Fiber Identification

Elizabeth Garfield

Student Projects, Pigments/Dyes/Binders

Introduction

In this series of experiment I will develop a system of fabric identification through burn tests, staining, and microscope analysis. I will be testing five different types of fabric, three natural and two synthetic; cotton, silk, wool, Dacron 64 (polyester), and Viscose (rayon). I will test my results, and try to classify six different fabrics on an unknown multi-fiber strip. I will be using Textile ID Stains, and multi fiber fabric from Testfabrics, Inc. In my experiment I will use TIS #1, #3A, and #4, along with mulitfiber fabric #43. In the stain test, the stains will act as the variable, while the fibers are constant. In the burn test the fibers will act as the variable.

Background

There are many different types of fibers, created and used with many different purposes. All fibers can be put into two main categories, natural and synthetic. This will be one of the categories I use to define my unknown samples. TIS #3A, and #4 are best to identify synthetic fibers; #1 is best for natural fibers. Before and after I stain the fibers I will use the colorimeter to test the L*a*b* coordinates of the color. The L* corresponds to the lightness of the color, the a* with the red/green attributes, and the b* with the yellow/blue attributes. This will allow me to get an exact color of the fabrics, and then be able to compare how the known fibers reacted to the dyes, as well as the unknown fibers.

Procedure

Burn Tests

Supplies

  1. Obtain a sample of cotton.
  2. Hold sample with tweezers, light on fire with a match.
  3. Drop onto aluminum foil.

Repeat with each different fabric sample.

Stain

Supplies


Stain #1

  1. Weigh material to be tested, let it be “x” grams.
  2. Use enough tap water to cover specimen to be tested. Bring water to rapid boil
  3. Add 2(x) cc of 0.1% solution of stain #1 solution and continue to boil for 5 minutes.
  4. Add sample to be tested, stir and boil for 5 minutes
  5. Rinse until clear, dry.

Stain #3A

  1. Weigh material to be tested, let it be “y” grams.
  2. Use enough tap water to cover specimen to be tested, bring to boil
  3. Add 0.03(y) cc of 0.1% solution of stain #3A; bring it to a rapid boil
  4. Add “y” cc of 10% acetic acid, boil for an additional 5 minutes.
  5. Add sample to be tested and continue boiling and stirring for 5 minutes
  6. Rinse in hot water.
  7. Soap in non-optical detergent at 120F for 5 minutes

Stain #4

  1. Weigh material to be tested, let it be “y” grams.
  2. Use enough tap water to cover specimen to be tested, bring to boil.
  3. Add 0.03(y) cc of 0.1% solution of stain #3A; bring it to a rapid boil
  4. Add “y” cc of 10% acetic acid, boil and additional 5 minutes.
  5. Add sample to be tested and continue boiling and stirring for 5 minutes..
  6. Rinse in hot water
  7. Soap in non-optical detergent at 120F for 5 minutes

Microscope

  1. Remove individual fibers from the strip.
  2. Place on microscope slide.
  3. Tape cover slide onto slide.
  4. Place in microscope and focus.
  5. Place the lens of the camera onto the eyepiece to take picture.

 

Observations and Data

Burn Test

Fabric Flame Smell Ash
Cotton steady orange flame burning leaves very crumbly, falls apart easily
Silk rapidly burns, uneven flame burning hair very brittle
Wool hard to light, wouldn't stay lit, burning hair very hard, stuck to the fiber sample

Polyester

 won't light, fibers melt and stick to the sample, black smoke burning plastic, slightly sweet no ash is created, the fibers curl back
Rayon steady, rapid orange flame burning leaves no ash present

Stain Test

Fabric Unstained Stain #1 Stain #3A Stain #4
Cotton matte white, feels rough white with a light blue tint white, slightly darker than unstained off white, slightly darker than unstained
Silk off white, slightly yellow, very smooth light violet light taupe, off white light taupe
Wool fibers in weave are coarse, rough to run finger across raspberry dark taupe light grape

Polyester

 white, silky, easy to caress with finger white off white off white, slightly orange tinted
Rayon white, finger skips when trying to run it across fabric shiny white shiny white shiny white

Stained Multi-fiber strips

Labeled Unstained

 

Unstained

 #1 #3A #4

L*a*b* results

Unstained Fibers

Fabric L* a* b*
Cotton 97.24 +0.70 +0.31
Silk 93.93 +0.69 +5.76
Wool 87.77 -0.71 +7.15

Polyester

 96.54 +0.74 -0.80
Rayon 92.19 +0.01 +0.19

Stain #1

Fabric L* a* b*
Cotton 88.87 -1.27 -0.39
Silk 77.68 +8..68 -5.78
Wool 75.25 +18.13 +3.06

Polyester

 90.38 -0.66 +1.49
Rayon 89.76 -0.27 +0.81

Stain #3A

Fabric L* a* b*
Cotton 87.87 -.055 +.093
Silk 82.36 -1.36 +5.82
Wool 79.75 -2.92 +9.71

Polyester

 87.50 -1.36 +2.75
Rayon 86.86 -1.09 +3.05

Stain #4

Fabric L* a* b*
Cotton 86.65 +0.12 +8.84
Silk 76.27 +4.83 +11.29
Wool 66.41 +8.37 +10.88

Polyester

 84.22 +2.64 +14.68
Rayon 86.00 +0.68 +7.08

Microscope Pictures

Cotton Silk

Wool
Polyester

Rayon

 

Unknown Strip

Burn Test

Strip # Flame Smell Ash Similar Fibers
1 steady orange burning hair black ash, easily broken apart, brown at the end of the fibers wool, silk
2 rapid orange slightly sweet, burning hair black, hard, and brittle silk
3 wont light, melts no distinct smell black and sticky synthetic

4

slow orange sweet melts, rolls back, black polyester
5 rapid, enveloping orange wood very little ash synthetic
6 rapid wood melts and drips synthetic

Stain Test

Strip # Unstained Stain #1 Stain #3A Stain #4 Similar Fibers
1 light taupe in color, weave feels rough raspberry color taupe, slightly darker than unstained light grape wool
2 white, weave feels ribbed white, slightly darker than unstained hot pink very light baby pink synthetic
3 white, similar feeling to #2, easier to run fingers across white, slightly darker than unstained white, same as unstained off white, slightly darker than unstained  

4

white, soft feeling, nearly fuzzy dark orange/rose light blue/green grape purple  
5 white, coarse, harsh to the touch, finger skips across fibers, rather than glides white with a very slight blue tint bright white, same as unstained off white, slightly darker than unstained cotton
6 white and shiny, fingers run easily across fibers, almost slippery light yellow very light pink peach  

Stained Multi-fiber strips

Unstained #1 #3A #4

L*a*b* Results

Unstained Fibers

Strip L* a* b*
1 92.72 -0.64 +9.73
2 98.33 +0.47 +0.20
3 97.14 +0.68 -0.69

4

 96.01 +0.82 -0.75
5 97.20 +0.60 -1.35
6 95.54 +0.24 -1.81

Stain #1

Strip L* a* b*
1 72.4 +17.68 +1.90
2 92.85 -0.71 +1.66
3 93.58 -0.87 +2.14

4

 72.50 +15.16 +9.22
5 90.01 -1.85 -0.22
6 95.47 -4.09 +10.11

Stain #3A

Strip # L* a* b*
1 76.75 -2.71 +11.24
2 79.41 +40.27 -1.11
3 87.88 -1.72 +3.47

4

 70.43 -9.16 +5.62
5 88.66 -0.65 +0.14
6 83.91 +19.04 +2.75

Stain #4

Strip # L* a* b*
1 61.28 +9.40 +9.76
2 84.44 +7.13 +5.60
3 84.08 +2.75 +15.18

4

 51.12 +6.69 +3.41
5 86.77 -0.38 +7.98
6 79.79 +11.15 +29.73

Microscope Pictures

1 2 3
4 5 6

 

Conclusions

After analyzing the burn tests, stain tests and the microscope pictures, I have been able to label the unknown fibers as follows:

1 wool
2 acrylic
3 unknown-synthetic
4 nylon
5 cotton
6 spun diacetate

The known multifiber strip included fibers other than those that I focused on in my tests. Using the stain test results I was able to use these other fibers in identifying the unknown samples.

If I could do more with this project I would go back and do further tests on the fibers I have predicted to be one of the unknowns, but did not focus on in my project, such as acrylic, nylon and spun diacetate. I would also test other fibers to try and identify the still unknown, #3.

Links

Testfabrics, Inc

Acknowledgements

Dr. Bordley

Dr. Bachman

Miranda Klaas of Testfabrics, Inc.