This process of slitting should be taken seriously and must not be taken lightly. This paper summarizes the purpose and technological process of slitting by the slitting machine 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 slitting. Next, let's go and see with Deguang.
Slitting machine cutting method
The slitting process of the slitting machine can be roughly divided into three methods: flat knife slitting, round knife slitting, and extrusion slitting.
Slitting machine flat knife slitting
Just like a razor, the slitting machine fixes a single-sided blade or a double-sided blade on a fixed knife holder, and drops the knife during the running of the material, so that the knife cuts the material longitudinally to achieve the purpose of slitting.
There are two ways of razor slitting:
One is grooving and slitting; the other is suspended slitting.
Grooving and slitting is when the material is running on the grooved roller, drop the slitting machine knife 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, which is not easy to drift. . This kind of slitting method is often used when slitting cast PP films or films with narrow margins, which can improve the slitting efficiency of the slitting machine. But for suspended slitting, its disadvantage is that the slitting machine is more inconvenient for the knife.
Suspended slitting is when the material passes between the two rollers, the razor falls to cut the material of the slitting machine longitudinally. At this time, the material is in a relatively unstable state, so the slitting accuracy is slightly worse than that of die slitting, but this slitting method is convenient for knife setting and operation. The flat cutter is mainly suitable for cutting very thin plastic films and composite films.
Slitting machine circular knife slitting
Circular knife slitting can be divided into tangential slitting and non-tangent slitting.
The tangent slitting is that the material is cut from the tangential direction of the upper and lower disc knives of the slitting machine. This kind of slitting is more convenient for knives. The upper and lower disk knives can be easily adjusted directly according to the requirements of the slitting width. Location. Its disadvantage is that the material is easy to drift at the slitting position of the slitting machine, so the accuracy is not high, and it is generally not used now.
Non-tangential slitting means that the material and the lower disc knife have a certain wrapping angle, and the lower disc knife falls to cut the material. This cutting method can make the material less prone to drift, and the cutting precision is high. However, it is not very convenient to adjust the knife of the slitting machine. When the lower disc knife is installed, the entire shaft must be removed. Circular knife slitting is suitable for slitting thicker composite films and papers.
Slitting machine extrusion slitting
Extrusion slitting is not common in domestic slitting machines. It is mainly composed of a bottom roller that is synchronized with the material speed and has a certain angle with the material and a pneumatic knife that is easy to adjust. This cutting method can not only cut relatively thin plastic films but also relatively thick paper, non-woven fabrics, etc. It is a more convenient way of cutting. It is a development direction of the cutting method of the slitting machine.
slitting machine
The purpose of the slitting machine
1. Provide precise specifications according to user requirements.
2. When slitting and unwinding, you can re-inspect the large roll of composite film that is compounded during extrusion and compounding in the entire previous process to see if there is any quality problem.
3. It can correct the staggering layer of the composite film of the slitting machine or cut off part of the printing and compounding defects, and improve the grade rate of the product.
4. The slitting of the slitting machine can make the finished product obtain a good winding state.
Slitting machine cutting process
Before starting the machine, firstly inspect the appearance of the large film roll from the previous process, printing and compounding, and test the hardness and surface flatness of the large film roll to see if it can meet the requirements of slitting. Then, fully understand the condition of the slitting machine that is about to run, the performance of the slitting machine, and check the main operating parts and electrical control parts of the slitting machine. At this time, the large film roll is placed, the blade is adjusted according to the specifications required by the user, and the production is started according to the normal production process.
The normal operation of the slitting machine is the basis for ensuring the quality of production. Because, after each slitting machine runs at high speed for a long time, the running accuracy of some important key components will decrease, which is a bit difficult to ensure the running accuracy of some small-sized film rolls.
Because the composite film is a polymer product, its thickness is relatively thin, and it is easily damaged during processing. Therefore, when the running accuracy of the slitting machine is not enough, quality problems such as longitudinal stripes are likely to occur on the film. For this reason, it is confirmed that the longitudinal stripes generated in the slitting are the main quality problems in the slitting and must be solved.
When entering normal production, the speed of the slitting machine should be strictly in accordance with the process requirements. Too high will also affect the cutting quality. Therefore, by controlling the slitting speed, the quality required for slitting can be obtained. Because, in production, some operators artificially increase the cutting speed in order to increase the output and improve their own economic benefits, which will make the film prone to longitudinal stripes and staggered quality problems under high-speed operation. Therefore, in normal production, we must adopt appropriate slitting process for production according to the equipment performance and the intrinsic performance of the film, as well as the different types and specifications of the film.
Due to the different process parameters, identification methods and values of various thin films to be cut, the process must be carefully adjusted for each product. In production, the frequency of use of each station of the slitting machine is different, so the degree of wear is also different. Therefore, there will be some differences in performance. For example, for a station slitting product in better condition, there are fewer longitudinal streaks.
On the contrary, there are more vertical stripes. Therefore, each operator must pay attention to the correct selection of the station, give full play to the best state of the slitting machine, grasp the on-site use situation, constantly sum up 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 re-rolled, which creates conditions for the entry of external foreign matter, and since the film itself is mainly used for the packaging of food and medicine, Therefore, the hygiene requirements are very strict, so the cleanliness of each roll of film must be guaranteed.
Well, the above is all about the slitting machine today. It introduces the three slitting methods of the slitting machine in detail, as well as the purpose and technological process of the slitting machine. It is better to use the slitting machine in the future.
More information is continuously updated, see you in the next issue.
For more information, please follow the link below: