Conventional Liner Research Articles

Thermo Mechanical Analysis of Composite Cylinder Liners using Finite Element Analysis

Background/Objective: Cylinder liners are very important part of an automobile engine and working of the liner directly affects the engine performance. Conventional cylinder liners are being replaced with high temperature composite materials. The present work is to identify the performance of cylinder liners under combined mechanical and thermal load in terms of radial, longitudinal and hoop stresses by selecting different high temperature composite materials. Methods/ Findings: Different high temperature composite materials such as Carbon/Polyimide, Woven Carbon/Phenolic, Woven Graphite Phenolic, Carbon/Carbon composite, Boron/Aluminum, Silicon/Carbide composite cylinder liners are analyzed by applying pressure and thermal load. The variation in the radial stresses (σr ), longitudinal stresses (σl ) and hoop stresses (σθ ) are identified for selected materials. Thermo mechanical strains in radial, axial and circumferential directions are also identified. The analysis is performed by Finite element based software ANSYS. Solid 8node 183 elements are selected to perform the analysis. The Fe models are validated with the analytical equations. Application: Among all the materials considered in the analysis, Carbon/Carbon composite performance is good under considered loading and boundary conditions. Compared to all the stresses, the severity of axial stresses is more than radial and hoop stresses. The present work is used for the effective design of cylinder liners with high temperature composite materials. Keywords: Axial Stress, Cylinder Liner, Finite Element Method, High Temperature Composite Materials, Hoop Stresses, Radial Stresses

Isolated Acetabular Liner Exchange for Polyethylene Wear and Osteolysis with Well-Fixed Metal Shell

BackgroundThe isolated liner and head exchange procedure has been an established treatment method for polyethylene wear and osteolysis when the acetabular component remains well fixed. In this study, the mid-term results of this procedure were evaluated retrospectively.MethodsAmong the consecutive patients operated on from September 1995, two patients (three hips) were excluded because of inadequate follow-up, and the results of remaining 34 patients (34 hips) were evaluated. There were 20 men and 14 women with a mean age of 49 years. A conventional polyethylene liner was used in 26 cases and a highly cross-linked polyethylene liner was used in eight cases. In three cases, the liner was cemented in a metal shell because a compatible liner could not be used.ResultsAfter a follow-up of 5 to 20.2 years, re-revision surgery was necessary in 10 cases (29.4%): in eight for wear and osteolysis at 55 to 101 months after liner exchange and in two for acetabular loosening at 1 and 1.5 years after liner exchange. Re-revision surgery included all component revision (four cases), cup revision (four cases), and liner exchange (two cases). In all re-revision cases, a conventional polyethylene liner was used initially. There was no failure in the cases in which a highly cross-linked polyethylene liner was used.ConclusionsThe results of this study suggest that isolated acetabular liner exchange is a reasonable option for wear and osteolysis when the metal shell is well fixed. More promising long-term results are expected with the use of highly cross-linked polyethylene liners.

Wear analysis of explanted conventional metal back polyethylene glenoid liners

IntroductionGlenoid component wear and loosening is the Achilles heel of total shoulder replacement. Analysis of failed, revised implants might give an insight into the causes of component failure. Volumetric assessment of conventional total shoulder replacement glenoid liner wear rate and scanning electron microscopy was accomplished in this study for the purpose. Coherence scanning interferometry (white light scanner) 3D images were acquired. This method requires no physical contact, ionising radiation or extensive surface preparation. MethodsTwenty-four Nottingham total shoulder replacement system metal - back glenoid liners were explanted from revision shoulder arthroplasty cases. A Phase Vision Quartz DBE 800 scanner was used to scan the explanted polyethylene liners. The images of worn liners were registered to the reference image. Differences in wear and wear rate were quantified and central and non-central wear groups were distinguished. The Central wear group had a polyethylene wear rate of 115 ± 55mm3/year (mean ± SD). The non-central group showed a wear rate of 112 ± 42 mm3/year (mean ± SD), which was not significantly different from the central wear group (p = 0.426) Polyethylene liners showing edge wear from unstable shoulder replacements showed a wear rate of 545 mm3/year.Scanning electron microscopy images showed that the polyethylene was wearing in laminar flakes which indicated fatigue wear. ConclusionThe volumetric wear rate was found to be more than twice as fast as in the case of total hip replacement with the acetabular liner made of the same type of polyethylene. Use of coherence scanning interferometry is proposed for wear analysis.

A Comparison of microleakage at gingival wall in composite restoration using cocured and precured technique with conventional and modification liner: An in vitro study

Microleakage of composite restoration in proximal surfaces often occurs at the gingival wall. The purpose of this study was to analyze the microleakage at gingival wall in composite restoration using cocured and precured techniques with conventional and modified liner. Standardized class II cavities were prepared on 120 extracted human upper premolar mesial and distal fossae and categorized into 4four groups. Within box-like cavities, Group 1 was restored using a precured technique (conventional & modified liner), Group 2 was restored using a cocured technique (conventional & modified liner), Group 3 was restored using conventional liner (precured & cocured techniquea), and Group 4 was restored using modified liner (procured and cocured techniques). The specimens were subjected to thermocycling, followed by immersion in 1% methylene blue dye for 24 h. The teeth were sectioned mesiodistally and evaluated for microleakage under 25× magnification using a stereo microscope and scored using an ordinal scale (0–3). Statistical analysis was performed with the Kolmogorov–Smirnov test. Microleakage in Group 2 was significantly lower than Group 1 (p = 0.047). There was no significant difference between Group 3 and 4 (p = 0.985). The cocured technique showed lower microleakage than the precured technique. However, there was no statistically significat difference between conventional and modified liners.

Study on the Potential of Fabricated Non-Biodegradable Plastic Waste (N-BPW) Liner as Alternative to Conventional Geomembrane

This study investigates the potential application of Non-Biodegradable plastic waste (N-BPW) from household (plastic food packaging (PFP)) namely plastic snack packaging (PSP) and plastic bread packaging (PBP) as an alternative to conventional liner material in landfill. The samples were prepared into a single and fabricated layer. The fabricated layers were prepared by applying hot-pressing technique to joint between layers. Then the prepared liners were tested for its chemical and physical properties through Ultimate Tensile Strength Test (UTS) and Fourier Transforms Infrared Spectroscopy (FTIR). The tested samples were compared with conventional geomembrane. Obtained results from FTIR showed that proposed PFP had 70% similar characteristics to geomembrane. In addition, the fabricated samples can sustain high maximum load as compared to conventional geomembrane based on UTS. The proposed liners offer an option to the landfill operators in choosing a good reusable material at a lower cost, solved N-BPW landfilling problems and has great potential to promote as an alternative landfill liner.

Duct modes damping through an adjustable electroacoustic liner under grazing incidence

This paper deals with active sound attenuation in lined ducts with flow and its application to duct modes damping in aircraft engine nacelles. It presents an active lining concept based on an arrangement of electroacoustic absorbers flush mounted in the duct wall. Such feedback-controlled loudspeaker membranes are used to achieve locally reacting impedances with adjustable resistance and reactance. A broadband impedance model is formulated from the loudspeaker parameters and a design procedure is proposed to achieve specified acoustic resistances and reactances. The performance is studied for multimodal excitation by simulation using the finite element method and the results are compared to measurements made in a flow duct facility. This electroacoustic liner has an attenuation potential comparable to that of a conventional passive liner, but also offers greater flexibility to achieve the target acoustic impedance in the low frequencies. In addition, it is adaptive in real time to track variable engine speeds. It is shown with the liner prototype that the duct modes can be attenuated over a bandwidth of two octaves around the resonance frequency of the loudspeakers.

Application of sintered liners for explosively formed projectile charges

The paper presents the results of experimental investigations on the formation and penetration efficiency of EFP charges with liners performed by applying a powder metallurgy method. Two types of sintered powder liners were tested: liners of the shape of a spherical surface sector and the conical liners with an open apex angle. Liners were made of copper powder and have a base diameter of 45 mm and a mass of 30 g. Explosive charges with sintered copper liners were examined using X-ray pulse technique and a high-speed digital camera. Dynamic shaping of explosively formed projectiles was recorded and the perforation of a steel barrier was tested. Concluding, liners for EFP charges made using powder metallurgy technology proved to be a fully featured substitute for conventional spherical liners produced with a technologically more complicated manufacturing process.

Effects of Lithium and Phosphorus on the Efficacy of a Liner for Increasing the Shear Bond Strength Between Lithium Disilicate and Zirconia.

To evaluate the effect of the chemical formulation of liners on the shear bond strength (SBS) between lithium disilicate veneering ceramic and zirconia core. Four experimental groups (n = 12) were designed according to liner composition: negative control group (lithium and phosphorus removed from the conventional liner), Li group (lithium added to the negative control group), P group (phosphorus added to the negative control group), and Li+P group as the positive control (conventional liner). After applying the liner, lithium disilicate was pressed on zirconia. Specimens were stored in distilled water (37°C, 24 h) before testing the SBS. To test the SBS, shear force was applied perpendicular to the lithium disilicate-zirconia interface. The differences in the SBS between the veneer lithium disilicate and zirconia substructure were evaluated with one-way ANOVA (significance level of 0.05). The presence or absence of lithium and phosphorus influenced the efficacy of the liner. The negative control and P groups showed mainly cohesive failures, and the Li group mainly showed mixed failures. Both adhesive and mixed failures were observed in the Li+P group. The groups including lithium showed significantly higher SBS than the negative control or Li+P group (p < 0.05). The group including phosphorus, which showed higher crystallinity, showed significantly lower SBS than the negative control and Li+P groups (p < 0.05). The differences in the composition of the liner can affect the wettability and reactivity, and as a result, the SBS was different.

An updated structure for a stainless steel liner and the estimation of its buckling strength

Stainless steel liner has been used for the trenchless rehabilitation of damaged pipelines in China, but its limited buckling strength severely constrains its wider application due to the lack of ring stiffness. The increase of liner thickness to some extent results in a greater buckling strength, but still unavoidably causes a higher cost. With the intention of improving the stability of the thin-wall structure as well as saving project cost at the same time, an updated structure, consisting of numbers of arch liners, was introduced in this paper. Like the conventional circular liner, arch liners are in-situ manually welded to the host pipe to form a cylinder. To predict the buckling strength of rigidly encased arch liners, a theoretical model, modified from Glock’s buckling model, was also proposed, based on which the enhancement factor K was defined. With this theoretical model, a series of calculations was done to demonstrate the arch liner’s improved stability. Meanwhile, finite-element method (FEM) was used to estimate the buckling strength of arch liners, and the Arc-Length Control Method was applied in the simulation to trace the pre-and post-buckling behavior. Comparison between the theoretical model and FEM results was performed and the excellent agreement showed the model’s correctness.

Reuse of dredged marine soils as landfill liner: Effect of pH on Escherichia coli growth

A potential reuse area yet to be explored is the utilization of dredged marine soils (DMS) as geosorbent to retain pathogenic bacteria in landfill leachate. The use of DMS as geosorbent in landfill site could be considered as a new way of environmental friendly solid waste management. By laying DMS at the base of landfill like conventional clay liners, the geowaste could be simultaneously disposed of and act as passive geosorbent for microbes in leachate. DMS are known to serve as a hospitable environment for bacteria growth. Environmental factors such as soil’s pH, salinity and particle size could affect the bacteria growth rate. This study investigated the effect range of pH value on the growth of indicator bacteria, Escherichia coli (E. coli) isolated from landfill leachate. The results showed that the number of E. coli grew higher in alkaline compared to acidic condition. Findings from this study will serve as a base for future studies for removing bacteria in leachate using DMS as geosorbent in a landfill site.

Line Resistance Reduction in Advanced Copper Interconnects

Via resistance reduction in Cu interconnects was achieved through a pre-liner dielectric nitridation process prior to pure Ta liner deposition. Replacing TaN with Ta in the conventional liner stack reduces Cu via resistance, while the nitridation treatment maintains the interconnect integrity and reliability. Comprehensive evaluations including adhesion tests, parametric measurements, and electromigration evaluations of the pre-liner dielectric nitridation process were carried out to confirm the feasibility of reducing via resistance in advanced-node Cu/ultralow-k back-end-of-the-line interconnects.

Highly Cross-Linked Polyethylene Reduces Wear and Revision Rates in Total Hip Arthroplasty: A 10-Year Double-Blinded Randomized Controlled Trial.

Highly cross-linked polyethylene (XLPE) was developed to address the problem of wear and osteolysis associated with metal-on-conventional ultra-high molecular weight polyethylene (UHMWPE) bearing surfaces. The purpose of this study was to compare in vivo wear rates and clinical and radiographic outcomes between XLPE and UHMWPE in a prospective double-blinded randomized controlled trial with a minimum of 10 years of follow-up. We randomized 122 patients to receive either a conventional UHMWPE liner (Enduron; DePuy) or an XLPE liner (Marathon; DePuy). Ninety-one patients were assessed clinically and radiographically at a minimum of 10 years (range, 10.08 to 12.17 years). Oxford Hip Scores and Short Form-12 Health Survey scores were collected. The radiographs were analyzed for osteolysis and for 2-dimensional (2-D), 3-dimensional (3-D), and volumetric wear using validated software. All 122 patients were accounted for at the 10-year follow-up evaluation. Twelve patients had undergone revision surgery, 21 patients had died (1 of whom had previously undergone revision surgery), and 2 patients were unable to return for follow-up, leaving 91 patients available for clinical and radiographic evaluation. At a minimum of 10 years, 3-D wear rates were significantly lower (p < 0.001) in the XLPE group (mean, 0.03 mm/yr) than in the conventional UHMWPE group (mean, 0.27 mm/yr). The prevalence of osteolysis was also significantly lower in the XLPE group (38% versus 8%, p < 0.005), as was the revision rate (14.6% versus 1.9%, p = 0.012), with 10 of the 12 revisions being in the Enduron group. There was no significant difference between the clinical scores of the 2 groups. XLPE liners have significantly reduced wear and are associated with a greater implant survival rate at 10 years compared with conventional UHMWPE liners. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Neer Award 2017: wear rates of 32-mm and 40-mm glenospheres in a reverse total shoulder arthroplasty wear simulation model

Larger glenosphere diameters have been used recently to increase prosthesis stability and impingement-free range of motion in reverse total shoulder arthroplasty. The goal of this study was to evaluate the rate of polyethylene wear for 32-mm and 40-mm glenospheres. Glenospheres (32 mm and 40 mm, n = 6/group) and conventional polyethylene humeral liners underwent a 5-million cycle (MC) wear simulation protocol. Abduction-adduction and flexion-extension motion profiles were alternated every 250,000 cycles. At each interval, mass loss was determined and converted to volume loss and wear rate. At 0, 2.5 MC, and 5 MC, liners were imaged using micro-computed tomography to determine surface deviation. White light interferometry was performed on liners and glenospheres at 0 and 5 MC to quantify surface roughness. Wear particle morphology was characterized by environmental scanning electron microscopy. Total volume loss was significantly higher in 40-mm liners from 1.5 MC onward (P < .05). Overall, volumetric wear rate was significantly higher in 40-mm liners compared with 32-mm glenospheres (81.7 ± 23.9 mm3/MC vs. 68.0 ± 18.9 mm3/MC; P < .001). However, micro-computed tomography surface deviation results demonstrated increased linear penetration on 32-mm glenospheres compared with 40-mm glenospheres (0.36 ± 0.03 µm vs. 0.28 ± 0.01 µm; P = .002). Surface roughness measurements showed no difference for liners; however, increased roughness was noted for 40-mm glenospheres at 5 MC compared with 32 mm (P < .05). Larger glenospheres underwent significantly greater polyethylene volume loss and volumetric wear rates, whereas smaller glenospheres underwent greater polyethylene surface deviations. The enhanced stability provided by larger glenospheres must be weighed against the potential for increased polyethylene wear.

Effect of ammonium on the hydraulic conductivity of geosynthetic clay liners

Hydraulic conductivity and swell index tests were conducted on a conventional geosynthetic clay liner (GCL) containing sodium-bentonite (Na-B) using 5, 50, 100, 500, and 1000 mM ammonium acetate (NH4OAc) solutions to investigate how NH4+ accumulation in leachates in bioreactor and recirculation landfills may affect GCLs. Control tests were conducted with deionized (DI) water. Swell index of the Na-B was 27.7 mL/2 g in 5 mM NH4+ solution and decreased to 5.0 mL/2 g in 1000 mM NH4+ solution, whereas the swell index of Na-B in DI water was 28.0 mL/2 g. Hydraulic conductivity of the Na-B GCL to 5, 50, and 100 mM NH4+ was low, ranging from 1.6–5.9 × 10−11 m/s, which is comparable to the hydraulic conductivity to DI water (2.1 × 10−11 m/s). Hydraulic conductivities of the Na-B GCL permeated with 500 and 1000 mM NH4+ solutions were much higher (e.g., 1.6–5.2 × 10−6 m/s) due to suppression of osmotic swelling. NH4+ replaced native Na+, K+, Ca2+, and Mg2+ in the exchange complex of the Na-B during permeation with all NH4+ solutions, with the NH4+ fraction in the exchange complex increasing from 0.24 to 0.83 as the NH4+ concentration increased from 5 to 1000 mM. A Na-B GCL specimen permeated with 1000 mM NH4+ solution to chemical equilibrium was subsequently permeated with DI water. Permeation with the NH4+ converted the Na-B to “NH4-bentonite” with more than 80% of the exchange complex occupied by NH4+. Hydraulic conductivity of this GCL specimen decreased from 5.9 × 10−6 m/s to 2.9 × 10−11 m/s during permeation with DI water, indicating that “NH4-bentonite” can swell and have low hydraulic conductivity, and that the impact of more concentrated NH4+ solutions on swelling and hydraulic conductivity is reversible.

Evaluation of a new methodology to simulate damage and wear of polyethylene hip replacements subjected to edge loading in hip simulator testing

Wear and fatigue of polyethylene acetabular cups have been reported to play a role in the failure of total hip replacements. Hip simulator testing under a wide range of clinically relevant loading conditions is important. Edge loading of hip replacements can occur following impingement under extreme activities and can also occur during normal gait, where there is an offset deficiency and/or joint laxity. This study evaluated a hip simulator method that assessed wear and damage in polyethylene acetabular liners that were subjected to edge loading. The liners tested to evaluate the method were a currently manufactured crosslinked polyethylene acetabular liner and an aged conventional polyethylene acetabular liner. The acetabular liners were tested for 5million standard walking cycles and following this 5million walking cycles with edge loading. Edge loading conditions represented a separation of the centers of rotation of the femoral head and the acetabular liner during the swing phase, leading to loading of the liner rim on heel strike. Rim damage and cracking was observed in the aged conventional polyethylene liner. Steady-state wear rates assessed gravimetrically were lower under edge loading compared to standard loading. This study supports previous clinical findings that edge loading may cause rim cracking in liners, where component positioning is suboptimal or where material degradation is present. The simulation method developed has the potential to be used in the future to test the effect of aging and different levels of severity of edge loading on a range of cross-linked polyethylene materials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1456-1462, 2018.

Clinical and Radiographic Outcomes of Total Hip Arthroplasty With a Specific Liner in Small Asian Patients: Influence of Patient-Related, Implant-Related, and Surgical Factors on Femoral Head Penetration

BackgroundWe evaluated the clinical and radiographic outcomes, including femoral head penetration, of total hip arthroplasty performed using a specific polyethylene (PE) liner in small Asian patients at 10 years after the index surgery. In addition, we investigated whether femoral head penetration was affected by patient-related, implant-related, and surgical factors. MethodsBetween August 2002 and June 2005, for cementless primary total hip arthroplasty, we used acetabular PE liners that were manufactured from GUR 1050 resin, machined from isostatic compression-molded bar stock, and sterilized with a gamma ray irradiation in argon gas. We assessed 82 hips in 78 patients who received these liners. ResultsThe mean Harris hip score improved from 41.0 preoperatively to 84.5 at 10 years postoperatively. Periprosthetic osteolysis was observed in 7 hips (9.8%). No acetabular component migration was detected, and no revision surgery was performed 10 years postoperatively. The mean steady-state wear rate was 0.031 mm/y, which was lower than the wear rate for other conventional PE liners of the previous studies. Among the patient-related, implant-related, and surgical factors, sex was significantly associated with the mean steady-state wear rate, with a higher rate in male patients than in female patients. ConclusionPE acetabular liners used in small Asian patients show similar clinical outcomes and reduced wear compared with those of other liners. In addition, sex is significantly associated with the mean steady-state wear rate, and the steady-state wear rate is higher in male patients than in female patients.

Design and assessment of a distributed active acoustic liner concept for application to aircraft engine noise reduction

Acoustic liners are a widespread solution to reduce turbofan noise in aircraft nacelles, due to lightweight and relatively small dimensions for integration within nacelles. Although conventional liners might be designed so as to target multiple tonal frequencies, their passive principle prevents the adaptation to varying engine speeds and therefore lowers their performance during flight, especially in the take-off and landing phases. This paper presents a novel concept of active acoustic liner based on an engineered design of microphones and loudspeakers, aiming at absorbing noise over a broad frequency bandwidth. Integration issues have been taken into account so as to fit to the targeted application to aircraft engines, yielding thickness minimization, with a view to challenging existing passive, narrow-band, liners. The sound absorption performance of the proposed active lining concept is evaluated, through commercially available finite-element software, in a configuration mimicking an aeronautical ins...

Reduced aerodynamic drag concepts for acoustic liners

The objective of this paper is to describe the development of reduced aerodynamic drag concepts for acoustic liners in turbofan engine nacelles. Conventional acoustic liners help aircraft to achieve U.S. governmental noise regulations, however they are responsible for a measurable increase in the total aerodynamic drag of the aircraft. As regulations on commercial aircraft noise become more strict, additional surfaces may be covered with acoustic liner, heightening the need for the understanding and reduction of aerodynamic drag caused by liners. A linear force balance has been designed at the Mach 0.6 Wind Tunnel at the University of Notre Dame to evaluate the aerodynamic and acoustic characteristics of both conventional and 3D-printed liner samples. Through multi-parameter characterization, reduced drag concepts for future liners have been created. This paper will discuss the experimental work done to develop these reduced drag concepts, outline the future work to be done, and discuss the potential acoustic coupling effect on aerodynamic drag.

Hydraulic Performance of Organo Clay Enhanced Sand Bentonite as Secondary Liner

The leakage of petroleum from the storage tanks poses a serious threat to soil and groundwater. Hence an additional layer of impermeable material is usually provided as secondary containment systems in underground and above ground storage systems meant to store petroleum products. However the use of conventional mineral liner material is found to be ineffective for their use in secondary containment system to contain organic fluids. The conventional liner materials such as compacted sand–bentonite (SB) mixtures needs to be amended with materials of high organic sorption capacity. Therefore studies were carried out to assess the hydraulic performance of sand bentonite mixture amended with different percentages of organo clay (SOB) and to evaluate their possible use in secondary containment of petroleum product. The hydraulic conductivity of different SOB mixtures compacted at optimum conditions was evaluated with water and diesel as permeants. The coefficient of permeability was measured for various mixtures under different loads varying from 0 to 300 kPa. The permeability coefficient was evaluated both for loading and unloading cases. A decrease in the coefficient of permeability with diesel by an order of two, was observed on increasing the organo clay content from 0 to 10% in SB mix, where as a reverse trend was noted with water as permeant. The hydraulic performance of SOB mixture was found to be largely influenced by the proportion of organo clay, the nature of pore fluid and the applied pressure suggesting a need for careful proportion of mixture to be used as secondary liner.

Preliminary Study on The Potential of Hybrid Rice Husk with Kapok Fiber and Hybrid Rice Husk with Coconut Fiber as Landfill Liner Material

Abundance of agricultural waste in Malaysia namely rice husk (RH), kapok fiber (KF) and coconut fiber (CF) has been increasing over the years. This cause disposal problem and air pollution problem from burning activity. In line with the Malaysian Government Policy on the application of green technology concept through the 5R's practice, this agricultural waste has a potential to be commercialized as material for landfill liner. A factor that governs the workability of landfill liner materials is the permeability should be less than 1x10 -9 m/s. Therefore, a low permeability material needs to be installed to minimise the environmental impact on the leachate intrusion into groundwater. A series of standard tests to find environmental and geotechnical properties such as atterberg limit test (liquid limit, plastic limit, compaction test), permeability test (falling head method), leachate characteristics and heavy metal test were conducted at various ratio of hybrid materials (KC:RH and KC: CF in the ratio of 1:1 and 1:2 respectively). Experimental results confirmed that the hydraulic conductivity of the mixture of KC:RH:KF in the ratio of 1:1:1 is 7.29 x 10- 11 m/s was less than 10 -9 m/s, satisfying the requirement for landfill liner materials. Heavy metal testing showed that this hybrid material (RH:KF and RH:CF for ratio 1:2) were able to reduce at least 50 % of the leachate contaminants. The proposed hybrid materials (RH:KF and RH:CF) is a green material for the landfill (as it can improve heavy metal adsorption), increase the workability of the landfill by improving the conductivity of the conventional liners), minimizing manpower on site (no need expertise for installation) and reduction in cost (in terms of the use of waste materials).