What Do You Know About The Three Slitting Methods And Their Technological Processes Of Slitting Machine?

Flat knife cutting

Just like a razor, the single blade or double blade is fixed on a fixed knife rest, and the knife is dropped in the process of material operation, so that the knife can cut the material longitudinally to achieve the purpose of cutting.

There are two ways of shaving:

One is slotting and the other is hanging slitting.

When the material is running on the grooving roller, the cutter is placed in the groove of the slotting roller and the material is cut longitudinally. At this time, the material has a certain angle in the slotting roll, which is not easy to drift. When the PP film or the film with narrow edge material is re cut, the slitting efficiency can be improved. But for hanging slitting, its disadvantage is that it is inconvenient to set the cutter.

When the material passes through the two rollers, the razor falls down and cuts the material longitudinally. At this time, the material is in a relatively unstable state. Therefore, the slitting accuracy is slightly worse than that of the cutting die. However, this cutting method is convenient for tool setting and operation.

The flat cutter is mainly suitable for cutting thin plastic film and composite film.

Circular knife cutting

Circular cutter can be divided into tangent slitting and non tangent slitting.

Tangent slitting means that the material is cut from the tangent direction of the upper and lower disc cutters, which is more convenient. The upper disc cutter and the lower disc cutter can adjust the position directly according to the requirements of the slitting width. Its disadvantage is that the material is easy to drift at the slitting point, so the accuracy is not high, and it is generally not used now.

Non tangent slitting means that the material has a certain angle with the lower disc cutter, and the lower disc cutter falls down to cut the material. This kind of slitting method can make the material not easy to drift and has high cutting accuracy. However, it is not very convenient to adjust the cutter. When installing the lower disc cutter, the whole shaft must be removed. It is suitable for cutting thick composite film and paper.

Extrusion slitting

Extrusion slitting is not common in domestic slitting machine. It is mainly composed of bottom roller which is synchronized with material speed and has a certain angle with material and pneumatic knife with convenient adjustment. This kind of slitting method can not only cut thin plastic film, but also thick paper and non-woven fabric. It is a more convenient way of slitting. It is a development direction of slitting machine.

The process of slitting should be paid attention to and should not be taken lightly. This paper summarizes the purpose of slitting, process flow and so on, so that the majority of composite film manufacturers can solve a series of quality problems in the future slitting production, to ensure the stable quality of composite film cutting.

The purpose of slitting

1. According to the requirements of users, provide accurate specifications.

2. In the process of slitting and unwinding, the large roll composite film compounded in the whole previous process can be inspected again to see if there is any quality problem.

3. It can correct the wrong layer of composite film or cut off part of printing and lamination defects, and improve the grade rate of products.

4. It can make the finished product get good winding state.

Slitting process

Prepare to start up, first of all, inspect the appearance of the large film roll after the previous process, printing and lamination, and inspect the hardness and surface flatness of the large film roll to see whether it can meet the requirements of slitting. Then, we should fully understand the condition and performance of the slitting equipment which is about to run, and check the main operation parts and electrical control parts of the equipment. At this time, install the large film coil, adjust the blade according to the user's requirements, and start the production according to the normal production process.

The normal operation of the slitter is the fundamental to ensure the production quality. Because each Slitter often runs at high speed for a long time, the operation accuracy of some important key components will be reduced. It is difficult to ensure the operation accuracy for slitting some small-sized film rolls. Because the composite film belongs to polymer products, its thickness is relatively thin, and it is easy to be damaged in processing. Therefore, when the running accuracy is not enough, the film is easy to produce quality problems such as longitudinal stripes. For this reason, we have observed and studied for many years that the longitudinal fringes are the main quality problems in slitting, which must be solved.

In normal production, the speed of the slitter should be strictly in accordance with the process requirements. Too high will also affect the quality of slitting. Therefore, if the slitting speed is well controlled, the required quality of slitting can be obtained. In order to improve the output and economic benefits, some operators increase the slitting speed artificially, which will make the film prone to longitudinal stripe and staggered layer quality problems under high-speed operation. Therefore, in normal production, we must adopt appropriate slitting process according to the equipment performance, internal performance of film and different types and specifications of film.

Because the process parameters, identification methods and values of various sliced films are different, the process must be carefully adjusted for each product. In production, the use frequency of each station of the slitting machine is different, so the wear degree is also different. Therefore, there will be some differences in performance. For example, for the better condition of the station slitting products, the longitudinal stripe is less.

On the contrary, there are more longitudinal stripes. Therefore, each operator must pay attention to the correct selection of the station, give full play to the best state of the equipment, grasp the field use situation, constantly summarize experience, and find the use method of the best characteristics of the equipment.

In addition, it should be noted that during the slitting process, each roll of film is re opened and rewinding, which creates conditions for foreign matters to enter. As the film products are mainly used for food and drug packaging, the hygiene requirements are very strict, so it is necessary to ensure the cleanness of each roll of film.