Discover How Thread Is Made
The Science Behind Threadmaking
You can't sew without it, but when was the last time you gave thread a second thought? To find out how this notion is made, take a tour of a Coats & Clark spinning mill and dye house in Marion, North Carolina, and a finishing plant in Toccoa, Georgia.
The process begins with giant bales of cotton or polyester. Each of these bales weighs 613 pounds and will produce about 25,000 spools of thread.
The cotton or polyester bales are opened into tufts, blended with like fibers in a garden-shed-size machine, and rolled into sheets called laps. Because cotton is a natural fiber, it also goes through a cleaning process to remove dirt, seeds, and other impurities.
Individual fibers are separated, straightened, cleaned, and brought together into fluffy ropes called slivers.
The slivers are coiled in giant bins. They are still 200 to 600 times thicker than finished thread.
Drawing and Roving
Six to eight slivers travel overhead and are then blended into one thick sliver. Cotton slivers must go through additional blending and combing processes. Finally, both cotton and polyester slivers undergo a drawing process to ensure fibers are uniform and parallel to each other. At this point slivers are reduced in thickness and given a slight twist in order to hold the weakened fibers together for spinning. These finer slivers are called rovings.
Next a series of rollers spins the rovings into yarns that are the necessary weight and thickness for the type of thread being produced. After the yarn is twisted, it is wound onto a ring tube.
Some thread types must go through an additional core-spinning process, in which the cotton or polyester yarns are wrapped around another material, such as continuous polyester filament.
Clearing, Splicing, and Winding
From ring tubes (pictured), the yarn then passes through detectors to find faults that may affect the thread's future sewing performance. If a fault is removed or short yarns need to be lengthened, ends are spliced together. The number of yarns necessary for the final thread are laid side by side. (For example, Dual Duty XP, a two-ply thread, requires two polyester core-spun yarns.)
A twist applied in a left direction gives the fibers strength and flexibility. The twisted fibers, called greige thread, are wound onto a notched dye center tube, which is similar to a hair curler, to create a dye package.
In the color kitchen a fully automated computer system weighs and mixes dyes and chemicals according to the necessary color recipe. The mixture moves through a series of pipes to the dye room.
New colors for Coats & Clark's consumer thread lines and for manufacturing clients are also developed in the color kitchen. These samples were developed for spring 2011 fashion lines. Demand for colors is largely dependent on the season and trends.
In the dye room the dye packages are loaded onto a carrier and submerged in a dye vat, which works like a pressure cooker.
Holes in the dye centers allow the mixed dye to permeate the thread completely. Each one of these dye packages contains about 38,000 yards of thread.
Pulleys transfer carriers of dyed thread to huge dryers that steam the thread dry.
After the thread is dyed, it is transported to the finishing plant. It arrives from the dye house on a dye package. Some thread is heated to remove stray hairs that could cause lint to build up when the thread is used.
Lubing and Drying
A lubricant formulated specifically for the thread's final purpose is applied next. It gives the thread a finish that allows it to slide easily through a machine or a needle's head. The lubricant takes eight hours to dry.
Hand Quilting Thread
Hand quilting thread is not singed or lubricated. Instead, a machine applies a glacé finish to the thread so it won't tangle, knot, or twist while hand sewing. The glacé finish also reduces abrasion that may cause fraying. After the glacé finish dries, the thread is then transferred directly to spools.
Thread is transferred to retail-size spools by spooling machines. The empty spools are dispensed from a clear bin that resembles a gum ball machine.
After snap spools are loaded, they drop down and the machine closes them.
Loading Thread on Tubes
A different machine transfers thread onto the large tubes used for brands such as Star quilting thread.
Some thread, such as monofilament thread must be handled with care throughout the process, especially after it is transferred to spools.
After the spools are filled, an operator inspects them as an automated system turns them upright, preparing them for the next step.
The ticketing machine also prints stickers and adheres them to the tops and bottoms of the spools.
After the spools have stickers, they make their way on a conveyer belt through the machine to be packaged in boxes.
The same ticketing machine also assembles the boxes. After the spools drop into a box, a lever pushes down on them to ensure they fit snugly. The machine then closes and adds labels to the boxes.
Packaging Tubes of Thread
Tubes of thread are shrink-wrapped by a different machine and labeled and boxed by hand.
Samples from every lot go through many rounds of vigorous tests to ensure the thread meets the company's standards for quality. The thread color is also checked at several steps in the process.
Many Types of Thread
The boxes are shipped to a distribution center that later sends the thread to stores.
Other Thread Applications
Coats & Clark produces enough consumer thread to circle the world about 6.8 times.
Besides the consumer thread we use for our sewing projects, Coats & Clark also makes thread for the following applications:
- Medical sutures
- Manufactured apparel, uniforms, and shoes
- Airbags, seatbelts, steering wheels, and tires
- Feminine hygiene products
- Mattresses and furniture
- Major League baseballs
- Tents and outdoor awnings
Many home sewing thread types were developed from technology used for these commercial applications.