Introduction

In my project I worked with dyes and resist. The purpose of this experiment is to examine the affects of pressure when using a resist when dyeing fabrics. I did this by applying different amounts of pressure to the resist using a c-clamp. I first did a series of tests with a soft wood resist with a metal plate layered on top. Then I explored other types of resist:  cork and wood without the metal. I used wool swatches and wool dyes with acetic acid and a NaCl solution. I at first only used one dye when testing the resist. Then I explored using multiple dyes. I measured the dimensions of the resist and compared them with the dimensions of the area of resist on the wool swatch after being dyed, knowing that if the area on the swatch is smaller than the resist then dye leaked into the resisted area. 

Background

Dyes are solutions that contain colorants. Through the dying process the dyes are bonded to the fibers in the fabric. In this experiment I am working with acid dyes which are usually used on silk and wool. Wool dying first was established as a Roman craft in 715 BC. Some of the early chemical dyes were formed in 1774 with the use of Prussian Blue and Sulphuric acid.

Procedure

Preparing the wool swatch and resist

• Cut 1 gram wool sample
• Soak in RO water for at least 30 minutes
• After soaked take swatch from water and remove excess water
• Apply resist to the area that you want untouched by the dye (make sure the resists are even on both sides of the swatch)
• Sandwich the resist with metal plates
• Screw on a c-clamp to hold the resist in place while in dye bath

Preparing the Dye

• Obtain at least 500mL of RO water or enough so that the wool swatch and resist are completely covered by the solution
• Heat the water to 41°-43°C
• Add 2mL of NaCl solution to the heated RO water
• Add 2mL of acetic acid solution to the heated RO water
• Add 1mL of concentrated dye solution
•  Stir the solution in the dye bath

Dying Process

• Add the wool swatch with resist into the dye bath
• Stir 3-5 minutes to distribute dye evenly to the wool swatch
• Raise the bath to a light boil
• Stir intermittently for 60 minutes or until the dye has exhausted
• Allow dye bath to cool to room temperature
• Remove and rinse the swatch with water (you can chose to leave the resist on until completely dried or take the resist off immediately)
• Let swatch air dry

Before Dye Bath Exhausts	Exhausted Dye Bath

Observations and Data

Swatch Number	Turns of C-Clamp after initial contact (Pressure)	Observations: In dye bath	Observations: Wet sample	Observations: Dried sample	L*a*b Results	Image & Border Width (viewed at 800%)
Control: Wool Swatch	------	------	------	Actual Wood Resist Dimensions: 2.6cm x 2.7cm	L:83.69 a:-1.69 b: 7.66
Control: Leaf Green	------	32 minutes to exhaust; Solution was extremely exhausted	Dye is evenly distributed	Dries lighter than when wet	L:41.68 a:-21.60 b:-1.35
Control: Sun Yellow	------	38 minutes to exhaust; Solution was extremely exhausted	Dye is absorbed evenly and distributed equally	Still very saturated, little difference from wet sample	L:79.57 a:-7.11 b:98.31
1	4	45 minutes to exhaust; swatch has tendency to stick to the top of the metal plate because the boiling water pushed it up; hard to rotate and to stir solution in 700 mL	Washed out some of they dye; Allow swatch to dry with resist on	Very clean lines, very little bleeding, color of swatch is not evenly dispersed Resist Dimensions:2.7cm x 2.6cm	Swatch-L:39.28 a:-8.66 b:-0.53 Resist- L:59.81 a:-1.18 b:14.81	Border Demensions: 0.9 x 1.5 x 1.0 x 0.7 cm
2	3	61 minutes to exhaust; bubbles push fabric to top of metal plate, add 2mL of acetic acid after 50 minutes	Allow swatch to dry with resist on; appears saturated and evenly distributed	Overall even color distribution; fuzzier lines on some sides but not all Resist Dimensions: 2.7cm x 2.6cm	Swatch-L:38.67 a: -8.22 b:-1.16 Resist- L:61.44 a:-1.10 b:11.00	Border Demensions: 0.8 x 1.7 x 1.0 x 1.3 cm
5 (Sun Yellow Before Resist)	------	48 minutes to exhaust; increased amount of dye, NaCl, and acetic acid because dyed multiple swatches (proportions suited 4g wool swatch), had to add acetic acid to exhaust solution	Allow swatch to dry with resist on; appears saturated and evenly distributed	Very consistant color; very saturated and evenly distributed	Swatch-L:80.83 a:-8.70 b:97.54
5 (After Resist)	4	60 minutes to exhaust; Because swatch was already sun yellow the leaf green dye bath turned to a yellowish solution when heated; a lot of solution evaporated (300mL total); added 4mL of acid to exhaust, swatch seemed be fully saturated	Kept resist on while drying; non resist area was a  yellowish green, very saturated; swatch evenly absorbed dye	Fabric looks greener, fairly straight lines; compared to sun yellow swatch yellow resist is fairly similar, a little more green; leaf green area compared to control is more evenly saturated and has a lot more yellow Resist Dimensions: 2.3cm x 2.5	Swatch-L:36.21 a:-25.75 b:26.72 Resist- L:52.98 a:-3.85 b:39.98	Border Demensions: 1.3 x 1.5 x 1.6x 1.3 cm
8 (Sun Yellow Before Resist)	------	48 minutes to exhaust; increased amount of dye, NaCl, and acetic acid because dyed multiple swatches (proportions suited 4g wool swatch), had to add acetic acid to exhaust solution	Allow swatch to dry with resist on; appears saturated and evenly distributed	Very consistant color; very saturated and evenly distributed	L:80.70 a:-8.71 b:97.78
8(Cork; After Resist) Cork Resist Demensions: 3.1 cm x 3.2 cm	4	43 minutes to exhaust; used cork as resist, no metal plates; swatch seemed ver saturated with dye; added more acetic acid	Allow swatch to dry without resist; appears saturated and evenly distributed ; cork seemed to change color of parts of resist	Uneven surface of cork allowed ink to bleed into resist area; part of cork stained yellow areas of resist; Resist Dimensions: 3.0cm x 3.0cm	Swatch-L:33.55 a:-25.05 b:25.47 Resist- L:67.03 a:-4.60 b:75.17	Border Demensions: 3.0 x 5.1 x 3.7 x 2.3 cm
9	1	41 minutes to exhaust; very consistent simmer; added 2mL of acetic acid to help exhaust	Resist fell off because not enough pressure to hold it on when being washed off in water	Very uneven lines, the resist was probably uneven, not as sharp lines; Resist Dimensions: 2.4cm x 2.3cm	Swatch-L:44.72 a:-20.01 b:0.95 Resist- L:80.47 a:-3.07 b:19.57	Border Demensions: 1.2 x 1.5 x 1.8 x 1.3
10 (Without Metal)	4	40 minutes to exhaust; did not use metal plates to help distribute pressure; fabric is more evenly exposed to dye in dye bath	Allow swatch to dry with resist on; appears saturated and evenly distributed	Lines are fussy and not as distinct; ink bled in some areas Resist Dimensions: 2.5cm x 2.6cm	Swatch-L:48.31 a:-23.88 b:3.90 Resist- L:83.95 a: -6.14 b:24.49	Border Demensions: 1.7 x 1.9 x 1.6 x 1.6 cm
11	2	35 minutes to exhaust; very loose resist, just enough pressure to keep resist on in dye bath; solution exhausted quickly, plates were able to rotate around central pressure	Resist almost fell off but there was just enough pressure to keep the resist on while drying	Not as heavily saturated compared to others; lines are fuzzy and ink bled into some areas Resist Dimensions: 2.5cm x 2.6cm	Swatch- L:44.57 a:-23.47 b:4.04 Resist- L:76.23 a:-5.85 b:19.69	Border Demensions:1.9 x 1.4 x 2.5 x 1.5

Conclusions

Colorimeter Conclusions Overall the swatch that’s resist maintained the original colorimeter results was Swatch 2 with the second highest pressure. Overall there  was little change with the resist. The resist had a tendency to become duller than the control plain wool swatch and had a higher positive coordinate for b, meaning the resist gained more properties of yellow. Visually this distinction can be made but the difference is not overly drastic. Thus, in conclusion the pressure of the resist does not affect the color of the resist because the overall trends in each are very similiar Maintaining Resist Size For the most part the size was basically maintained. It is evident the less pressure used the more dye that will be able to reach the resist area but the overall shape is maintained. With swatch 9 the lines are more diagonal and the shape is obscured. I believe the reason for this is that the resists were not aligned properly. The plain wood resist pressure was not as evenly distributed creating more rounded edges and the cork’s uneven surface created uneven borderlines. Through visual means and through measurements the more pressure used creates the most distinctive borderline. Using a wood resist with metal plates to distribute pressure more evenly served as the best form of resist.

Links

http://www.straw.com/sig/dyehist.html

http://en.wikipedia.org/wiki/Dye

http://www.answers.com/topic/lab-color-space

Other References

Minolta, Colorimeter Handbook; p. 5, 2006

Acknowledgements

I would like to thank Stuart Leonard for making sure I always had the supplies I always needed, Dr. Bordley and Dr. Fitz for making sure I was always on the right track and answering my questions as well as Elizabeth Crawford for helping me create my webpage.