Pima Cotton originates from Gossypium barbadense, which is a species of cotton plant. A particularity of this plant is that it is an extra-long staple cotton. Interestingly, this type of cotton honors the name of the Pima Indians, who contributed on the experimental farms in Arizona of the United States Department of Agriculture (USDA) in the mid-1900’s.
The demand for such cotton type arose in the early 1900’s when the First World War gave the government and research a push. The defense department was motivated to develop such cotton because it had very useful applications such as the making of tire cords and the innovation of high-quality fabrics to cover the fuselage and wings of airplanes.
In general, Pima cotton is grown in the southwest of the United States of America, Australia, and Peru, however, it originated from South America as a fairly coarse and medium staple cotton. An interesting fact about this plant with yellow flowers and black seeds is that it has a natural phenol called gossypol, which acts as a disinfectant in order to repel insects and fight damage caused by fungi.
Looking further into the process of this material, pima cotton is developed by the means of ginning, a word derived from the term ‘engine’. After being collected, it is compacted in cylinder shaped bunches and stored in a large outdoor space.
When the time comes to start processing Pima cotton, it is first cleaned, and then dried. Since cotton can absorb up to 27 times its own weight in water, moisture control is vital in the manufacturing of the material. If the cotton is too moist, small lumpy balls will tend to form. In order to dry the cotton to 5% moisture, it is heated using large gas burners which gradually dry the cotton.
Next is another cleaning process, which involves a large cylinder cleaner, which is an inclined toner with small rollers inside which serve to separate the trash from the lint. The rollers force the cotton upwards into a conveyor leading to a secondary cylinder cleaner called a stick machine, while the trash remains at the bottom of the toner. The lint is blown by warm air in a large container with more rollers in order to eliminate to leftover trash.
Once this is done, the process of seed separation is applied; saw gins rotating at very high speeds essentially grind and pull the fibres away from their seeds. However there is still remaining dirt despite all the previous cleaning processes applied, so a final cleaning phase, which involves blow-dry cleaning through an air-jet cleaner is used, along with another trip through the cylinder cleaner, and finally, the saw gins, once more.
Now that the lint is impeccable, it is transferred to a battery condenser, which gives the cotton a blanket-like appearance. Moisture is then reintegrated with more steam in order to reach 7.5%. Finally, the cotton is compacted into cubes and shipped, ready to create fabric.
As discussed earlier, there are wide ranges for the uses of Pima cotton. The reason Pima cotton is a very enjoyable fabric is because of its property of being an extra long staple cotton. As a result, Pima cotton is considered to be the ideal fabric for t-shirts, loungewear, and socks, because it is durable, soft, dense, warm yet lightweight. As a matter of fact, the weave uses many strong yet threads, making it especially pleasant for consumers of dress shirts. Above and beyond, Pima cotton can be blended with silk in order to prove an extra level of luxury.
The Ginning process. 18 February 2015. https://www.youtube.com/watch?v=hCAsg4iUkVQ. Accessed July 18th 2017.
“Pima Cotton.” Cotton Marketing Services. http://www.calcot.com/ourcotton.asp?post=pima&. Accessed July 15th 2017.