What is a punching machine?
Punching machine is a kind of mechanical equipment which can be used to punch the material, which can also be called CNC punch. In general, the punching equipment consists of two tool parts - a support punch and a support die. When the punch enters the mold, the material is machined into an arbitrary hole shape.
Punching is mainly used to make a round or special-shaped hole on the material, but it is also suitable for the application of metal pipe cutting.
Can process the following materials: metal or plastic film and paper, can also be used in packaging, food, health, medical and pharmaceutical industries thicker materials, such as packaging materials, compounds, leather and sheet metal.
In the past few years, punching has also become very important for processing metal foils in technologically complex products, such as aerospace or electronics.
Another application is the stamping of profiles into metal plates for use in metals and construction.
What are the different stamping technologies of punching machine?
In general, there are two different punching technologies in punching machine, conventional flat stamping and rotary stamping. These two processes are described in detail below.
Plate punching
The flat punching unit is composed of a punch with an integrated punching tool. Punching tools usually consist of upper and lower tools. The tool is installed in parallel in the linear guide and precisely adjusted to make the punch enter the mold correctly. The sheet runs between vertically moving tools. When the punch enters the mold, the entire punch pressure acts on the material immediately (surface load). The punch waste is pushed into the mold and falls vertically.
The metal material is fed into the punching unit intermittently, that is, the feeding movement of the material is interrupted due to punching. If the punched material needs to be further processed in a later conversion step, the material feed needs to work accurately without any slippage or clearance. Otherwise, inaccuracy and registration problems may occur
Rotary punching
The punching tool of rotary punching unit can be directly installed in high-precision bearing and can be adjusted on two cylinders. The sheet runs continuously between the two rotating tools. Depending on the application, the entire punching unit can be integrated into the rack or into a separate unit.
When punching, the tool rotates continuously, so the punch enters the mold on time. The punching force required for punctual punching is lower than that for plate punching. The scraps after punching are sucked out by hollow mold barrel or vacuum hub.
General technical data
Plate punching
For plate punching, the output per minute in linear meters depends on the length of the punch tool in the web direction, i.e. the feed motion and the number of strokes per minute.
The high performance punching machine can punch 350 times per minute. Depending on the width of the material, the feed motion ranges from 50 mm to 1000 mm.
Rotary punching
The working width of rotary punching currently ranges from 10 mm to 2000 mm. According to the application, the speed can reach 1 m / min to 800 m / min. The punching diameter ranges from 0.5 mm to about 50 mm.
Advantages of each technology
Plate punching
In some cases, the tool cost is lower than rotary punching. It is beneficial to change the stamping contour frequently.
Rotary punching
Higher productivity, because continuous material supply makes working speed very high. Precise, controllable mesh tension results in a high stamping quality and a precise stamping position. Because the material is in time progressive shear (line load), the punching force is greatly reduced, thus prolonging the tool life, reducing energy consumption, and reducing noise and vibration.
What should be considered when deciding on punching technology?
Both of them have their own advantages and disadvantages. So choose the most appropriate technology for you.
The press investment cost of flat punch unit is usually higher than that of rotary punch unit. However, the tool cost of flat punch is often lower than that of rotary punch. Therefore, the flat punching device is mainly conducive to small production and frequent change of stamping contour.
If further processing of the product requires high precision or high production speed, rotary punching is usually the best. Due to the low punching force required, the noise generated by rotary punching is also quite small, which may be an important point if certain noise requirements have to be met.
In addition, upstream processes (such as printing or material lamination) and the size of available space should also be considered.
