What are the different cutting methods of a slitting machine, and does everyone know about them?

The slitting machine is composed of an unwinding mechanism, a cutting mechanism, a rewinding mechanism, functional rollers, tension control, deviation control, and detection devices. Its working principle is as follows: the metalized thin film material is released from the unwinding mechanism, passes through the flattening roller, tension detection roller, energizing roller, deviation correction system, enters the cutting mechanism, and after slitting, the raw material is rewound into standard film rolls. So what are the different cutting methods of a slitting machine? Let me explain.

The slitting machine can be roughly divided into three cutting methods: straight knife cutting, circular knife cutting, and pressure cutting.

1. Straight knife cutting:

Similar to a razor blade, single-sided or double-sided blades are fixed on a fixed frame, and the blade falls during the material running process to cut the material longitudinally for slitting purposes.

There are two ways of straight knife cutting:

a) Slotting cutting: When the material runs on the slitting roll, the blade is dropped into the groove of the slitting roll to cut the material longitudinally. At this time, the material has a certain wrap angle on the slitting roll, which prevents drift. This cutting method is commonly used when slitting flow cast PP film or narrow-width films to improve cutting efficiency. However, the drawback of slotting cutting is that it is not convenient for blade changes.

b) Suspended cutting: When the material passes between two rolls, the blade drops and cuts the material longitudinally. At this time, the material is in a relatively unstable state, so the cutting accuracy is slightly lower than that of slotting cutting. However, this cutting method is convenient for blade changes and operation.

Straight knife cutting is mainly suitable for cutting very thin plastic films and composite films.

2. Circular knife cutting:

Circular knife cutting can be divided into tangential cutting and non-tangential cutting.

Tangential cutting is when the material is cut along the tangential direction of the upper and lower circular knives. This cutting method is convenient for blade changes, as the position of the upper and lower circular knives can be easily adjusted according to the width requirements. The drawback is that the material is prone to drift at the cutting point, resulting in lower accuracy. Therefore, this method is generally not used now.

Non-tangential cutting is when the material has a certain wrap angle with the lower circular knife, and the lower circular knife drops to cut the material. This cutting method prevents material drift and achieves high cutting accuracy. However, blade adjustments are not convenient as the entire shaft needs to be disassembled when installing the lower circular knife. Circular knife cutting is suitable for cutting thicker composite films and paper.

3. Pressure cutting:

Pressure cutting is not commonly used in domestic slitting machines. It mainly consists of a bottom roller that synchronizes with the material speed and has a certain wrap angle, as well as an easily adjustable pneumatic knife. This cutting method can be used for thin plastic films or thicker materials like paper and non-woven fabric. It is a convenient cutting method and a direction for the development of slitting machine cutting methods.

The slitting process should be taken seriously and not underestimated. This article summarizes the purpose, process, and other aspects of slitting to ensure stable quality in the slitting of composite films. For the cutting process of the slitting machine, you can choose the cutting method according to your own requirements. I hope this introduction helps you understand the three cutting methods of a slitting machine.