Technology of Free Chrome Tanning Process: Optimal Level of Formaldehyde as Tanning Agent for Mondol Stingray (Himantura gerrardi)

Abstract

Chrome (VI) has a high level of toxicity. Formaldehyde is potential to be developed as a substitute of chrome tanning agent. The aims of this study are to explain the amount of formaldehyde bound, shrinkage temperature, tensile strength, and tear strength on Mondol stingray (Himantura gerrardi) leather. Pickled mondol stingray has been used as raw material. The study was divided into 4 treatments, that is P.I (formaldehyde 2%), P.II (formaldehyde 4%), P.III (formaldehyde 6%), and P.IV (formaldehyde 8%). The method used is drum tanning. Shrinkage temperatures, tensile strength and tear strength of P.I and P.II are significantly different from P.III and P.IV, but P.I is not significantly different from P.II, whereas P.III is not significantly different from P.IV. P.III is shown to improve the quality of leather stingray more than P.I and P.II, and has fulfilled the requirements of leather stingray according to SNI. 06-6121-1999. It can be concluded that the optimal level of formaldehyde tanning agent that can be used as a chrome tanning agent substitute in tanning Mondol stingray skin is formaldehyde 8% (P.III).

Influence of Retanning Agents on Physical Characteristics of Snow-White Glove Leather from Goat Skin

“…The presence of distinct peaks ranges at 3309.90cm -1 (Ca), 3308.90 cm -1 (Al), 3301.56 cm -1 (Fd), 3300.85 cm -1 (Cr), and 3301 cm -1 (Ct). This implies that the N-H linkages to amino acid groups are present in this region which is in congruence with other studies (Rachmawati et al, 2020;Wibowo et al, 2018). The strong band within the range of 3200-3500 cm -1 indicates the presence of hydroxyl groups, particularly those with a high concentration of carboxyl groups (Qiang et al, 2016).…”

“…The resulting absorption values within the specified range of 1650.16 cm -1 for Ca, 1634.9 cm -1 for Al, 1634.64 cm -1 for Fd, 1634.77 cm -1 for Cr, and 1634.75 cm -1 for Ct. The spectrum of this wavenumber relates to C=O bonds, as reported by Hassan (2019), Rachmawati et al (2020), andVyskocilova (2019). Therefore, the presence of a sharp peak in the carbonyl group observed in chrome-tanned leathers might be due to the formation of additional carbonyl groups by chromium ions as they interact with collagen molecules (Hassan, 2019).…”

“…Absorption range of 1551.22 cm -1 (Ca), 1549.91 cm -1 (Al), 1549.36 cm -1 (Fd), 1550.02 cm -1 (Cr), and 1550.50 cm -1 (Ct) refers to C-N-H bond (Hassan, 2019;Rachmawati et al, 2020;Vyskocilova, 2019). The absorption at wave number 1553 cm -1 corresponds to the bending vibration of -NH2 and the stretching vibration of CN in amide group II.…”

Hydrophobic Coating of Vegetable-Tanned Leather with Dodecylamine

“…About 5 mL of DDA solution in various concentrations was wiped onto it and then dried (Table 1). The coated leathers were characterized using FT-IR analysis (Perkin Elmer 96681) [15][16][17][18], SEM-EDX analysis (JEOL JSM-6510LA) [1,19,20], and water resistance test.…”

“…Amide III is shown at a range of 1234-1236 cm -1 from carboxylate group stretching [17,28,29]. The methylene group is detected at 1455-1458 cm -1 from its bending vibration [18]. Furthermore, absorption of C-H asymmetric stretching vibration appears at 2926-2927 cm -1 [30].…”