How To Choose An Air Shaft For A Slitting Machine

Slitting machine is a kind of wide paper, mica tape, plastic film, adhesive tape, copper foil aluminum foil, slitting into multiple narrow materials of mechanical equipment, often used in papermaking machinery, wire and cable mica tape and printing and packaging machinery. The slitting machine is mainly used in: non-woven fabrics, mica tape, paper, insulating materials and various film materials slitting, especially suitable for narrow strips (non-woven fabrics, paper, insulating materials, mica tape, film, etc.).

Why did the slitter choose to use a slip shaft?

The form of winding of the slitting machine: center coiling, surface coiling, surface center coiling. The center coil uses a slip shaft, and the surface coil uses an inflatable shaft.
1) The slitting machine is a device that divides the whole coil into multiple rolls, which requires the tension of the winding shaft inside it to be accurately controlled in sections, only in this way can the elongation of the product and the uniformity of the end face be guaranteed. However, due to the thickness error of the material itself, in the process of slitting and coiling, the diameter of each coil produces a large accumulation error, resulting in a large gap between speed and tension, different tightness of the coil, uneven end face, and tensile deformation of some coils due to excessive tensile force. Therefore, it is necessary to have a winding shaft that can overcome these problems, and the slip shaft can just overcome these phenomena, and its slip ring can slip with a certain slip torque, and the amount of slip can just compensate for the speed difference, and at the same time can accurately control the tension of each roll of material. Depending on the material, slitting width, thickness, and tension, the ideal effect can be achieved by selecting the appropriate slip axis.
2) With the improvement of people's living standards and the development of science and technology, higher and higher requirements have been put forward for flexible packaging products, the elongation of the film is required to be smaller and smaller, and the uniformity of the winding surface is getting higher and higher, which puts forward extremely high requirements for the tension control of the material film. The tension control accuracy of the winding shaft directly determines the elongation of the slitting product and the uniformity of the end face, so it is necessary to use the slip shaft as the winding shaft.
3) After using the differential shaft, the degree of automation, humanized operation, speed and winding accuracy of the slitting machine can be improved.
4) The use of differential shaft to coil valuable materials (metal foil, battery separator, special paper, etc.) can greatly improve the authenticity rate and reduce costs; With the use of slip shafts, the difficulty of slitting and winding is reduced.

What is the slip axis?
Differential shaft, also known as differential shaft and friction shaft, is used as a winding shaft and special unwinding shaft of the slitting machine. The differential shaft is composed of a shaft core and multiple sets of differential slip rings, each differential ring slips independently, and the torque is controlled by the central air pressure or the pressure transmitted from the side. So as to ensure that each coil is evenly and neatly rewound with constant tension from the inside to the outside.

How the differential shaft works:
The differential shaft takes the precision hollow core ventilation spindle as the core, and uses compressed air to push the piston in the cavity, so that the shaft core generates friction torque between the friction parts and the differential slip ring, and further drives the oblique expansion plate on the inclined base to expand in the direction of the outer diameter, squeezes the winding cylinder, and transmits the torque of the winding cylinder, so as to achieve constant tension winding.

Structural characteristics of the slip shaft:
The differential slip shaft has a special structure, composed of a plurality of slip rings, when working, the differential slip rings are controlled to slip with a certain slip torque value (torque), and the amount of slip just compensates for the speed difference generated, so as to accurately control the tension of each roll of material, and to achieve constant tension winding, ensuring the quality of coiling. It can be applied to the range from very low to high tension, and is suitable for high speed, large material thickness error, multi-stage tension control, high tension control accuracy, and neat end face winding. Therefore, the inflatable unit of the differential slip shaft is composed of a cavity, an oblique base, a piston, an air seal, a bearing, a spring and an expansion plate, which plays a very important role. The fit between each fitting is also relatively important.

There are three types of differential shafts: central air pressure differential shaft, mechanical side pressure differential shaft, and pneumatic side pressure differential shaft.
1) Central air pressure slip differential shaft: input the corresponding air pressure into the shaft core air cavity (bladder), compressed air compression friction part - apply
The pressure is applied to the slip ring - the corresponding friction torque is generated, and the constant tension is always maintained, and the extremely low tension to the large tension range is controllable.
The central air pressure slip differential shaft is divided into two types: pneumatic locking type and mechanical locking type.
*Pneumatic locking type central air pressure slip differential shaft, air pressure at the same time locks the core and generates friction torque, which can realize automatic unloading
Winding, forward and reverse coiling, and the film is broken in the middle of winding, no unwinding, no offset, and high control accuracy to achieve constant tension winding.
Representative products: Japan East Extension Differential Shaft (DS Series), Nishimura Differential Shaft (XC Series)
*Mechanically locking type central air pressure slip differential shaft, mechanical eccentric mechanism locks the core, and the friction torque is generated by air pressure. control
High precision, constant tension winding.
Representative products: Ball type slip shaft (GZ series), key type slip shaft (JS series), toothed type slip shaft (CP series),
Kataoka Differential Axis (PG series) and Fujitetsu Differential Axis (BRT series).
2) Mechanical side pressure slip differential shaft
The mechanical side differential pressure slip shaft is axially pressed by the two end head compression springs to compress each slip ring, and the end face is rubbed during the rotation of the mandrel
The force acts to produce torque. It is suitable for low-speed machines (200m/min), and the tension cannot be adjusted in real time.
3) Pneumatic side pressure slip differential shaft
The principle of the pneumatic side pressure slip differential shaft is the same as the structure and the mechanical side pressure slip differential shaft, the difference is that the compression spring is changed to a plane cylinder,
The air pressure is adjustable. It can realize large torque and large friction tension coiling. Constant tension or taper tension control is possible.

Precautions for the use of differential shafts:
Before the use of the slip shaft, it is necessary to ensure that the linear speed of the slip winding shaft is 3% greater than the linear speed of the feeding roller, but not more than 5%. Otherwise, the slip shaft will be overheated, resulting in damage to the slip ring, airbag, friction parts, and mandrel. In order to improve the service life of the differential shaft, please install and use it correctly, and do a good job of maintenance.
Notes:
1) Depending on the paper core of different materials and quality, the slip ring must be removed every week to a month, and the dust, paper scraps and other debris in the slip ring must be cleaned to ensure the smooth steel balls and key strips. Wipe off the debris on the mandrel and drop an appropriate amount of white oil on the wool felt, and assemble the slip shaft as it is.
2) It is recommended to replace the wool felt and airbag for half a year. Due to the different torsion of different materials, the wool felt is found to be bright and hard in use, and it should be replaced immediately, otherwise the torque will be affected.
3) Do not overload the slip shaft, whichwill deform and break the mandrel.

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