We know that the needle is a main element in the sewing machine. Earlier people used tiny pieces of material for sewing. Initially they were made from hones or bones of animals. In this session we will follow the gradual improvement of the needle. According to the type of material, there are different types of needles available. How ever the structural parts of a needle is common to all types. Needles are available in a wide range of sizes. The selection of the correct size of needle is essential to make a good seam. Needles are made to different sizes. Different manufacturers use different methods or scales to indicate needle size. Therefore in this session we will deal with the structural parts of a needle and also the common methods of needle sizing. 1 History of the needle
As mentioned in the introduction tiny pieces of material made from the horns or bones of animals were used by mankind for sewing purposes. These tools had a drilled hole, which corresponds with eye of a present day needle. Later people made it from copper and iron, but they had a very poor surface finish. Until the early 15th century, hand sewing needles production was not well established in Germany. However today, Germany is the world centre of sewing machine needle manufacture. From the 15th to the 18th centuries, needle manufacture was highly labour intensive. However, the invention of the sewing machine brought about changes in the needle manufacturing process. By the 1820's sewing needle manufacture became mechanised. This enabled needles to be produced in large quantities by machines. Functions of a sewing machine needle
(i)The needle should be able to make a hole in the material to be sewn in order to pass the needle thread through the material. When doing this, material should not be damaged. (ii)Carry the needle thread through the material in order to be caught by the bobbin hook in lock stitch machines or by the looper in chain stitch and overedge stitch machines. 2 The structure of the needle
According to the type of application, there are different types of needles now in use. But the structural parts in a needle are common for all types of needles. A needle consists of following parts. (Figure .1).
Figure 1 Parts of a needle
Butt The top of the needle is called as the butt. It is a flat area Shank The area below the butt is called shank. The shape of it may be cylindrical or flat. The shank is placed into the needle bar clamp in order to fix the needle to the machine. Shank is the thickest part in a needle. The brand name and the size of the needle is printed on the shank. The shank diameter also determines the position of the needle point in relation to the hole in the throat plate of the sewing machine. Shoulder The conical area in between the shank and the blade is the shoulder. The size of the shoulder depends on the size of the shank and the blade. The blade The end of shoulder to the top of eye is the blade. The blade contacts the material being sewn during sewing, the blade is subjected to higher frictional forces. The blade has a long groove and a short groove. The blade is sometimes made smaller in diameter over a part of its length extending from just above the eye. This is done to minimize needle - cloth friction. Care should be taken to avoid making the needle too blade diameter in this way. Long groove The long groove is the protective channel for the needle thread during the cycle of stitch formation. The sewing thread is subjected to high abrasion during sewing as it penetrates through the material so many times. The long groove gives somewhat protection for the thread. Short groove This is the reduced...