Sewing Needles

Suitable sewing needle type is one of the most important parameters for ensuring the effective and fault free sewing process it will depend on the characteristics of the needle type, needle point, needle fineness, fabric material, the size of sewing thread, the seam type and stitch type.

It is important to use correct needle size for the type of fabric being used. The metric size “Nm” of a needle defines the diameter of the blade (in 1/100 mm) at a point just above the scarf. Fine needles are around Nm 70, medium needles are abound Nm80-Nm90 while thicker needles are around Nm100. The convention for sizing is that the length and thickness of a needle increases as the size number decreases. Delicate fabrics such as silk, chiffon, voile, fine lace and organdie would need a fine “size 9” needle. Lightweight fabrics such as synthetic sheers, taffeta, velvet, stretch fabric and tricot would need a “size 11” needle. Medium weight fabrics such as poplin, linen, chambray, wool crepe, flannel, knits, jersey, wool and satin would need a s “size 14” needle. Medium-heavy weight fabrics such as sail cloth, gabardine and tweed fabrics would need a “size 14-16” needle. Heavy fabrics such as denim, upholstery and canvas fabrics would need a “size 16-18” needle. Most readily available machine needles are sized from 9 to 18. The smaller the number, finer the needle.

• Skip stitches are caused at seam cross sections and thick material parts
• Needle Breakage is due to high penetration forces and strong needle deflection
• Needle point damage is generally caused due to poor adjustment with looper causing contact with hardened looper
• Thread breakage is caused by poor loop formation and in sufficient space between thread and needle for picking up by looper
• Use Threading Air Needle for faster threading the needles to avoid wasting time
• Advantages of using correct needle can  give straight un-staggered seams less skip stitch problems, fabric damage, less puckering, less needle breakage and higher productivity, optimum protection of Hook point, reduced machine load, reduced thread loss, and reduced production cost.

Seam Puckering in Stretchable fabrics

• Use smallest size of needle and smallest thread size
• Use smaller ball Point needle
• Use minimum pressure on presser foot
• Tension of needle thread and bobbin or looper thread must be minimal
• Use feed dog with finer teeth
• Do not use bigger SPI (stitch per inch)
• Check needle for wear or damage at point area. Stitch skipping and thread breakage while sewing synthetic fabrics.
• Always use special finish needles with special coating to reduce friction and overheating
• Decrease needle temperature by using special lubricants or pre-lubricated sewing threads for smoothness and reduced friction
• By cooling needles using stream of air through blower
• By reducing revolution of sewing machine causing lower generation of heat on sewing needle.

Shank locates the needle in the needle bar. Shank is following types:

• Shanks with a circular section
• Shanks with a flat side which serves to locate the needle in a specific position in the needle bar
• Shank thickness is maintained all the way down to needle blade. These kinds are used in speciality needles.

Blade of needle runs from the end of shoulder to the beginning of the eye. Blade increases in thickness from eye to shoulder to increase stiffness. Curved blade needles are used for Blind stitch machines.

Groove is the threading side of needle. Its function is to guide the thread while forming the stitch and to protect it against excessive friction.

Eye is the hole before needle point for sewing thread. The shape of eye is always extended in its length as the needle thread has to pass diagonally through the needle in the length direction.