#6 Bamboo & Cotton

 

Bamboo & Cotton
Gina Christopher 

Bamboo:

When bamboo fabric is made, cuts need to be as clean as possible to allow new shoots to grow and naturally replenish. Stalks are cut into smaller Bamboo chips and then soaked in a globally organic textile standard-approved soaking liquid. A bamboo pulp is produced after soaking, and then the pulp is dried into sheets. Once dried, the sheets of pulp are ground and spun into bamboo fiber.

 

Cotton:

The exact origin of the cotton plant is unknown. Cotton fiber was traditionally processed by hand until the early 18th century, when the first automated processing machine was invented. Before cotton arrives at the textile mill to be spun into thread and woven into fabric, it makes the journey from field to bale. Cotton takes about 5 months to grow from planting. A cotton picker plucks fluffy seed cotton out of the plant's boll, leaving a trail of burrs and sticks behind. The machine empties the plucked cotton into a tractor-drawn buggy. This machine builds the seed cotton into a harmonious rectangular block called a module. A truck then transports the module to the processing plant, known as a cotton gin. Once the cotton arrives at the processing plant, sticks, burrs, and any lingering debris and seeds are removed. A truck dumps the module into a feeder, which moves the packed cotton into a dispenser. The cotton falls onto a conveyor belt, which leads to the hot box. The hot box mixes this seed cotton with hot air, which allows the moisture to evaporate, making this seed cotton easier to clean. The wad Buster machine breaks up the clumps of seed cotton by tossing it against the screen. Loose debris falls through the screen openings and down a narrow chute. The seed cotton moves through a machine called the steady flow, which divides it equally between two processing lines. On each line, the seed enters a fur machine, which grabs the seed cotton with a circular saw and swings it against metal bars. This shakes off the heavier debris. The seed cotton exits the machine through one pipe and the debris through another. The seed cotton is now ready for the final stage of processing. A network of pipes feeds a row of machines called gin stands. The gin stand separates the seed from the fluffy stuff, called the lint. Inside each stand are 116 circular saws, which are arranged horizontally and separated by a steel rib. The saw teeth grabbed the seed cotton and pulled the lint through the narrow gap between the saw and rib. The seeds are too large to pass through, so it spins in front of the rib and then drops onto a conveyor belt. The lint goes into a flue, which leads to a packing area. Cottonseed is sold as livestock feed, particularly for dairy cows. Cottonseed is also milled into cottonseed oil. The cotton lint is now ready to be formed into bales. Pipes feed the loose lint to the press area. When it arrives, a pusher moves the lint into a machine called the tramper, which shoves it down into a bale-shaped box. Once the box reaches 500 lbs. of cotton lint, a press compacts the lint and tie-wraps the Bale. Next, a conveyor belt moves the ball to a bagging machine and passes grippers, which pull a sample from each side. While the Bale slides into protective plastic bags, the grippers deposit the sample into a bin. Technicians then label the bill with an ID number and open the bin to retrieve the corresponding sample. The factory submits the sample to the United States Department of Agriculture, where it is analyzed for fiber length, cleanliness, and other criteria. Once the analysis is complete, the bail is given a grade and processed accordingly for use.

 

One Step Further:

Since we were given more resources regarding cotton, I wanted to do a little more research on Bamboo textiles for my one step further section. I learned that due to bamboo's hollow cross-section, bamboo fiber is very cool and comfortable to wear. Bamboo also has high hygroscopicity, which makes it easy to dye and finish. Its hygroscopicity property is able to absorb 3 times its weight of water, due to the presence of micro gaps and micro holes in the fiber. Bamboo fabrics also have high breathability properties and thermal regulating properties, even higher than those made from cotton and hemp. Bamboo also exhibits lower shrinkage, better color clarity, more wrinkle resistance, and better luster without mercerization in comparison to cotton fabrics.

 

References:

FIELD TO FABRIC

How Bamboo Fabric is Made

How Cotton is Processed in Factories | How It’s Made

Majumdar, A., & Arora, S. (1997). Bamboo fibres in textile applications. ENVIS Centre on Forestry, National Forest Research Institute, Dehradun, 285-304.