A cutting plate is a fundamental component in diecutting. During the process, the cutting die with its cutting rules presses against the cutting plate using preset cutting pressure to ensure precise cuts and clean cut edges.
The basics
– general product information
By carefully matching the hardness ratio between the cutting rule and the upper platen, the life of both the cutting rule and the cutting plate is extended, while at the same time reducing dust and the formation of angel hair.
When it comes to cutting plates, a distinction is made between conventional cutting plates and the significantly more complex, custom-made cut-crease plates.
Cutting plates can be used as a base for creasing matrices or Pertinax dies. To this end, the contours are cut to match the machine layout, and the cutting plates can then be used on the diecutter without any further machining steps.
Cut-crease plates are produced by milling the creasing channels in the cutting plate. The cut-crease plate offers impressive benefits, including very short set-up times on the machine and very long running times thanks to low wear.
The CITO portfolio
– optimal solutions for every requirement
CITO offers cutting plates with various degrees of hardness (see below).The portfolio offers everything from a single source: BOBST OEM cutting plates as well as adapted cutting plates for all common diecutting machine manufacturers such as Heidelberg / MK, Koenig & Bauer / IBERICA, WPM, ASAHI, KAMA as well as for platen presses.
The product lines:
CITO Cutting Plate 35
This cutting plate is made from the well-known BOBST OEM raw material and is laser-cut to match customer’s needs for various diecutters. The CITO Cutting Plate 35 offers the largest selection of formats in the entire portfolio. On request, customers can submit individual drawings or have them created by CITO. This makes the CITO Cutting Plate 35 ideal for maximum flexibility and for meeting individual requirements.
BOBST OEM Cutting Plate
The BOBST OEM Cutting Plate is fully compatible with the original BOBST items. This makes it the first choice for BOBST users: CITO recommends the BOBST OEM Cutting Plate to anyone who uses BOBST machines. The plates are available in different hardness grades: 18 HRC, 35 HRC and 50 HRC.
CITO Cutting Plates 40+
The CITO Cutting Plates 40+ are characterised by their excellent finishing. The cutting knives are subject to significantly less wear, resulting in reduced burr formation – and thus optimised cutting results and less angels hair. With a cutting plate life that is around 50 % longer, costs can be significantly reduced. The 40+ Plate combines cost-effectiveness with quality and long durability.
The different types
– an overview of the various hardness grades
Soft cutting plates (18 HRC)
Soft cutting plates are usually only used for shorter-run jobs (up to 100,000 sheets) for cost reasons, as the plates wear quickly due to their low hardness.
Medium-hard cutting plates (35 and 40+ HRC)
Medium-hard cutting plates are the standard plates most commonly used. They are suitable for lives of up to 2,000,000 sheets.
Hard cutting plates (50 HRC)
Hard cutting plates are used for specific requirements, particularly with regard to the cardboard qualities. Rigid cardboard grades, such as kraft board or cardboard with a special coating, which require greater cutting force, generally need a plate with higher material hardness; otherwise, the cut would penetrate too deeply into the plate.
The characteristics
– what makes a good cutting plate
In general, cutting plates should have the following technical characteristics:
- Excellent flatness
- High plane parallelism
- Perfect surface finish
- Burr-free edges
Machining
– milling the cut-crease plates
Cutting plates with higher hardness are the right choice for milling cutting plates. Special solid carbide milling tools (VHM) are used to machine the cut-crease plates; these are particularly suitable for dry machining or machining methods with minimal lubrication. As no cooling lubricant, or only a minimal amount, is used, the time required to clean the cutting plates after milling is significantly reduced.
Cylindrical or conical milling tools can be used for this purpose, although conical milling tools are the preferred choice. The use of conical milling tools makes it easier to pull the cut sheet out of the creasing channel and reduces the tensile stress in the sheet, particularly at the holding points.
The following milling parameters are recommended:
- Milling tool clamping length: 23 mm
- Type of entrance: Ramp 10
- Feed rate: 480 mm/min
- Milling tool feed rate: 3 m/min
- Spindle speed: 27,000 rpm
- Infeed depth per pass: 0.125 mm
Monitoring
– process reliability through measuring instruments
To ensure a stable and smooth process, the quality of the creasing channels in the cut-crease plates should be checked. Only by monitoring the depth and width of the creasing channel can accuracy in the cutting process be ensured. This also allows the wear of the plates and the condition of the creasing channels to be checked during repeat jobs.
The accessories
– perfectly equipped for easier handling
The vacuum lifter, a practical accessory, makes it easier to handle and transport cutting plates. Whether you’re removing the cutting plates from the transport box, inserting them in diecutter or transporting them for archiving: the vacuum lifter enables ergonomic working and reduces the risk of injury.
