The ancient ancestors evolved the technology of needle and thread sewing with one stitch and one stitch, and created various types of sewing threads; in the production of clothing, one stitch and one stitch and its continuous improvement of craftsmanship have created many brands. It goes without saying that thread plays a pivotal role in clothing.
1. Classification of Sewing Threads
Sewing threads include pure cotton, nylon, polyester-cotton, blended, polyester and rayon, etc. They are generally made of two, three, four, and six single yarns twisted together. The twisting direction can be divided into S twist and Z twist. kind. Lockstitch machines generally use Z twist stitches, and S twist threads with good quality can also be used on other sewing machines. Cotton sewing thread has good sewing performance, but shrinks more than synthetic fiber thread during washing. Its strength, chemical resistance and abrasion resistance are also worse than synthetic fiber. High-quality mercerized cotton thread is expensive, so cotton sewing is rarely used now. String. Short fiber polyester sewing thread has low cost, excellent sewing stability, durability and sewing performance, so it is suitable for all conventional garment sewing. The sewing thread used in the overlock sewing machine is generally cotton thread, but due to the high cost of cotton fiber at present, polyester-cotton thread is generally used instead.
(1) High-strength polyester thread: It is currently one of the most conventional and widely used sewing thread varieties on the market. It is characterized by good luster, no elasticity, good color fastness and strong tensile force. It is widely used in the sewing of PVC, thicker fabrics and nylon leather products.
(2) Fishing net line (transparent line): The transparent line is divided into nylon and polyester monofilament, which are also different in terms of expansion, hardness, tension and use. It is often used in weaving, sewing trademarks, suit pants, sewing transparent materials and various craft products.
(3) Pure cotton thread (polyester staple fiber thread): Polyester staple fiber thread is a conventional thread that is widely used and commonly used. It has a few hairs on the surface, and its tensile strength, luster and wear resistance are inferior to other threads. It is used for thinner fabrics, pure cotton thread is made of natural cotton combed and singeed, and it is specially produced for the sewing of pure cotton fabrics.
(4) Waxed rope thread (walking horse thread): Waxed rope thread is divided into two materials: nylon and polyester. The linear shape is flat and the tension is extremely strong. After waxing, wax rope thread is often used for thick leather sofas, outdoor appliances and casual shoes. , leather and other thick products sewing or hand sewing operation.
Second, the relationship between sewing thread and sewing needle
(1) Select the thickness of the suture
When choosing the thickness of the sewing thread, the use of thin sewing thread should be considered first. Specifically, consider the following aspects: (1) The bobbin volume of the lock stitch sewing machine is limited, and the use of thinner sewing thread can accommodate longer sewing thread, saving the time of shuttle change and achieving high work efficiency. ②The thin sewing thread is small in size and feels good in chain sewing. ③The space occupied by fine sewing thread is very small, and it is less likely to cause fabric deformation and sewing wrinkles. ④ Small needles can be used for fine sewing threads to avoid needle holes in the fabric. ⑤ The fine sewing thread can also reduce the prominent seam marks, making it trapped in the inner layer of the fabric surface and reducing the impact of abrasion.
In the sewing process, in order to form correct stitches, it is necessary to ensure that the specifications of the needle, the suture and the sewing material match. In addition, the following two points should be noted:
First, the twist of the suture should also be considered during the sewing process. The purpose of twisting the suture is to increase the strength and elasticity, but if the twist is too large, it will cause the suture to roll and affect the normal formation of the loop. Under normal circumstances, take a 1-meter-long suture and grab the two ends of the thread to make it close. The natural twisting turns of the two strands should not be greater than 6, otherwise it is easy to cause skipping failure.
Second, when sewing, if the sewing material is thin and soft, a fine needle must be used. At the same time, the lifting amount of the machine needle should be increased, because the friction between the sewing thread and the sewing material is small. If the width is reduced, it will affect the normal hooking and cause skip stitch failure. In the case of rough fabrics, the opposite is true.
(2) Selection of needles
In the case of selecting a good suture, the bur is also an important sewing machine to be considered in sewing. The working nature of the machine determines the selection of needles. Machines of different natures need to be equipped with different types and specifications of needles, such as 96'1 type or 88'1 type needles for lockstitch machines; 18'1 type machines for overlock sewing machines. Needle etc. No matter what type of machine, in the sewing process, the specification of the machine needle, that is, the needle size, must be selected according to the nature and thickness of the sewing material. Generally speaking, the needle points of the machine needles used for textiles and knitwear are ground into a conical shape, and the needle points of special shapes, such as spear points, diamond points, reverse twist points, etc., are used when sewing leather and similar sewing materials. It is to increase the strength of the needle and obtain a good sewing effect.
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