Recycled High Density Polyethylene Research Articles

Modification of Recycled HDPE Composite with OPEFB Microfibers Through the Melt Blend Extruder Process

Oil palm empty fruit bunches (OPEFB), have not many been used as a have economic value material. OPEFB fiber content can be using as a filler to composites fabrication. The fiber contained in the OPEFB can be increase composites quality because have high thermal and mechanical properties. SEM analysis shows that OPEFB waste with a size of 63 and 90 ?m is suitable to be use as a filler because of the compatibility of the fiber and matrix matrix. As with the results of the DSC analysis, the melting point of HDPE-TKKS composite with 63 ?m fiber size reaches 133.58 0 C while the melting point of HDPE-TKKS composite with 90 ?m fiber size reaches 134.41 0 C. The FTIR test results also show that the indications of the two samples have the same chemical composition, namely lignicellulose. The best tensile strength is obtained which is equal to 21.11 MPa and the force required to break the composite is 391.56 N, these results were obtained from composites with a ratio of 60: 40 (matrix : filler) and 90 µm fiber size. Key words : Plastic, HDPE, fiber, OPEFB, composit e

Effect of wood particle size on the water absorption of wood-plastic composites

The main aim of this paper is to present the research findings which come out from the experimental determination of the influence of input raw material properties and composition on the water absorption of wood-plastic composites. During the WPCs production, important raw material parameters such as wood sawdust particle size, wood/plastic concentration ratio or type of plastic matrix can be recognized. In this research study, the aim was to produce WPCs of an acceptable and competitive level of quality which is determined from the final mechanical properties of WPCs. Particle size of wood sawdust used for production of WPC has significant influence on mechanical properties of composites and also on other important properties (water absorption, hardness, frost resistance, etc.). Using a variety combination of influencing variables the final quality of composites and also the operating parameters of the injection molding press can be improved. Their effect can be seen from the quality indicators and from the operating parameters of the injection press which has a direct impact on the production costs. The paper deals with the determination of the impact and the relationship between the input wood sawdust particles sizes, wood/plastic concentration ratio and water absorption of composites. By side intention of authors is to determine the possibilities of waste raw materials usage. The experimental research findings were obtained using a semi-operational injection molding press where the injection is provided by a working screw. As the input raw material, spruce sawdust, HDPE plastic matrix and recycled HDPE, represented by lids from PET bottles, was used. The effect of the input wood sawdust particle size on water absorption was determined according to a combination and default levels of wood/HDPE concentration ratio, using recycled HDPE instead of virgin HDPE and particle size of wood sawdust.

Hydrological Behaviour of Extensive Green Roofs with Native Plants in the Humid Subtropical Climate Context

Different mitigation measures with vegetation have been proposed to sustainably manage rainwater, among which green roofs have demonstrated to be a valid solution in urbanized areas. Green roofs have gained interest also in Italy, but their spreading is generally based on application of ready-to-use packages, poorly tested in the specific climate conditions. A study was carried out to evaluate the green roof solution most suitable in the humid, subtropical climate context of Veneto Plain (north-eastern Italy) to reduce outflow volumes from building roofs into the urban drainage systems. Twelve different microcosm combinations of extensive green roof (three plant mixtures × two substrates × two storage/drainage layers) were tested and compared with gravel (considered as a conventional flat roof with gravel ballast). The tested drainage/storage layers were a preformed layer in recycled HDPE (PL) and an expanded perlite mineral layer (ML), and the growth medium layers were recycled brick substrate (RS) and volcanic substrate (VS). Three different mixtures of native plant species were transplanted: Sedum (SE), herbaceous perennial (HE), and suffruticose (SF). Results showed that all the green roof systems have a good ability to manage rainwater, with a retention ranging on average from 46.2% (SE-RS-PL microcosms) to 62.9% (SF-RS-ML microcosms) of the precipitation in the two-year period (September 2014–August 2016), against 15.4%, retained by gravel. Over the two-year period, the retained rainfall volumes were about 100% for all the light rainy events (<10 mm) and varied within a range of 48–95% for medium rainy events (≥10 and <25 mm) and 20–88% for heavy rainy events (≥25 mm), depending on rainfall depth and the antecedent weather period. The layer that gave the highest relative contribution to the stormwater retention was the vegetation layer, followed by the drainage/storage layers and then the substrate layer. In particular, SF plants decreased the outflows by 15.2% on average compared to SE, and ML layer retained more than 10% of precipitation compared to PL layer. At last, the analysis of variance showed that, within each layer, the more effective in water retention, able to generate less outflow volumes, was similarly suffruticose and herbaceous mixtures, the crushed bricks substrate, and the mineral drainage/storage layer.

New methods to remove volatile organic compounds from post-consumer plastic waste

While the annual European demand for polyolefins is 25 million tonnes, only 3 million tonnes of recycled polyolefins find their place in the market, despite collecting 15 million tonnes of post-consumer polyolefins every year. Brand owners of care products are showing their interest in using post-consumer recycled plastics for their packaging. However, there is a general concern in using these materials, as recycled polymers can contain unwanted substances that may expose the consumer to health risks or make the packaging unattractive. Accordingly, the presence of these contaminants narrows the market opportunity of recycled plastics to applications with low-quality requirements and in which the product is not in direct contact with the consumer.Though mechanical recycling is the most widespread solution presents limitations in terms of decontamination, as only superficial substances are removed. Thereby, the volatile organic compounds (VOCs) migrated to the polymer matrix remain inside. Consequently, there is a need to find a solution to purify recycled plastics and increase their market share.This study focuses on removing VOCs from post-consumer recycled HDPE through two innovative methods applied for the first time in this field, steam stripping and polyethylene glycol (PEG) extraction. The methodology implemented to analyze the volatile organic compounds in HDPE was HS-SPME-GC/MS. Both methods showed a decrease above 70% in the VOCs content compared to extrusion-degassing. Moreover, these were compared to hot air stripping, a new technology developed at an industrial scale for the removal of VOCs. As a result, steam stripping improved efficiency in reducing the overall VOCs compared to hot air stripping. The PEG extraction method lowered the volatile polar compounds further than using hot air stripping. Additionally, none of these technologies modified the HDPE melting flow index.

An evaluation of thermoplastic composite fillers derived from construction and demolition waste based on their economic and environmental characteristics

The use of waste is often justified by the economic and environmental benefits of their use. This study compares the use of waste materials derived from construction and demolition waste—namely wood waste, mineral wool waste, gypsum board waste, and stone cutting dust—as alternative fillers in the production of thermoplastic composites using recycled high-density polyethylene as a matrix material. In total, nine alternative composites were studied in terms of their production costs, as well as their climate change impacts in three distinct product applications. Compared with the plastic matrix, the wood fiber achieved a cheaper price of €0.8–1.2/kg and the best properties in relation to weight. The price of mineral-based fillers varied between €0.5–1.1/kg, but the effect of the higher density on the weight increased the total price of the products. The unfilled recycled plastic was the cheapest solution in the application where the covered volume was important. The impact of using recycled high-density polyethylene in composites production totals at −1.24 kg CO2-eq./kg, out of where 1.75 kg CO2-eq. is the avoided impact from avoided waste disposal and 0.51 kg CO2-eq. is induced impact from producing the composites. When also accounting for the avoided impact from the substitution of virgin high-density polyethylene with the recycled high-density polyethylene composites, the avoided impact further increases to −3.17 kg CO2-eq./kg. The mineral fillers with were preferable in the application where mass was important, however, had lower avoided impacts than unfilled polyethylene ranging between −2.06 kg CO2-eq. and −2.47 kg CO2-eq. Wood fiber filler was the preferred filler option in the application where the material properties were taken into account in the amount of required material, but resulted in the lowest cumulative avoided impacts ranging between −1.79 and −2.25 kg CO2-eq., with most of the avoided impact originating from the replacement of virgin high-density polyethylene.

Rheological and Mechanical Investigation of PET, LDPE and HDPE Wastes Blended for Re-Use in Bio-Pipes

This work focuses on the re-use of biopolymer wastes to produce the pipes and reduce the impact of these materials on the environment. The ratios of 10, 20, 30 and 40wt% of recycled polyethylene terephthalate (RPET) were added to the reference blend, which consists of recycled low-density polyethylene (RLDPE) and recycled high-density polyethylene (RHDPE). Rheological and mechanical tests were performed on these blends. The blend of RLDPE and RHDPE was already successful in the manufacturing of pipes. The capillary rheometer was used to check the shear viscosity and shear stress behaviour with the shear rate increasing for different blends. The density, tensile strength, elastic modulus and impact strength were also tested for all blends. The results showed that the shear viscosity decreases and the shear stress increases with the shear rate increasing for all blends. In general, the addition of RPET to the reference blend decreases the viscosity at each shear rate. The blends of ten wt% and 20wt% are more compatible with the reference blend, while the blends of 30wt% and 40wt% exhibit a clear deviation after a shear rate of 300. The density indicates an increase with the increase of RPET to the reference blend. The tensile strength increases and impact strength decreases with the increase of RPET up to 30%. After that, the tensile strength decreases and impact strength increases up to the 40wt% RPET. The results showed that the rheological test can be used to predict the mechanical behaviour. Additionally, there was a good agreement observed between the rheological and mechanical tests. The ten wt% and 20wt% blends were more suitable for this task.

Application of short-term methods to estimate the environmental stress cracking resistance of recycled HDPE

Environmental stress cracking is a serious problem for polyethylene because it can cause failure without any visible warning due to the slow crack growth accelerated by aggressive agents. Tie molecules and entanglements are the main macromolecular characteristic increasing environmental stress cracking resistance, thus in this work mechanical and thermal properties governed by those macromolecular characteristics are determined by performing simple tests executable in the industrial laboratories for quality control on recycled high-density polyethylene. The mutual relation between the determined properties confirms their dependence on the investigated macromolecular characteristics and allows to predict in a comparative way the expected environmental stress cracking. The mechanical properties related to the environmental stress cracking resistance are the strain hardening modulus and the natural draw ratio. The strain hardening modulus is an intrinsic property that measure the disentanglement capability of the inter-lamellar links and the natural draw ratio is a highly sensitive parameter to the macromolecular network strength via the intercrystalline tie molecules. Since the measurement of these properties according to the standard ISO 18,488 requires a temperature chamber not often available in the industrial laboratories, the tensile test was performed also at room temperature and displacement rate 0.5 mm/min; a proportionality between the data obtained at different test condition emerged. The thermal property related to the environmental stress cracking resistance is the stepwise isothermal segregation ratio that state the chain fraction that generates a high rate of tie molecules responsible of environmental stress cracking resistance.

Effect of Surface Treatment on Mechanical Properties of Rice Husk Reinforced Recycled High Density Polyethylene (rHDPE) Composites

The aim of this work was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatment on rice husk were carried out which were maleated treatment, alkaline treatment and acrylic acid treatment. The characteristics and mechanical properties of the composites were analysed. The results for all treatments showed that tensile strength and break elongation of composites decreased significantly when the rice husk filler loading increased. Further findings showed that maleated treatment on rice husk can further enhance the mechanical properties due to the present of ester bond formed in FTIR analysis.

Influence of Azodicarbonamide on Physical and Mechanical Behaviours of Thermoplastic Blend

Foaming technology is promising in producing foamed materials which can offer benefits such as lowering the cost and weight of materials as well as their utility in many applications. In this study, the thermoplastic blend of recycled high density polyethylene and recycled polyethylene terephthalate was foamed with azodicarbonamide chemical foaming agent (CFA) at 0.5-2.0 phr. The blending of thermoplastic was carried out via extrusion and the foaming process occurred during hot/cold pressing. The cell morphology, density and mechanical properties were examined. Field emission scanning electron microscope (FESEM) micrograph showed that the thermoplastic blend foamed with 1.5 phr CFA had the cellular morphology structure with non-collapsed cells and better cell distribution. As the CFA content increased, the density of blend foams decreased accordingly. The minimum density was achieved at 1.00 g/cm3 for 2.0 phr ADC. Tensile and bending properties generally decreased with the content of CFA added. The impact strength of blend foams increased when the CFA added up to 1.0 phr and then reduced with further CFA content. It can be concluded that the fabricated foamed blend can give value added to the recycled polymers.

Assessment of Mechanical Properties of Recycled HDPE and LDPE Plastic Wastes

Most plastic materials can be recycled, and turning them into some useful products can be one of the options in reducing environmental pollutions. In this project, High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE) were used, shredded into smaller pieces and were hot-pressed to become flat plates. Both materials were then mixed with industrial waste sawdust with an aim to investigate their material properties and their suitability to be used in domestic applications such as bricks, pavement and roof tiles. Three destructive and one non-destructive methods have been conducted: tensile, impact, water absorption and ultrasonic testing. It was found that the tensile properties and impact resistance of the recycled HDPE are better than the recycled LDPE, but 10% lower than their virgin polymers. Higher stiffness and lower impact resistance were observed from specimens with additional sawdust filler in comparison to their original polymers. From the ultrasonic measurement, higher wave velocity and lower attenuation in HDPE specimens were observed, compared to the LDPE specimens, attributed by a higher modulus and density of the HDPE specimens. The ultrasonic velocity, which reflects the elastic modulus, and the attenuation that reflect the microstructure inhomogeneity are respectively decreased and increased when more fillers were added to the original specimens. This study reveals that the mechanical properties of the recycled HDPE and LDPE are closer to their virgin materials, and they have huge potential for plastic recycling.

Incorporation of recycled high-density polyethylene to polyethylene pipe grade resins to increase close-loop recycling and Underpin the circular economy

High-density polyethylene (HDPE) is one of the most used and demanded plastic, not only for packaging, but also for construction and within this application especially for non-pressure and pressure pipes, which makes this material the most abundant in the municipal waste stream. On the basis of the Circular Economy and the sustainable life that promotes, it is important to explore new applications for recycled HDPE (rHDPE) to increase the polymer recycled uptake. However, recycled HDPE is not currently being used in pressure pipes, mainly due to the high structural and loading requirements that must be met. The present study evaluates the potential use of post-consumer rHDPE from different origins in the manufacture of polyethylene pressure pipes. Different rHDPE sources are blended in different ratios with raw HDPE with PE100 grade quality. Blends are fully characterized to determine their feasibility to be used for pipe applications. Properties such as tensile strength at yield, elongation at break and flexural modulus for all blends yield values above the minimum required for PE100 grades. Furthermore, two important mechanical properties of polyethylene pipes, Slow Crack Growth (SCG) and Rapid Crack Propagation (RCP) resistances, are deeply evaluated. Remarkably, a dual correlation of SCG and RCP with the content of recycled PE in blends was established, allowing to develop predictive capabilities that guarantee the requirements and specifications for pressure pipe applications. Finally, through the evaluation of different waste streams, it can be concluded that handling, sorting, separation and selection of polyethylene’s waste is critical to achieve the required pipe specifications, and to increase the percentage of post-consumer rHDPE into the final product. This investigation is in line with the sustainability objective and the commitment to boost the circular economy by replacing part of the conventional HDPE raw material with recycled HDPE to increase close-loop recycling on PE for pipe application, and the basis for the recycling of rHDPE from pipe at its end-life, after 50 years in service.

Basalt fibre-reinforced high density polyethylene composite development using the twin screw extrusion process

Offshore renewable energy can lead the way towards sustainable energy harvesting and support the achievement of the CO2 reduction target by 2030. To achieve this goal it is necessary to decrease the manufacturing and deployment cost of the offshore devices. This paper focusses on the mechanical, chemical and microstructural assessment of a novel high density polyethylene (HDPE) reinforced with short basalt fibres for potential application as a hull material for wave energy devices. The choice of short fibres ensures the new composite can utilise existing low cost manufacturing methods for HDPE structures. In particular this study compares the properties of material with a recycled HDPE matrix with the properties of a material using a virgin HDPE matrix. The mechanical properties achieved by the novel composites exceed an improvement of ~300% in the properties of the monolithic polymer hence indicating the potential of this material, both for recycled and virgin HDPE. Furthermore, exploration in detail of the interaction fibres/matrix indicated the dynamic reaction between coupling agent and polymeric matrix showing the formation of molecular bonding perpendicular to the fibres, hence enhancing a 3D network that further increases the reinforcement abilities of the fibres.

Eco composites with synergistic combinations of natural rubber latex and wood flour toughened recycled HDPE

The recycling of thermoplastic waste reinforced with agricultural products has gained significant attention owing to its benefits towards the economy and the environment. Natural rubber latex (NRL), abundantly found in South East Asia, and wood flour (WF) were added to recycled high-density polyethylene (reHDPE) forming a three-phase composite with the aim of improving the composite’s mechanical resilience, where WF strengthens the composite. The composition of reHDPE was fixed at 80 wt. % and the two fillers were varied to observe the effects of fillers on the mechanical properties, specifically impact resistance. The addition of only 5 wt.% NRL (WF15 NRL5) raises the impact resistance up to 100 % with respect to the composite with only 20 wt.% wood flour. The composition with 5 wt.% WF and 15 wt.% NRL (WF5 NRL15) exhibited the highest impact resistance of 483 J/m and the best processing conditions due to the dispersion of NRL in the polymer matrix. The flexible properties were improved in the NRL-dominated composition. Additionally, higher NRL content increases the decomposition temperature, thus allowing tunable adjustments to the compositions for practical applications. Processing a three-phase reHDPE/WF/NRL composite showed favorable results towards low-cost products from recycled raw materials.

THE EFFECTS OF r-HDPE/r-PP FORMULATION RATIO INTO MECHANICAL, THERMAL AND MORPHOLOGICAL BEHAVIOR OF r-HDPE/r-PP POLYMERIC BLENDS

This study has reported the effects of different formulation ratio between recycled high density polyethylene (r-HDPE) and recycled polypropylene (r-PP) into the resulted mechanical, thermal and morphological properties of r-HDPE/r-PP polymeric blends. About five (5) different formulation ratio of r-HDPE/r-PP have been prepared and tested. The best combination ratio between r-HDPE and r-PP was determined in this work. It was found that the 70/30 wt.% of r- HDPE/r-PP blend possessed an outstanding mechanical and physical strength. About 59.80% and 2.30% of positive improvement in comparison to 0/100 wt.% of r-HDPE/r-PP was achieved for both of tensile strength and hardness, respectively. Interestingly, for 70/30 wt.% of r-HDPE/r-PP blend had also experienced major increased in their elongation at break up to 473%. The fracture morphological behavior of the tested samples that were observed via SEM observation, had established the interaction between the structure and properties of produced r-HDPE/r-PP blends, especially on the miscibility state between the r-HDPE and r-PP phases. Thermal evaluation by using the DSC had confirmed the partial miscibility state due to dominant peak shifting at 120 - 140°C and obvious melting peak reduction pattern. Overall, from this study, it was found that the blending between r-HDPE and r-PP into r-HDPE/r-PP blends are feasible to improve the properties of primary phase.

Recycling of European plastic is a pathway for plastic debris in the ocean

Polyethylene (PE) is one of the most common types of plastic. Whilst an increasing share of post-consumer plastic waste from Europe is collected for recycling, 46% of separated PE waste is exported outside of the source country (including intra-EU trade). The fate of this exported European plastic is not well known. This study integrated data on PE waste flows in 2017 from UN Comtrade, an open repository providing detailed international trade data, with best available information on waste management in destination countries, to model the fate of PE exported for recycling from Europe (EU-28, Norway and Switzerland) into: recycled high-density PE (HDPE) and low-density PE (LDPE) resins, “landfill”, incineration and ocean debris. Data uncertainty was reflected in three scenarios representing high, low and average recovery efficiency factors in material recovery facilities and reprocessing facilities, and different ocean debris fate factors. The fates of exported PE were then linked back to the individual European countries of export. Our study estimated that 83,187 Mg (tonnes) (range: 32,115–180,558 Mg), or 3% (1–7%) of exported European PE in 2017 ended up in the ocean, indicating an important and hitherto undocumented pathway of plastic debris entering the oceans. The countries with the greatest percentage of exported PE ending up as recycled HDPE or LDPE were Luxembourg and Switzerland (90% recycled for all scenarios), whilst the country with the lowest share of exported PE being recycled was the United Kingdom (59–80%, average 69% recycled). The results showed strong, significant positive relationships between the percentage of PE exported out of Europe and the percentage of exports which potentially end up as ocean debris. Export countries may not be the ultimate countries of origin owing to complex intra-EU trade in PE waste. Although somewhat uncertain, these mass flows provide pertinent new evidence on the efficacy and risks of current plastic waste management practices pertinent to emerging regulations around trade in plastic waste, and to the development of a more circular economy.

Potential use of waste from tree pruning and recovered plastic to obtain a building material: Case study of Merida, Mexico.

This work presents a study on the use of wood and plastic wastes generated in abundance in Merida, Mexico, to help to reduce them in order to mitigate environmental deterioration. The use of these wastes is proposed to obtain a low-cost building material. So, the escalation process (i.e., extrusion) at the pilot level to obtain a prototype of a wood-plastic composite (WPC) corrugated sheet to evaluate the technical feasibility to make a low-cost product is reported. A corrugated sheet with recycled high-density polyethylene (R-HDPE) was produced. The R-HDPE was collected from Merida's Separation Plant. The wood came from the trimmings of different varieties of trees and shrubs that are periodically pruned. WPC sheets with virgin HDPE were prepared to assess its effect on the materials' mechanical performance. The wood/HDPE weight ratio was 40/60. The performance of the WPC sheets was compared with that of commercial products with similar characteristics, namely acrylic and polyester sheets reinforced with fibreglass, and black asphalt-saturated cardboard sheets. Thus, the effect of natural weathering on the maximum tensile tearing force and on the maximum flexural load of the different types of sheets was evaluated. Although the mechanical performance of the WPC sheets was lower than that of the acrylic and polyacrylic sheets, their performance was much better than that of the cheap black asphalt-saturated cardboard sheets. So, they are a good option to be used as low-cost temporary roofing.

Influence of Raw Material Properties on Parameters of Injection Press during the Injection of Composites Based Biomass and Plastic Waste

The main aim of this paper is to present the research findings which come out from the experimental determination of the influence of input raw material properties and composition on the operating parameters of an injection press during the injection of biomass-plastic composites (BPC). During the injection process, important operating parameters such as injection speed, injection pressure and the temperature profile along the chamber can be recognized. In this research study, the aim was to produce BPCs of an acceptable and competitive level of quality which is determined from the final mechanical properties of BPCs. Using a variety combination of influencing variables the final quality of composites and also the operating parameters of the injection moulding press can be improved. Raw waste material variables influence, especially (a type of plastic matrix, type of biomass, particle size, moisture content) and biomass/plastic concentration ratio can be recognized during the production of composites. Their effect can be seen from the quality indicators and from the operating parameters of the injection press which has a direct impact on the production costs. The paper deals with the determination of the impact and the relationship between the input raw material variables and the operating parameters of the injection process (pressure, speed, and temperature profile). The experimental research findings were obtained using a semi-operational injection moulding press where the injection is provided by a working screw. As the input raw material, wheat straw and spruce sawdust, HDPE plastic matrix and recycled HDPE, represented by lids from PET bottles, was used. The effect of the input raw material composition was determined according to a combination and default levels of biomass/HDPE concentration ratio, using recycled HDPE instead of virgin HDPE and particle size of biomass.

Effect of Uncarbonized and Carbonized Eggshell Powder on Mechanical and Thermal Properties of Recycled High Density Polyethylene/Ethylene Vinyl Acetate Blend Composites

The blend composites of recycled high density polyethylene (rHDPE)/ethylene vinyl acetate (EVA) were prepared by melt blending technique at 160 °C with rotor speed of 50 rpm within 10 minutes. Based on Fatimah et al. study[1], the optimum ratio rHDPE/EVA at 70/30 were studied and prepared for different loading of uncarbonized (fresh) and carbonized eggshell powder (5 to 25 wt%). The ESP was collected, washed, crushed, and sieved to obtained size 63 µm by method Farahana et al,.[2]. But she founded that, the mechanical properties reduced with incorporation of ESP filler. Nowadays, carbonized natural filler are the focus of some researchers and the CESP was undergoing a combustion process for 3 hours at 700 °C with air combustion via muffle furnace. The result showed tensile properties decreased with increasing filler loading for both fillers. Then, the mass swell percentage after 46 hours soaked in dichloromethane, the results showed an increment of both fillers were increased the mass swell caused by the hydrophilic nature of fillers. The intensity ratio, interlayer spacing, and crystallinity percentage value decrease with increasing filler loading for both filler give better interaction between matrix and filler. The thermal stability increase for both filler with increasing filler loading. Overall, rHDPE/EVA/CESP blend composites had excellent properties with the addition of carbonized filler.

Recycled Wood Plastic Composites as Floor Panels for Ship Containers

Within the framework of this study, we aim at the replacement of plywood as ship containers floor material, with a lighter and friendlier-to-rainforests composite material. Wood fibre-reinforced thermoPlastic Composites (WPC) were developed using double-screw extrusion, consisting of recycled waste wood fibres reinforcing recycled High Density PolyEthylene (HDPE) matrix. This shift to WPCs has the dual positive effect of containers freight reduction as well as elimination of the use of natural resources, radically contributing to climate change measures. Following international shipping standards for container flooring, high quality recycled WCPs were developed. HDPE was found to provide acceptable structural performance. To that respect, WPC blends of HDPE matrix reinforced with 30%, 40% and 50%wt wood fibre flour, were fabricated and subjected to 3 point-bending mechanical testing. It was found that the studied WPCs reveal mechanical performance adequate to qualify as replacements of plywood timber flooring in ship containers.

Sepiolite as a nanofiller to improve mechanical and thermal behavior of recycled high-density polyethylene

Regarding the current demand for controlling plastic pollution, recycling of polymer sounds a promising solution. However, recycling causes mechanical and thermal shortcomings in polymers. Addition of nanoparticles to recycled materials may overcome these shortcomings. Nanocomposites can be achieved either by blending or through polymerization. Sepiolite as a nanoparticle enhances the thermal properties of polymers. In this study, the effect of sepiolite as a nanoparticle has been investigated on the thermal and mechanical behavior of recycled high-density polyethylene (HDPE). Hardness, density, Vicat softening temperature, melt flow rate (MFR), and differential scanning calorimetry has been investigated on recycled HDPE containing different amount of sepiolite. Results showed that both the amount of recycled HDPE and the sepiolite content affect the mechanical and thermal behavior of samples. Increasing the amount of recycled component resulted in increasing of MFR, a slight increase in density, and decrease in Vicat softening point, hardness, melting temperature, and degree of crystallization. As an opposite effect of these to factors on crystallinity of HDPE, sepiolite content has better effects to be considered separately for each recycle content. Sepiolite can be introduced as a low-cost reinforcement filler in recycling industry for tuning new compositions based on process condition, or vice versa.