Calendering, also known as calendering. A process of fabric finishing. The finishing process uses the physical plasticity of fibers under high pressure or high temperature conditions to flatten or roll out patterns on the surface of the fabric to enhance the luster of the fabric.
Based on the roll surface material, rolling pressure, temperature, different soft and hard roll combinations and wear Fabric method can achieve different calendering effects. Commonly used calendering equipment for garment fabric finishing in Jiangsu and Zhejiang can be summarized as mirror calender, oil calender, film calender, seven-roller calender and embossing machine.
Mirror Calender ▲
The upper rod is a metal rod with a highly polished surface. The heating roller has a nylon rod in the middle and a metal rod at the bottom, which mainly serves as a supporting rod. During production, the cloth passes between the upper roller (heating roller) and the middle roller (nylon roller). Under pressure, the heating roller and the nylon roller form a rolling point, and the cloth passes through the rolling point to achieve the calendering effect. There are also two-roller mirror calenders and controllable mid-to-high mirror calenders on the market, which are essentially the same!
Technology: The temperature ranges from cold pressing to 160 degrees, the speed is 70 meters/min, and the pressure is 8 to 10 kilograms.
Uses: Mostly used for fabrics that require calendering to have a general luster, to improve the feel (the handfeel will become softer and smoother after calendering), to smooth the surface of the calendered cloth, and to remove dyes. The whole fabric is starched (the cloth looks like a white watermark), the color is changed (the color will become lighter after calendering), and the previous process of coating finishing (the coating after calendering can increase the water pressure resistance of the fabric, The rubber surface is smoother, softer and smoother, and glue is saved at the same time), and rolled fabrics that are anti-velvet are also often finished with a mirror calender, such as the light and thin down jacket fabric that has become popular in recent years – 380T nylon (no gallbladder and anti-velvet).
Oil surface calender▲
Oil surface calender and mirror calender The difference is that the stick under the oil surface is a rubber stick (soft stick), while the mirror surface is a nylon stick (hard stick). The working principle is basically the same!
Process temperature 160-220 degrees, pressure 6-8 kg, speed 70 meters/min.
Purpose: Calendering finishing of fabrics requires ultra-bright luster, or slightly bright and soft luster. Oil finishing is also commonly used for fabrics requiring little color change after calendering ( The color of the fabric changes greatly after mirror rolling).
Film Calender▲
The middle is a metal rod (heating roller) and the upper and lower are nylon rods (Imported nylon is better). During operation, the fabric passes through the lower roller and the heating roller and then passes between the heating roller and the upper roller, thus forming two rolling points, which is equivalent to the fabric being rolled twice. There are also film calenders with a metal rod in the middle and a ceramic rod on the surface. After rolling, the gloss becomes more matte and has a matte effect!
Process temperature 120-160 degrees, pressure 8-10 kg, 40 meters/min.
Usage: The fabric needs to be glossy and matte, soft, thick and waxy to the touch, skin-like, and have a film effect, such as multi-F polyester taffeta film calendering finishing.
Seven-roller calender ▲
It has two heating rollers, three cotton sticks and It consists of two upper and lower metal rollers. During operation, the cloth passes between the rollers, forming five rolling points to achieve the calendering effect repeated many times. Similar to the seven-roller machine, there are five-roller calenders and six-roller machines that replace the bottom two rollers of the seven-roller machine with a nylon roller. The working principles are basically the same!
Process temperature 110-140 degrees, pressure 4-8 kg, speed 60 meters/min.
Usage: Mainly used for down jacket lining fabric anti-down finishing, such as the most common 290T polyester taffeta liner fabric!
Frequently Asked Questions
Temperature, speed and pressure are the three elements of the calender. If it is not ideal, we must first look for the reasons from these three aspects.
1. The hand feels hard. If the hand feels hard after finishing, it should be considered that the temperature, pressure and speed are too high and too slow. If the hand feels hard after oiling, you can cold press it with a mirror surface. Of course If the fabric is too hard before finishing, it is unlikely to become too soft after rolling!
2. The glossiness is too bright or too dark. Brightness is mainly determined by temperature. If it is too bright, the temperature should be lowered, the speed should be accelerated and the pressure should be reduced. If it is too dark, the opposite is true.
3. Side difference and head-to-tail difference. When both sides are bright, the pressure should be reduced, and when the middle is bright, the pressure should be increased (the roller has a medium height); the head-to-tail difference should mean that the temperature is not maintained. Consistent, the general temperature is controlled within plus or minus 5 degrees!
4. The anti-lint effect is poor. If the anti-lint effect is not good, you should slow down the speed and increase the temperature and pressure, or increase the number of calendering times!
5. Wrinkle marks. Rolling marks are a common problem in calendering. Wrinkles on both sides should increase the tension of the fabric, and wrinkles in the middle should reduce the tension of the fabric. If there are wrinkles in the middle, you should also check whether the lower cloth rack is clean. Too much friction can easily cause scratches on the cloth surface. Generally processed in bulkThe cloth should be rolled into large rolls before processing to achieve constant tension!
6. Calendering spots: Calendering spots are the most common defects caused by unclean roller surfaces (for example, there are threads on the roller surface). The roller surface must be wiped frequently during production. ! Damage to the roller surface will also produce calendering spots (such as small pits caused by the nylon rod pressing against hard objects, etc.). </p
