Patent TW-226411-B (TW)
Title: Method of making automobile sofa leather without relieving vaporous and polluting volatile material under high temperature
Inventor: DUH DONG-YUEH
IPC: C14C3/28
Filed: 1993-12-23
Granted: 1994-07-11
Abstract: Method of making automobile sofa leather without relieving vaporous and polluting volatile material under high temperature contains: (1) dipping water and dipping ash: dipping salt-wetting ox leather in a water and ash dipping drum, adding 100 % water (12000kg of water, and all the percentage according to leather weight ); rotating drum for 60 minutes, removing water, adding water again, non-ionic fat removing agent 0.15%, pure soda 0.2%, rotating drum for 60 minutes, removing water, adding water 150% again, dipping accelerater 0.5%, non-ionic fat removing agent 0.2%, NaHS 0.2%, rotating drum for 3 hours, testing PH until reaching 9.5, rotating drum 10 minutes per hour in the next 16 hours; then rotating drum 15 minutes and maintaining pH 9.0, adding ash-dipping agent 0.5%, NaHS 0.8%, Ca(OH)2 0.5%, rotating drum 30 minutes; adding Na2S 1.1%, Ca(OH)2 1.5% rotating drum 40 minutes, staying 60 minutes; adding Ca(OH)2 1.5%, Na2S 1.1%, rotating drum 30 minutes, staying 30 minutes, rotating drum 2 minutes per hour in the next 16 hours, then rotating drum 30 minutes, maintaining pH 12, then removing water, washing leather and removing leather; (2) applying fleshing machine to flesh and spliting machine to cut leather to 3.0m/m thickness of plate leather; (3) removing ash, decomposing with enzyme, washing with water, dipping in acid, Cr tanning: placing plate leather 5000kg and water 100% (5000kg of water, and all the percentage according to plate leather weight) in Cr tanning drum, rotating drum 20 minutes, removing water, adding water 80%, and ash removing agent 4%; rotating drum for 30 minutes, maintaining pH 8.5, adding water 100%, enzyme decomposing agent (100-1500 enzyme unit) 1%; rotating drum for 60 minutes, maintaining pH 8.0; removing water and washing plate leather twice; adding water 80%, HCOOH 1%, rotating drum for 20 minutes; adding H2SO4 (1:10) 1.2%; rotating drum for 3 hours; maintaining pH 2.8; adding Cr2O3 8%, rotating drum for 2 hours; applying boiling test until pH 3.6-4.0, the removing water and leather; (4) squeezing water, shaving leather with shaving machine to obtain face leather, and placing face leather in re-tanning drum; (5) re-tanning, neutralizing, re-tanning, dyeing, adding fat, acid solidifying, washing with water: placing face leather 300kg and 200% water (600kg) and all the percentage according to face leather weight) in re-tanning drum, adding oxalic acid 0.2% rotating re-tanning drum for 20 minutes, removing water, washing with water; then adding water 100%, Cr2O3 powder 4%, oil 1.5% and rotating re-tanning drum for 40 minutes; adding glutaraldehyde 2%, rotating re-tanning 30 minutes, and removing water; then adding water 100%, neutralizing agent 1.8%, NaCOOH 2%, NaHCO3 0.8%, rotating re-tanning drum for 40 minutes, testing pH 5.0, B.C. G. reagent turning green, removing water and washing with water; then adding water 100%, vegetable tanning 3%, natural oil having emulsifier 2.5%, rotating re-tanning drum 50 minutes, removing water, washing with water; adding water 30%, dyeing assisting agent 0.8%, light-resisting dye 2%, rotating re-tanning drum for 40 minutes, then adding 100% water at 60 deg.C, 10% natural oil having emulsifier, rotating re-tanning drum for 40 minutes; then adding HCOOH 1.8%, rotating re-tanning drum for 30 minutes, removing water and washing with water; (6) haning leather overnight, setting out leather, toggling (at 80 deg.C for 6 hours), drying, re-wetting, softening and clamping the leather with rubber net in vacuum; (7) applying coating dyestuff on the leather, the dyestuff having 100 parts of light-resisting dystuff, fog-proof resin 250 parts, water 650 parts to spray the base of leather and dry the leather; then applying light-resisting dyestuff 100%, fog-proof resin 250%, assisting agent 150% and water 500% to spray, then dry, then spray, then dry twice; mixing water soluable varnish 200 parts, water 800 parts to spray and dry; then ironing and pressing leather, softening leather, clamping leather with rubber net in vacuum, and spraying varnish again, then cutting edges and weighing leather and packaging leather.