how to select blades for slitting machine

The slitting machine blade is one of the important components of the slitting machine equipment. If the slitting machine blade is not properly selected, it is likely to lead to a shortened service life of the slitting blade, failure to meet the slitting index requirements, the occurrence of burrs on the slit materials, and the generation of a large amount of slitting powder debris, etc.

How to select the slitting machine blade is determined according to the different types and thicknesses of the materials to be slit. Generally, the slitting forms of the slitting machine blades include square blade slitting and circular blade slitting.

1、Square blade slitting is similar to using a razor. The blade is fixed on the cutter frame of the slitting machine. During the running process of the material, the blade is lowered so that the blade can cut the material longitudinally to achieve the purpose of slitting. Square slitting machine blades are mainly divided into single-sided blades and double-sided blades:

Single-sided blades are better for slitting thicker and more rigid thick films. Because in the case of high speed of the slitting machine, the hard blade is not easy to displace, ensuring the product quality. For materials with a thickness of 70-130um, it is recommended to choose single-sided blades.

Double-sided blades are relatively soft and are suitable for slitting thinner materials. In this way, the flatness of the film edge is guaranteed, and the service life can also be extended. For materials with a thickness of less than 70um, it is recommended to choose double-sided blades.

In terms of the slitting methods of the slitting machine, square blade slitting is generally divided into two types: slitting in the groove and suspended slitting:

(1) For slitting in the groove, when the material is running on the grooved roller, the cutting blade is dropped into the groove of the grooved roller to cut the material longitudinally. At this time, the material has a certain wrap angle on the grooved roller, and it is not easy to have the drifting phenomenon. When slitting the cast polypropylene (PP) film or the film with a relatively narrow edge material, this slitting method is often used, which can improve the slitting efficiency. However, compared with suspended slitting, its disadvantage is that it is more troublesome to align the blade.

(2) Suspended slitting means that when the material passes between two rollers, the blade drops to cut the material longitudinally. At this time, the material is in a relatively unstable state. Therefore, the slitting accuracy is slightly worse than that of slitting in the groove. But this slitting method is convenient for blade alignment and operation. Square blade slitting is mainly suitable for slitting very thin plastic films and composite films.

2、Circular blade slitting mainly includes two methods: shearing with upper and lower circular blades and circular blade extrusion slitting.

Circular blade slitting is the main slitting method for materials such as thick films, composite thick films, and paper. For materials with a film thickness of over 100um, it is recommended to choose circular blade slitting.

(1) The slitting method using upper and lower circular blades is widely applied, mainly including tangential slitting and non - tangential slitting.

In tangential slitting, the material is slit in the tangential direction of the upper and lower circular blades. This slitting method is quite convenient for blade alignment. The upper and lower circular blades can be easily adjusted in position according to the slitting width requirements. Its drawback is that the material is prone to drifting at the slitting point, so the slitting accuracy is not high, and it is generally not used nowadays.

In non - tangential slitting, the material has a certain wrap angle with the lower circular blade. When the lower circular blade drops, the material is cut. This slitting method can prevent the material from drifting easily, resulting in high slitting accuracy. However, it is not very convenient to adjust the blade. When installing the lower circular blade, the entire shaft must be removed. Circular blade slitting is suitable for slitting relatively thick composite films and paper.

(2) Circular blade extrusion slitting is not commonly used in the industry. It is mainly composed of a bottom roller that synchronizes with the material speed and has a certain wrap angle with the material, and a pneumatic slitting blade that is easy to adjust. This slitting method can be used to slit both relatively thin plastic films and relatively thick paper, non - woven fabrics, etc. It is a relatively convenient slitting method and also a development direction for the slitting methods of slitting machines.

Don't one - sidedly pursue imported blades; only seek the machine - used blades that suit you.

There is no such thing as the best blade, only the suitable one. The quality of slitting machine blades is relative, and the key to the cutting effect of the blades lies in their application. For example, improper use of imported blades won't yield good results, while proper use of domestic blades can also achieve satisfactory effects. This requires us to accumulate more experience and make more summaries in practice to truly find the slitting machine blades that suit us.

Correctly handle the relationship among the performance, price, and stability of machine - used blades.

Among these three aspects, the stability of the blade is of vital importance, and high cost - effectiveness is the goal to pursue. For instance, imported blades are often used in high - speed slitting. However, they are a double - edged sword. While bringing a brand - new and efficient production mode, imported blades have high requirements for equipment, processes, blades themselves, and blade clamping systems. Therefore, the investment in the early and later stages is relatively high. In high - speed slitting, many conditions are on the verge of the limit, and the stability of imported blades will become a major issue, especially in the middle and later stages of equipment use when the blade accuracy decreases, which is more obvious. Therefore, don't blindly pursue high - speed. If the goal of high - efficiency can be achieved without using imported blades, we should unhesitatingly give up imported blades.