Humankind has used various materials to make sewing needles throughout history, and during the Stone Age, artisans made needles from readily available bone and ivory. With the advent of the Metal Ages, craftsmen started to make sewing needles from copper, bronze, and iron.
In the last 500 years, manufacturers have achieved great developments in the manufacturing process of sewing needles. The hand-sewing needle manufacturing trade in Germany started during the 1500s.
By 1807, 13 needle factories in Aachen, Germany, employed over 7,500 workers and supplied much of Europe with sewing needles. Aachen remained the center of the needle industry for over 150 years, and at one time, manufacturers produced well over half of the world’s sewing machine needles in this part of Germany.
When inventors created sewing machines in the mid-1800s, needle manufacturers in Aachen, Germany, were nicely positioned to take control of the sewing machine needle manufacturing process.
Almost two hundred years later, companies like Schmetz mass-produce millions of high-quality needles each year using sophisticated equipment and high-tech automatic machinery. The manufacture of the sewing needle involves over twenty steps.
Manufacturers use the same techniques and equipment employed in producing syringe needles when manufacturing sewing machine needles. The process starts with workers drawing wire from a spool and includes stamping, milling, annealing, plating, and finishing.
Sewing machine needle manufacturing starts with wire. Workers draw the wire from spools and straighten it. Machinery simultaneously pulls the wire from two coils, guiding it through narrow passages to straighten out any kinks.
Workers cut the wire to length, drop it into a shaking chute, and move it into bins. Then, a process called swaging shapes the shank and blade of the needle. Swaging is a cold-working process where pressure forces metal to form a different shape. Workers stamp the trademark and other markings into the needle during swaging.
After the needle forms into shape, workers stamp the eye of the needle into the newly swaged needle. A carrier strip holds the needles in place while workers perfectly stamp the needles with a precision high-speed stamper.
Perfect stamping creates an eye that can hold the thread without weakening it, but the needle still has several steps to go through before it is smooth enough for use in a sewing machine. The milling or grinding process determines the final quality of the needle.
After the stamping, workers grind the needle fine by turning it repeatedly. This grinding is a precision process known as milling.
In metal manufacturing, milling refers to the process of removing material using rotary cutters. In manufacturing sewing machine needles, workers form the point during milling.
Manufacturers use several methods for hardening or tempering metal, and annealing is one of the most exact methods. Annealing softens the metal and improves its structure. Once the workers mill the needle, they must harden it through a process known as annealing to ensure that it can hold up to the pressures of sewing at high speeds.
In this process, workers heat the metal and then quench it in oil. Then, workers slowly cool the needles, increasing their strength and reducing brittleness. Finally, they deep freeze the needles to make them even more elastic.
In sewing machine needle manufacturing, the finishing process of smoothing is achieved through vibration polishing and chemical treatment. Workers place the needles in a tub-like machine with abrasive tumbling media.
The tumbling media churns with the needles to remove burrs and imperfections. The chemical deburring process smoothes the eye and the needle’s point further. Manufacturers ensure the needles are smooth enough to prevent damaging material and fraying thread.
The chemical deburring is a finely tuned process because if the needle is made too smooth, it will create excessive temperatures during sewing. The combination of punching tools and finishing treatments produces perfect needles, but workers require a final hard straightening.
Manufacturers must completely straighten the needles to produce precise stitches, and the annealing process causes them to become slightly deformed. When a worker bends a needle even slightly, it can touch the throat plate and cause skipped stitches, so every needle must be individually straightened. After workers straighten the needle, they have to plate it.
But first, they must completely clean it to guarantee quality at the highest level. Production units pass through a washing unit several times to be cleaned with perchloroethylene, which removes even the smallest impurities.
Manufacturers use perchloroethylene, or perc for short, a colorless solvent often used in dry cleaning. It’s used in many other manufacturing processes, including sewing machine needle production, because it cleans metal without weakening it.
Sewing machine manufacturers follow strict guidelines and use sealed bypass systems and filtration techniques to maintain ecological standards. Whenever workers use water in the manufacturing process, they filter and purify it to protect the environment.
Because of the grinding process, needles are subject to corrosion and must be plated. Plating protects the final needle and allows it to glide through fabrics. Manufacturers commonly plate sewing machine needles with nickel or chromium through a dipping process.
First, workers fit the needles into clamps to ensure they are plated correctly. The computer controls the plating operation to determine the thickness of the plating. After the final plating, inspectors observe the needles with human and machine optical controls to ensure a successful modern manufacturing process.
Once workers inspect the needles and they meet strict quality control requirements, they pass to the next phase. Here, workers polish the needles with fine brushes as a finishing touch.
Manufacturers package sewing machine needles in practical modules to keep them safe until they are ready for use. Machines insert the needles into small plastic containers. They may also insert them into envelopes, boxes, or other types of packaging that keep them safe and contained.
Sewing machine needle production starts and ends with testing and quality control. Workers constantly test needles throughout the production process to guarantee quality. Qualified professionals conduct different tests and inspections, including spot checks, lab tests, measuring tests, and breaking tests.
The wire from which manufacturers make the needles must meet high-quality standards and be spot-checked frequently. Laboratory testing ensures the correct metallurgical composition.
Modern sewing machines sew at speeds up to 9,000 stitches per minute, and the metal has to be both strong and flexible to withstand high-speed movement and friction. Manufacturers further test sewing machine needles after annealing to ensure balanced elasticity and rigidity.
Workers test the final plating of the needle with an x-ray device that measures the thickness of the plating. Highly sensitive cameras and other quality control gauges inspect the needles throughout manufacturing. From beginning to end, testing ensures that workers make needles to quality standards and that the precision equipment operates properly.
Content for this question contributed by Raymond Massey, resident of Vermilion, Erie and Lorain counties, Ohio, USA
