1. About the needle inspection
1. Purpose of needle detection:
In order to check for broken sewing needles left in the garment when the garment is sewn.
The main components of sewing broken needles: iron (Fe), nickel (Ni)
Needle tip danger!
2. The principle of needle detection:
Using the principle of the N pole → S pole of the magnetic field line, there is a magnetized material passing in the middle, which affects the change of the magnetic field, which is manifested as: the needle detector chirps (iron, cobalt, and nickel are all easily magnetized substances).
3. The standard of needle detection:
NC-A (promulgated by the Japan Textile Inspection Association) is converted into a steel ball with a diameter of 0.80mm or less.
4. The sensitivity of the needle detector:
Steel balls of Φ0.80mm can be blocked, and steel balls of Φ0.68mm can pass;
5. Reasons for not checking:
①The broken needle is left in the garment;
②The sensitivity of the needle detector is too high;
③ In the process of garment fabric processing and sewing, a small amount of metal powder is adsorbed on the fabric;
④After the sewing needle hits the zipper, a small amount of metal debris remains at the impact;
⑤ The chemical substances added in the customer's washing or other treatment process may contain a small amount of substances that cannot pass the needle detection, and may be stained on the fabric or zipper;
⑥ Larger pull tabs or circular pull tabs.
2. About nickel content
6. Anti-nickel: ANTI-Nickel---the release of nickel does not affect human skin;
7. Nickel-free: Nickel Free---absolutely free of nickel
8. The influence of nickel on the human body:
Nickel comes into contact with human skin, making the skin think that there is an "imaginary enemy" intrusion, and secretes a certain substance to resist, manifesting as skin allergies, rashes, itching, etc.
9. Standard: EN1811/EN12472 standard stipulates that the release amount of nickel is less than or equal to 0.5μg/cm .week
10. OTS product features:
Nickel in cupronickel products exceeds the standard (Ni-Cu);
Brass white plated products are recommended.
3. About the color
11. Light source: D65---international standard light source
12. Standard: QB/T 2171～2173-2001 stipulates to reach level 4
13. Color sample:
a. The size of the color sample must be larger than 4×4cm2;
b. The color sample must be marked on the front and back;
c. The color of wool and reflective fabrics is not allowed.
14. Light-colored fabrics with contrasting colors:
a. Light-colored fabrics cannot be in direct contact with red, black and dark blue zippers;
b. Light-colored fabrics cannot be in direct contact with aluminum zippers;
c. Light-colored fabrics are equipped with metal zippers. When packaging, they should be separated by paper or plastic bags between the zipper and the fabric to avoid dust and other debris contaminating the clothes;
d. When there is a high requirement for color fastness, the special color fastness must be specified when placing an order, and the corresponding fabric should be provided for binding color shifting test.
15. Coated fabric:
a. Since the coating part of the coated fabric will aggravate the occurrence of dye migration, the coating such as PU or PVC cannot directly contact the dark zipper;
b. When choosing dark zipper with different color coating fabric, it should be separated by paper or cloth in the middle;
c. When the purchased zipper is used for coated fabrics, it is necessary to specify the special fixation color when placing the order, and provide the corresponding fabric for the color transfer test.
16. Leather fabrics: Since the chemical components such as acid or chrome added during the mixing process of leather will react chemically with metal parts, the chemical components in the leather must be neutralized and washed and dried.
Fourth, the matters needing attention in the process of garment processing
17. Front lead sewing method:
a. When sewing a closed zipper, in order to prevent the slider from being stuck at the top stop, the front head should be in a natural state;
b. The distance between the parking space and the top stop is kept at 2~3mm
18. Shrinkage rate: In order to prevent the arching of the chain elements after the zipper is sewn, the length of the zipper should be appropriately deducted according to the elastic shrinkage rate of the fabric;
20. Flat car position
a. When sewing the zipper, the parking space should be about 3mm away from the chain teeth, leaving enough passages for the slider, otherwise the slider will be blocked or damaged and the chain teeth will be arched;
b. When sewing a zipper, avoid the presser foot colliding with the slider, otherwise the slider will be deformed, the paint will fall off or the coating will fall off.
21. Double-opening zipper: When sewing the double-opening zipper, the parking space should be kept consistent. If the parking space at the rubber cloth is too close to the latch block, the force angle will increase, and the latch block may fall off.
22. Post-processing: After sewing, the sewing thread should be cleaned up, otherwise the thread will be stuck in the slider, and the opening of the slider will become larger when it is forcibly pulled, which will cause the zipper to break open;
23. Bend angle: When the zipper is used in tents or bags, the plane angle should not be greater than 90 degrees, otherwise there will be a blocking blockage, and the zipper may be broken when it is forced to close.
24. When the garment is dyed, metal parts such as sliders, squares, and latches will be corroded by chemicals.
a. Before the garment is dyed, it should be proofed and tested;
b. After dyeing, it must be cleaned and dried in time.
c. Dyeing dyes such as cotton and linen fabrics will undergo redox reactions with metal substances, so that the dyes are reduced and decomposed, thereby leaving reverse color marks on the fabrics;
d. After finishing the dyeing, it must be cleaned and dried in time.
25. Commonly used washing methods
General washing: the water temperature is about 60~90℃, add a certain detergent to wash for 15 minutes;
Enzyme wash: Enzyme is a kind of cellulase, which can degrade the fiber structure under a certain pH value and temperature, so that the cloth surface can be mildly faded, fading (producing "peach skin" fruit), and get Long-lasting softness effect;
Stone grinding: that is, adding a certain size of pumice stone to the washing water, so that the pumice stone and the clothes are polished. After washing, the cloth surface appears gray and old, and the clothes are slightly to severely damaged. Commonly used yellowstone, white stone, AAA stone, artificial stone, rubber ball, etc. for washing;
Sand washing: Use more alkaline and oxidative additives to make the clothes have a certain fading effect and old feeling after washing. If it is matched with stone grinding, a layer of soft frost white fluff will appear on the surface of the fabric after washing, and then add some softeners. , which can make the fabric soft and soft after washing, thereby improving the comfort of wearing;
Rinsing: Rinsing can be divided into oxygen bleaching and chlorine bleaching. Oxygen bleaching is to use the oxidation of hydrogen peroxide at a certain pH value and temperature to destroy the dye structure, so as to achieve the purpose of fading and whitening; chlorine bleaching is to use the oxidation of sodium hypochlorite to destroy the dye structure, so as to achieve the purpose of fading;
Ma Liu wash: commonly used potassium permanganate plus oxalic acid to achieve the purpose of fading.
26. Damage to the zipper by washing
When washing, the surface of the slider or the fastener element is controlled by the hole wall of the inner tank of the washing machine, which causes the coating or plating layer to be worn, thus causing the paint to fall off or the copper bottom to be exposed;
When washing, the slider falls into the inner hole of the washing machine, and the pull tab is broken, twisted, and the cap falls off during washing;
Because the zipper is not closed during washing, the blocks, latches, chain teeth and other components are damaged;
When washing, the zipper should be closed, the pull tab should be fixed, and the slider and the teeth should be wrapped for protection;
Especially when doing stone washing or choosing black nickel zippers, special attention should be paid to proofing in advance for washing tests, and chemical reactions occur on the zippers during washing.
Washing makes the aluminum zipper elements chemically react, and the elements become smaller, so that the elements break or fall off;
If it is not cleaned and dried in time after washing, the dyes or residual chemicals in the fabric will undergo redox reactions with metal parts, causing discoloration of the fabric or metal parts.
27. Garment ironing causes bad
The protective layer on the surface of the metal zipper elements is dissolved by heat, leaving stains on the fabric;
When the injection-molded zipper is ironed at high temperature, the teeth are softened and deformed, the block mouth is closed, which leads to inability to insert and pull out, and the double pin becomes smaller, which causes the slider to fall off there, etc.;
Steam ironing or wet weather in rainy days causes blue rust stains (Cu) on the surface of metal accessories 2+;
After the garment is ironed, it must be fully dried before packaging.
28. Packaging
The packaging should be breathable and moisture-proof;
If the light-colored zipper is placed in the polyethylene bag for too long, the zipper will turn yellow.
29. Storage
The zipper should be stored in a dark and ventilated environment, and should not be directly exposed to the air or sunlight for a long time;
The high concentration of H S gas in the storage or use environment will make the metal parts of the zipper black, and the high concentration of CL gas will make the zipper yellow.
30. Transportation
During sea transportation, the environment of high temperature, high humidity and high salt content will cause corrosion of metal parts;
For orders that require long-distance shipping, the salt spray test requirements must be indicated when placing the order.