Sewing Threads are manufactured by twisting short fibres or by continuous filaments yarns. At times two or more yarns are combined to make the thread to get the required strength.
All sewing threads begin as simple yarns. Twisting together short fibres or continuous filaments produces these yarns. Two or more yarns are combined to make the thread. There are various factors depending on general and specific end uses, which when carefully analyzed can help in better selection of appropriate thread for sewing apparel to achieve optimum performance. Factors like type of seam, stitch type, stitches per inches, sew-ability, loop strength, linear seam strength, type of material being sewn, type of sewing machines, elongation, shrinkage, abrasion resistance, colourfastness, and resistance to chemicals, heat light conditions under which the product must perform; normal life of the product; and cost effectiveness etc. must be considered while selecting sewing thread.
The more thread contained in the seam the higher the seam elasticity
The higher the stitch density (SPI), the higher the seam elasticity
Sufficient seam elasticity is primarily determined by thread storage in that particular seam, which means the amount of thread (Top + Bottom thread) continued in 1 meter seam length.
- Lockstitch type contains a total of 2.80 meter of thread
- Double chain stitch contains a total of 4.80 meter of thread
- Four thread over lock stitch contains a total of 17.10 meter of thread
Right thread selection
- For solid colour fabric select thread that is the same colour or shade/tone darker than fabric For plaid, print or tweed fabrics select thread to the dominant colour in the fabric.
- Knit fabric is best kwon with polyester on nylon thread as thread will stretch a big, giving the seams some elasticity
- If sewing a cotton knit, a cotton-wrapped polyester thread is the best
- Choose thread made from long, continuous fibers and examine the thread for “fuzziness”.
- If the thread is fuzzy, it is made of short firer, resulting in weaker thread causing lint build-up on the machine, poor stitch formation and frequent breakage Always match colour of the thread under a standard light box using neutral grey colour background
- Always check thread colour by stitching on actual bulk fabric
- Always provide a minimum of 2.5”x2.5” fabric colour swatch to thread supplier for better matching
Type of Thread-Construction
Air entangled Thread is made from continuous filaments of polyester that are entangled as they pass through a high pressure air jet. This yarn is when twisted, dyed and wound on cones with lubricant. Air entangled threads are used in everything from seaming flags to heavy denim jeans.
Core spun Thread is made by spinning a wrap of staple cotton or polyester around continuous filament of polyester fibers. Two or more of these single yarns are twisted together to form the thread. Core threads have fuzz on their surface giving them good lubricated characteristics and also a continuous filament core that contributes to high strength and durability. When wrapped with a cotton wrap, core threads have very good needle heat resistance. When wrapped with a polyester wrap, core threads have excellent chemical resistance and colourfastness.
Monocord Thread is made from continuous filaments of nylon that have been bonded together with very little twist so that they look like a single cord of yarn. These threads appear to be flat and ribbon-like, which provides a high degree of resistance of abrasion and strength. Monocord threads are used in the manufacturing of shoes and other heavy duty applications.
Monofilament Thread is produced from a single nylon continuous filament. It is translucent and can be blend well with many colours. Since it is a single filament, it may unravel easily if the thread is not locked in the seam adequately. Most common use of monofilament threads is in quilting operations on quits and blind stitch operations for hems in apparel.
Spun Thread is made from cotton or polyester staple fibers that are spun into single yarns and them two or more these yarns are plied to make a sewing thread. Spun threads are round threads and have fuzz on their surfacing giving them a soft hand and good lubricate characteristics. These threads have good sewing performance with good dimensional stability.
Textured Thread is made from continuous filaments of polyester or nylon that have been textured and then heat set to insure proper bulk retention. These threads have high extensibility and good elastic recovery. Textured threads are ideas for over edge, chain stitch, and overstitch of the finished seam and offers good seam elasticity for garments like swimwear, children wear, performance wear etc. Textured threads are typically used in the loppers of a serge or over locker.
Twisted Multifilament Thread is made from continuous filaments of polyester or nylon that are twisted together into a cohesive bundle and then plied to make the thread. They are then dyed, stretched, and heat set to achieve the desired physical characteristics like abrasion resistance and durability. These threads are used in performance wear and automobile upholstery.
Types of thread-materials
Cotton Thread is readily available in wide range of colours and is suitable for light to medium weight cotton, rayon and linen fabrics. Avoid using glazed or waxed quilting threads on sewing machine as the finish will wear off and can cause serious tension problems. Cotton thread is without stretch and is usually mercerized, a finishing process that gives strength, makes it smooth, lustrous, gives better affinity for dye and colour fastness.
Polyester Thread is made from 100% polyester and is suitable for most of sewing process. It provides strength and elasticity for sewing on fabrics made of synthetic, natural or blended fibers. All purpose polyester thread is great for knit, stretch and permanent press fabrics because of its stretch and recovery and its non-shrinkage. Most polyester threads have wax or silicone finish helping them slip through the fabric with a minimum of friction.
Rayon Thread is silk like in appearance for decorative stitching, and appliqué monograms. 100% Rayon is strong but fine, making it suitable for machine embroidery.
Cotton Wrapped Polyester Thread – is an all purpose sewing thread for sewing on knits or woven of synthetic or natural fibers or blends where extra strength is required. The polyester core gives strength and elasticity the cotton wrapping gives it a tough heat resistant surface. This thread requires a slightly larger needle, to keep the tread from stripping the cotton wrapping from the polyester core.
Nylon Thread is a fine, soft, stretchy but strong thread for sewing light to medium weight synthetics. Most important is its ability to stretch and recover its sheen and filled in appearance. This is especially suited to nylon tricot. When sewing using nylon thread it is important to loosen top tension slightly to compensate for its stretchy nature.
Metallic Threads are speciality threads that can add sparkle to apparel sewing but are quite fragile. Not recommended for garments that will receive rough or heave use. Ideal for machine quilting, decorative stitching satin stitching on appliqués. Metallic thread is suitable for embroidery and cross stitch.
Silk Thread – is strong thread for sewing on silk and wool. Its fineness makes it ideal for basting all fabric types, as it does not leave holes from stitching or imprints after pressing. Because of its elasticity, silk is also suitable for sewing any type of knit. Silk thread used in making High Fashion expensive tailoring as it can be moulded along with the fabric in shaped areas.
Elastic Thread – comes in various colours. These threads are great for stitching any area that need to be stretched.
After construction, the thread is finished to enhance its suitability for various sewing uses.
Soft: No further processing to change its physical characteristics. It is only dyed and lubricated.
Bonded: Treating continuous filament nylon or polyester with a special resin that encapsulates the filaments is called bonding. The result is a tough smooth coating that ads significantly to the thread’s ability to resist abrasion and greatly enhances ply security.
Mercerized: In this process cotton thread is treated in a caustic solution under controlled tension. This causes the fibers to swell, resulting in a greater affinity for dying. Mercerization also increases the lustre and ads some strength.
Gazed: Passing cotton thread through a flame at high speed to reduce the fuzz is know as gazing. This process also produces a higher sheen.
Glazed: This is a process in which cotton threads are treated with starches and special chemicals under controlled heat and then polished to a high lustre. The glazed process results in a thread with a hard finish that protects the thread from abrasion and enhances ply security.
The number of component yarns that are twisted together to produce a thread is the ply. Two-ply threads, therefore are simply two yarns which have been twisted together.
Twist is simply the number of turns per cm or inch put in the thread. A thread with too little twist may fray and bread. One with too much twist can cause snarling, looping knotting. Balanced twist is the key of a good quality thread. As threads pass through a sewing machine some additional twist may be added. For this reason he direction in which the thread is twisted becomes important. The action of the sewing process tends to increase the twist of Z-twisted thread but can actually untwist a thread with S-twist or right twist. Thread constructions that involve twisting (such as spun, core and twisted multifilament) are twisted in the following directions:
- S-twist direction or right twist for single strand yarn (such as spun)
- Z-twist direction or left twist for ply yarn (such as core and twisted multifilament)