THE STUDY OF GAMBIR QUALITY AND ITS RELATIONSHIP WITH CHARACTERISTICS OF TANNED LEATHER

Anwar Kasim, Alfi Asben, Sri Mutiar

Abstract

This study aimed to investigate the quality of gambier taken from gambier production center in West Sumatra, the characteristic of tanned leather which was tanned by gambier, and the relationship between gambier quality and tanned leather product. This study was conducted by firstly taking the samples from ten location randomly, secondly analizing some of its characteristics, and later applicating them in leather tanning. The relationship between some gambier parameters with tanned leather was determined by linear regression. The result was finding that the quality was varied among different gambier production centers, comprise of water content, tannin level, cathecin level, ash level and water-insoluble substances. Sixty percent of producton centers had given gambier which was capable to produce leather met the quality requirements. The result also found there were a strong relationship between gambier characteristics and quality of tanned leather, e.g. gambier tannin level and bonded-tannin in tanned leather (r=0.980), gambier catechins level and bonded-tannin in tanned leather (r=0.967) and gambier ash content and bonded-tannin in tanned leather (r=0.852). Highest tannin level would produce good tanned leather.
Keywords: gambier, tanning, tanned leather, the correlation.

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UTILIZATION OF TINGI (Ceriops tagal) BARK’S EXTRACT AS VEGETABLE TANNING MATERIAL: THE INFLUENCE OF ALUM AND MIMOSA ADDITION

Emiliana Kasmudjiastuti, Sri Sutyasmi, Titik Purwati Widowati

Abstract

This research aimed at determining the effectiveness of the Tingi bark’s extract as vegetable tanning material and the optimum formulations of Tingi extract for lining leather tanning, when combined with alum and mimosa. The research variables included the solution compositions of alum, Tingi extract, and mimosa, as well as the process sequences in which the hides were exposed to each aforementioned solution. There were 8 (eight) different treatments performed in this research; those are alum (4%)-Tingi, alum (6%)-Tingi, alum (4%)-Tingi-mimosa (5%), alum (6%)-Tingi-mimosa (5%), Tingi-alum (4%),Tingi-alum (6%), Tingi-mimosa (5%)-alum (4%), and Tingi-mimosa (5%)-alum (6%). Characterization methods included chemical and physical tests. The results show that the Tingi extract can be used as vegetable tanning material, and the optimum properties were obtained when the alum (4%) was added after the Tingi extract {Tingi-alum (4%)}.The optimum properties were shrinkage temperature of 86 oC; total ash content of 0.73%; water soluble matter of 0.89%; pH of 3.78; degree of tannage of 96.37%; tensile strength of 370.65 kg/cm2; elongation at break of 36.52%; rubfastness of 5 (dry); and 4 (wet). The resulting leather also meet the requirements of Ethiopian Standard 1185:2005, Leather-Lining leather-Specification.

 Keywords: Tingi bark’s extract, alum, mimosa, vegetable tanning, lining leather.

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Utilization Of Pickle Skin Trimming Waste as Flocculant Through Alkaline Hydrolysis of Collagen for Water Treatment

Sugihartono Sugihartono, Sri Sutyasmi, Prayitno Prayitno

Abstract

Wastes in the form of skin derivatives from leather tanning industries remain serious problems if not managed properly and quickly, since they can cause environmental pollution. This research aimed at studying the influence of base type and concentration for the hydrolysis of trimmed collagen from pickled sheepskin to the yield and properties of gelatin, as well as the gelatin’s potential as flocculant. The hydrolysis of trimmed collagen from pickled sheepskin was performed using KOH or NaOH solution, each with varied concentrations of 1, 2, 3, and 4% w/v, for 16 hours. The extraction of the resulting gelatin was performed using water (2.5 water part : 1 waste part), at 70-80 oC, for 3 hours. The results show that the yield of gelatin from hydrolysis using KOH (16.50-28.60%) is lower than that using NaOH (23.68-34.42%). The water and fat contents of the resulting gelatin were relatively similar, while the protein content from KOH treatment was higher than that from NaOH treatment. Hydrolysis with KOH 1% and NaOH 1% and 2% resulted in gelatin that can be used as flocculant. Hydrolysis with NaOH 2% was the best treatment to produce gelatin as flocculant.

Keywords: pickled sheepskin, trimming waste, hydrolysis, gelatin,  flocculant.

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BIOCOMPOSITE OF RAMIE FIBER AND MODIFIED SECRETION OF LAC INSECT BY INCORPORATING HYDRATED AND UNHYDRATED LATEX

Eli Rohaeti, Mujiyono Mujiyono, Rochmadi Rochmadi

Abstract

Biocomposites are composite materials comprising one or more phases derived from a biological origin. Biocomposite with natural matrix developed more rapidly because they are more environmentally safer. The objective of research was to modify natural matrix from lac insect secretion with adding hydrated latex, to study effect of adding hydrated latex to the functional groups and the intrinsic viscosity of lac insect secretion, and to measure mechanical properties of biocomposite from modified lac insect secretion and ramie fiber. A sulfuric acid solution was used as catalyst in hydration of latex and then natural matrix of lac insect secretion was modified by adding hydrated latex. Biocomposite was prepared by mixing rami fiber and modified  lac insect secretion. It was then pressed with hydraulic press at 150 kgf/cm2 and 150oC for 15 minutes. Biocomposites were characterized using tensile tester according to ASTDM D 638-90 Type IV. The adding of catalyst caused the decreasing of intrinsic viscosity of latex. The adding of hydrated latex to natural matrix caused the increasing of intrinsic viscosity and functional group of matrix. The using 30% of catalyst and adding 10% of hydrated latex produced biocomposite with strength at break of 0.982 MPa, elongation at break of 1.189%, and Young modulus of 0.929 MPa.

Keywords: biocomposite, hydration, latex, lac insect secretion, ramie fiber.

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MANUFACTURING OF NANO VEGETABLE TANNING MATERIALS AND ITS APPLICATION IN LEATHER TANNING

Herminiwati Herminiwati, Sri Waskito, Christiana Maria Herry Purwanti, Prayitno Prayitno, Dwi Ningsih

Abstract

This study aimed to create nano vegetable tanning materials of acacia bark extract. The process started with size reduction of acacia bark (16.7 mm x 4.9 mm x 1.8 mm), followed by counter current extraction of acacia bark with water at 80ºC with 1:3 bark to water ratio in order to obtain extracts with density of 9-10ºBe. Drying was done with a spray dryer. Particle size of the resulting powders was measured with particle size analyzer. Planetary ball mill was used for 6 hours to obtain average particle size of 72.9 nm. A variety of vegetable tanning materials were applied in the vegetable tanning process with varied concentrations of 15, 20, and 25%. The use of 25% nano vegetable tanning material of acacia bark extract gave the best results compared to liquid extract of acacia bark and mimosa. The properties of the leather obtained were tensile strength of 27.04 kg/cm2, elongation at break of 50%, shrinkage temperature of 84oC, and degree of tannage of 79.65%.Keywords: vegetable tanning material, nano particle, acacia bark, extraction, planetary ball mill.

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CHARACTERISTICS OF BIODEGRADABLE PLASTIC FROM POLYPROPYLENE PLASTIC WASTE AND DURIAN SEED STARCH

Tengku Rachmi Hidayani, Elda Pelita, Dyah Nirmala

Abstract

Manufacturing of biodegradable plastic has been conducted by blending polypropylene plastic waste and durian seed starch. Polypropylene plastic waste was refluxed by xylene solvent and durian seeds starch was prepared by precipitation method with hard water and aquadest. The composition of blends were 94:6, 92:8, and 90:10 (%w/w). The mechanical and thermal properties of the resulting plastics were characterized. Based on the test result, biodegradable plastics with the ratio of 94:6 met the expectation. The mechanical properties obtained were tensile strength of 25.722 N/m2 and elongation at break of 5.292%. Thermal properties analysis showed that the melting point temperature was 163.68°C and the decomposition temperature was 445.62oC.
Keywords: biodegradable plastic, polypropylene plastic waste, durian seeds starch, characteristic.

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UTILIZATION OF CASSAVA PEEL WASTE MODIFIED ALKANOLAMIDE AS FILLER IN NATURAL RUBBER LATEX PRODUCTS: THE EFFECT OF DRYING TIME

Hamidah Harahap, Kelvin Hadinatan, Adrian Hartanto, Elmer Surya, Indra Surya

Abstract

The purpose of this research was to study the effect of drying time on the mechanical properties of natural rubber latex filled with cassava peel waste modified alkanolamide. Cassava peel is a waste, containing cellulose which is potential as fillers in natural rubber latex products. Cassava peel waste was dried and milled until the size of 100 mesh. Alkanolamide is one type of non-ionic surfactant which is synthesized from RBDPS (Refined Bleached Deodorized Palm Stearin) and diethanolamine. Alkanolamide has polar group which can modified cassava peel waste and make strong chemical bonding with natural rubber latex. The production of natural rubber latex products was started from pre-vulcanization at 70°C until the system was cured and the chloroform number has reached number 3. Natural rubber latex was formed into films by coagulant dipping and drying method at 120°C for 10 minutes and 20 minutes. Results show that longer drying time will improve the crosslink density and tensile strength of natural rubber latex products until the addition of 15 phr cassava peel waste powder.

Keywords: drying time, alkanolamide, cassava peel, natural rubber latex.

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