Perforated plate (semi-finished product)
Perforated plates are perforated sheets that, as semi-finished products, give form and function to a wide range of products and objects. During the stamping process the hole fillings fall as waste (slugs, Bunzen). In addition to plastics , metals are primarily processed, with steel, galvanized steel, aluminum and stainless steel being used in particular.
definition
The term perforated plate refers to DIN 4185-2 and DIN 24041, which replaced the terms "perforated sheet" and "perforated sheet". However, manufacturers continue to primarily use the term "perforated sheet". A perforated plate according to DIN refers to a plate (sheet metal, sheet, etc.) that is provided with openings (holes) of the same type in a regular arrangement by punching, perforating or drilling.
production method
Basically, perforated sheets are manufactured either in large series from coils , from sheets or as individual orders with special dimensions. The following manufacturing processes are mainly used:
- Wide press
- A tool that is as wide as the board / tape to be punched can punch an entire row of holes with one stroke. There are also multi-row tools that punch several rows at the same time with one stroke . Suitable for large quantities with the same hole pattern. For tools with single punch control, it is also possible to generate patterns and contours.
- Strip press
- A tool that only makes the perforations in sections. Although the tool can have several punches, it does not punch entire rows, but usually only individual holes (or groups of holes). Suitable for special perforations with small quantities and for difficult perforations, e.g. B. in thick material.
- Automatic punching machine
- A special tool takes over the computer-controlled punching. Complex hole patterns are possible with this method. Suitable for small quantities with difficult perforations.
- Roller perforation
- Method rarely used today. A shaped roller presses the holes into the material. Suitable for micro perforation.
- Lasers / water jet cutting / flame cutting
- In the case of very hard or very thick materials that can no longer be punched, the holes are made in the material using lasers etc. This method is the slowest and most expensive solution. Suitable for small quantities when punching is no longer possible.
Further processing
After the punching process, the individual sheets are flat again with the help of a straightening machine. According to DIN 8580, there are various options for processing methods:
- Forming by deep drawing, pressing, upsetting, bending, rounding, folding, profiling, flanging .
- Cutting with scissors, punches, saws or flame , plasma or laser beam cutters .
- Drilling, milling and grinding for machining.
- Treatment of the surface by brushing, pickling , degreasing, polishing, sandblasting .
- Riveting, screwing, flanging, folding , gluing, clinching , welding or soldering to join the sheet metal.
- In the last step, the coating or covering can be done by dip or spray painting, powder coating , electroplating , hot-dip galvanizing , enamelling , gumming, gluing or anodizing .
Hole shapes
|
DIN 24041 |
|---|---|
| Area | Semi-finished products |
| title | Perforated panels - dimensions |
| Brief description: | Types and names of perforated panels |
| Latest edition | 2002-12 |
| ISO | - |
In Germany, perforated panels are standardized according to DIN 24041. The earlier standards DIN 24041 (round perforations), DIN 24042 (square perforations) and DIN 24043 (elongated perforations) were replaced in December 2002 by the new DIN 24041: 2002-12, which encompasses all perforation shapes.
The RAL - quality mark RAL-GZ 615 defines requirements (dimensions, tolerances, etc.) to perforated plates and coils of hot rolled steel having a tensile strength up to 500 N / mm².
A distinction is made between the following hole shapes (the respective abbreviation from DIN 24041 in brackets):
- Round perforations in straight rows (Rg), in diagonally offset rows (Rd) or in 60 ° offset rows (Rv)
- Square perforation in straight rows (Qg), in diagonally offset rows (Qd) or in offset rows (Qv)
- Slotted in straight rows (Lg), with square holes (LGE) or in offset rows (Lv)
In addition, other shapes such as hexagonal perforations, decorative perforations and special perforations are possible (see also grid ).
The shape of the holes and the arrangement of the holes to one another determine the efficiency. For example, "perforation Rv5-8" means that it is a round perforation with a staggered arrangement. The hole diameter is 5 mm and the distance from hole center to hole center is 8 mm (= 3 mm wide web between the holes).
Quality features
Depending on the intended use, there are different quality requirements for the perforated sheet. The following criteria come into consideration:
- Compliance with specified tolerances
- Flatness of the perforated plate
- Exactness of the hole pattern
- Precision of the further processing stages
Basically, these quality features are defined by DIN 24041.
application
Perforated sheets are transparent and decorative due to the combination of direct and indirect light. This aesthetic property of perforated sheets is popular in interior and exterior architecture as well as in the arts and crafts. As a timeless, versatile construction element, perforated sheets can also be used as a filling in the banister. In the furniture industry, the advantage of seating furniture with seat shells and backrests made of perforated steel, stainless steel or aluminum lies in their property as a fire-retardant material. Perforated sheet metal seating can be seen at airports or in train stations. Shopping baskets and shelves made of perforated sheet metal are used in retail because the stability of the material guarantees a long service life for the shop fittings.
Perforated sheets are also used in warehouse management, since high-bay warehouses need stable and dimensionally accurate containers. Furthermore, perforated sheets take on functions such as sieving, classifying, filtering or dosing. As sieves, grids or shaking floors, perforated plates separate dry bulk goods such as gravel, road construction material, ore, coke, potatoes, grain, seeds etc. according to quality and size. In spinners and centrifuges, perforated plates filter and separate liquid products of different consistencies from one another. Small perforated sheet metal plates are also used as connectors .
Perforated sheets also act as noise protection walls, for example on motorways, in factories or offices. In particular, perforated sheets are used as ventilation grilles in vehicle, machine and apparatus construction. The ventilation grille prevents the engine or machine parts from overheating, while at the same time protecting them from external influences.
See also
Individual evidence
- ↑ [Steel Information Center: Perforated steel sheets. Leaflet 317th edition 2006, ISSN 0175-2006 , p. 4.]
- ↑ Archived copy ( memento of the original from November 25, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. RAL-GZ 615
- ↑ [Steel Information Center: Perforated steel sheets. Leaflet 317th edition 2006, ISSN 0175-2006 , p. 5 f.]
- ↑ [Steel Information Center: Perforated steel sheets. Leaflet 317th edition 2006, ISSN 0175-2006 , p. 6 ff.]
