High-density Polyethylene Research Articles

Thermo-mechanical performance characteristics of glass reinforced HDPE composites: A comprehensive review

Millions of tonnes of plastic and glass waste is produced worldwide, with only a limited quantity being recycled with the majority ending up in landfill, our oceans or in stockpiles. Even though current applications exist for recycled glass and plastic, there is still a need to introduce recyclate to different industries. This review presents an investigation aimed at mechanical and thermal property improvements by the incorporation of reinforcement material into a polymeric matrix. The performance of high-density polyethylene (HDPE) and glass composites manufactured with different levels of glass, additives and surface treatments have been evaluated by analysing several past investigations. The critical parameters influencing the mechanical and thermal performance of HDPE-Glass composites were identified to be the type of reinforcement, glass content, additives utilised, and the different manufacturing methods employed. Optimised mix designs proposed by researchers have been analysed along with reaction mechanisms. This review has identified a composite material to be further refined and optimised with the potential to be improved by integrating reclaimed waste to manufacture composites by promoting a zero-waste economy. Improvements in tensile strength up to 71% can be observed with the implementation of 20% by weight of glass reinforcement in HDPE composites. The use of maleic anhydride grafted polyethylene (MAgPE) as a compatibilizer facilitates the stress transfer between the two phases by improving their bonding with tensile and flexural strength increments up to 85% and 25%, respectively. This review is a valuable resource for future researchers as it identifies crucial research gaps in HDPE-Glass composite manufacturing and synthesises key findings in existing literature.

Tube net cultivation of Kappaphycus alvarezii in floating high density polyethylene raft - a feasibility study in exposed coastal waters in Northeastern Indian Coast

Tube net cultivation of Kappaphycus alvarezii in floating high density polyethylene raft - a feasibility study in exposed coastal waters in Northeastern Indian Coast

Comparative assessment of microplastics and microalgae as vectors of mercury and chlorpyrifos in the copepod Acartia tonsa

Microplastics (MPs) raise concerns not only as pollutants themselves, but also due to their ability to act as vectors of pollutants adsorbed from seawater, transferring them to marine organisms. However, the relevance of MPs as carriers of pollutants compared to microalgae needs further exploration. This study compared the role of MPs (2–10 μm non-oxidized and 10–15 μm oxidized high-density polyethylene) and natural organic particles (Rhodomonas lens microalgae, MA) as carriers of mercury (Hg, 2.3 μg Hg/L) and chlorpyrifos (CPF, 1.0 μg CPF/L) to adult Acartia tonsa copepods, after 24–48 h exposure. Dose-response experiments were first performed with adult female copepods exposed to oxidized MPs (0.25–4.0 mg/L), waterborne Hg (0.01–10.0 μg/L) and Ox MPs + Hg (0.25–4.0 mg oxidized MPs/L + 0.50–8.0 μg Hg/L) for 48 h, to complement previous studies that focused on the pesticide CPF. Effects were evaluated with four replicates for physiological and reproductive responses (6 females/replicate), biochemical techniques (40 individuals/replicate) and Hg/CPF bioaccumulation measurements (1000 individuals/replicate). Copepods accumulated Hg/CPF similarly from dissolved pollutants (6204 ± 2265 ng Hg/g and 1251 ± 646 ng CPF/g) and loaded MPs (3125 ± 1389 ng Hg/g and 1156 ± 266 ng CPF/g), but significantly less from loaded MA (21 ± 8 ng Hg/g and 173 ± 80 ng CPF/g). After 24–48 h, copepods exposed to MPs + Hg/CPF showed generally greater biological effects than those exposed to dissolved Hg/CPF or to MA + Hg/CPF, although differences were not statistically significant. MA + CPF had significantly lower AChE inhibition (1073.4 nmol min−1 mg−1) and MA + Hg lower GRx induction (48.8 nmol min−1 mg−1) compared to MPs + Hg/CPF and dissolved Hg/CPF (182.8–236.4 nmol min−1 mg−1 of AChE and 74.1–101.7 nmol min−1 mg−1 of GRx). Principal component analysis suggested different modes of action for Hg and CPF.

Effects of Storage Period, Storage Conditions and Packaging Type on Maize Inbred Line Seed Qualities

The aim of this research was to study the effects of storage period, storage condition and packaging type on maize inbred seed qualities over 12 months storage. The experimental design was split-split plot with four replications. The study manipulated storage period (0, 3, 6, 9, and 12 months) as the main plot, uncontrolled storage condition (USC) and controlled storage condition (CSC) as the sub-plot, and packaging types including woven polypropylene (WPP), high density polyethylene (HDPE), polyamide (PA) with linear-low density polyethylene (LLDPE) and vacuum packing (PA + LLDPE + VACUUM, PLV) as the sub-sub plot. The results showed that the storage period did not affect seed germination; however, seed vigor decreased progressively with increased storage period. Seeds stored under USC exhibited lower moisture content, seed germination and vigor compared to those in CSC. Notably, seed vigor declined after the sixth month in USC storage. Among the packaging types, seeds in WPP had the lowest moisture content. Packaging type did not significantly influence seed germination throughout the storage period. However, different packaging types were able to maintain seed vigor for varying duration, especially for 6 months in PLV and 3 months in WPP packaging.

Moisture damage resistance of pyro-oil modified bitumen with hydrated lime using surface free energy approach

Moisture damage (MD) in bituminous mixtures occurs due to the loss of cohesion in the bitumen or adhesion between the binder and aggregates. The existence of moisture may influence the bonding between aggregates and bitumen, which may affect the moisture susceptibility of the bituminous mix. Therefore, there is a need to understand the bonding-debonding properties and the moisture susceptibility of binders and mixes, at the material selection stage. Surface free energy (SFE) method is one of the proven techniques to quantify the moisture susceptibility of bituminous mixtures, by using contact angle (CA) determination of the component materials of the mix. This study aimed to evaluate the effect of hydrated lime (HL) on the moisture susceptibility of bituminous mixtures, with control (VG30) bitumen and pyro-oil modified bitumen (POMB) having different percentages of pyro oil, using the SFE approach. Also, the study compared the SFE characteristics of VG30 and POMB with and without the optimum content of HL. POMB binders were prepared by the addition of high-density polyethylene (HDPE) pyro oil in percentages of 1, 3, and 5% in a control bitumen. HL was added as 20%, 25%, and 30% by weight of bitumen in VG30 and POMB bitumen. The aggregates used in the study were limestone, basalt, gravel, and their SFE components were directly considered from the literature. The sessile drop method was used to measure the CA of bitumen and, in turn, determine the various SFE parameters using Van Oss–Chaudhury–Good theory. The moisture susceptibility of mixtures with and without HL was evaluated and compared. From the results, the MD resistance of the bituminous mixtures with modified and unmodified bitumen was found to be increased after the optimum of HL, depending upon the type of aggregates used. Basalt has a 27.41%, 23.38%, and 10.48% greater energy ratio (ER) with POMB1/25, POMB3/25, and POMB5/30, respectively, than VG30/30, the highest ER in modified base bitumen. This indicates that HDPE pyro-oil treatment improves MD resistance for basalt. Whereas for limestone and gravel, VG30/30 gives a maximum value of ER as compared to any other combination of HL modified POMB. The ER values would assist highway agencies in selecting the most compatible binder–aggregate combinations.

Asphalt binder modified with high density polyethylene: 2S2P1D rheological modelling and damage characterization

ABSTRACT The new needs in the paving industry have led to the intensification of the use of modified binders, and the use of plastics (non-biodegradable waste) can be an ally in facing both environmental and technical challenges. This study evaluated the feasibility of modifying a conventional asphalt binder with high density polyethylene (HDPE) at contents of 1, 3 and 5% for performance improvement, using rheological and performance tests. The linear viscoelastic properties were obtained by the temperature-frequency sweep test, and for the first time the 2S2P1D rheological model was used to describe these data for an HDPE-modified binder. Resistance to permanent deformation and fatigue was verified by the Multiple Stress Creep Recovery (MSCR) and Linear Amplitude Sweep (LAS) tests, respectively. The Fatigue Factor of Binder was obtained at 3 levels of strain for the first time for this material. HDPE made the material stiffer and more elastic observed by the coefficients of the 2S2P1D model. The modification resulted in better performance regarding permanent deformation and in general had an impact of less than 10% on the fatigue life of the material. Thus, it is possible to state that HDPE can be incorporated into the asphalt binder without harming its performance.

Co-pyrolytic investigation of waste bakelite with different thermoplastics using microwave and conventional batch pyrolysis reactor

Bakelite, a thermosetting plastic, is harder to recycle as compared to than thermoplastic polymers through thermal method due to its inherent property to harden on application of heat. This study co-pyrolyzes waste bakelite with polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), and polymethyl methacrylate (PMMA) in a conventional semi-batch pyrolysis reactor and microwave pyrolysis reactor to determine how the reactor type and thermoplastic blending affect product distribution, yield, and composition of condensable fraction. The blending of thermoplastics and pyrolysis reactor types greatly affects product distribution. Bakelite, on pyrolysis, produces 39.12 wt% condensable product, which increased to 45.42 wt%, 58.76 wt%, 61.53 wt%, and 66.76 wt% in conventional pyrolysis and 49.87 wt%, 61.26 wt%, 66.51 wt%, and 72.88 wt% in microwave pyrolysis by blending HDPE, PP, PMMA, and PS respectively. The composition analysis through Gas chromatography-mass spectrometry and Fourier-transformed infrared spectroscopy confirms the formation of alkanes, cycloalkanes, alkenes, cycloalkenes, aromatics, and oxygenated compounds, from both pyrolysis processes. However, their percentage differ significantly in both processes. Microwave-assisted pyrolysis with activated carbon yields superior oil in both quantity and composition compared to conventional pyrolysis, effectively transforming waste plastics into valuable products.

Selective Upcycling of Polyethylene over Ru/H-ZSM-5 Bifunctional Catalyst into High-Quality Liquid Fuel at Mild Conditions.

It has been known that plastics with undegradability and long half-times have caused serious environmental and ecological issues. Considering the devastating effects, the development of efficient plastic upcycling technologies with low energy consumption is absolutely imperative. Catalytic hydrogenolysis of single-use polyethylene over Ru-based catalysts to produce high-quality liquid fuel has been one of the current top priority strategies, but it is restricted by some tough challenges, such as the tendency towards methanation resulting from terminal C-C cleavage. Herein, we introduced Ru nanoparticles supported on hollow ZSM-5 zeolite (Ru/H-ZSM-5) for hydrocracking of high-density polyethylene (HDPE) under mild reaction conditions. The implication of experimental results is that the 1Ru/H-ZSM-5 (~1 wt % Ru) acted as an effective and reusable bifunctional catalyst providing higher conversion rate (82.53 %) and liquid fuel (C5-C21) yield (62.87 %). Detailed characterization demonstrated that the optimal performance in hydrocracking of PE could be attributed to the moderate acidity and appropriate positively charged Ru species resulting from the metal-zeolite interaction. This work proposes a promising catalyst for plastic upcycling and reveals its structure-performance relationship, which has guiding significance for catalyst design to improve the yield of high-value liquid fuels.

Microplastic accumulation, morpho-polymer characterization, and dietary exposure in urban tap water of a developing nation

The recent detection of microplastics (MPs) in a large number of commercially important food items and beverages, including tap water, has drawn significant attention because of direct exposure and negative health effects on humans. Nevertheless, there is insufficient information on microplastic contamination in the tap water of developing countries. In the present study, we primarily analyzed supplied tap water samples from four major cities in Bangladesh to determine and characterize MPs using a stereomicroscope and Fourier transform infrared spectroscopy (FTIR). Several indices were employed to calculate human health exposures to microplastics. MPs were found in all of the water samples tested, with an overall mean of 35.33 ± 19.55 particles/L. The results of this study diverge from those of comparable research conducted globally, revealing that tap water in Bangladesh exhibited higher levels of contamination compared to other nations. MPs were found in three different shapes (fibers, fragments, and films), with fibers dominating the samples (96.2%), and 98.1% of the microplastics were less than 0.5 mm in size. Six different colors of MPs were observed, and transparent particles were dominant (63.9% of all observed MPs). FTIR infrared spectrum analysis revealed two major types of polymers: low-density polyethylene (LDPE) and high-density polyethylene (HDPE). The projected daily consumption of microplastics was determined to be 2.65 particles per person per day, raising potential concerns for human health. The findings show that the treatment process of the water supply system is inadequate. Additionally, the sources of microplastics in tap water may come from where the water was collected for treatment and may be linked to a variety of anthropogenic activities, such as urbanization, sewage discharge, industrial waste disposal, and runoff from catchment areas.

Optimizing high-density polyethylene (HDPE) performance: utilizing diatomaceous earth filler and an innovative reversible crosslinking reaction agent (RXR)

Optimizing high-density polyethylene (HDPE) performance: utilizing diatomaceous earth filler and an innovative reversible crosslinking reaction agent (RXR)

A comprehensive evaluation of damping, vibration, and dynamic modulus in reclaimed asphalt pavement: The role of rejuvenators, polymer, temperature, and aging

Reclaimed asphalt pavement (RAP) is increasingly essential in pavement engineering to enhance environmental sustainability. The use of rejuvenators and polymers has solved concerns about the dynamic performance of RAP; however, its damping and vibration properties still need to be investigated. Pavement vibrations pose a threat to public health, impeding sustainability. This research investigates RAP's damping performance, resonant frequency, and dynamic modulus using a non-destructive impact resonance (IR) test. Three RAP percentages (0 %, 50 %, and 100 %), three waste oil rejuvenators (paraffin oil, fatty acid, and base bitumen), and recycled high-density polyethylene (r-HDPE) were employed. Rejuvenators and r-HDPE were used separately and simultaneously at varying percentages. Evaluations were conducted under two conditions (long-term aged (LTA) and unaged) and two temperatures (25 °C and −12 °C). Findings reveal a performance hierarchy: under unaged conditions, rejuvenators exhibit superior efficacy, while simultaneous application of rejuvenator and recycled polymer optimally performs in prolonged aging scenarios. Statistical analyses underscore the pivotal role of rejuvenator quantity, irrespective of recycled polymer presence, aging, and temperature, as determinants in sculpting RAP's damping performance, resonant frequency, and dynamic modulus.

Submucosal Trans-Septal Suturing Technique After a Septal Extension Graft with Porous High-Density Polyethylene: A Technical Report.

Porous high-density polyethylene (pHDPE) is an alternative material for a septal extension graft (SEG) in oriental rhinoplasty when autologous cartilage is limited. Although nasal packing (NP) and trans-septal suturing (TSS) techniques are routine procedures to obviate the dead space after septoplasty, they are associated with certain discomforts and complications. To investigate the application of a submucosal trans-septal suturing (STSS) technique after SEG with pHDPE. A prospective study was conducted on 60 female participants who underwent SEG with pHDPE. The participants were randomly divided into the NP group and STSS group. The extra surgical duration of NP and STSS, pain, nasal obstruction, and sleeping disturbance as well as postoperative complications were recorded and compared between groups. No significant difference was found between group NP and group STSS in terms of mean age. The mean extra surgical duration of group STSS was significantly longer than group NP. There were significant higher pains of group NP at 24 hours and 48 hours postoperatively, compared with group STSS. The NP group also experienced significantly more nasal obstruction and sleep disturbance within 48h postoperatively compared to the STSS group. There was one infection in each group, minor bleeding in two NP patients, and one STSS patient. There was no major bleeding, hematoma, graft exposure, or septal perforation in both groups. Although STSS needs a longer extra surgical duration than NP, it significantly improves the patient's postoperative comfort with a faster return to normal respiration compared to NP. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Simple Water Sample Storage Test for Water Isotope Analysis

Water is pivotal for human societies’ sustainability and resilience. Isotope hydrology and hydrogeology research plays an important role in understanding and managing water resources. Reliable scientific results hinge on high-quality data. Preventing water sample evaporation is essential for accurate isotopic analysis. In this study, the impacts on the quality of isotopic data were tested for the storage of water samples and the repetitive opening of a laboratory reference material (LRM) sub-sample replica during daily operation. Twenty 15 mL water samples were stored in high-density polyethylene (HDPE) bottles at room temperature and humidity to simulate storage conditions. One 60 mL water sample was collected from the same starting batch to simulate the LRM sub-sample. Each 15 mL sample was analysed once over 80 days for the isotopic composition of oxygen (δ18O) and hydrogen (δ2H). The 60 mL sample was repeatedly analysed in the same period. The data were tested to identify shifts in the isotopic composition induced by evaporative processes. The main results of the work are the following: (i) storage of the 15 mL water samples did not cause detectable evaporation in the testing period; (ii) the 60 mL δ18O values showed evidence of evaporation as proved by the positive shift of the isotopic data; (iii) the repetitive opening of the 60 mL sample was the main cause of evaporation; (iv) five openings can already cause detectable isotopic enrichment. Careful manipulation and frequent replacement of the LRM are thus necessary to prevent deterioration of the quality of the analyses.

ANN and RSM Prediction of Water Uptake of Recycled HDPE Biocomposite Reinforced with Treated Palm Waste W. filifera

ABSTRACT This study examined the water uptake (WU) behavior of recycled high-density polyethylene (RHDPE). The biocomposites made of palm waste Washingtonia (PWW) fibers were treated with 3% sodium bicarbonate (NaHCO3) for 24 h. Several RHDPE materials reinforced with different concentrations of PWW fibers (5 to 30 wt.%) until saturation, or roughly 25 days, were developed to investigate the WU kinetics and diffusion in biocomposites. An artificial neural network (ANN) and the response surface methodology (RSM) methods were applied to model the behavior of uptake measured in experiments and optimize the immersion period and PWW fiber content in RHDPE/PWW biocomposite WU. The WU moved swiftly during the first test phase and was completed after 400 h of soaking. The outcomes demonstrated a perfect fit between the observed and anticipated data. Findings showed that the ANN models’ training, test, and validation correlation coefficients were 0.9984, 0.9955, and 0.9723, respectively, for predicting WU. Concerning accuracy and reliability, the ANN model outperformed the RSM model, making it suitable for various industrial uses. The results offer helpful information for professionals to consider when developing and implementing PWW fiber biocomposites.

Feasibility of Repairing Concrete with Ultra-High Molecular Weight Polyethylene Fiber Cloth: A Comprehensive Literature Review

This review explores the use of Ultra-High Molecular Weight Polyethylene (UHMWPE) fiber cloth as an innovative solution for the repair and reinforcement of concrete structures. UHMWPE is a polymer formed from a very large number of repeated ethylene (C2H4) units with higher molecular weight and long-chain crystallization than normal high-density polyethylene. With its superior tensile strength, elongation, and energy absorption capabilities, UHMWPE emerges as a promising alternative to traditional reinforcement materials like glass and carbon fibers. The paper reviews existing literature on fiber-reinforced polymer (FRP) applications in concrete repair in general, highlighting the unique benefits and potential of UHMWPE fiber cloth compared to other commonly used methods of strengthening concrete structures, such as enlarging concrete sections, near-surface embedded reinforcement, and externally bonded steel plate or other FRPs. Despite the scarcity of experimental data on UHMWPE for concrete repair, this review underscores its feasibility and calls for further research to fully harness its capabilities in civil engineering applications.

Plastic Waste Identification Using Deep Learning for Adequate Waste Management

Plastic waste management has emerged as a critical global challenge, prompting concerted efforts from conservation authorities and international organizations like the United Nations to enhance detection and classification strategies. This research distinguishes itself by harnessing advanced deep learning techniques to identify plastic materials at the micron level, surpassing traditional macro-level methods. The primary goal is to classify plastics into four major distinctions, addressing a key challenge in plastic segregation by accurately measuring thickness. Leveraging the YOLOv8 architecture, this approach enables precise classification of plastics into Polyethylene terephthalate (PETE), High Density Polyethylene (HDPE), low density polyethylene (LDPE0, and Polyvinyl Chloride (PVC) categories based on thickness. To achieve this, incorporation of hardware components such as ultrasonic sensors and NodeMCU for detecting thickness variations is used. By facilitating effective segregation according to environmental impact, this innovation revolutionizes waste reduction efforts, offering real-time identification and enhancing overall sustainability in plastic waste management.

Preparation and properties of high-density polyethylene / thermoplastic polyurethane / calcium sulphate whisker composites

Preparation and properties of high-density polyethylene / thermoplastic polyurethane / calcium sulphate whisker composites

The Mechanical Behavior of High-Density Polyethylene under Short-Time Hydraulic Pressure Test

The Mechanical Behavior of High-Density Polyethylene under Short-Time Hydraulic Pressure Test

Effect of the incorporation of plastic waste on the mechanical properties of composite materials

Through this scientific research, we have tried to study the effect of the incorporation of plastic waste on the mechanical properties of concrete, in order to obtain good concrete with high resistance at a lower cost. To carry out this work, we adopted the following steps: Knowledge of the properties of concrete, which contains plastic waste of High Density Polyethylene (HDPE). Thus, the natural aggregate was replaced by concrete formulated with plastic waste in partial substitution varying between 0%, 10% and 20%. In all the concrete mixtures, the components, water, cement, gravel 3/8 and 8/15 and sand 0/3, remained constant while the HDPE waste varied according to the substitution rate. Through this process, the mechanical properties of concrete in fresh and hardened states were determined. The analysis of the results of the study allowed us to know the incorporation of plastic waste and its effect on the behaviour of the manufactured concrete. The results showed that the density of concrete made from plastic waste is lighter than the reference concrete without waste (C0), which contains only natural aggregates, in a fresh state. In the case of hardening, the results showed a decrease in the compressive strength of composite concrete produced from plastic waste compared to (C0) the reference concrete. In the study's second part, a numerical model for precision and effectiveness is constructed using the finite element (FE) method. Furthermore, manufacturing experiments are scheduled to use computer simulations that account for labour, materials, tests, and time. The nonlinear stress-strain relationship for time-dependent concrete deformations and tension cracks presents a challenge for concrete modelling. ANSYS software is used to use three-dimensional nonlinear finite elements in order to determine this kind of complex mechanical behavior.

Development of Dry Fruits Laddoo

Abstract: The aim is to prepare Balls (ladoo) as a nutritional point of view and to provide convenience to the consumer. The ingredient which was used for preparation of balls is Dates (Phoenix dactylifera) which contains Energy: 282 cal, Protein: 2.5 g. Carbohydrates: 75 g, Fat: 0.4 g etc. Vitamin B-6 (PYRIDOXINE) is present. Minerals such as Calcium, iron, Magnesium are present in Dates. The flax seeds are very important in regular diet for humans especially for females. They increase nutrient absorption, help in weight loss, gluten free, rich in antioxidants and omega 3 fatty acids. Owing to these health benefits, dietitians and doctors advise to take flax seeds every day. Balls (ladoo) are good and typically made from various flours and dry fruits by various ways. Balls (ladoo) are usually round, sweet, small or large in size. For preparation of Balls (ladoo) ingredients used are pitted dates,flax seeds, almonds, cashews, Jaggery syrup, oats etc. all these ingredients were finely grounded. The formulation was made by varying levels of ingredients. For preparation of Balls (ladoo) all ingredients were roasted and then grounded into fine powder. The dates were pitted and then grounded in mixer grinder. All these grounded ingredients were made into dough by adding Jaggerysyrup. Three trials have been done T1, T2, and T3 by varying proportion of all ingredients and T3 has been selected. Proximate composition of ladoo ware fat content was found out to be 7.08 ± 0.02%, the protein content is 7.85 +0.09 %, the total carbs are 58.40 ± 0.07 %, the energy in ladoo was 328.72 kcal and ash content is about 2.01 ± 0.11% respectively). It was concluded that the Balls (ladoo) can be store for one month in High density polyethylene pouches at room temperature. These balls are rich source of iron so they satisfy consumer’s needs.