1) Specifications and models The size of the zipper refers to the width and size range of the two chain teeth and the tooth chain. The unit of measurement is millimeters. The size of the zipper is the basis for the shape and size of each component, and it is the most important and important size. The zipper model is an important reflection of the shape, structure and performance characteristics. The zipper model not only contains the zipper specification requirements, but also reflects the zipper performance characteristics, that is, the zipper technical parameters and use functions. 2) Powerful The strength of the zipper is the most important performance index, which determines the use range and durability of the zipper. In the zipper standards of various countries, the strength is clearly defined, and it is also the basis for testing the quality of the zipper. Zippers of different specifications and models have different strengths suitable for different uses. Zipper suppliers will generally give a reference selection of specifications, models and scope of use. The specifications and models of the zipper must meet the requirements for use. Once confirmed, the specifications and models of the zipper must meet the requirements of the order. There are many ways to measure the strength of the zipper, but the basic strength requirements can be tested by the following methods. From the results of these tests, the quality of the zipper for different purposes can be judged. a) Pulling smoothness Under the specified conditions, the maximum force in the zipper process. b) Load pull The number of times the zipper can withstand reciprocating movement under the specified horizontal and vertical tension. c) Flat pull strength test Flat pull strength is the most basic strength indicator. It is used to test the ability of the zipper teeth to resist lateral forces in an interlocked state, which is very similar to the actual state of use. d) Self-locking strength test The slider is self-locked in the middle of the fastener element. The fastener element is divided into left and right parts. Stretching the left and right parts of the zipper can test the locking strength and the resistance of the slider internal components. e) Top-stop force test The zipper teeth interlock, pull the slider to the top stop, and pull the slider. At this time, the strength of the top stop of the zipper can be measured. This is to simulate the zipper in the holding state, the slider over the top stop pull or pull The ability to resist external forces when moving from the ribs. f) Power stop test Pull the slider to the lower end, the sprocket is divided into left and right parts. Pulling the sprocket on the left and right sides can measure the force required to break the bottom stop and the resistance of the internal components of the slider. g) Open tail flat pull strength test To test the situation that the open end zipper cannula and socket resist the damage of external force, the left and right sides of the open end are fixed on the jig up and down, and when the zipper is closed, the test instrument is started. h) Socket displacement test Pull the socket longitudinally from the fastener chain to remove the ultimate force of damage. i) Pull head pull tab combined with strong test Apply the puller force in the direction perpendicular to the pull tab until the pull tab is separated from the pull body. The value recorded at this time is the bonding strength of the pull tab. j) Torsion resistance test of pull tabs 3) Length The length of the zipper relates to the size of the garment and the closed body or part of the garment, and is the most important dimension. The method of measuring the length of the zipper is: place the zipper flat on a flat table so that it is in a natural state. Use a steel ruler to measure from the top of the slider to the outer end of the bottom stop. Measure to the outer end of the socket. During the manufacturing process of the zipper, due to the inertia of the equipment and the integrity of the sprocket, the length of the zipper is allowed to vary, but it must be within a certain range. 4) Straightness of zipper The test method for the straightness of the zipper is: take a finished zipper and lay it flat on a flat table to make it in a natural state, and then use your fingers to move back and forth once along the edge of the fastener element and gradually move closer to the bend with a ruler Then use another ruler to measure the distance between the chain element foot and the ruler, this distance is the straightness. 5) Color of chain teeth and cloth belt The color of the zipper and zipper tape must match the confirmation sample of the confirmation sample card. If you are required to match the body color, you must check with the fabric again, and check the same zipper for color difference, the same batch of zipper for color difference, generally should be above GRADE3. 6) Appearance a) Straightness and flatness of the zipper: make the zipper naturally sag, without wave bending. b) Chain element of zipper: The fastener element of the injection zipper is bright, there is no depression in the middle of the front, no missing teeth, the metal fastener elements are arranged neatly, not skewed, and there is no broken fastener chain. c) The color of the injection zipper: uniform color, bright and bright, no color difference. d) Adhesive for zipper tape: The position of the zipper tape is symmetrical, without skew, and the adhesive is repeatedly turned 180 degrees 10 times and continuously. e) Slider: The plating layer of the plating slider is bright, free from skin, no foreign body scratches, the thickness of the coating is not less than 3UM, painted, bright color coating on the surface of the plastic slider is uniform and firm, no bubbles, no dead corners and other defects. 7) Special performance requirements a) Dyeing fastness: It is generally required that the pull-link is soaked in hot water at 80°C for 15 minutes, compared with the original, it is greater than 4 grades. b) Hand shrinkage rate: The washing shrinkage rate of the zipper is not more than 3%, and the shrinkage rate of dry cleaning is not more than 3%. c) Resistant to organic solvents: Immerse the zipper in a four-record ethylene solution at a temperature of 20±2 degrees Celsius for 2 hours, let it dry naturally, and the opening and closing of the zipper will maintain its original function. d) Corrosion resistance of metal plating: in 3% sodium chloride solution, after 180min (3 hours), take it out and dry it naturally, visually check for rust spots. e) Does not contain toxic or harmful substances.