Polyethylene Terephthalate Strips Research Articles

Exploring the Feasibility of Using Recycled PET Strips with Palm Leaf Ash for Sustainable Soil Stabilization

This research paper addresses the urgent environmental concern of waste management by focusing on sustainable consumption by utilizing waste plastic and palm leaves to stabilize soil in geotechnical engineering. The study examines the impact of incorporating recycled polyethylene terephthalate (PET) strips and palm leaf ash (PLA) into clayey sand to enhance its engineering properties. The investigation involved mixing varying proportions of recycled PET strips (10 mm, 20 mm, and 30 mm in length) with clayey sand, ranging from 0% to 2% by weight of the soil with a 0.5% increment for PET strips. Similarly, PLA was mixed with the clayey sand at proportions ranging from 0% to 12% by weight of the soil with a 3% increment. The strength parameters of lateritic soil were analyzed through the execution of unconfined compressive strength (UCS), triaxial, and California bearing ratio (CBR) tests. The optimum mixture was determined to be 2% recycled PET strips with a length of 30 mm and 12% PLA by weight of the soil. This specific combination exhibited significantly improved strength parameters for the lateritic soil, highlighting its potential for sustainable soil stabilization in geotechnical applications.

Using woven recycled plastic fibers in reinforced concrete beams

The modern lifestyle, along with the advancement of new technologies has produced plastic waste and the recycling of these waste materials has become an important challenge for human societies. Polyethylene terephthalate (PET) is one of the most consuming waste materials. A solution to repel these materials is to use them in the civil engineering industry and buried them in concrete. PET layers and strips were used in reinforced concrete beams instead of steel reinforcements by some researchers. But, in this study, the longitudinal and transverse steel bars were replaced by woven recycled plastic fibers and tested experimentally. These woven PET bars are produced by the authors and used as a structural element. Six beams with different combinations of steel and woven PET bars are tested under two-point loading and the experimental and analytical results are presented. The results show that using these fibers concludes to increases the ductility of reinforced concrete beams. By replacing PET ropes instead of one, two and three tensile steel reinforcements, the ductility ratios of the beams are about 1.73, 1.76 and 4.12 times of the reference reinforced concrete beam. Moreover, some theoretical formulation is presented and compared with experimental data.

Performance of clay soil reinforced with PET plastic waste subjected to freeze-thaw cycles for pavement subgrade application

The freeze-thaw (F-T) cycle is a common weathering process that often occurs in cold climates, and it can deteriorate the mechanical performance of the subgrade soil, leading to pavement failure and economic loss. Plastic wastes have been adopted as a soil reinforcement element to improve the geotechnical properties and stability of expansive clay soils used as subgrade material. Previous research has mainly focused on the application of polyethylene terephthalate (PET) plastic waste to soil reinforcement under ambient temperature, but few studies have investigated the geotechnical performance of expansive clay soils reinforced with PET plastic waste under freeze-thaw conditions for pavement subgrade application. Moreover, there is a lack of knowledge on the dynamic properties of expansive clays modified with PET plastics exposed to the F-T process. This study conducted a series of mechanical experiments, including repeated load triaxial tests and unconfined compressive strength tests, for the first time to investigate the mechanical performance of expansive clay soil reinforced with different percentages of PET strips (i.e., 0, 1, 1.5, and 2% by the weight of dry soil) after being exposed to 0, 2, 5, and 8 F-T cycles. The experimental results showed that the F-T process significantly reduced the compressive strength and resilient modulus. However, the compressive strength and resilient modulus of the PET strips-reinforced samples were higher than those of the unreinforced samples after F-T cycles. The optimum content of PET strips was found to be 1% by weight of dry soil, as it exhibited the highest strength and stiffness under various F-T cycles.

Mechanical, physical, blast waves and ballistic impact resistance properties of a concrete incorporating thermally treated PET inclusions

Polyethylene terephthalate (PET) plastics are widely used worldwide, and large amounts end up discarded in nature as waste after use. While the incorporation of PET in the concrete composite is known to be environmentally beneficial, it appears to also improve some characteristics of concrete. In this work the effect of PET strip shaped inclusions on concrete performance is investigated with PET fractions up to 20 kg/m3, while focusing on thermally treated plastic. The heat treatment has been shown to elevate the tensile strength of the inclusions by up to 120 %. This has led to a significant improvement in the mechanical properties of the concrete. In addition, the use of PET strips reduces thermal conductivity by up to 30 %. The ballistic impact resistance and blast waves resistance of concrete with treated PET strips is also investigated. The results show a better protection against the threat of explosive and bullet attacks.

Effect of NaOH Treated Polyethylene Terephthalate (PET) Plastic Bottle Strips on Stabilization of Soil

Plastics such as polyethene bags, bottles, and so on are growing increasingly common as science progresses. The disposal of discarded material is a significant issue because most plastic wastes are non-biodegradable and unsuitable for combustion due to the emission of hazardous gases. By just using controlled compaction, soil stabilization enhances the engineering capabilities of weak sub-soils or the addition of stabilizing agents such as cement, lime, fly ash, bitumen, tar etc. But these additions have also been quite costly in recent years. This research report gives a thorough examination of the performance and effectiveness of waste plastic bottle strips in soil improvement. This waste plastic bottle is made of Polyethylene Terephthalate (PET). The size of PET plastic strips used in this study is not more than 5 mm in length and 2 mm in width. These strips were treated with Sodium Hydroxide (NaOH) to perform the proper dispersion of PET bottle fibres in soil. Although sodium hydroxide is a noncombustible solution, it is a highly reactive substance. It interacts with PET strips to exhibit changes in its properties. This work comprises replacement of soil by NaOH treated PET bottle strips in the varying percentage of 0.75%, 1%, 1.5%, 2%, 3% and 4% by dry weight of soil sample and to find out the optimum percentage mix of PET strips. The strength and geotechnical property of soil mixed with NaOH treated PET strips was evaluated and compared with the strength of soil and non-treated PET strips mix. The result shows the benefit of adding NaOH treated PET strips over non-treated strips by improving the maximum dry density (MDD), unconfined compressive strength (UCS) and California bearing ratio (CBR) value appreciably at an optimum mix of 1.5%. This soil stabilizing approach may be utilized efficiently to fulfil social and environmental problems. This exploratory inquiry would lead to the ecologically friendly management of this waste material.

Patterned Colouring via Variable-Speed Single Stretching

We demonstrate a cost-effective, highly reliable/stable and environmentally friendly approach for the patterned colouring of a commercial transparent polyethylene terephthalate (PET). We show that different colour patterns (transparent, white/translucent, complete white/silver and different combinations of these three colours) can be realised in PET strips upon varying the speed during continuous stretching. The conditions for good quality colour patterns are investigated, and the length of transient region during speed change is investigated.

Influence of adding waste polyethylene terephthalate plastic strips on uniaxial compressive and tensile strength of cohesive soil

Unconfined compressive strength and tensile strength are important geotechnical characteristics whichare used for performance prediction and mix design in civil engineering projects. In recent years, theuse of waste materials as reinforcement elements such as glass, rubber and plastic waste increasedsignificantly. Nowadays, the use of polyethylene terephthalate (PET) has grown substantially for drinkbottles which is one of the most important environmental hazards. In the current study, the effect ofadding PET strips as reinforcement elements to a clayey soil has been studied by unconfinedcompressive strength and tensile strength tests. The compressive and tensile strengths of reinforcedspecimens with different PET contents (0%, 0.4%, 0.6%, 0.8% and 1% by the soil weight), lengths (12mm to 21 mm) and widths (3 mm and 6 mm) have been investigated. It was found that addition of thePET strips to the clay resulted in an increase in both the compressive and tensile strengths. The optimumPET content was dependent on the both width and length of the PET strips. The maximum UCS was321 kPa which observed in the specimen containing 0.8 % PET strips with 3 mm width and 18 mmlength. The maximum tensile strength was 33 kPa which observed in the specimen containing 0.6 % ofPET strips with 6 mm width and 15 mm length. The reinforced specimens containing I-shape PETelements exhibited a higher UCS value than that of the reinforced specimens with PET strips in mostcases which is may be due to increase of friction between the soil particles and the PET elements.

Braided composite stent for peripheral vascular applications.

Braided composite stent (BCS), woven with nitinol wires and polyethylene terephthalate (PET) strips, provides a hybrid design of stent. The mechanical performance of this novel stent has not been fully investigated yet. In this work, the influence of five main design factors (number of nitinol wires, braiding angle, diameter of nitinol wire, thickness and stiffness of the PET strip) on the surface coverage, radial strength, and flexibility of the BCS were systematically studied using computational models. The orthogonal experimental design was adopted to quantitatively analyze the sensitivity of multiple factors using the minimal number of study cases. Results have shown that the nitinol wire diameter and the braiding angle are two most important factors determining the mechanical performance of the BCS. A larger nitinol wire diameter led to a larger radial strength and less flexibility of the BCS. A larger braiding angle could provide a larger radial strength and better flexibility. In addition, the impact of the braiding angle decreased when the stent underwent a large deformation. At the same time, the impact of the PET strips increased due to the interaction with nitinol wires. Moreover, the number of PET strips played an important role in the surface coverage. This study could help understand the mechanical performance of BCS stent and provides guidance on the optimal design of the stent targeting less complications.

Effect of Recycled Polyethylene Terephthalate Strips on the Mechanical Properties of Cement-Treated Lateritic Sandy Soil

The civil engineering construction industry is nowadays one of the largest consumers of natural resources. Therefore, the proposal of using alternative materials that seek to reduce waste production or the use of previously generated waste is becoming increasingly necessary. This paper evaluated the effect of recycled polyethylene terephthalate (PET) strips on the mechanical properties of a cement-treated lateritic sandy soil. Unconfined compression strength (UCS) tests were conducted in natural and PET strips mixtures in different strips lengths and contents. In addition to UCS tests, compaction tests were also conducted in order to analyze the effect of these inclusions on the properties of a lateritic sandy soil. Lastly, direct shear tests were conducted on natural soil-strip, soil-cement, and soil-cement-strip composites using optimum UCS results. The addition of strips to the soil-cement composite showed an increase in the soil cohesion parameter. The inclusion of strips also provided a more ductile behavior to the soil, presenting greater deformations with fewer stress peaks. Results showed that the recycled strips’ inclusion in soil-cement can provide a material with high strength, ductility, and a highly sustainable alternative.

Large Scale Direct Shear Experiments to Study Monotonic and Cyclic Behavior of Sand Treated By Polyethylene Terephthalate Strips

The continuously increasing production of plastics in the last few decades has taken a heavy toll on the environment. Soil reinforcement with the use of randomly distributed fibers, plastics and glass has recently received a lot of attention. The use of polyethylene terephthalate (PET) strips as soil reinforcement has been observed to result in the increase in the shear strength. In this paper, the monotonic, cyclic, and post-cyclic properties of sand reinforced with different contents and aspect ratios of PET strips are investigated by carrying out a set of monotonic and cyclic direct shear tests. Accordingly, the influence of various parameters on the direct shear response of sand-PET mixture is examined. Results show that in the monotonic tests, for mixtures containing 0%, 0.5%, 0.75% and 1% PET with AR = 1, the peak friction angle is 37.5°, 41.8°, 42.7°, and 44.6°, repectively, while these values increase to 41.8°, 45.4°, 48.2°, and 50.4°, respectively, for post-cyclic monotonic tests. In addition, in the monotonic tests, for mixtures containing 0.5%, 0.75% and 1% PET with AR = 5, the peak friction angle is 48.8°, 52.2°, 54.0°, respectively, while these values increase to 50.9°, 54.8°, 55.9°, respectively, for post-cyclic monotonic tests. Results clearly imply that normal stress and cyclic shear strain amplitude contribute jointly to the contractive behavior of the reinforced mixtures. Moreover, the hardening behavior becomes less eminent when the sand is reinforced with PET strips due to the resistance mobilized against particle rearrangement. The post-cyclic shear strength of the PET-sand mixture is higher than their monotonic strength due to the densification occurring during the cyclic loading. In summary, the favorable impact of PET inclusion on the monotonic and cyclic performance of granular materials is deduced.

Flexure and shear behaviour of self-compacting reinforced concrete beams with polyethylene terephthalate fibres and strips

One of the major environmental concerns is the disposal of the solid waste. The limited landfill sites intensify the issue and increase the need for alternative use of solid waste. Plastic drinking bottles made of Polyethylene Terephthalate (PET) are one of the major portions of solid waste. Beverage containers are made by PET and are intended for single use only. This study is focused on the use of PET as Fibres cut from waste drinking bottles in concrete. Long strips and Short PET fibres cut it from waste beverage bottles were used in self-compacting reinforced concrete (SCRC) beams as reinforcement. Together with the steel reinforcement in beams, the PET strips or fibres were used with, and without shear reinforcement. In SCRC beams detailed for the flexural and shear failure, the 1 percent volume fraction of short strips or fibres were used. Material properties such as compressive strength, elastic modulus were performed along with the beams tested under four-point bending. The results were analysed and compared with strips or fibres reinforced beams with a control beam. Based on the results, it was found that PET bottles as strips or fibres could be used as shear and flexural reinforcement in concrete as enhance in ductility, load capacity and shift of mode of failure were observed with strips and fibres.

Using diffuse reflectance spectroscopy (DRS) technique for studying biofilm formation on LDPE and PET surfaces: laboratory and field experiments.

Biofilm formation on plastic debris needs to be further investigated, because microorganisms attached to plastics are transferred in all three dimensions to new regions by ocean currents. The current study aims to investigate biofilm formation on plastic strips in aquatic ecosystems using a simple physicochemical method commonly used to characterize solid surfaces, namely, the diffuse reflectance UV-Vis spectroscopy (DRS) method. Using virgin polymers that have not being exposed to the environment as a reference, DRS peaks can be attributed to the microorganisms attached to the polymer surface with time. The polymers tested were low-density polyethylene (LDPE) and polyethylene terephthalate (PET). For LDPE strips for all sampling times in the field, the development of the peaks among 10 similar samples was rather uniform in terms of peak wavelength with time. For PET strips during the early sampling time, the development of the peaks among 10 similar samples was rather uniform in terms of peak wavelength but varied in terms of intensity. This last observation phased out with longer exposure times that the peaks had similar distribution in terms of peak wavelength and intensity. Similar experiments were run for longer exposure times both in an oligotrophic laboratory bioreactor and in the marine environment. In both cases, the biofilm on PET samples seems to reach a steady state faster than LDPE with similar peaks found on both samples DRS proved to be a robust and useful tool to study the formation of biofilm on plastic samples without any pretreatment and without sample destruction. Graphical abstract.

Mechanical characterizations of braided composite stents made of helical polyethylene terephthalate strips and NiTi wires.

The novel braided composite stent (BCS), woven with both nitinol wires and polyethylene terephthalate (PET) strips, were characterized and compared with the braided nitinol stent in the same weaving pattern. Finite element models simulating the stent compression and bending were developed to quantify its radial strength and longitudinal flexibility. The interaction between the nitinol wires and the PET strips were also delineated. Results showed that the PET strips enforced more constrains on the BCS and thus enhance its radial strength especially at a larger compression load. The longitudinal flexibility of the BCS was less sensitive to the presence of the PET strips. This work suggested that the novel design of the BCS could acquire the advantage of a covered stent without compromising its mechanical performance. The fundamental understanding of the braided composite stent will facilitate a better device design.

Examination of Concrete Elements Bending Strength Reinforced by Polyethylene Terephthalate (PET) Waste

Ukrainian enterprises of PET (Polyethylene Terephthalate) waste recycling are still capable of processing only 1 thousand tons, and more than 10 thousand tons of PET granulate are imported to Ukraine every month. Therefore, the issue of reuse and disposal of used polyethylene terephthalate, especially in construction, is one of paramount importance. The aim of the research is experimental-theoretical study of the strength of bending of prisms, reinforced with fibers and strip reinforcement of used PET bottles. Objectives of the research: the study of the percentage of reinforcing fibers in volume (1% and 1.5%) influence on the flexural strength of concrete reinforced prisms, and the possibility of using ribbon reinforcement from used PET bottles for bending concrete elements, elaboration of proposals for the deformation method of calculation of PET fibrobone bent elements. In this research the experimental methods for determining the bending strength of prisms, reinforced by fibrous, trips and PET waste tapes; methods of materials resistance theory have been used. During the research, two concrete prisms of 400x100x10 mm were constructed and tested for compression together with two concrete prisms of three-point bend for a run of 350 mm, two PET-fibrous concrete prisms for bending with percentages of reinforcement in volume of 1% and 1, 5% and two prisms for bending, reinforced with glued PET strips, with 1% reinforcement per section area. As a disperse reinforcement, pre-fabricated PET bottles of 50x3x0.2 mm were used, designed in way that the required length of sealing in the concrete is no longer than half the length of the fibers. Strip fittings are made of 4 fragments of PET bottles of 200x80x0.25 mm in size, glued with cyanacrylate adhesive with each other, and 2 fragments of 120x80x0.2 mm in size, which glued on both ends to 4 glued sheets with a length of 30 mm. Thus, the total length of the reinforcing strip is equal to 380 mm. At the final sections of the tapes, 6 openings with a diameter of 5 mm were punched to improve the anchoring. The reinforcing strips were placed in the forms located 10 mm from the lower edge. According to the results of the tests, the average cubic strength of concrete is 31.21 MPa, of prisms - 23.23 MPa, the initial module of deformation - 28.02·103 MPa. The flexural strength of prisms without a fibre is 58.54 kN·cm, with 1% fibers in volume - 64.31 kN·cm, with 1.5% fibers in volume - 71.84 kN·cm, and of prisms, reinforced with glued PET ribbons – 79.80 kN·cm. As a result of the tests, it was demonstrated that the strength of the tapes was not used properly, and the fracture was fragile due to the loss of adhesion to concrete. Analysis of the results of experimental studies allowed us to develop a deformation methodology of calculating PET-fiber-concrete bending elements.

Impact Assessment of Plastic Strips on Compressive Strength of Concrete

This work attempts to analyze the impact of plastic strips on the compressive strength of concrete. Three sets of concrete mixes, one of conventional concrete (CC) and the other two modified concrete with plastic [polyethylene terephthalate (PET)] strips, viz., horizontally oriented plastic strips (MC-H) and randomly oriented plastic strips (MC-R) were tested. Load and deflection controlled analyses show the PET strips as contributing toward 5%–15% enhancement in compressive strength and a substantial reduction in the standard deviation (60%–65%). Further, modified concrete in comparison with conventional concrete exhibits higher stiffness and the early arrival of peak load with relatively steeper response in the postpeak regime. An analytical model attempting to quantify the role of PET strips in offering confinement is proposed in the study. The model describes the contribution of PET in terms of confinement stress and is used to justify early arrival of peak load. It also closely predicts the inclination of failure plane. This study reveals the positive role of PET strips in controlling heterogeneity in concrete behavior, increasing stiffness, and attaining early peak load.

Two Atmospheric-pressure Plasma Sources for Polymer Surface Modification

Two atmospheric-pressure plasma sources were studied. One was a helium plasma generated by a RF discharge, and the other was an air plasma generated by a dielectric barrier discharge (DBD). The two plasma sources were characterized on electron density, emission spectrum, and ozone density. The modification of polyethyleneterephthalate (PET) surfaces by the two plasmas was investigated. PET strips were exposed to the plasma at the exit of the plasma source. Water contact angles were measured for surfaces modified with different processing parameters. The change in contact angles was monitored as a function of time. Modification mechanisms were also investigated.

Surface modification of polyethyleneterephthalate by an atmospheric-pressure plasma source

The modification of polyethyleneterephthalate (PET) surface by an atmospheric-pressure plasma source was investigated. The plasma was generated by a RF discharge at atmospheric pressure using a gas mixture of helium and oxygen. PET strips were exposed to plasma for different durations at the exit of the plasma source. Water contact angles were measured for surfaces modified with different RF powers, oxygen concentrations and exposure durations. The changes of the contact angles of the modified surfaces were monitored as a function of time. The surface modification was determined to be mainly a photochemical and chemical process through the analysis and experiments on ions, ultraviolet photons, oxygen atoms and ozone molecules.

Validation studies of a quick test for predicting the sorption and washing properties of refillable plastic bottles

Quick tests are proposed in the literature as alternatives to the large scale contamination and washing studies performed to date to assess the acceptability of plastic beverage bottles for refilling. These tests use small plastic specimens ('strips') in place of bottles and use mixtures of surrogate contaminants to model the myriad of chemicals that could in principle contaminate returned bottles because of consumer mis‐use. The work reported here has measured the sorption and wash perfomance using the quick test protocol with PET (polyethyleneterephthalate) strips and laboratory washing and compared the results with tests using actual bottles and a commercial washing process. The comparison indicates that the quick test satisfactorily simulated contamination and commercial washing of intact bottles. The results also show that repeated washing of PET bottles does not cause higher sorption of contaminants.