How to choose the slitter blade depends on the type and thickness of the slitting material. Usually the slitting form of the slitter blade includes square knife slitting and round knife slitting.
1. The square knife slitting is like the razor, the blade is fixed on the knife holder of the cutting machine, and the knife will drop during the material running, so that the knife will cut the material longitudinally to achieve the purpose of cutting. The square slitter blades are mainly divided into single-sided blades and double-sided blades:
One-side inserts are better for thicker and stiffer slitting thick films because the hard blades do not easily displace at the high speed of the slitter, ensuring product quality. Single-sided blades are recommended for thickness 70-130um.
The double-sided blade is relatively soft, suitable for thin material cutting, so that the film edge of the flatness is guaranteed, but also can extend the life. Thickness below 70um recommended the use of double-sided blade.
In terms of the slitting mode of the slitter, square knife slitting is generally divided into slit slitting and hanging slit slitting:
1) Groove slitting is when the material is running on the grooving roller, and the cutter is placed in the slot of the grooving roller, and the material is cut in the longitudinal direction. At this time, the material has a certain wrap angle on the grooving roller, and the drift phenomenon is not easy to occur. When slitting a PP film or a film with narrow side material, the slitting method is often used to improve the slitting efficiency. However, for the splaying slitting, its disadvantage is that it is relatively troublesome to set the knife.
2) Suspension slitting is when the material is passing between the two rollers, the blade is dropped and the material is cut longitudinally. At this time, the material is in a relatively unstable state. Therefore, the slitting accuracy is slightly worse than that of the slitting of the slit, but this The slitting method is convenient for the knife and easy to operate. The square cutter is mainly suitable for slitting very thin plastic films and composite films.
2. Circular knife slitting There are mainly two methods: upper and lower disc knife cutting and round knife pressing slitting.
Circular knife slitting is the main slitting method for slitting thick film, composite thick film, paper and other materials. It is recommended to use a round knife to cut the film thickness of the slitting material above 100um. 1) The cutting methods of upper and lower disc cutters are widely used. There are mainly two kinds of tangential slitting and non-tangential slitting.
The tangential slitting is the cutting of the material from the tangential direction of the upper and lower two disc cutters. This kind of slitting and cutting is more convenient. The upper disc knife and the lower disc knife can easily adjust the position according to the slitting width requirements. Its disadvantage is that the material easily drifts at the slitting point, so the accuracy is not high and it is generally not used now.
The non-tangential slitting is that the material and the lower disc knife have a certain wrap angle, and the lower disc knife falls and the material is cut open. This kind of slitting method can make the material less susceptible to drift and the slitting accuracy is high. However, the adjustment of the knife is not very convenient. When the lower knife is installed, the entire shaft must be removed. Round knife slitting is suitable for slitting thicker composite films and papers.
2) The application field of rotary knife cutting in the industry is not very common. It is mainly composed of a pneumatic cutting knife which is synchronous with the material speed and has a certain angle of the bottom roller and the adjustment is convenient. This kind of slitting method can not only cut relatively thin plastic films, but also can cut relatively thick paper, non-woven fabrics and so on. Is a more convenient way of cutting, but also a development direction of the slitting machine.