#7 - FIBER TESTING AND PROPERTIES

 

Cotton

Every bale of cotton in the US is tested. At a cotton testing facility in Memphis, Tennessee, cotton samples come in bags and are then taken out and put into trays. They are given a barcode that travels with the sample throughout the facility to ensure it can be traced back. The samples are first set out to adjust to the heat and humidity levels of the facility. This ensures the tests are as accurate as possible. A small amount of the sample goes into a micron air chamber. It is pressed down and then released to measure the resistance of the fiber. A large amount of the sample goes into a camera, which shows the whiteness of the sample. Another portion of the sample is placed in a machine that combs through the samples. It separates and straightens the fibers. This tests the length, uniformity, and elasticity of the fiber. The samples are then placed back into their correct trays.

Rayon Production

Creating rayon or artificial silk is a chemical process. To produce this at a smaller scale, you can start with

about 4 grams of basic copper carbonate. This begins as a greenish-blue powder-like substance. About 14 mL of

25% ammonia solution can be poured into the copper carbonate. This creates a solution that becomes a bright royal

blue color. The copper carbonate doesn’t completely react with the ammonia solution and leaves a residue in the

beaker. This substance can be poured into a separate beaker, leaving the residue behind. 1 gram of cotton wool can

now be added to the solution, a little bit at a time. The cotton wool dissolves and forms viscose, which is the raw

material for producing artificial silk. The viscose solution is now thick. A syringe can be used to pull the viscose

out of the beaker. A needle can be added to the syringe, and the viscose can be added to a beaker with sulphuric

acid. Thin blue fibers of rayon are formed in the solution. After some time, the sulphuric acid will draw the blue

color from the fibers, leaving colorless rayon fibers. These fibers are removed from the solution to display soft

rayon fibers.

One Step Further

For my One Step Further, I watched the video about Supima Cotton and did some further research on it.

Supima cotton was developed over 100 years ago in Arizona. The name Supima came from the words “superior”

and “pima”. This describes the rare extra-long staple cotton fiber. It is mainly grown in the San Juan Valley in

California. This fiber is known for making the world’s finest cotton because of its softness and lasting color. It is

the first choice for all major designers. It is 35% longer than a normal cotton fiber, which allows for smoother and

cleaner yarns. It also makes it more resistant to pilling. Supima cotton is also 45% stronger than regular cotton. It

creates a lightweight fabric that drapes beautifully. It also creates clothing that is more comfortable and lasts

longer. Supima cotton also produces fabrics that have lasting color. It has finer fibers that allow the dyes to absorb

deeper and cause less color fading. Overall, Supima is the best choice for a cotton fabric. 

References:

Supima. (2013, November 19). The Supima story [Video]. YouTube. https://www.youtube.com/watch?v=Uds7rJRQ-wA

Uploader/Channel Name. (n.d.). Title of video [Video]. YouTube. https://www.youtube.com/watch?v=f_AvqnMTJjg

USDA Agricultural Marketing Service. (2013, April 21). Testing cotton fiber quality [Video]. YouTube. https://www.youtube.com/watch?v=PFL6QlKsUy0

WellFabric. (2023, n.d.). Supima cotton vs Egyptian cotton: Your best choice? WellFabric. https://wellfabric.com/supima-cotton-vs-egyptian-cotton/