log-units, which equates to over 99%, when compared to the bare LDPE film. Additionally, the modified film demonstrated liquid-repelling properties against food-related contaminants, such as blood, beverages, and sauces. Moreover, the modified film demonstrated enhanced durability and robustness compared to one of the prevalent industry methods, dip-coating. We anticipate that the developed LDPE/nano-silica composite film represents a promising advancement in the multidisciplinary aspects of food hygiene and safety within the food industry, particularly concerning FCMs.

Enhancing polyethylene degradation: a novel bioprocess approach using Acinetobacter nosocomialis pseudo-resting cells.

Despite the discovery of several bacteria capable of interacting with polymers, the activity of the natural bacterial isolates is limited. Furthermore, there is a lack of knowledge regarding the development of bioprocesses for polyethylene (PE) degradation. Here, we report a bioprocess using pseudo-resting cells for efficient degradation of PE. The bacterial strain Acinetobacter nosocomialis was isolated from PE-containing landfills and characterized using low-density PE (LDPE) surface oxidation when incubated with LDPE. We optimized culture conditions to generate catalytic pseudo-resting cells of A. nosocomialis that are capable of degrading LDPE films in a bioreactor. After 28days of bioreactor operation using pseudo-resting cells of A. nosocomialis, we observed the formation of holes on the PE film (39 holes per 217 cm2, a maximum diameter of 1440μm). This study highlights the potential of bacteria as biocatalysts for the development of PE degradation processes. KEY POINTS: • New bioprocess has been proposed to degrade polyethylene (PE). • Process with pseudo-resting cells results in the formation of holes in PE film. • We demonstrated PE degradation using A. nosocomialis as a biocatalyst.

Modelling the piezoelectric effect in a composite polymer film filled with disperse piezoelectric

Mesoscopic modelling of a composite material constituted by an electroneutral polymer (matrix) film filled with micropowder of piezoelectric ceramics (filler) is presented. The calculation scheme resembles that of the RVE (Representative Volume Element) method. The representative element (cell) is a right-angle prism with square cross-section, the height of which is equal to the film thickness. Around the midsection of the prism, there are a few (from 2 to 4) spherical piezoelectric particles positioned close to one another. The length of the base side of the prism is determined from the assumed solid phase content of the composite. To simulate the film, the cells are arranged in a continuous flat layer, inside which they are coupled by means of periodic boundary conditions imposed on their lateral surfaces. To reduce the artifacts of the model, the position of the center of each particle is chosen randomly within the area of the prism cross-section. In the framework of this approach, a low-density polyethylene film with embedded barium titanate particles is considered as an example. One of the surfaces of the film is fixed (no displacements), and the other one is left free. For the characteristics of the particles close to those used in the experiment and the typical matrix material parameters (elasticity moduli, Poisson coefficients, dielectric permittivity), the voltage output (piezoeffect) induced in the film in response to the uniform pressure applied to its free surface is evaluated. It is shown that the electric potential along the thickness of the film is nonuniform: it grows inside the particles and falls down in the interparticle gap. In order to present the results in the form applicative for comparison with the experimental data, for each variant of the system (number of the particles, weight fraction of the solid phase), the calculated values are averaged over a few tens of realizations of the particle positions inside the element.

Development of a cap liner composite film incorporating zinc oxide, celite, and zeolite for kimchi-storing bottles to absorb volatile sulfur compounds

Bottle cap liner films (“ZnO[celite]–zeolite film”) that absorb volatile sulfur compounds from kimchi were developed for kimchi-packaging plastic bottles using zinc oxide (ZnO) in celite (ZnO[celite]), zeolite, and low-density polyethylene (LDPE). The ZnO[celite] concentration-dependent deodorizing effect of the films and their physicochemical properties were evaluated. When the ZnO[celite] and zeolite mixture concentration in the film was 18% (w/w), the concentration of allyl methyl disulfide absorbed in the film increased by 98% compared with when this mixture was not used. Addition of ZnO[celite] and zeolite into the LDPE films altered their surface and cross-sectional morphologies and yellowness, but did not change their thermal stability, thermal properties, oxygen barrier, or tensile properties. These results suggest that the bottle cap liner prepared using the ZnO[celite]–zeolite film can effectively absorb volatile sulfur compounds and may be used as a liner for kimchi-containing bottles, replacing the conventional LDPE liner.

Computational fluid dynamics and artificial neural networks for modelling lined irrigation canals with low‐density polyethylene and cement concrete liners

AbstractThis study numerically investigated the lining effect on the discharges and seepage losses of five reaches which belong to the El‐Sont Canal, Asyut, Egypt, using FLOW‐3D and Slide2 models, respectively. Two lining materials were considered, cement concrete (CC) and CC with low‐density polyethylene (LDPE) film. A cost analysis was performed to explore the feasibility of the proposed lining materials. Moreover, a parametric study was conducted by the Slide2 model to investigate the effect of canal geometry and liner properties on seepage losses. An artificial neural network (ANN) model was developed based on the Slide2 model scenarios to estimate the seepage losses from lined irrigation canals. The results showed that reach the discharge calculated from the FLOW‐3D model increased by 92%–97% and 149%–156%, while the calculated seepage losses from the Slide2 model decreased by 81%–87% and approximately 97% under CC and CC with LDPE film liners, respectively. Cost analysis revealed that the overall cost of CC with LDPE film was higher by 14% than CC. Relying on the importance of saving irrigation water and conveying water to the last reaches, CC with LDPE film is recommended for lining irrigation canals. A parametric study showed that the seepage losses were reduced by more than 96% when the ratio between liner and soil hydraulic conductivities was less than 0.01. A thick liner could maximally decrease the seepage losses by 68%, regardless of the canal geometry. As the developed ANN model showed a close agreement with the Slide2 results with coefficient of determination (R2) and mean squared error values of 0.99 and 0.05, respectively, the ANN model is recommended as a robust and rapid tool for estimating seepage losses from lined irrigation canals.

Antimicrobial potential of linear low-density polyethylene food packaging with Ag nanoparticles in different carriers (Silica and Hydroxyapatite)

Silver nanoparticles incorporation into polymeric packaging aims to prevent microbiological contamination in food products, thus ensuring superior food safety and preservation. In this context, this study aimed to verify the antimicrobial efficacy of linear low-density polyethylene (LLDPE) films incorporated with silver nanoparticles (AgNPs) dispersed in silica (SiO2) and hydroxyapatite (HAP) carriers at different concentrations. AgNPs + carriers polymer films were characterized at 0.2, 0.4, and 0.6% concentrations using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission gun-scanning electron microscope (FEG-SEM), thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), and migration in acidic and non-acidic simulants. Antimicrobial action was investigated on Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, and the Penicillium expansum and Fusarium solani fungi with antimicrobial activity by direct contact test and bacterial imaging by scanning electron microscopy. AgNPs addition to the LLDPE matrix did not interfere with the films' chemical and thermal properties and presented no significant migration to the external medium. For antimicrobial action, silver nanoparticles showed, in most concentrations, an inhibition percentage higher than 90% on all microorganisms studied, regardless of the carrier. However, a greater inhibitory action on S. aureus and between carriers was found, making hydroxyapatite more effective. The results indicated that nanostructured films with AgNPs + hydroxyapatite showed more promising antimicrobial action on microorganisms than AgNPs + silica, making hydroxyapatite with silver nanoparticle potentially useful in food packaging, improving safety and maintaining quality.

Development of Low-Density Polyethylene Films Coated with Phenolic Substances for Prolonged Bioactivity.

The current study proposes an efficient coating methodology for the development of low-density polyethylene (LDPE) films with prolonged bioactivity for food packaging applications. Three natural phenolic-based substances were incorporated at optimized concentrations in methyl-cellulose-based solutions and used as coatings on LDPE films. The amount of surfactant/emulsifier was optimized to control the entrapment of the bioactive substances, minimizing the loss of the substances during processing, and offering prolonged bioactivity. As a result, the growth of Escherichia coli was substantially inhibited after interaction with the coated films, while coated films presented excellent antioxidant activities and maintained their mechanical performance after coating. Considerable bioactivity was observed after up to 7 days of storage in sealed bags in the case of carvacrol- and thymol-coated films. Interestingly, films coated with olive-leaf extract maintained a high level of antimicrobial and antioxidant properties, at least for 40 days of storage.

Fabricating chitosan/low-density polyethylene (CS-LDPE) films and its efficacy to prolong shelf life of rainbow trout fish

This study aimed to explore how fabrication methods can influence surface morphology, physical, and mechanical characteristics of chitosan and low-density polyethylene (CS-LDPE) films to fulfill requirements of sustainable food packaging. The efficacy of CS-LDPE film for improving shelf life of rainbow trout fish products was also investigated. The field emission scanning electron microscopy assessment revealed that employing the two-step fabrication approach in the presence of grafted maleic anhydride (PE-g-MA) as a compatibilizer modified the surface morphology of the films, implying a better miscibility of constituents. Adding chitosan adversely influenced the thermal, mechanical, and morphological characteristics of the CS-LDPE films, which were mitigated by reducing chitosan size and application of 10 % PE-g-MA compatibilizer. According to the experimental assessments, two-step fabricated films consisting of 15 % chitosan and 10 % grafted maleic anhydride (PE-g-MA) was the best sustainable composite displaying the closest properties compared with the conventionally utilized LDPE films. Exploring several biochemical indices, including pH, peroxide level, membrane integrity (TBARS), free fatty acids (FAAs), and total volatile basic nitrogen (TVB-N) manifested that packaging fish samples with CS-LDPE improved the shelf life. The most pronounced differences between two packaging types were observed in the sixth day of storage time. Moreover, total viable count, Pseudomonas spp. count, and Enterobacteriaceae count markers revealed that the employing CS-LDPE film declined in the microbial proliferation rate, thereby prolonging shelf life of fishes. This study underlined the significance of CS-LDPE films to fulfilling needs for sustainable food packaging, conferring competitive advantage, and prolonging the food shelf life.

Linking polymer architecture to bubble shape in LDPE film blowing through multistage modeling

To meet the challenge of efficient modeling of film blowing with realistic constitutive equations for commercial thermoplastic melts, we present a multistage optimization modeling framework that integrates polymerization reaction modeling, rheology modeling, and bubble-shape prediction. A direct link is thereby created between the polymer architecture and the bubble shape of low-density polyethylene (LDPE) through a three-stage modeling protocol. Stage 1 aims to get complete polymer structure information from a limited set of linear and nonlinear rheological data and the measured averaged molecular weight. An optimization loop uses the Tobita algorithm for polymer reaction and the BoB model for rheology to minimize the deviation between experimental data and model predictions. Stage 2 is designed to obtain a representative reduced ensemble of LDPE in the Rolie-double-poly (RDP) model to reduce the computational cost of rheology calculations during processing. The parameters of the reduced molecular components are obtained by fitting the RDP model to a wide range of rheology data predicted by the BoB model applied to the full ensemble of polymer architectures obtained in stage 1. In stage 3, the reduced-ensemble RDP model is coupled to measured temperature profiles using time–temperature superposition, and the bubble shape and strain rate history of a fluid particle in the bubble are obtained by minimizing error in the momentum balance equations. We show that each stage of the process yields successful fitting, and at the end, we obtain an a priori prediction of height-dependent bubble radius and velocity in agreement with experiment. With this multistage optimization strategy, we link the polymer compositions to the bubble properties during the film blowing of LDPE.

Biodegradation of low-density polyethylene by plasma-activated Bacillus strain

Plastic biodegradation by microorganisms is an eco-friendly and sustainable method without any ramifications. Herein, we used a cultivation method and 16S rRNA sequencing to screen bacteria that can efficiently colonize and degrade low-density polyethylene (LDPE) from various plastic wastes. We identified Bacillus safensis BS-10L through whole-genome sequencing analysis and verified its LDPE-degradation ability. However, the decomposition mechanism of the isolated bacteria was unclear and the decomposition efficiency was insufficient, so low-temperature plasma was used to increase the decomposition efficiency of the bacteria. The population and viability of bacteria treated with cold plasma increased. Plasma-activated bacteria could induce cracks, holes, and roughness on the surface of LDPE films over 90 days, and over 30 days; the LDPE film lost 13.40 ± 0.013% and 27.78 ± 0.014% of its mass by BS-10L and plasma-treated BS-10L, respectively. Fourier-transform infrared spectroscopic analysis identified new peaks of the C=O and C-O groups in the plasma-treated LDPE film, exhibiting high transmittance in the LDPE film that was inoculated with bacteria. X-ray photoelectron spectroscopic analysis showed that C-O bonds were generated by BS-10L strain, and relatively strong C=O bonds were generated in the film inoculated with plasma-treated BS-10L strain. Plasma treatment increased the colonization of the BS-10L strain and changed the chemical bonding of the LDPE film, suggesting that plasma-activated BS-10L could accelerate decomposition by oxidation by increasing the carbonyl group of the PE film. Therefore, plasma technology may be effective for enhancing the plastic-degrading ability of microorganisms.

Development of PE‐based antibacterial and antioxidant films with L‐ascorbic acid‐p‐hydroxybenzoate addition

AbstractIn this work, a PE‐based antibacterial and antioxidant material was successfully developed. L‐Ascorbic acid and p‐hydroxybenzoic acid were used as raw materials to synthesize L‐ascorbic acid‐p‐hydroxybenzoate (LPHB) by direct esterification method. LPHB was added to polyvinyl alcohol (PVA) solution and coated on corona‐treated low‐density polyethylene (LDPE) film coated with primer layer to prepare a composite film. The effects of different concentrations of LPHB on the performance of composite films were investigated to determine the optimal amount of addition, and then to prepare both antibacterial and antioxidant films. The antimicrobial properties of LPHB were analysed. The antibacterial, antioxidant, mechanical, barrier properties and morphology of the films were characterized and analysed. The results showed that the addition of LPHB significantly improved the antibacterial and anti‐mould properties, oxidation resistance, and barrier properties of the composite film compared to the LDPE film. The best overall performance of the composite film was achieved when the content of LPHB was 1.5%, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99%, and the free radical scavenging rate reached 67.22%. In addition, the cling film added with LPHB has better antioxidant and antibacterial properties, which has obvious effect on bread preservation and has potential for application in food packaging.

Improved biodegradability of low-density polyethylene using plasma pretreatment and plastic-degrading bacteria

Polyethylene is widely used and is a major cause of serious environmental problems because it is non-biodegradable and difficult to recycle. To overcome these environmental problems, in this study, low-density polyethylene (LDPE) was treated with low-temperature plasma at atmospheric pressure, an eco-friendly technology. After inducing oxidation on the LDPE film by plasma treatment, a method for improving the biodegradation efficiency of LDPE-degrading bacteria was identified, and the underlying mechanism was investigated. Fourier-transform infrared and X-ray photoelectron spectroscopy analyses showed that the plasma treatment resulted in the formation of new peaks corresponding to the C–O and –CC– bonds and stronger –CO– bond groups than the –C–O– bond groups, showing that the oxidation of LDPE film was strong. Additionally, the –C–H– bond ratio on LDPE surfaces inoculated with Pseudomonas putida increased by 13–25.5% compared to that on untreated controls. Pseudomonas putida reduced the thermal stability by forming a biofilm on the oxidized LDPE film during the plasma treatment. The weight of untreated LDPE film was reduced by 50%, while that of treated LDPE film was reduced by 80%, confirming more efficient degradation. Thus, LDPE decomposition efficiency can be improved using a short plasma treatment to increase the adhesion and fixation of LDPE-degrading bacteria on the surface of oxidized LDPE films. Therefore, plasma pretreatment technology could be used to reduce plastic contamination in agricultural environments.

Effect of pressure on the supercritical solvent impregnation of pomegranate peel extract into low-density polyethylene films

Effect of pressure on the supercritical solvent impregnation of pomegranate peel extract into low-density polyethylene films

In-situ photocatalytic degradation of low-density polyethylene: A pathway towards eco-sustainability and circular economy

The present study demonstrates the accelerated rate of photo-degradation in low-density polyethylene (LDPE) films using nanomaterials like titanium dioxide (TiO2) in a photochemical reactor, an efficient, environmentally benign, and sustainable chemical. The effect of various parameters such as source of light, catalyst loading, pH, and temperature was investigated to achieve maximum degradation on a laboratory scale. The surface morphology with molecular and chemical structure changes in the nanocomposite films was monitored before and after degradation using various analytical techniques. It is found that the degradation reaction rate is greatly affected by pH and temperature and follows the first-order photo-thermal kinetics reactions. The calculated activation energies for the different properties range from 77.6 kJ/mol for carbonyl group formation to 55 kJ/mol for vinyl group formation at an optimum pH of 4 and temperature of 30 °C, respectively. The optimized sample's storage modulus (Esm) increased from 17.76 to 210 MPa, demonstrating the loss of tensile strength after irradiation and increased elasticity. Thus, it clearly demonstrated that the LDPE sample loaded with 12% catalyst and exposed to 288 h at pH 4 and 30 °C temperature degraded most efficiently with 6.25% weight loss. In addition, there is a high correlation between the area of degradation and carbonyl index with R2 > 0.96, which helps in validating the fact that during the degradation process, there is volatilization of degradation products that leads to the formation of 0.523 mm (in length) of holes (microscopic analysis). This study brings new insights into reducing plastic pollution by minimizing waste prevention and generation at the source by promoting the usage of intermediates (formed during degradation) as a secondary material for producing new plastic products.

Modelling the respiration rate of dabai fruit (Canarium odontophyllum Miq.) stored in different packaging films

Dabai (Canarium odontophyllum Miq.) is a highly nutritious fruit that has a huge potential to be marketed both locally and globally. However, the lack of promotion leads to an oversupply during peak season, thus reducing its market price. Proper handling and packaging are therefore necessary to maintain the quality and extend the shelf life of dabai. In the present work, nylon film with an oxygen transmission rate (OTR) of 55 cc/m2/day and water vapour transmission rate (WVTR) of 334 g/m2/day; polyethylene terephthalate (PET) film with an OTR of 90 cc/m2/day and WVTR of 35 g/m2/day; and low-density polyethylene (LDPE) film with an OTR of 8000 cc/m2/day and WVTR of 200 g/m2/day were used to pack dabai and stored at 5°C for 14 d. All films had a dimension of 200 × 300 mm, and a thickness of 0.01 μm. It was found that dabai maintained its hue angle (h°) values within the dark purple region (299.73° to 338.64°) and its lightness (L*) values throughout storage. However, the colour intensity (chroma) significantly changed (p < 0.05) between different films throughout storage (p < 0.05). The control sample had the most significant decrease in firmness and weight (p < 0.05) between day 0 and 14, followed by the samples stored in PET, LDPE, and nylon. Whereas the samples in LDPE demonstrated the lowest respiration rate as compared to nylon and PET. The uncompetitive Michaelis-Menten equation model was used to model the respiration rate of dabai. Results showed that all films obtained good fit (R2 of near to 1). Additionally, the mean relative percentage (E%) was less than 10%, thus indicating that the data were suitable for real-time application.

Degradation of low-density polyethylene by the bacterium Rhodococcus sp. C-2 isolated from seawater

Low-density polyethylene (LDPE), which accounts for 20% of the global plastic production, is discharged in great quantities into the ocean, threatening marine life and ecosystems. Marine microorganisms have previously been reported to degrade LDPE plastics; however, the exploration of strains and enzymes that degrade LDPE is still limited. Here, an LDPE-degrading bacterium was isolated from seawater of the Changjiang Estuary, China and identified as Rhodococcus sp. C-2, the relative abundance of which was dramatically enhanced during PE-degrading microbial enrichment. The strain C-2 exhibited the degradation of LDPE films, leading to their morphological deterioration, reduced hydrophobicity and tensile strength, weight loss, as well as the formation of oxygen-containing functional groups in short-chain products. Sixteen bacterial enzymes potentially involved in LDPE degradation were screened using genomic, transcriptomic, and degradation product analyses. Thereinto, the glutathione peroxidase GPx with exposed active sites catalyzed the LDPE depolymerization with the cooperation of its dissociated superoxide anion radicals. Furthermore, an LDPE degradation model involving multiple enzymes was proposed. The present study identifies a novel PE-degrading enzyme (PEase) for polyethylene bioremediation and promotes the understanding of LDPE degradation.

Analysis of Mechanical Properties and Structural Analysis According to the Multi-Layered Structure of Polyethylene-Based Self-Reinforced Composites.

In this research, a self-reinforced composite material was manufactured using a single polyethylene material, and this self-reinforced composite material has excellent recyclability and is environmentally friendly compared to composite materials composed of other types of material, such as glass fiber reinforced composites (GFRP) and carbon fiber reinforced composites (CFRP). In this research, the manufactured self-reinforced composite material consists of an outer layer and an inner layer. To manufacture the outer layer, low density polyethylene (LDPE) films were laminated on high density polyethylene (HDPE) fabrics and knitted fabrics, and composite materials were prepared at various temperatures using hot stamping. A 3D printing process was utilized to manufacture the inner layer. After designing a structure with a cross-sectional shape of a triangle, circle, or hexagon, the inner layer structure was manufactured by 3D printing high-density polyethylene material. As an adhesive film for bonding the outer layer and the inner layer, a polyethylene-based self-reinforced composite material was prepared using a low-density polyethylene material. Input data for simulation of self-reinforced composite materials were obtained through tensile property analysis using a universal testing machine (UTM, Shimadzu, Kyoto, Japan), and the physical property values derived as output data and actual experimental values were obtained. As a result of the comparison, the error rate between simulation data and experimental data was 5.4% when the shape of the inner layer of self-reinforced composite material was a hexagon, 3.6% when it was a circle, and 7.8% when a triangular shape showed the highest value. Simulation in a virtual space can reduce the time and cost required for actual research and can be important data for producing high-quality products.

Municipal Solid Waste Composition and Generation with Emphasis on Plastics in Nablus City, Palestine

The aim of this study was to characterize the municipal solid waste (MSW) in Nablus city in Palestine, while focusing on the plastic waste fraction. The plastic fraction—an environmentally problematic waste stream—was further characterized into the different polymer types and formats with the aim of suggesting feasible recovery and recycling solutions. Locally generated studies lack data about the recyclable fractions in the MSW and a thorough characterization of the plastic waste stream, although there is global action to minimize and optimally treat this waste fraction. The composition analysis was conducted by collecting 60 samples from five districts with different characteristics (e.g., income, density, level of education, building formats). The fraction of bio- and organic waste is significant in the collected MSW in Nablus, representing about 68% of the total MSW. The recyclables (paper and cardboard, glass, metals and plastics) amount to 27.4% of the generated MSW in the city. The plastic fraction (10.1%) is mainly composed of low-density polyethylene (LDPE) films (39.8%), polyethylene terephthalate (PET) bottles (21.9%), high-density polyethylene (HDPE) rigids (19.0%), and polypropylene (PP) rigids (11.5%), all of which are technologically recyclable. The polymer types and container formats indicated that the collected plastics originate mostly from packaging. The outcomes of this research indicate the need to implement a separate collection system for the organic waste fraction, which could be used to produce compost for the agricultural activities in the region. By having such a system, the dry recyclables (including plastics) can be easily recovered with less degree of contamination for recycling, helping the local recyclers to access cleaner materials. Furthermore, the state of Palestine lacks strict regulations for the end-of-life treatment of the different waste fractions; therefore, having clear guidelines and incentive systems will result in the minimization of the generated waste as well as better achievement of recovery and recycling targets. In addition, expertise, funding, public awareness, facilities, equipment and other provisions are currently lacking or inappropriate. In future, these factors must be addressed to enhance sustainable solid waste management.