The slip shaft and inflatable shaft of the slitting machine

Differential shafts and inflatable shafts are often used as winding or unwinding shafts in the production process of slitter machines. After the air shaft is inflated by high pressure, the key strip on the surface will expand up to lock the paper core, and the key strip will return to its original position after deflating, and the roll can be removed, which is widely used in the slitting machine rewinding and unwinding. The slip shaft is the principle of independent slip of the slip ring to balance the tension of multiple groups of coils, the structure is more complex, the cost is more expensive, and it is mostly used in the winding mechanism of the slitting machine, and it can also be applied to unwinding in individual occasions.

Introduction to the inflatable shaft of the slitting machine

There are many names for the inflatable shaft of the slitting machine, which can also be called inflatable roller, pressure shaft, inflatable shaft, pneumatic shaft, expansion shaft, inflation shaft and so on. Generally, there is a round air bag inside the air expansion shaft, which is filled with about 7 kg of compressed air through the air nozzle to expand, and the key bar or slats are jacked up to fix the core. According to the structure of the expansion parts, it can be divided into key bar inflatable shaft, tile inflatable shaft, long through bar inflatable shaft and so on. The key bar type air shaft is also known as the convex key type air expansion shaft, the expansion part is the key bar, the expansion height can reach about 5mm on one side, and the balance force is supported by the key bar, which is suitable for the slitting machine to carry and rewind heavier coils. The tile type inflatable shaft is also known as the slat-type air shaft, the force area of the expanded plate is larger, and the force on the fulcrum is more uniform, compared with the key type inflatable shaft, the placement requirements of the plate inflatable shaft are relatively loose, and it is suitable for coils with higher winding precision or light weight of the slitting machine. The through-strip inflatable shaft adopts an integral long key, which is suitable for the rewinding work of high-precision slitting machine, especially for some narrow film coils. In addition, the cantilever air shaft will be designed according to the need, multi-airbag air shaft and other structural forms, interested can consult the engineers of Delishi Machinery, the relationship between the length will not be repeated here.

The air shaft has simple structure, easy maintenance and high work efficiency, and provides a cost-effective slitting machine winding scheme for large coil diameter and large width coil. The adhesion of the shaft body and the coil can be controlled by varying the amount of high-pressure air injection, and it has a wide load-bearing range, making it widely used in machinery and equipment such as printing and packaging. Still, there are limitations to some materials that are easily damaged, stretched, and bruised. Due to the accumulation of thickness error in the winding process, it is impossible to guarantee that several coils of the air shaft have the same diameter, generally speaking, the more coils on the shaft, the greater the difference, which leads to the inconsistent winding tension of each coil of materials, simply put, there are loose and tight, and even the end face is not neat, wrinkled, deformed, etc., resulting in a lot of waste.

Introduction to the slitting machine slip shaft

The slitting differential shaft of the slitting machine is also called the friction shaft, differential shaft or differential slip inflatable shaft, which is generally composed of the main shaft, the slip differential air expansion unit, the coupling and other accessories, and is divided into ball slip shaft, key slip shaft, column slip shaft and various hybrid convex slip shafts according to the different convex parts. The spindle of the differential shaft is very precise, and the shaft body mills many grooves to place the wool felt and the airbag, and the shaft intake will make the flat airbag expand and prop up the wool felt and exert force on the slip ring. With the increase of the diameter of the coil, the torsional force of the material on the slip ring is also gradually increasing, so it is necessary to increase the air pressure to increase the force of the wool felt on the slip ring to balance, avoid the excessive loss of the wool felt caused by the friction between the slip ring and the shaft, and shorten the service life of the slip shaft of the slitting machine.

In the winding process of the slitter, with the accumulation of the difference in the diameter of the coil, the main winding tension is transmitted to the coil with a larger diameter, which means that the coil with a large diameter will be wound tightly and the coil with a smaller diameter will be wound loosely. When the material is too tight, the slip ring will slip under a certain torque force, and the sliding is used to make up for the speed difference between each cylinder, eliminate the tension and keep the tension between each coil on the coaxial to be constant, achieve the ideal tightness, ensure the high-quality curling effect, and are often used in the slitting machine of the center crimping method. Especially for some polyester film materials with poor tensile resistance, or some expensive materials, the use of slip shaft for phased rewinding can greatly reduce material scrap and improve the yield rate, which is difficult to do with inflatable shaft. In addition, the differential shaft can be interchangeable or replaced separately between each group of differential units, which improves the life cycle and facilitates maintenance.