Prayitno Prayitno
Center for Leather, Rubber, and Plastic Yogyakarta Indonesia

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Pengaruh bahan water repellent terhadap morfologi dan sifat-sifat fisika pada pembuatan kulit atasan sepatu ramah lingkungan Prayitno Prayitno; Emiliana Kasmudjiastuti; Dona Rahmawati
Majalah Kulit, Karet, dan Plastik Vol 32, No 2 (2016): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (552.087 KB) | DOI: 10.20543/mkkp.v32i2.922

Abstract

The term of eco-friendly leather can be interpreted as chrome-free tanned leather. Recently, almost 80% of leather is tanned using chrome tanning agent because of the ease in processing and excellence of the physical properties. Nevertheless, people nowadays want an eco-friendly leather product. Vegetable tanning materials can be said as eco-friendly tanning material because their waste degrades easily. One of the weaknesses in the use of vegetable tanning is a high water absorption capability. In this research used a water repellent material that has the properties to suppress the ability of water absorption. The purpose of the research was to determine the effect of water repellent on physical properties and morphology of leather tanned by vegetable tanning materials. Because one of the weaknesses in the vegetable tanning is its high water absorption capability, in this research, water repellent was used and varied by 5; 7.5; 10; 12.5; and 15% . Physical properties obtained were compared with analysis of variance with the significance level of 95%. The water repellent increased from 5% to 15%. The results showed a decrease in water absorption capability from 77.6% to 65.39%, tearing strength from 41.64 to 20.05 kg/cm, tensile strength from 227.10 to 163.53 kg/cm2, and elongation at break from 57.11 to 49.68%, strong swelling and WVA have no significant changes, while for WVP, the maximum use of water repellent at 12.5%. SEM results indicate the presence of a thin layer on the leather fiber that can inhibit the absorption of water.Keywords: water repellent, upper leather, vegetable tanning, water absorption.
Pertumbuhan cacing tanah Eisenia fetida sp. Pada kompos limbah fleshing Prayitno Prayitno
Majalah Kulit, Karet, dan Plastik Vol 31, No 2 (2015): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (198.009 KB) | DOI: 10.20543/mkkp.v31i2.499

Abstract

The use of earthworm as a source of income and a means for managing organic solid waste such as fleshing waste has been widely applied. The aim of this research was to find the optimum ratio between fleshing waste and cow dung in the growing medium of Eisenia fetida sp. This research was conducted by growing the E. fetida sp. earthworm in the medium containing fleshing waste mixed with cow dung. The ratio of fleshing waste and cow dung was varied at 0:100; 10:90; 20:80; 30:70; 40:60; and 50:50. In addition, 2 parts of chopped stubbles per part of every sample was added as a carbon source. The prepared media were fermented for three weeks with EM4 as a starter, followed by incubation of the earthworm for six weeks. The weight and the number of earthworm were evaluated every two weeks. The optimum growth of earthworm was achieved at the 2nd week of incubation with 185.48% and 121.10% increase of weight and number of earthworm, respectively, at 40:60 ratio of fleshing waste and cow dung in the growing medium.Keywords: earthworm, fleshing waste, incubation.ABSTRAKPenggunaan cacing tanah sebagai sumber pendapatan dan juga sarana untuk penanganan limbah padat organik seperti limbah fleshing saat ini telah banyak dilakukan. Penelitian ini bertujuan untuk mengetahui kondisi optimal perbandingan antara limbah fleshing dan kotoran sapi untuk pertumbuhan cacing tanah E. fetida sp. Penelitian dilakukan dengan menumbuhkan cacing tanah E. fetida sp. dalam media campuran limbah fleshing dan kotoran sapi dengan variasi perbandingan berturut-turut 0:100; 10:90; 20:80; 30:70; 40:60; dan 50:50 dan sebagai tambahan sumber karbon ditambahkan cacahan jerami sebanyak 2 bagian untuk setiap perlakuan. Semua media perlakuan difermentasikan selama tiga minggu dengan bantuan larutan starter EM4, dilanjutkan dengan inkubasi cacing tanah selama enam minggu. Berat serta jumlah cacing tanah dievaluasi setiap dua minggu. Pertumbuhan optimum cacing tanah dicapai pada minggu ke-2 dengan kenaikan bobot cacing tanah sebesar 185,48% dan jumlah 121,10% pada perlakuan perbandingan limbah fleshing dengan kotoran hewan 40:60.Kata kunci: cacing tanah, inkubasi, limbah fleshing.
Peningkatan ketahanan suhu dingin kulit atasan sepatu melalui pengurangan daya penyerapan air dan pengaruhnya terhadap sifat fisik dan morfologi Prayitno Prayitno; Emiliana Kasmudjiastuti
Majalah Kulit, Karet, dan Plastik Vol 33, No 1 (2017): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (955.543 KB) | DOI: 10.20543/mkkp.v33i1.1614

Abstract

A research has been undertaken to increase the cold resistance of upper leather by decreasing its water absorption ability. Fluorinated acrylic polymer, a water repellent substance, was added at fatliquoring and finishing stages of upper leather with different concentrations levels. Research findings showed that an increase in the water-repellent concentration, i.e. by 5; 7.5; 10; 12.5; and 15%, result in increases in tensile strength, tearing strength, and elongation at break, whereas decreases in water absorption ability. No significant differences for the other physical properties such as water vapor absorption, water vapor permeability, and flexing resistance and they met the standard for shoe leather. Results of scanning electron microscopy indicated an increased thin layer of water repellent on leather fibers as the water-repellent concentration increased. The leather fibers looked smoother, glistened, and thicker. This indicates the penetration of water repellent onto leather fibers.Keywords: water absorption, water repellent, cold resistance, upper leather.