Coater consists of unwinder, puller, coating station, dryer and winder. The main and critical part of the machine shown in Figure 6.5 determines the speed of the coating line web by its ability to grip the web and controls the speed at which the web moves from the unwinder to the winder. If the web is loosened, this part loses the ability to control the speed of the web.
So a good leading part needs to be able to catch the frame at all times when the speed is increased to the most designed speed, even during the transient , or when the speed is stable . In order to control the web speed, the bucket guide part needs to be able to apply driving torque or resistance torque to the web.
An example of a good leading part of a coating line is the coating drum. A typical coating roll diameter can be 38in, circumference is about 10ft, about 10ft of web will be pulled out of the unwinding station for each rotation of the coating roll, through the pull roll to the coater and dry Dryer, and sent to the winding section along the next mechanical section. When the guide part can effectively control and keep the web speed constant, the coating machine is performing normal coating-1 drying with an appropriate coating thickness to produce good quality rolls. If the key part cannot control the web speed and web slippage, there may be thick or thin coating, insufficient drying or excessive drying, scratches on the web or coating scratches, and poor winding of the roll, etc. ills. Web breaks are usually caused when the control of the web sliding tension system is unstable. What's worse, when the assorted web passes through the machine, the mountain slides vertically or laterally so that the web cannot run along the film path. When there is slippage, the machine will run at a low speed, but like in the moment of acceleration or deceleration, it will slide quickly from side to side and eventually lead to breakage. Severe slippage can even produce nails such as threading on the machine . Simply put, the important characteristic of the steering part of a machine is that the main roller will be driven by the motor through the spoke tube without web slippage. The ability to transmit torque to the web.
