A Method for In Situ Enzymatic Coloring of Leather. Anabela Martins Centre for Nanotechnology and Smart Materials

Transcription

1 A Method for In Situ Enzymatic Coloring of Leather Anabela Martins Centre for Nanotechnology and Smart Materials Kokkola, 24 th September 2014

2 Outline A Method for In Situ Enzymatic Coloring of Leather Some words about CeNTI Enzymatic Coloring Enzymatic Coloring of Leather Conclusions

3 A Method for In Situ Enzymatic Coloring of Leather Some words about CeNTI

4 High Level Shareholders

5 CITEVE / CeNTI technological campus

6 R&D Services Functional Materials & Solutions Smart Materials & Systems Solutions Design & Engineering

7 Main Applications Health, Protection & Well-being Automotive & Aeronautics Architecture & Construction

8 Figures & Facts Brainware 50 FTE (Full-time equivalent) high skilled professionals > 10 Students Submitted Patents 16 in the last 3 years Ongoing collaborations > 20 w/ R&D Centers > 50 w/ Companies

9 Figures & Facts Projects European: 6 ongoing National Industry Driven: > 40 Science Driven: 6

10 A Method for In Situ Enzymatic Coloring of Leather Enzymatic Coloring

11 Enzymatic Coloring the motivation Imagine this is a dyeing house: Let s have a look

12 Enzymatic Coloring the motivation

13 Enzymatic Coloring the motivation

14 Enzymatic Coloring the motivation Main Objective: to develop a new and more sustainable process capable of coloring several materials Taking advantage of the capability of a class of enzymes oxidoreductases of providing color to various materials/ substrates by using suitable enzymatic precursors Searching for cleaner technologies for processing leather (and other materials) that might prevent or mitigate the damages in the environment

15 100% wool Enzymatic Coloring WO/2012/ METHOD FOR COLORING MATERIALS WITH NATURAL COLORANTS AND ITS ARTICLES Oxidoreductases are able to promote in situ polymerization of several phenolic compounds, such as vegetable extracts, producing colored polymers at the substrate surface

16 Enzymatic Coloring Examples of materials colored by the enzymatic coloring process

17 A Method for In Situ Enzymatic Coloring of Leather Enzymatic Coloring of Leather

18 Enzymatic Coloring of Leather Lab scale Pilot scale

19 Enzymatic Coloring of Leather Lab scale

20 Enzymatic Coloring of Leather Colors palette - Wet-blue base - tanned with chromium (black) - Wet-white base - tanned without chromium Precursors (DABSA, ABTS) Modifiers (Cathecol, Resorcinol, Cafeic Acid, Vanilic Acid, )

21 Enzymatic Coloring of Leather Colors palette - Wet-white base - tanned without chromium Natural Precursors/Modifiers: vegetable extracts for leather processing (mimosa, quebracho, pine, chestnut tree)

22 Enzymatic Coloring of Leather Process optimization main variables Enzyme dosage Precursor and Modifier dosages Time of enzymatic coloration Temperature of enzymatic coloration Color intensity, K/S: concentration of the colorant on the substrate

23 Enzymatic Coloring of Leather Process optimization Wet-blue base (black) Time of enzymatic coloration = 8h Enzyme, Precursor and modifier dosages = maximum Enzyme, Precursor and modifier dosages = minimum k/s=18,39 k/s=15,85 Time of enzymatic coloration = 4h Enzyme, Precursor and modifier dosages = maximum Enzyme, Precursor and modifier dosages = minimum k/s=14,64 k/s=12,07 Temperature of enzymatic coloration = 40 C

24 Enzymatic Coloring of Leather Pilot scale

25 Enzymatic Coloring of Leather Scale up main variables Enzyme, Precursor and Modifier dosages (minimum) Temperature of enzymatic coloration = 40 C Time of enzymatic coloration = 3,5h Pre and post-treatments Foulons battery

26 Scale up Enzymatic Coloring of Leather Color intensity Color deepness Color fastness properties Physical-mechanical properties Chemical analysis

27 Enzymatic Coloring of Leather Scale up Color intensity Enzyme, Precursor and Modifier dosages - Maintaining the concentration on bath coloration, g/l - A - Maintaining the % of weight of leather, g/kg - B A B A B

28 Enzymatic Coloring of Leather Scale up Color deepness Post-treatment - Formic acid: to ensure the deep fixation of the color Enzymatic coloring process: wet-white base Conventional dyeing: wet-blue base Transversal cut of leather samples (optical microscope Leica DM 2500M)

29 Enzymatic Coloring of Leather Scale up Color fastness properties Standard Color fastness properties Results Friction ISO Leather - Tests for colour fastness - Colour fastness to cycles of to-and-fro rubbing Hair/degree of staining dry (100 cycles) Hair/degree of staining wet (50 cycles) 5 (in the grey scale) 4 (in the grey scale) ISO Leather - Tests for colour fastness - Colour fastness to perspiration Sweat acrylic, cotton, lyocell, nylon 6.6 and polyester wool 4 (in the grey scale) 3/4 (in the grey scale) ISO 105-B02 - Textiles - Tests for colour fastness -- Part B02: Colour fastness to artificial light: Xenon arc fading lamp test Light 4 (in the blue scale)

30 Enzymatic Coloring of Leather Scale up Physical-mechanical properties Standard Physical-mechanical properties Results ISO Physical and mechanical tests - Determination of tear load - Part 2: Double edge tear Tear resistance >20 N (thickness<1,0mm) ISO Leather - Physical and mechanical tests - Determination of tensile strength and percentage extension Stretching and traction resistance Tensile strength >20 N/mm 2 Elongation >7,0 mm

31 Enzymatic Coloring of Leather Scale up Chemical analysis Chemical species Heavy metals Barium Cobalt Lead Aluminum Chromium Aromatic amines Pentachlorophenol Tetrachlorophenol Trichlorophenol Formaldehyde Results <5 ppm <5 ppm <5 ppm <100 ppm <500 ppm <30 ppm* <5 ppm* <0,1 ppm* <5 ppm* <50 ppm * quantification limit

32 A Method for In Situ Enzymatic Coloring of Leather Conclusions

33 Conclusions The innovative method for coloring leather implies the use of oxidoreductases and suitable precursors/modifiers (such as vegetable extracts), to provide color to several materials/substrates. An extensive range of colors could be attained by the appropriate choice of the enzyme and the vegetable extracts. The enzymatic coloring process was effective in terms of deepness of the color, since the color penetrated into all the leather thickness.

34 Conclusions The enzymatic coloring leather showed high values for color fastness to sweat, friction (dry and wet) and light - satisfactory characteristics in terms of color fastness. The enzymatic coloring leather showed high resistance of the hair side to cracks and rupture - satisfactory characteristics in terms of physical-mechanical properties. The enzymatic coloring leather is free from harmful substances (such as heavymetals, chlorophenols) and for that reason, more appealing to the end-user, with increasing awareness and exigency.

35 Conclusions The enzymatic coloration process was successfully performed on leather (among other materials) and proved to be an ecologically attractive alternative to conventional dyeing.

36 A Method for In Situ Enzymatic Coloring of Leather ACKNOWLEDGMENTS NANOLEATHER - NANOREVESTIMENTOS APLICADOS À FUNCIONALIZAÇÃO DE COURO, nº3126 (national funding program)

37 A Method for In Situ Enzymatic Coloring of Leather