Serger Thread
Serger thread is sewing thread used on an overlock machine to form stitches with multiple strands for edge finishing and seaming.
Contents7 sections
Definition and Overview
Serger thread is thread for overlock sewing that forms stitches by combining needle thread and looper thread. In addition to overedge stitching that prevents fraying at fabric edges, it is also used for applications that sew and finish the edge at the same time, such as on knits.
While a standard lockstitch sewing machine forms stitches with upper and lower threads, a serger uses multiple threads. For this reason, thread stretch, loft, and tension stability affect the appearance and strength of the stitch.
Materials, Twist, and Structure
Serger thread includes polyester spun thread and nylon or polyester filament thread. Spun thread is made by twisting short fibers together and is used widely, from general woven fabrics to knits.
When stretch and stitch softness are needed, processed thread with a lofty finish or woolly thread may be used for the looper. Woolly thread spreads out and easily covers the stitch, making it suitable for products that need a soft feel and good response to stretch.
However, even for serger use, material, twist, and processing are not uniform. Use thread according to its role, such as stronger, smoother thread for the needle and more covering, stretch-oriented thread for the looper.
How Thickness Is Indicated
Thread thickness is indicated by count or nominal count. Count is one way of showing thread thickness, but there are different notation methods, so numerical values alone cannot be simply compared across different systems.
For sewing thread, nominal count is also used as a manufacturer or distribution standard. Even with the same nominal count, thickness, stretch, and sewing performance vary depending on the material, whether it is single yarn or double yarn, and whether it has been processed, so it is easier to check if the specification sheet also lists the material, structure, and color.
Main Applications
Main applications are joining and overedging knit products such as cut-and-sew items, underwear, and sportswear. It is also used to prevent fraying on cut edges of woven fabrics and for seam allowance finishing on the reverse side.
The number of threads used varies depending on the sewing specification. In specifications focused on overedging, on maintaining stretch, or on increasing stitch strength, the required properties of the needle thread and looper thread also change.
- Overlock finishing on woven fabric seam allowance edges
- Joining and overedging knit fabric
- Reinforcing stitches in stretch materials
- Creating soft seams for underwear and sports applications
Selection and Sewing Notes
Choose thread according to the fabric material, thickness, stretch, sewing specification, and product usage environment. If a non-stretch thread is used on stretch fabric, thread breakage or seam tightness may occur during wear. Conversely, if a bulky thread is used on lightweight fabric, the stitch may appear too thick.
On a serger, adjust the needle size, differential feed, presser foot pressure, and thread tension to match the thread and fabric. If the looper thread does not fully cover the seam allowance edge, or if the thread is pulled too tightly, check not only thread tension but also thread thickness, compatibility with the needle, and sewing conditions.
Before mass production, test sew with the same number of fabric layers as the actual product and check stitch stretch, puckering, thread breakage, and appearance after washing. For color matching, it is important to check not only the fabric surface but also the state where the thread is visible at the seam allowance edge.
Differences from Similar Terms
Sewing thread is a broad term for sewing threads in general, including household and industrial use. Serger thread refers mainly to thread used on sergers. However, because thread itself is not always limited to a single application, machine compatibility and sewing specifications need to be confirmed.
Woolly thread is thread given stretch and bulk through a lofty finish. It may be used as a type of serger thread, but not all serger thread is woolly thread. Overlock refers not to the name of a thread, but to the sewing method or the type of sewing machine used to edge-finish fabric.
Frequently Asked Questions
Can serger thread and ordinary sewing thread be used interchangeably?
In some cases, yes, but it depends on the fabric and sewing specification. General sewing thread may be used for overedging woven fabric edges. On the other hand, for knits and stretch materials, using processed thread or woolly thread for the looper makes it easier for the stitch to follow fabric stretch.
Should the needle thread and looper thread on a serger be different?
They can be the same, but they are separated depending on the required performance. Needle thread needs strength and ease of passing through the needle eye, while looper thread needs covering ability to wrap the seam allowance edge and stretch. When changing thread, always check the stitch with a test sew.
What should be checked when thread breakage occurs on a serger?
Check whether the thread tension is too strong, whether the needle is worn or deformed, and whether the needle size matches the thread thickness. In addition, threading path, looper timing, differential feed, and presser foot pressure relative to the fabric can also cause thread breakage or skipped stitches.
