Rubber Sheet Research Articles

Enhancement of mechanical properties of natural rubber latex sheets by incorporating allyl-modified microcrystalline cellulose (AMCC)

Microcrystalline cellulose (MCC) was chemically modified with allyl bromide through the hydroxyl groups of cellulose to obtain allyl-modified microcrystalline cellulose (AMCC). To enhance the curing and mechanical properties of natural rubber latex, this AMCC was then compounded with a natural rubber latex formulation to produce rubber sheets. Unmodified MCC was also compounded and prepared into rubber sheets, which served as a reference. The formation of AMCC was confirmed using Fourier Transform Spectroscopy (FTIR). Furthermore, the thermal behavior of AMCC was examined by thermogravimetric analysis (TGA), and the degree of crystallinity before and after modification was evaluated by X-ray diffraction (XRD). The results of the rubber sheets showed that overall, maximum torque (MH), degree of crosslinking density, vulcanization rate (cure rate index), and tensile strength increased in AMCC-loaded rubber compared to MCC-loaded sheets. On the other hand, optimum cure time (t90) and elongation at break were lower in the AMCC-loaded rubber than in the MCC-loaded sheets. In overall, this method outlines a successful incorporation of modified cellulose into natural rubber-based products to obtain enhanced mechanical properties.

Assessment of residual pesticides and other organic pollutants using passive samplers in Can Tho River, Vietnam, and Cagayan de Oro River Basin, Philippines

Agriculture-dependent developing Southeast Asian countries need to assess residual pesticides in receiving water from agricultural runoff as one of the basis for the establishment of baseline data. Monitoring residual pesticides in surface water is challenging due to pesticides’ irregular/intermittent emission and low solubility in water. To address the challenge of pesticide assessment, passive samplers composed of silicon rubber sheets (SR) and speedisk (SD) were used to capture hydrophobic and hydrophilic organic pesticides and other organic pollutants, respectively. Samplers were submerged uninterruptedly for at least 30 days in three selected sites in Can Tho River, Mekong Delta, Vietnam, and Cagayan de Oro River Basin, Philippines, for 2 years. Passive samplers (SR spiked with 232 pesticides) captured 83 and 69 residual pesticides at concentrations of ng/L levels in Vietnam and the Philippines, respectively, which is unattainable through conventional grab sampling methods. Trace concentrations of banned compounds such as OCPs, PCBs, and PAHs were also detected at pg./L levels. The success of this alternative methodology can be attributed to the combination of passive samplers tailored for nonpolar (water-insoluble) and polar (water-soluble) organic contaminants coupled with sensitive analytical instruments, including GCMSMS and LCMSMS.

Recent investigations using an artificial player for brass instruments

Artificial players show great interest for scientific studies on musical instruments: they allow sound production mechanisms to be reproduced, while making it possible to monitor several variables of the system that are usually difficult to measure on human players. In brass instruments, where the reed consists of the lips of the players, several systems have been developed over the years in research laboratories. In order to build artificial lips, one crucial element of the system, different solutions were proposed, such as latex tubes filled with water or rubber sheets. Although very realistic sounds can be obtained with some systems, one difficulty remains to build an apparatus which is relatively easy to control, stable, and repeatable. In this presentation, we will introduce the latest version of the brass artificial player developed in Yamaha and recently at LMA, which is based on a quite efficient, yet relatively simple, solution for the lips. The system then provides ease of use, stability and repeatability, while generating very realistic sounds. We will present some studies conducted with this new apparatus, and also demonstrate a portable version of it, that can trigger some ideas for other applications than research.

Electromagnetic wave absorption properties of La-Ca-Co-Al substituted M-type Sr-hexaferrite-rubber sheets in 50–75 GHz range

This study reports on the electromagnetic (EM) wave absorption characteristics of M-type hexaferrite-rubber sheets, where Al was additionally substituted into high-performance permanent magnet compositions, Sr0.2La0.4Ca0.4Co0.25Fe9.75-xAlxO19-d (LCCA-SrM, x = 0, 0.2, 0.4). While non-substituted SrFe12O19 powder-rubber sheet had a ferromagnetic resonance frequency (fFMR) of 48.5 GHz, the LCCA-SrM (x = 0, 0.2, 0.4) rubber sheets showed increased fFMR values of 63.3, 66.2, and 68.5 GHz, respectively, with the increasing x values. The frequency of minimum reflection loss (fRLmin) also increased correspondingly with the change in fFMR. This significant increase in fFMR and fRLmin is attributed to the greatly enhanced magnetocrystalline anisotropy from the La-Ca-Co substitution in SrM and the incremental increase in magnetic anisotropy field (Hani) due to Al substitution. The absorption band (Δf) satisfying RL < −10 dB, was 45.0–53.4 GHz for SrM, and 52.9–75, 50–75, and 59–74.2 GHz for the x = 0, 0.2, and 0.4 samples, respectively. The x = 0.2 sheets demonstrated the widest absorption, covering 50–75 GHz. This study is highly promising as it is the first to demonstrate the feasibility of developing an EM wave absorber sheet for frequencies above 50 GHz using hexaferrite powder synthesized via the solid-state method, which offers scalability and cost-efficiency for mass production.

Review of thermal neutron scintillators: Evaluation metrics and future prospects for demanding applications

Neutron applications are progressing rapidly, requiring detectors to meet increasingly rigorous criteria. Specifications such as high neutron counting rates, fast timing resolution and low background have a significant impact on choice of scintillator and how scintillators are evaluated. This work considers detector requirements for neutron scattering instruments that are becoming more stringent as the sources and scattering technologies continue to improve. Meanwhile, both prominent scintillators used for neutron scattering detectors, ZnS:Ag/6LiF and GS-glass, remain stagnant. While these scintillators have been suitable for many years, they are becoming a limiting factor for neutron scattering instruments. ZnS:Ag is inhibiting count rate capability and GS-glass is too gamma sensitive so alternatives need to be found. A brief explanation of neutron scattering, its detector requirements and how those relate to scintillator properties will be discussed. Furthermore, this work explains how standard characterization methods and reporting of scintillation properties are not entirely suitable for high count rate, low background applications like neutron scattering. As a result, modifications to characterization of gamma discrimination, light output, and decay kinetics are suggested. Additional steps are suggested including neutron activation and a more appropriate assessment of count rate capability. A non-exhaustive set of 6Li containing neutron sensitive scintillators including ZnS:Ag/6LiF, GS20 glass, ZnO:Zn/6LiF, Cs6LiYCl:Ce, 6LiI:Eu, 6LiI:Ce, 6LiCaAlF:Eu, LiCaAlF:Ce, transparent rubber sheet (TRUST) 6LiCaAlF:Eu, TRUST 6LiCaAlF:Eu with added fluorophore and EJ-270 (6Li containing plastic) are reviewed and studied from this different perspective. Finally, new scintillator developments relevant to high count rate, low background applications are discussed.

Zn-Zr substituted M-type Sr-hexaferrites for effective electromagnetic wave absorptions in the 26.5–40 GHz range

This study explores the electromagnetic (EM) wave absorption properties of Zn-Zr substituted M-type Sr-hexaferrites (SrFe12–2xZnxZrxO19, x = 0.3, 0.4, 0.5, 0.6) integrated into polymer composites (10 wt%, epoxy or rubber). The hexaferrite powders were synthesized using solid-state reaction processes with and without the molten-salt (M-S) method. Compared to non-M-S samples, those processed with M-S exhibited larger grain sizes and more defined grain edge shapes without clustering. High-frequency characteristics (ε', ε", μ', and μ") and EM wave absorption properties, specifically reflection loss (RL), were evaluated over the frequency range of 26.5 ≤ f ≤ 40 GHz. Regardless of the M-S method application, hexaferrite-epoxy composites (10 wt%) demonstrated excellent EM wave absorption properties with RLmin < −40 dB and a shifting absorption band corresponding to variations in x, reflecting changes in the ferromagnetic resonance frequency (fFMR). For the x = 0.4 sample, flexible rubber binder (10 wt%) sheets dispersed with hexaferrite powder were fabricated, showing superior broadband absorption characteristics compared to epoxy composites. In rubber sheet form, M-S processed samples exhibited enhanced μ', μ" spectra and improved absorption performance compared to non-M-S samples. The M-S processed hexaferrite-rubber sheet demonstrated broad EM wave performance with RL < −10 dB across the entire frequency range, achieving RLmin = −61 dB at 32 GHz. This study underscores the potential of Zn-Zr-substituted SrM-polymer composites for robust EM wave absorption performance in the Ka-band (26.5–40 GHz), crucial for applications in 5 G communication frequencies.

Development of low-cost portable spectrometer equipped with 18-band spectral sensors using deep learning model for evaluating moisture content of rubber sheets

While the choice of spectrometer can vary depending on its intended use, the increased cost of high-performance spectrometers may not be justified in certain applications. Therefore, this research developed an affordable and portable device using 18-band spectral sensors incorporating a deep learning model for accurately determining the moisture content in rubber sheets. A set of 286 rubber sheets was randomly separated into two categories: 200 for model calibration and 86 for model validation. In the calibration process, the spectral data were calibrated using a one-dimensional convolutional neural network (1D-CNN) and then were compared with a recognized linear model using partial least squares regression (PLSR). The experiments revealed the exceptional performance of the 1D-CNN model in predicting the moisture content of rubber sheets, outperforming the PLSR model. The 1D-CNN model had a better prediction accuracy, with a coefficient of determination (R2) of 0.962, a root mean squared error of prediction (RMSEP) of 0.410 %, a prediction-to-deviation ratio (RPD) of 5.2, and an error range ratio (RER) of 18.0. A portable device was constructed by incorporating the 1D-CNN model into a 32-bit microcontroller, which was embedded within the measurement device. During testing of the instrument, the results indicated that its predictive performance did not differ significantly from that of the primary calibration model. Therefore, it could be concluded that the designed instrument was capable of accurately measuring the moisture content of rubber sheets and is suitable for field use due to its portability and cost-effectiveness.

Promoting Adhesion of Natural Rubber/Styrene-Butadiene Rubber to Brass Using Vietnamese Natural Rubber-Based Adhesives

Abstract This study aimed to enhance the adhesion between brass and NR/SBR rubber sheets using solvent-based adhesives derived from Vietnamese natural rubber. The effects of silane coupling agents and iron nanoparticles on adhesion were investigated. (3-Aminopropyl) Triethoxysilane (APTES) and iron nanoparticles are incorporated into the adhesives at varying concentrations to enhance adhesion levels. The characteristics of the adhesive, such as viscosity, peel-off tensile strength, and the surface morphology of the adhesive bond failure, have been studied and evaluated. The research results demonstrated that as the APTES content added to the adhesives increases gradually, the peel strength between the NR/SBR and brass significantly improves. The highest peel strength value achieved was 5.27 N/mm at 25 phr APTES, representing a 974% increase compared to the sample without silane. The continued addition of iron nanoparticles to the adhesive further improves the peel tensile strength, reaching a maximum value of 5.93 N/mm at a nanoparticle content of 5 phr. This information will be crucial for developing practical applications for this type of adhesive.

The Benefits of Using Rubber Material in Two Variances: The Rubberized Concrete and the Natural Rubber Sheet, to Strengthen Concrete Barriers for Crash Energy Absorption

The Benefits of Using Rubber Material in Two Variances: The Rubberized Concrete and the Natural Rubber Sheet, to Strengthen Concrete Barriers for Crash Energy Absorption

Structural Improvement in Crane Boom Rest

Crane boom rests are critical components that endure both static and dynamic loads, leading to deformation and a shortened lifespan. This paper addresses these issues by proposing a redesigned model with enhanced stiffness and load-bearing capacity. The new design incorporates gussets and Styrene-Butadiene Rubber (SBR) sheets. A series of trials were conducted to analyze various stiffener configurations, with results showing a significant reduction in deformation. The optimal configuration, consisting of three L-shaped stiffeners placed at specific intervals, reduced deformation from 17.2 mm to 2.2 mm. Additionally , the integration of SBR rubber sheets further minimized deformation to 0.15 mm. These modifications demonstrate the effectiveness of the proposed improvements in enhancing the durability and performance of crane boom rests. The findings provide a robust solution for extending the operational life of crane boom rests under dynamic loading conditions. Future research can explore different rubber materials and stiffener designs to further enhance structural integrity and load-bearing capacity.

Structural Improvement in Crane Boom Rest

Crane boom rests are critical components that endure both static and dynamic loads, leading to deformation and a shortened lifespan. This paper addresses these issues by proposing a redesigned model with enhanced stiffness and load-bearing capacity. The new design incorporates gussets and Styrene-Butadiene Rubber (SBR) sheets. A series of trials were conducted to analyze various stiffener configurations, with results showing a significant reduction in deformation. The optimal configuration, consisting of three L-shaped stiffeners placed at specific intervals, reduced deformation from 17.2 mm to 2.2 mm. Additionally , the integration of SBR rubber sheets further minimized deformation to 0.15 mm. These modifications demonstrate the effectiveness of the proposed improvements in enhancing the durability and performance of crane boom rests. The findings provide a robust solution for extending the operational life of crane boom rests under dynamic loading conditions. Future research can explore different rubber materials and stiffener designs to further enhance structural integrity and load-bearing capacity.

Role of strain softening and viscoelastic memory for the rolling friction of two tire tread compounds.

Rolling friction is of great importance for many applications, such as tires and conveyor belts. We study the rolling friction for hard cylinders rolling on flat rubber sheets. The rolling friction depends on the number of rolling cycles, the rolling speed, and the temperature. We show that when the rubber is cooled down below the glass transition temperature, the deformations of the rubber surface are frozen-in, resulting in a non-flat rolling track where uphill and downhill rolling movements strongly affect the rolling force. The experimental data are analyzed using the Persson rolling friction theory; good agreement with the experiments is obtained when the non-linear (strain-softening) properties of the viscoelastic modulus are taken into account.

Experimental and numerical study on a new type of lead shear damper

This paper proposes a novel lead shear damper (LSD) composed of lead blocks surrounded by laminated steel shims and rubber sheets. The configuration and shock absorption mechanism of LSDs are thoroughly elucidated. Additionally, these innovative lead dampers undergo cyclic loading and fatigue tests, demonstrating commendable energy dissipation capacity and fatigue performance. Based on the test findings, a uniaxial constitutive model is introduced to characterize the hysteretic behaviour of LSDs, with corresponding parameters determined using the differential evolution method. The substantial agreement between experimental data and numerical simulations confirms the accuracy of the proposed uniaxial constitutive model, utilizing material parameters derived from the differential evolution method, which can be used for further study.

Effect of Particle Swarm Optimization Convolutional Neural Network in An Iris Recognition System

An iris recognition system based on Convolutional Neural Network with Particle Swarm Optimization (CNN-PSO) was developed to improve the identified hitches in the existing systems. Iris images of 150 and 108 persons were acquired from LAUIRIS (Nigeria) and CASIA (China) respectively. The images were resized and cropped after which Hough transform was used for effective localization of the iris region and normalised using Daugman’s rubber sheet model, while an efficient Cumulative Sum-based analysis method was used to extract discriminative features from the normalised iris images after which the iris code was generated. The iris code generated in a vector form was optimised with PSO after which they are fed into Convolutional neural network; the same procedure was engaged during enrolment and authentication to generate the iris template. Euclidean distance was used for decision making on test sample template and stored template. The system was implemented with MATLAB R2013a. The performance of the developed system was evaluated on LAURIS and CASIA, and compared with the existing systems (CNN, BPNN-PSO and BPNN) using False Acceptance Rate (FAR), False Rejection Rate (FRR) and Recognition Rate (RR). CNN-PSO has the highest recognition rate of 98.67% and 97.22% for LAUIRIS and CASIA respectively among the systems which showed an improvement over other three recognition technique. The developed CNN-PSO has not only produced an improved Iris recognition system over the others, with the highest recognition rate for both datasets but it also provides a significant recognition rate of black Iris images despite the limitations identified with black Iris images in separating Iris image from other part of the eyes. The developed

Effect of Particle Swarm Optimization Convolutional Neural Network in An Iris Recognition System

An iris recognition system based on Convolutional Neural Network with Particle Swarm Optimization (CNN-PSO) was developed to improve the identified hitches in the existing systems. Iris images of 150 and 108 persons were acquired from LAUIRIS (Nigeria) and CASIA (China) respectively. The images were resized and cropped after which Hough transform was used for effective localization of the iris region and normalised using Daugman’s rubber sheet model, while an efficient Cumulative Sum-based analysis method was used to extract discriminative features from the normalised iris images after which the iris code was generated. The iris code generated in a vector form was optimised with PSO after which they are fed into Convolutional neural network; the same procedure was engaged during enrolment and authentication to generate the iris template. Euclidean distance was used for decision making on test sample template and stored template. The system was implemented with MATLAB R2013a. The performance of the developed system was evaluated on LAURIS and CASIA, and compared with the existing systems (CNN, BPNN-PSO and BPNN) using False Acceptance Rate (FAR), False Rejection Rate (FRR) and Recognition Rate (RR). CNN-PSO has the highest recognition rate of 98.67% and 97.22% for LAUIRIS and CASIA respectively among the systems which showed an improvement over other three recognition technique. The developed CNN-PSO has not only produced an improved Iris recognition system over the others, with the highest recognition rate for both datasets but it also provides a significant recognition rate of black Iris images despite the limitations identified with black Iris images in separating Iris image from other part of the eyes. The developed technique can be applied to various field of life like security, surveillance systems.

Analysis and Design of Engraving Machine Movement

CNC routers play a significant role in several markets such as furniture design, circuit board manufacturing, plastic and foam fabrication. It can allow to complete projects in few hours that used to take several days CNC routers can work on sheets of woods, plastic, rubber, acrylics, and non-ferrous metal and CNC router machine moves and cuts in three directions using computer aided design software.A computer program has been established to design the power screws of any engraving machine. The power required to cut material was calculated by the program. The resisting force was analyzed and all stresses act on the power screws. The power screws were designed by using the main common theory of failures. The buckling and maximum deflection was checked in this program.An example of the output results was designed and drawn in Advanced Centre of Technology using solid works software. The nut connected to the screws was also drawn. The parts of engraving machine have been manufactured and tested in Advanced Centre Technology A.C.T in Libya.

Stratified numerical heat and mass transport mechanism in MHD Maxwell fluid flow with nonuniform heat source/sink

The present boundary layer flow of Maxwell fluid over a stretching sheet has good number of practical applications in metallurgy, drawing of plastics, polymer sheet extrusion including hot rolling extrusion, glass blowing, spinning of fibers, rubber and plastic sheets, crystal growing and many more. Due to these extensive applications of Maxwell fluid in engineering, medicine and manufacturing industries including the above-mentioned applications, authors have motived, inspired and investigated the present problem. However, in this research paper, the influences of Soret and Dufour effects on the steady-state Maxwell fluid flow past a stretching sheet with nonuniform heat source/sink are considered numerically. The thermal and concentration stratifications impacts are also incorporated. The viscous dissipation and magnetic field effects are also included in the respective governing equations. The main novelty and uniqueness of this numerical research is to generalize the earlier studies and describe the salient features of magneto-thermo visco-elastic dissipative Maxwell fluid motion about a stretching sheet with cross-diffusion effects under the influence of double stratification phenomena. To differentiate the non-Newtonian fluids from those of Newtonian fluids, a well-known Maxwell fluid flow model is used in the present study. The investigated physical problem results the highly nonlinear coupled partial differential equations (PDEs) and which are not amenable to any of the direct methods. Suitable similarity transformations are deployed to reduce the highly complex PDEs into the system of ordinary differential equations (ODEs). A robust BVP4C Matlab function is employed to solve the rendered dimensionless system of ODEs. The numerically generated computed data is plotted in terms of velocity, temperature and concentration profiles including engineering quantities of interest such as skin-friction, Nusselt and Sherwood numbers in the flow region. It is evident from the current analysis that, the amplified magnetic field decreases the velocity field and increases the thermal and concentration distribution fields. Accelerating Maxwell’s number diminished the flow velocity and increased the temperature field. Increasing Soret and Dufour numbers enhances the concentration and temperature fields, respectively. Amplifying Maxwell’s number raises the skin-friction coefficient and enlarging the thermal stratification parameter magnifies the thermal transport rate. The mass transport rate amplified with a raise in concentration stratification number in the flow region. Finally, it is provided that, the current results are excellently matching with earlier published results in the literature and it confirms the accuracy of the used numerical method and the produced similarity solutions.

Business model development for installation of rubber floor mats to support productivity in dairy farming

Purpose. Ribbed smoked sheet (RSS) rubber gradually loses its quality as it is stored after production. Rubber floor mats are recommended as a marketable upstream production in the Thailand rubber industry to help add economic value to low-graded RSS. However, limited attention in research has been paid to business development, particularly on practical models focusing on the demand perspectives. This study helped fill the knowledge gap by analysing factors influencing labour production in dairy farming and proposing a business model based on productivity analysis. The aim of the project was to create a practical business model for cattle rubber floor mats made of low-graded RSS rubber used for nourishing and housing management to promote labour productivity in dairy farming. Methodology / approach. The study used mixed-methods research. A theoretical framework was developed concerning rubber floor mats used in dairy farming, which helped improve the nourishing and housing management of dairy cattle and promote labour productivity. This research adopted Osterwalder’s business model canvas to examine the demand and supply elements of dairy cattle floor mats made of low-graded rubber. It also used the knowledge-based entrepreneurship concept to scrutinise knowledge-based business development. A questionnaire survey was used to collect data required for multiple regression analysis of labour productivity using the Ordinary Least Square (OLS) method. It also used semi-structured interviews to scrutinise the subjective experiences of farmers. A focus group discussion was conducted to investigate academics and rubber promotional authorities concerning potential technology and the possibility of transfer of production technology to promote knowledge-based business development. Results. The empirical evidence presented in this paper confirmed that rubber floor mats could help enhance cattle nourishment, dairy housing management and labour productivity. Regional knowledge transfer network was revealed as a driver of knowledge-based development for assisting local upstream rubber farmers in pursuing eco-innovation in rubber production, aligning with the national initiatives of Industry 4.0 and Bio-Circular-Green economy (BCG) concepts. Originality / scientific novelty. The originality of this paper is that it presents the results of an empirical study using mixed methods for the first time aiming at clarifying practical elements of the supply and demand sides’ components of the Osterwalder`s Business Model Canvas for developing a business model delivered as a knowledge-based business model for the production of dairy cattle floor mats made of low-graded RSS rubber to help guide practical downstream rubber business development. The qualitative results, together with the quantitative analysis of labour productivity, are based on the perceptions of local farmers in Thailand regarding the use of rubber floor mats on the farm; previous studies scientifically prove its positive relation to an increase in dairy cattle nourishing, hence the daily productivity. Practical value / implications. The novel business model canvas could promote the practical cattle floor mats business development. University engagement and public support were included as the critical drivers in this knowledge-based business model. The model implementation could help encourage rubber farmers and smallholders in upstream rubber production to move towards downstream business development and become knowledge-based entrepreneurs in value-added rubber floor mats production. It could also guide the agricultural policymakers to benchmark and evaluate their policy targeting innovative knowledge-based business development for rubber extension.

Numerical Simulation of Forming a 3D Shape by a Multi-Point Die

Multi-point forming (MPF) is considered one of the flexible and creative three-dimensional sheet metal forming processes. Such a technique replaces traditional rigid punches with a set of adjustable-height discrete pins. By altering the relative height of each pin, a variety of three-dimensional curved surfaces can be formed. In order to avoid changing the height of the pins manually, they are attached to springs. Hence, when a load applies at the pins holder, these will take the shape of the die due to the spring properties quickly and easily. However, wrinkles and dimples are inevitable issues that appear when using MPF. In order to investigate and minimize these defects, a finite element approach using ANSYS 15.0 software has been applied to perform numerical simulations for this MPF operation. Two cases have been examined in this study. Whilst the first one includes direct forming between the pins and the metal, a sheet of rubber has been added among them in the second case. The simulation has been conducted on brass (Cu Zn 65-35) with a thickness of (0.71 mm) and rubber with a thickness of (2 mm). The boundary conditions, which are attached to the blank, enable the motion in the y-direction only with respect to the lower profile at a depth of (30) mm, and was immobilized by constraints in the x and z direction. The study has shown remarkable results since the dimples were visible on the sheet surface in the first case, whereas these defects were significantly reduced during the second one. Moreover, the blank profile’s maximum stress and strain have been studied. Due to force distribution, rubber reduces maximum stress and strain to approximately 27% and 49%, respectively, in the second case

Mathematical Models of Natural Rubber Sheets Drying: Difference Acid Coagulation Cases

The mathematical model for drying process is a useful tool in process optimization and drying chamber design. The research purposes of this study were to investigate the influence of drying temperature on drying time and the modelling the drying kinetics of the natural rubber (NR) sheets. The NR sheets which produce from commercial formic acid, commercial acetic acids, and ammonia plus commercial formic acid were studied at drying temperature of 40, 50, and 60oC and air speed of 0.5 m/s. The results indicated that the drying time was substantially reduced with an increase in temperature. The moisture content ratio of rubber sheets produce from commercial formic acid coagulation was similar to the sheets produce from commercial acetic acids coagulation. However, the drying time of them were longer than the drying time of the sheets produce from ammonia plus commercial formic acid coagulation. Finally, the logarithmic model was the best model which suitable to predict the moisture content ratio of the sheets drying with all experimental condition.