Dry Rubber Content Research Articles

Key Mechanical and Durability Characteristics of Concrete Admixed with Natural Rubber Latex and Sisal Fibre

Objectives: Significant infrastructure projects may require the use of high-performance concrete that possesses specific characteristics, including exceptional flexural strength, hardness, impact resistance and long-lasting durability. Polymer modified concrete is such type of concrete which improves the flexural strength and serviceability requirement of concrete buildings. Methods: The purpose of this study is to determine whether Natural Rubber Latex (NRL), a natural polymer, can replace synthetic latex and enhance the performance properties of concrete. Concrete is enhanced by the inclusion of natural rubber latex, which contributes a dry rubber content ranging from 0.5% to 1.5% of the weight of cement in the mixed composition. This study examines and compares the characteristics of latex modified concrete with sisal fibre-reinforced concrete with a constant sisal fibre content of 0.3%. It also investigates the combined effect of fibre and latex in concrete. Findings: The findings demonstrated a substantial enhancement in the ability of concrete to absorb energy (up to 166%) under impact loading. Additionally, the modification of concrete using latex resulted in an improvement in flexural strength of up to 39%. The decreased permeability of chloride ions and reduced water absorption in latex treated concrete are clear indications of its exceptional durability. Novelty: Polymer modified concrete using NRL is the next generation concrete and the sisal fibre incorporation in it is a relatively a novel approach in the field of concrete technology. It encourages the advancement of eco-friendly technology in the construction industry. Keywords: Sisal Fibre, Impact resistance, Chloride permeability, Natural rubber latex, Water absorption

Environmentally Friendly Natural Coagulants in the Coagulation Process in the Rubber Industry

This research evaluates the use of natural coagulants, such as soursop and Aegle marmelos (Maja), in the latex coagulation process of the GT 1 clone type, compared with chemical coagulants such as formic acid and acetic acid, to gain an understanding of the characteristics of the rubber produced. Three types of crumb rubber (SIR 3 CV, SIR 3L, and SIR 3 WF) are produced from latex, while SIR 5, SIR 10, and SIR 20 are produced from treated latex coagulum. Rubber quality criteria are explained in the Indonesian Rubber Standard (SIR 3L/3WF) SNI 06-1903-2011. The use of natural coagulants, especially soursop, and Maja, in the coagulation of GT 1 clone latex shows an influence on coagulation time, Dry Rubber Content (DRC), initial plasticity (Po), Plasticity Retention Index (PRI), ash content, dirt content, and substance content evaporate. The results showed that natural coagulants had slower coagulation times, higher DRC values ​​(especially in maja), and better PRI values ​​compared to chemical coagulants. Despite having higher ash content, dirt content, and volatile matter content, all types of coagulants meet rubber quality standards. This research provides in-depth insight into the potential and advantages of natural coagulants, especially soursop, and maja, in the environmentally friendly rubber industry. In addition, analysis of rubber characteristics, such as plasticity, resistance to heating, and content of certain components, provides a comprehensive understanding of the impact of the use of natural coagulants on rubber quality.

Design and development of a system based on transient hot wire technique to determine dry rubber content in natural rubber latex

Design and development of a system based on transient hot wire technique to determine dry rubber content in natural rubber latex

Research on the production technology of rubber epoxy from concentrated natural rubber latex

The results of research on epoxidation technology from concentrated natural rubber latex (CNRL) and in-situ peroxyformic acid, which is synthesised from formic acid (FA) and hydrogen peroxide (HP), are presented in the article. The study investigated the influence of technological parameters of the epoxidation process, such as stabiliser content (nonylphenol ethoxylate, NP9), dry rubber content (DRC), isoprene, stirring speed, reaction time, reaction temperature, and molar ratios of hydrogen peroxide and isoprene (IP), on the epoxy resin content of the product. Research results have shown that the epoxidation reaction with NP9 at 10% takes from 2.5 to 20 hours under the following conditions: latex composition contains from 16 to 24% DRC, stirring speed 100 rpm, reaction temperature response 30 to 70 °C, HP/IP molar ratio changes from 0.7 to 1.3, FA/IP ratio is 0.2, the product was stable and without coagulation. The product was obtained with an epoxy content of 23.4 to 43.6%. This is the basis for building an epoxidized natural rubber (ENR) production process to create a series of natural rubber products that are renewable, environmentally friendly, low-cost, and have many industrial applications.

Evaluation of an ammonia‐free natural rubber latex adhesive

AbstractNatural rubber latex (NRL) within the adhesives industry has had limited applications because of poor water and chemical resistance; additionally, conventional preservation methods with ammonia produce poor adhesive properties and introduce toxicity. Today, solvent‐based adhesives dominate the market because of their superior mechanical properties; however, they negatively affect the health of users depending on the application due to the toxic chemicals. In this study, we investigated using a novel NRL‐based ammonia‐free adhesive as primary materials with bio‐additives, specifically cellulose, and collagen, to enhance their mechanical property provide the industry with an adhesive safe to handle. The peeling strength of an ammonia‐free NRL, 60% dry rubber content (DRC) NRL, with cellulose and collagen (Industrial Adhesive) were compared to high‐performance adhesives used within the footwear and construction industry to prove these adhesives direct applicability within these industries. Our findings showed that the ammonia‐free NRL Industrial Adhesive exhibited superior mechanical properties when compared against resilient flooring adhesives and footwear adhesives. Additionally, the peeling strength of an ammonia‐free 35% DRC with only cellulose (Office Adhesive) was compared to PVA‐based Elmer's Glue and it was observed that the ammonia‐free NRL adhesive outperformed Elmer's Glue by almost reaching four times the peeling strength of Elmer's Glue.

Stiffness, rutting, and fatigue performance evaluation of cement-natural rubber latex stabilized recycled concrete aggregate

ABSTRACT The stiffness, rutting, and fatigue performance of cement-natural rubber latex (NRL) stabilized recycled concrete aggregate (RCA) were evaluated under cyclic loading. The RCA was stabilized with 3% cement content and dry rubber content to cement (r/c) ratios at 5%, 10% and 15%. The performance evaluation was carried out through advanced experiments, including indirect tensile resilient modulus test, indirect tensile fatigue test, and rutting susceptibility test using a Hamburg wheel tracking device. The results indicated that the r/c ratio of 10% was optimum for cement-NRL stabilized RCA (3C10R-RCA), which exhibited the optimum performance in terms of permanent deformation, fatigue cracking, and rutting susceptibility. The indirect tensile fatigue life of 3C10R-RCA was found to be 79.3% greater than that of the 3% cement stabilized RCA (3C-RCA), while the rut depth of 3C10R-RCA was 8% lower. Although the resilient modulus value of 3C10R-RCA was slightly lower than that of 3C-RCA, the tensile permanent deformation was found to be lower, which is associated with the lower rut depth. As a result of the significant improvement in fatigue life and rutting performance, the resistance to fatigue cracking and premature failure of cement-NRL stabilized RCA were improved.

Kombinasi Dosis Pemupukan dan Frekuensi Sadap terhadap Produktivitas Individu Tanaman Karet

Fluctuating rubber prices cause rubber planters to suffer losses, especially when prices are low as of right now. Planters apply high-intensity tapping to obtain maximum production but this is not balanced with optimal fertilization and actually has a negative impact on the sustainability of rubber plantations. The purpose of this study was to determine the effect of a combination of fertilizing doses and tapping frequency on the productivity of rubber plants and to obtain optimal fertilizer doses and tapping frequency when rubber prices are low. The research method used a randomized block design (RBD), with six combination treatments of tapping frequency and fertilization. The results showed that the highest volume of latex was produced in the S/2 d3 ET treatment of 2.5% 100% fertilization, while the variable dry rubber content (DRC), tapping frequency treatment d3 (B, D, F) produced higher DRC and was significantly different compared to tapping frequency treatment d2 (A, C, E). The highest KKK was obtained in treatment F, namely 38.6%. Observation of individual plant production (g per tree per tapping), 50% - 100% fertilization treatment can increase the production of both tapping frequency d2 and d3. The highest production was obtained in treatment F (S/2 d3 ET2.5% 100% fertilization). So, tapping with d3 tapping frequency combined with 100% fertilization dose produces the highest individual plant productivity. Tapping with d3 frequency combined with 50% fertilization can be an alternative when the rubber price is low.

Utilization of Aloe Vera Extract as A Natural Coagulant and its Effect on The Characteristics of IRR 118 Clone Rubber

Rubber is one of the plantation products as a foreign exchange earner for the country. The process of processing rubber requires coagulants to accelerate coagulation. Aloe vera is a plant that contains compounds of organic acids, is expected to be able to accelerate the coagulation process. The purpose of this study was to determine the effect of the use of natural coagulants of aloe vera extract on the characteristics of IRR 118 clone rubber. The variations of the extracts used are natural coagulant extracts of aloe centrifugation and no centrifugation and the chemical coagulant format acid 3% as a comparison. Centrifugation of natural coagulant extract of aloe vera is carried out at a speed of 3000 rpm for 1 hour. The characterization of rubber analyzed was DRC (Dry Rubber Content), Po (Initial Plasticity), PRI (Plasticity Retention Index), ash content, evaporating substance content, mooney viscosity, dirt content, and nitrogen content. From the results of the study, it was obtained that the percentage of DRC, Po, PRI, and Mooney Viscosity was highest in AV natural coagulants without centrifugation, namely 28%, 36%, 80%, and 80%. The lowest percentage of ash, dirt and nitrogen content in natural coagulants of AV centrifugation was 0.38%, 0.014%, and 0.36%. Aloe vera natural coagulants without centrifugation and centrifuged ones can be used as coagulants for the latex coagulation process because they have met all the requirements of SNI SIR 20 and can be used as natural coagulants.

Pengaruh Penambahan Ekstrak Jeruk Purut (Cytrus hitrix D.C) Sebagai Koagulan Alami Terhadap Karakteristik Karet

Natural rubber is a plantation commodity that has a significant role in the country's economy. This study aims to determine the effect of the natural coagulant extract of kaffir lime with centrifugation and non-centrifugation treatment on the coagulation process, pH and coagulation time, characteristics of rubber clone IRR 118 and comparison of the quality of rubber with 2% formic acid chemical coagulant. The volume of coagulant used was 75 mL mixed with 150 mL of latex, so that coagulation occurred and produced coagulum. Then the resulting coagulum is analyzed for the characteristics of the rubber to determine the quality of the rubber. Characteristic analysis carried out was Dry Rubber Content (DRC), Initial Plasticity (Po), Plasticity Retention Index (PRI), Mooney Viscosity, ash content, impurities content, volatile matter content, and nitrogen content. The results showed that the natural coagulant extract of kaffir lime could coagulate latex, lowering the pH of latex thereby speeding up coagulation time. From the rubber characteristic test using kaffir lime natural coagulant it complies with SNI 06-1903-2017 SIR 20. The quality of rubber produced from using kaffir lime natural coagulant extract as a coagulant can equate the quality of rubber produced by using 2% formic acid chemical coagulant, but coagulant The natural ingredients used have drawbacks, namely the availability of seasonal fruit, and the need for treatment before being used as a coagulant.

Development of a prototype for the rubber latex industry to detect dry rubber content of fresh natural rubber latex using a novel measurement system with proton-electron transfer

Abstract Rubber latex industry has been looking for techniques to rapidly estimate the dry rubber content (DRC) of rubber latex with accuracy, at a low cost, and to be used by non-technical people in the field. The basis of electrical charge in terms of proton-electron transfer (P.E.TF) was used to develop a new prototype. The prototype was created with the P.E.TF system, two electrode probe detectors, and a new code program on Arduino board. The data was collected using the P.E.TF system of fresh natural rubber latex and presented as the P.E.TF number and the percentage of dry rubber content (%DRC). The standard method (ISO126:2005(E)) was used to calculate %DRC. The comparison of the %DRC measurement using the prototype and the standard method was studied. It was found that the new code program on Arduino board could evaluate the data. In real-time, it converted the P.E.TF number into %DRC on the LCD screen. The %DRC measurement using the prototype was close to that calculated using the standard method. The correlation between the two methods is 0.9814 of Rsqr. Therefore, the novel measurement system can replace the standard method for the %DRC measurement of fresh natural rubber latex. The prototype is simple, fast to detect, small, and low-cost without operator training.

Improved fatigue properties of cement-stabilized recycled materials – Lateritic soil using natural rubber latex for sustainable pavement applications

This research project investigates the role of a new recycled pavement material and natural rubber latex (NRL), in improving the resilient and fatigue performances of cement-stabilized recycled materials and lateritic soil (LS) blends under traffic loads. Two types of recycled materials, being steel slag (SS) and recycled concrete aggregate (RCA) and 5% cement content by weight were studied in this research. The dry rubber content in NRL to cement (r/c) ratios of 0%, 3%, 5%, 10%, and 15% were designed as the influence factor. The results indicated that mechanical strength properties namely unconfined compressive strength (UCS) and indirect tensile test (ITS), as well as fatigue properties namely indirect tensile resilient modulus (IT Mr) and indirect tensile fatigue (ITF) were enhanced with the NRL additive. Beyond the optimum r/c ratio, the excessive amount of NRL generated thick NRL films and retarded the cement hydration products, resulting in low strength and performance improvement. The r/c ratios of 3% and 5% were found to be the optimum r/c ratios for cement-NRL stabilized SS:LS and RCA:LS blends, respectively. The brittleness and permanent deformation of cement-stabilized SS/RCA:LS blends were significantly improved by the NRL additive. The superior mechanical and physical properties of SS and RCA were also attributed to the enhancement of fatigue characteristics of the cement-NRL stabilized blends. Finally, the mechanistic and fatigue models of cement- and cement-NRL stabilized soil with recycled material replacements were proposed, which are important for pavement designers and engineers when using a mechanistic-empirical pavement design approach.

Rekomendasi Kualitas Getah Karet Terbaik Berbasiskan Sistem Pendukung Keputusan dengan Metode MAUT

Rubber latex is a raw material that is widely used as the main ingredient in the manufacture of various kinds of tools, so that the quality of the rubber latex must be paid close attention. In connection with this quality, there are several things that must be considered including the age of the tree, tapping time, dry rubber content, color and texture. The problem in determining the best quality of rubber latex is that it is not paid enough attention to by farmers and most farmers tap rubber tree sap only based on feeling or hunch. If this continues to happen, it will cause the production of tools that use rubber latex to become of less quality. In addition, the production department will also need a long time to select quality raw materials. Decision support systems can be used as an alternative to help with these problems. The Multi-Attribute Utility Theory (MAUT) method is used as a method for analyzing sample data from rubber latex based on the value of each existing criterion. The stages of the MAUT method have seven processes, namely the starting stage, determining alternatives and also criteria, displaying inputted data and alternatives, determining the weights for each criterion, creating a normalization matrix and decision matrix, then doing the sum of the results of normalization with criterion weights. After obtaining the decision value, the system will display the results of recommendations or decisions from each available alternative. From testing 30 rubber latex data, it was found that 17 data showed good quality with a value of 0.56 to 1.00 and 13 data showed bad quality with a value of 0.20 to 0.55. After a comparison between manual calculations and the system built did not show any difference in results, so that the decision support system built can be a tool to assist in making decisions regarding the quality of rubber latex

Preparation of spent coffee grounds-rubber composites using natural rubber latex as binder

The aim of this work was to explore the use of natural rubber latex (NRL) as a natural binder (according to the BCG concept) to replace commercial synthetic binders such as polyurethane resin. A composite sheet of spent coffee ground (SCG) and natural rubber (NR) was prepared by mixing of SCG in NRL compounds having concentrations of 30% and 60% dry rubber content (DRC). The amount of SCG in the composites was varied from 33 to 167 part per hundred rubber (phr). The mixture was cast in a mold to form a thin sheet then left drying at room temperature for 24 h. TGA thermogram shows 3 decomposition stages composed of moisture (including volatile matters), polysaccharide and lipid at 44%, 42% and 13% weight, respectively. Hardness (Shore A) increases gradually with increasing the amount of SCG, while tensile strength and elongation at break tend to decrease. Tensile strength decreases from 2.6 MPa to 1.2 MPa for the composites containing 33 phr and 133 phr of SCG, respectively. Alkaline surface treatment of SCG could improve the adhesion between SCG and NR as evidenced by the increase in tensile strength, elongation at break and compression set properties.

Indian natural rubber price forecast–An Autoregressive Integrated Moving Average (ARIMA) approach

The objective of this study was to forecast the price of natural rubber in India during April 2019 to March 2020 by employing autoregressive integrated moving average (ARIMA). The monthly pricing data for the period from April 2008 to March 2018 was used for the study. The analysis was carried out during the year 2018–19. RSS4 (Ribbed Smoked Sheets), latex (60% DRC (Dry Rubber Content)) and ISNR 20 (Indian Standard Natural Rubber) are the different types of Indian natural rubber that are competitive in international rubber market. The prices of these types of natural rubber were taken for modelling. AIC was used as a selection criterion for the best-fitted model. ARIMA(3,1,2) for RSS 4, ARIMA (3,1,2) for Latex 60% DRC, and ARIMA (4,1,3) for ISNR20were the most suited modelsto forecast the price.The evaluation metrics were R2, Adjusted R2, Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and Root Mean Square Error (RMSE). These were employed for validating the forecasting model. The price forecasting of natural rubber in India can be a better-suited tool for the policymakers to decide on their investment in natural rubber cultivation.

Fast determination of total solids content (TSC) and dry rubber content (DRC) of para rubber latex using near-infrared spectroscopy

A rapid measurement method of total soluble solids content (TSC) and dry rubber content (DRC) of para rubber latex (PRL) is required for trading and production control purposes. The objective of this study was to develop the TSC and DRC prediction model of a PRL sample based on the near-infrared (NIR) spectroscopy method. The samples were scanned using the transflectance method, wherein the effect of the pathlength to model accuracy and precision were investigated. NIR spectra were collected, incorporating a wavelength region of 860–1760 nm. The models were developed using partial least squares (PLS) regression with either raw spectra or spectra pre-treated by a baseline offset, a standard normal variate (SNV), multiplicative scatter correction (MSC), and a fractional order derivative (FOD). The results of the TSC model developed using NIR spectra from a 8 mm pathlength had the highest performance, with R2p, RMSEp, Bias, and RPD of 0.97, 1.15%, 0.43% and 6.17, respectively. Meanwhile, the NIR spectra from a 4 mm pathlength developed with a FOD at 0.25 gave the best performance in DRC prediction, whose R2p, RMSEp, Bias, and RPD were 0.96, 1.20%, − 0.52% and 5.40, respectively. Therefore, the author concluded that the developed models could be used to evaluate the TSC and DRC of a PRL sample as a real-time method in factory.

THE EFFECT OF UREA, KCl, SP-36 FERTILIZER ON PRODUCTION AT SOME AGE OF NATURAL RUBBER PLANT (Hevea brasiliensis Mull.Arg)

Gebi Hiskia Anggraini, Faculty of Agriculture, Widya Gama Mahakam University Samarinda 2020, " The Effect Of Urea, Kcl, Sp-36 Fertilizer On Production At Some Age Of Natural Rubber Plant (Hevea Brasiliensis Mull.Arg)" under the guidance of Mahdalena and Akhmad Sopian.
 The purpose of this study was to determine the correct dosage of fertilizer to increase the production of natural rubber plants, to determine the effect of rubber plant age and the combination of Urea, KCl, SP-36 fertilizers on increased production,this research was conducted for 3 months, from March 2020 to July 2020. The research location was in a rubber plantation located in Tondoh Village
 The study used a divided plot design or divided plot consisting of 2 factors with 3 replications, the main plot factor was the age of the rubber plant which consisted of 2 levels of age 8 years and 10 years, the second factor of the sub-plots was Fertilizer consisting of 5 levels, namely: P0 = Without fertilizer, P1 = Urea fertilizer 350 g, KCl 300 g, SP36 260 g / tree, P2 = KCl fertilizer 300 g, SP36 260 g / tree, P3 = Urea fertilizer 350 g, SP36 260 g / tree, P4 = Urea fertilizer 350 g, KCl 300 g / tree
 The results showed that the application of Urea, KCl, SP-36 fertilizers had a significant effect on latex productivity, latex wet weight, and latex dry weight on the production of rubber (Hevea brasiliensis Muell. Agr).
 At the age of 8 years and 10 years with the combination of Urea, KCl, SP-36 Fertilizer treatment did not manifest a significant effect on the results of Production, Wet Weight, Dry Weight, and Dry Rubber Content
 Dry Rubber Content Natural rubber (Hevea brasiliensis Muell. Agr) belongs to quality II which has a low Dry Rubber content that means that the water content in the latex is relatively high
 Key words: Latex and Inorganic

Investigation of Field Performance and Film Properties of Natural Rubber Latex Preserved with a Novel Chemical

The traditional long-term preservative system of latex has an impact on environmental air pollution by ammonia and leads to the production of carcinogenic nitrosamine substances by tetramethyl thiuram disulfide (TMTD). In this research, ammonia and a novel preservative with a polysulfidic link were compounded and tested as a novel traditional long-term latex preservative system, to overcome the drawbacks of traditional preservative systems. Control samples were prepared with ammonia as the standard preservative. In addition, ammonia and the novel chemical mixed samples were also prepared for investigating the combined effect. After the preservation treatment, the stable nature of field NR latex was evaluated via the Volatile Fatty Acid (VFA) test based on ASTM D 1076 standard. The Dry Rubber Content (DRC) test and Total Solid Content (TSC) test were carried out for VFA calculation purposes based on ISO126:2005 and ASTM D 1076 standards, respectively. The alkalinity test was carried out to maintain the required ammonia content in latex. In the first trial, traditional dispersion preparation of novel chemical dispersion failed due to the large particle size of the novel chemical. Therefore, two different novel chemical dispersions were prepared in the second trial, where dispersions 1 and 2 were prepared with wetting agents and without using a wetting agent, respectively. It was found that 0.020%v/v and 0.025% v/v concentrations of the novel chemical from dispersion 1 allowed the preservation of field NR latex for 8 days. A low concentration (0.015% v/v) of the novel chemical was able to keep latex with good stability for 5 days. The novel chemical dispersion without a wetting agent exhibited a marvelous preservative system to NR latex than with a wetting agent, because the wetting agent creates a barrier between particles of novel chemical and latex particles. The novel preservative acts as a good preservative while reducing the fumes of ammonia being emitted and eliminating the carcinogenic nitrosamine emission from TMTD.

THE EFFECT OF AVERRHOA BILIMBI EXTRACT AS NATURAL COAGULANTS ON THE CHARACTERISTICS OF RUBBER

Rubber is one of Indonesia’s main commodities resulting in a considerable number of people relying their incomes as rubber farmers. However, unstable rubber price proves to be a problem for these farmers. One solution to be offered is an alternative natural coagulant which is easily obtainable and able to produce good quality rubbers. Averrhoa bilimbi with its known acidic properties shows a prospect as a natural coagulant. This study aims to determine the effect of variation in the concentration of Averrhoa bilimbi extract on the characteristics of rubber clone IRR 118 as well as the advantages and disadvantages of using the extract as natural coagulant. The rubber clone used was IRR 118 with various Averrhoa bilimbi etracts of 20%, 40%, 60%, 80% and 100% and 2% synthetic chemical coagulant formic acid as comparison. The coagulant volume was 20 ml for each concentration and the volume of latex used was 100 ml. The characteristics of the rubber tested were TSC, DRC, Po and PRI. The results showed that the highest value of dry rubber content (DRC) was at 100% natural coagulant concentration which is 34% with a total solid content (TSC) value of 37% while the highest Plasticity Retention Index (PRI) value was at 100% concentration, which is 92%. This study exhibits the use of natural coagulant from Averrhoa bilimbi has met the Indonesian Rubber Standard SNI 06-1903-2000. Therefore, Averrhoa bilimbi extract can be used as an alternative coagulant for rubber latex.

Pengaruh Konsentrasi Ekstrak Buah Belimbing Wuluh (Averrhoa bilimbi) sebagai Koagulan Alami terhadap Karakteristik Karet Klon PB 260

Averrhoa bilimbi is a plant rich in benefits, one of which as natural coagulant. The aim of this research is to increase the potential of Averrhoa bilimbi as an environmentally friendly natural coagulant for the coagulation of rubber clone PB 260. The concentrations of Averrhoa bilimbi used were 45%, 55%, 65%, 75% and 85%. The characteristics of the rubber tested were dry rubber content (DRC), initial plasticity (Po) and Plasticity Retention Index (PRI). Based on the results of this study, the optimum concentration of Averrhoa bilimbi is 85% for latex coagulation time of 11 minutes with 33% DRC, 41% Po and 97% PRI. The highest the concentration of Averrhoa bilimbi used, the faster the coagulation process occurred. 2% formic acid was used as a chemical coagulant for comparison. From the results of this study, it can be concluded that Averrhoa bilimbi can be used as a natural coagulant producing rubber characteristics equal in quality as the ones using formic acid as a chemical coagulant and meets Indonesian Rubber Standard SNI 06-1903-2000.

Study on rapid measurement technic of dry rubber content in latex cup lump by electrical properties

Dry rubber content meter is substantial tool for Impartial trade on rubber cup lump. Department of Agriculture researchers proposed rapid measurement technic of dry rubber content in latex cup lumps by their electrical properties. Two probe types needle and roller were designed, in the first phase, constructed, installed and tested. Needle type probe of 25 mm. in length and 5 mm. apart was selected in measuring electrical properties of cup lump samples as its penetration depth is half of the thickness. Two cylindrical rollers probe of 220 mm. in length and 101.6 mm. (4 inches) in diameter powered by 2 HP gear motor were designed, constructed, installed and tested. Rubber cup lump samples were each statistical divided into 9 regularly measuring parts in needle type probe. Rubber cup lump samples in rollers type probe were typically enforced to pass through 1-inch gap between two rollers. Irregular size sample of more than 76.2 mm. (3 inches) thickness of rubber cup were sliced before measuring into 2 equal thickness pieces. Electrical properties of samples were acquired by standard electrical measuring instruments and percentage of dry rubber content were determined by standard oven method for all sample segments. As the results of this study, rubber content percentage of cup lump was correlated with electrical capacitance than resistance. Electrical capacity value of the latex cup lump from needle-type and two roller-type probes were inversely correlated with the percentage of dry rubber content within the range of 0 – 75 nF and 0 – 380 nF and coefficient of determinations were 0.90 and 0.97, respectively. These initiate features will be utilized in designing of percentage of dry rubber content prototype meter by electrical property values in the future. Percentage of dry rubber content from DRC method of lump from fresh latex and conventional cup lump by oven method was significantly correlate. Electrical properties of latex cup lump produced in the laboratory and farmers are also significantly consistent.