Detection method of fabric folding thickness and shrinkage rate

1. Folding thickness of the fabric. Fabrics can be divided into thicknesses, and garments made of fabrics also have thickness; this thickness is expressed by the amount of folding, so the amount of folding should be considered when the paper pattern is drawn. The amount of folding indicates the degree of folding thickness of the fabric, which is available for any garment. The folding amount is different in size. The thicker the fabric, the greater the folding amount; the thinner the fabric, the smaller the folding amount. Example: The folding amount of jeans made of denim W: 1.2cm K: 0.6cm H: 1.2cm SB: O.6 2. The shrinkage of fabrics There are two types of garment fabrics: natural fabrics and chemical synthetic fabrics a: Natural fabrics: woven from natural fibers, mainly plants, such as cotton, linen, etc., with a large shrinkage rate, animals such as silk, wool, and leather , Shrinkage rate calibration b: Chemical synthetic fabrics: mainly polyester, nylon, acrylic, chlorinated, and chlorinated non-shrinking fabrics woven from chemically synthetic fibers. (Another kind of fabric that is a mixture of natural and chemical, such as polyester-cotton, has a low shrinkage rate) 　　 Because of the characteristics of natural fabrics, natural fabrics shrink after washing. The largest shrinkage of cotton and linen fabrics is significant. In daily life , In particular, most casual clothes are made of pure cotton fabric, so the shrinkage rate must be considered when the paper pattern is produced. No shrinkage rate: a. The size before washing is m and the size is n after washing. Then au003dmn/m×100%　　 Since the yarn direction of the fabric has two directions: horizontal and vertical, there are also two shrinkage rates: 　　alongitudinal u003d mlength-nlength/mlength×100%　　awidthu003dmwidth-nwidth/mwidth×100%　　 Generally speaking, the shrinkage rate of the fabric will be informed when the paper pattern is produced. If we don’t know this fabric yet The shrinkage rate can be obtained by the following two methods. a: Regardless of the shrinkage rate, directly make a paper pattern of the middle size to make the board, and then take it to the washing plant to wash the water (note that the washing method must be the same as the washing method of the bulk product), and then after the washing is returned To measure this board, compare with the finished product specifications, subtract more and add less. This is more accurate for the board, but it takes too long to make the board. b: Take a piece of fabric that is made into a large product, sew around it, draw a square in the middle of the cloth with a pen, with a side length of 40cm, parallel patterns on both sides, and a vertical pattern of 40x40cm on both sides, and then wash with water. The washing method is the same as that of the bulk product. After washing back, and then measuring each side of the square, it becomes 36x36cm data. Reuse au003dmn/m×100%　　a longitudinal 40-38/40×100%u003d8%　　a horizontalu003d40-36/40×100%u003d10%　　 Therefore, the shrinkage rate of the fabric: straight: 5% horizontal: 10 %　　 However, considering the fixing effect of the stitches, the shrinkage rate of the garment is actually slightly smaller, so it should be determined according to the specific situation.　　 To find a vertical and a horizontal, use a to find the length, and a horizontal to find the circumference. The purpose of finding the shrinkage rate is to find the data K before washing. 　　 From the shrinkage rate formula, Ku003d? And then put forward: K vertical u003d e vertical / 1-a vertical (find the length of the clothing) 　　 K horizontal u003d e horizontal / 1-a horizontal (find the circumference of the clothing) 　 　 　 　 　 　 　 　 　 　 　 　 　 for the straight and horizontal parts, the shrinkage rate is the average , Such as the waist and trousers are perpendicular to each other. Example: w: 66cm-68.6cm (shrinkage rate: straight 3% / horizontal 4%) 　　SL: 55.9-57.5cm