Saturday, June 1, 2013

Subzero Fiber (Methods)

The experimental procedures are finished. Huge thanks to my boss (and CANBE) for not looking at me like a crazy person when I asked to do this. I have about ten gagillion data points to analyze and a bunch of variables to account for, but there was a clear early winner and it wasn't what anyone had guessed. So, without further ado...


I chose 10 different fiber types to use over the course of the experiment. 8 were selected initially, and 2 were added after pretesting revealed trends. Fibers were as follows: 98% Cotton 2% Elastic (Cascade "Fixation"); 70% Superwash Wool, 30% Nylon (Red Heart "Heart & Sole"); 100% Alpaca (Knitpicks "Alpaca Cloud"); 100% Tencel (Yarntopia Treastures "6/2 Egyptian Cotton Laceweight"); 100% Sugarcane (Arucania "Ruca Multy"); 55% Wool, 45% Silk (Fyberspates "Scrumptious Lace"); 100% Silicon (Rescue Tape); 100% PTFE (PTFE Thread Seal Tape Mil Spect-27730A), 25% Bufallo 75% Tencel (Buffalo Wool Company "Moon Lite"); 50% Soy Protein, 50% Milk Protein (Kollage "Milky Whey"). Ply number was recorded for each yarn.

Swatches knit on size 0 needles. The pattern used was as follows: long-tail CO 15 stitches, Stockinette stitch for 21 rows and traditional bind off. Natural fiber swatches were soaked briefly and blocked gently. Synthetic fibers were left unblockedA 10 nm T-type thermocouple (Copper and Constantan, Omega) was arc welded under Argon atmosphere into row 21 of each swatch.

Figure 1: The arc welder and a bowl full of Argon. Thermocouples use the junction between 2 metals to produce a charge. Temperature changes change the resistance between the metals, and thus change the overall charge at the junction. This change in charge can then be retranslated into temperature by a computer. or so I am told.
Figure 2: The swatch-electrode. You can almost see the tiny, tiny junction.  It's just above the BO edge. Constantan is a copper-nickle alloy. In terms of my relative frustration with each metal, copper is fragile and snaps if you breathe the wrong way. Constantan is sturdy but oxidizes far faster, so if you miss the weld, you're up a creek without a paddle. When you have the fine motor skills of a constant earthquake victim, each of these presents its own unique challenge.
Thermocouples readings were measured using Labview at 1000 data points per second.

Figure 3: Thermocouples are plugged in here. Our setup is capable of taking 20,000 measurements per second. When I work with tissue, I use all 20,000 but when you're measuring time in minutes instead of milliseconds, 20,000 readings will break excel (no. seriously. I have found the bottom of an excel spreadsheet. I was not a happy camper. I needed that data)
Heat transfer
Swatches were secured with 2 hemostats and the CO edge was plunged roughly 1 centimeter into liquid nitrogen. Temperature was measured until the thermocouple reported -196 C. 5 measurements were taken per swatch. Mean rates of change were compared across groups. Observational data was recorded for absorbancy and flexibility.
The super, technologically advanced styrofoam bucket that works better than anything you can purchase on the market today for keeping Liquid Nitrogen liquid. The yellow color in the bucket is the Nitrogen, which refracts the light differently from water, though both fluids are clear.
Figure 4: A wave form around -150 C. The computer is the limiting factor in our equipment. Our thermocouple unit can push 100,000 readings per second, but you've probably recognize good ol' Windows XP's desktop. If it ain't broke, don't fix it (but do write grants for better equipment.)

New swatches were secured between 2 hemostats and plunged completely into liquid nitrogen. Flexibility was evaluated on the following criteria: Horizontal stretch, vertical stretch, scrolling, 180 degree twist, breaks, and glass like nature. Observational data was also recorded for each swatch.

[You've probably noticed the distinct lack of polymers in this experiment. That has to do with 2 things. First, the tiny town I live in had hardly anything at the hardware store and this experiment is too time sensitive to allow for shipping (and we're poor; that's First.5; most of this yarn came from my personal stash). Second, the superwash sock yarn, which is 30% nylon, was remarkably stiffer than the other wool containing groups. Teflon would later confirm that I made a good call not pursuing the polymers. They are simply too stiff at low temperatures to do any real work.]

Next up: Results (Data analysis takes time... ugh)



  1. I am anxious for the results! Wish I had a need to use fibers at extreme temperatures just so I could make use of the info!

  2. The implications for socks knitted for someone in Antarctica are vast.....