DNT PERFORATION

ROUND HOLE PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

 Whether used for technical or decorative applications, round hole perforations are the most frequently used in perforated products. Geometrically, a round hole is the most solid shape. 

Round hole perforations provide the possibility of a large open area and strength and comes in triangular, diagonal, straight or staggered rows and also with decorative holes.

Our perforated sheets with round hole perforations are used in many applications for example:
Sieves  

  • for agriculture (sieves for sorting/grading of seeds and stones)
  • for the building industry
  • for the recycling industry (sorting of bulk materials)
  • Protection and ventilation sheets

Round holes are often used for acoustics and safety for the IT industry, as well as machinery construction for protection and ventilation panels.

Round holes offer a large ventilation opening with effective protection for the machine parts inside.
Facades

Round hole perforations offer an aesthetic decorative privacy shield and increases protection against the sun, and are also used for infill panels in balconies and balustrade panels.

Our vast experience as Europe’s largest producer and supplier of perforated products ensure we are your reliable and competent partner to process several types of raw materials.

Take inspiration offered by the vast number of possibilities and feel free to contact us for further information.

Find out more

SQUARE HOLE PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

 As with round holes, whether functional or decorative, perforated sheets with square holes can be used in many different ways. 


Square holes can be supplied with parallel rows, diagonal rows or staggered rows. In addition, square hole perforations allow a high open area for applications such as ventilation and guards.

Some examples of applications for perforated sheets with square hole perforation.

Safety and ventilation sheets  

  • Ventilation and safety guards for the machine building industry
  • Ventilation and security covers for computer server chassis 

Facades

  • Screens for defusing and sun protection
  • Balconies and balustrades

Our vast experience as Europe’s largest producer and supplier of perforated products ensures we can produce these patterns in many different materials. 

Take inspiration offered by the number of perforation possibilities and be guided by our experts.

SLOT HOLE PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Slot hole perforations can have either round ends or square ends (rectangular holes) and are typically used for sieves. 

 

Depending on the application requirements there are a range of slotted holes and patterns e.g staggered or straight rows, herring bone and chessboard from which to select.

Get inspiration from the numerous possibilities of perforation and please ask for any advice. 

A few applications for slot hole perforated sheets

  • Sieves for grain drying and sorting
  • Malting floors (drying-kiln and germ-hutches)

Sieves for seed processing machinery are used in both the pre-cleaning and main cleaning of grain, maize, oil seeds, legumes, malt, rice, coffee and soy beans. The cleaning and sorting of seeds (malformed, discoloured, germinated, broken, contaminated with other species or mouldy grains in seed lots) can severely impact seed quality, viability and vigour and therefore the market value.

When used for this application DNT sieves achieve high quality cleaning and accurate sorting of seeds.

Sieves for sorting machines

Sieves for revolving screen machines

  • Test sieves for grain according to DIN/ISO 3310
  • Laboratory sieves with a high degree of accuracy

Food processing industries

  • Fodder and grain mills

Recycling industries

  • Separation
  • Pellets and granulates production

DNT's screens for malting floors are manufactured to high quality standards giving reliability and effectiveness. For all processes, from drying-kiln to germ-hutches, perforated sheets incorporating slot hole perforation are predominantly used.
Brewery and Winery/Others

  • Malting floors made of steel and stainless steel for malt processing technology
  • Sieves for press houses and presses
  • Sieves for paring and polishing rice
  • Rope belt conveyers
  • Decorative applications 

HEXAGONAL PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Achieve high open areas with hexagonal perforation from DNT. 

Maximum ventilation

The need for effective cooling is increasing for many technical products. Flexible solutions and innovative products like our hexagonal perforation patterns are the answer.

Our hexagonal perforation provides an extremely high open area of up to 85%. Sheets with holes of this configuration are very lightweight. The stability of the parent material is of the utmost importance to maintain the shape of a honeycomb structure. This pattern produces an appealing, timeless design suitable for current and future product applications.

The ability to control airflow can be used not only for cooling, but also the opposite effect using a targeted heat supply.
IT

Whether it is racks or server cabinets the heat developed from the integrated systems and components must be removed to the outside efficiently, which is usually achieved by using internal fan modules. A sheet with a hexagonal perforation provides a very large open area giving optimal ventilation. Thanks to the high air flow, temperatures can be kept constant in the cabinet, whereas the other areas of the cabinet can remain obscured by non-perforated areas and are therefore protected.

Automotive

The need to cool heat producing parts of machines and engines e.g. tractors and other vehicles is a traditional application for perforated sheet metal products. Depending on the chosen open area, the heat can either be dissipated or be re-circulated. Small hexagon perforated sheets can also be used as protection against insects in the engine compartment.

BRIDGE SLOT PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Bridge slot perforation is a special perforation manufactured with exacting precision. The combination of heavy sheet thickness and very fine openings provides great resistance for filtering and ventilation.

Applications for bridge slot sheets

Bridge slot perforation is often used for water drainage shafts and drying. Bridge slot perforation is typically used for:

  • Drying and storing solid matters and materials of all kinds
    • including herbs, tea, grain and grass seed, maize, rape and wood chips
  • Filters for fountains and drainage

The open area of bridge slot perforation is variable and depends on the depth of embossing. An embossed depth of 1.5 mm (suitable for rape seed) provides an open area of 3.7 % for ventilation. Another example are sheets with an embossed depth of 3.0 mm giving an open area of 9.1%.

Ideally seed and grain need to be stored in an area with a moisture content of less than 14.5%.
If the storage area is too moist, fungus infestation and self-heating can follow. DNT Bridge slot sheets offer you a drying solution with appropriate optimised ventilation.
With their open area DNT Bridge slot sheets allow permanent free flowing ventilation.
Our service for you

  • Guidance for the optimal storage and drying solution
  • Additional ventilation sheets or replacement of existing damaged ventilation sheets
  • Production of different material thicknesses
  • Additional fixing holes and bending as required
  • Short delivery times

If you want to secure first choice solutions for ventilation you will always find the right partner for service, ideas and quality in DNT. We are your experienced partner for industry and agriculture.

DNT TRIEUR

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

DNT Trieur sheets are used for cleaning and sorting particularly grain and seeds. 

 The size of the “pockets” depend on your requirements, however the shape of the “pockets” is the most important consideration for the performance of the machine. DNT Trieur sheets are cut to size according to your specific requirements and then rolled or welded into a cylinder.

These products offer you the highest quality for sorting and separating seeds to minimize your waste. DNT Trieur sheets are made of steel or stainless steel. 

DNT PREMIUM PERFORATION

DNT PREMIUM PERFORATION

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Our goal is to fulfil the requirements of our customers by providing an extensive choice of high quality perforated products. With DNT Premium Perforation, we have therefore taken perforation solutions to the next level. The DNT Premium Perforation range offers perforation with hole diameters that are the same size as the sheet thickness, as well as holes that are smaller than the sheet thickness. 


DNT Premium Perforation product range

With DNT Premium Perforation, we offer products with holes the same size as sheet thickness, as well as hole sizes smaller than sheet thickness, such as:

1: Perforation with holes the same size as the material thickness (1:1 perforation) 

  • 0.50 mm holes in 0.50 mm stainless steel
  • 1.00 mm holes in 1.00 mm stainless steel

2: Perforation with hole size smaller than the material thickness

  • 0.20 mm holes in 1.00 mm stainless steel (DNT Perfocon)
  • 1.00 mm holes in 1.50 mm mild steel
  • 8.00 mm holes in 10.0 mm stainless steel

DNT is the world’s largest supplier of perforated sheets and one of the only companies to offer such an extensive range of these types of perforations from stock, as well as tailor-made solutions with other patterns and thicknesses.
DNT Premium - taking perforation to the next level...

DNT Premium Perforation gives you several advantages when compared to traditional and main-stream perforation in areas such as:

  • Durability (wearing)
  • Lifetime of screen (less replacement, fewer production stops for maintenance)
  • Cost effectiveness
  • Strength

DNT PERFOCON

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

DNT Perfocon offers specially shaped holes that allow easy exit of particles or air through the screen. A specialist product in order to obtain a perfect result in the milling process. 

Small holes in thick material

DNT Perfocon is an exclusive product from DNT which offers specially shaped holes that allow easy exit of particles through the screen – even with a combination of small holes in thick material. DNT Perfocon is extremely durable and long lasting compared to alternative products, giving you a more cost effective solution due to fewer production stoppages.

RMIG Perfocon is a specially designed product, produced with a special technique that enables us to manufacture sheets with a thickness many times greater than the hole diameter, e.g. 0.2 mm holes in 1.0 mm stainless steel. To make sheets with holes that small in a material so hard and thick is exceptional and opens the door to an entirely different use of perforated sheets.

The properties of directional perforation enable control in airflow and sieving. The design and the angle are developed specifically to reduce the possible blocking of the holes, thereby RMIG Perfocon minimizes the clogging effect. These qualities make RMIG Perfocon particularly suited for the separation processes.

An example of this is when selecting a stainless steel DNT Perfocon sheet that has subsequently been electro polished, it will distinctly minimize the risk of enzymes and other particles "sticking" in the holes and reducing the flow. The electro polishing process effectively de-burrs the hole and smoothes the surface eliminating the possibility of particle blockages. We offer DNT Perfocon in mild, galvanised and stainless steel.
Applications

  • Cheese moulds
  • Distributer plates in fluid bed dryers
  • Hammer mills
  • Centrifugal
    DNT Perfocon hole sizes
  • from 0.15 mm to 1.0 mm/stainless steel
  • from 0.15 mm to 3.0 mm/mild steel 

DNT EXPANDED METAL

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Thanks to its lightness, strength and anti-skid qualities, DNT Expanded Metal is a very popular material for today's building and industrial design.

Our many customers all over the world use DNT Expanded Metal for many different types of applications e.g for walkways, footbridges, footsteps, safety fences, reinforcing of concrete as well as for shielding in buildings and constructions.

There are many advantages in using DNT Expanded Metal. Below we have listed just a few.

  • Cost efficiency
  • Greater strength
  • Anti-skid qualities
  • Lightness
  • Ideal for secondary operations

Please follow this link for more information on the advantages of using DNT Expanded Metal. 

We offer some DNT Expanded Metal as stock sheets with immediate delivery and in addition we can produce tailor made products exactly designed for the actual purpose

ADVANTAGES OF DNT EXPANDED METAL

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

The advantages of using DNT Expanded Metal are numerous and depend on the specific application. Below we have listed a few of the reasons for selecting DNT Expanded Metal.

Light and cost efficient

It is a great advantage that expanded metal is not assembled nor welded, but always made in one piece.

  • No metal is lost in the expanding process, hence expanded metal is a cost effective alternative to other products.
  • Because there are no strained joints or welds, expanded metal is stronger and is ideal for forming, pressing and cutting.
  • Due to the expansion the weight per metre is less than that of the original sheet.
  • Due to the expansion a much bigger open area is possible compared to other similar products. 
    Greater strength

The three-dimensional shape of the meshes is another advantage since the areas where the meshes meet are strong and enable the material to stand a far heavier point load than similar products or a flat sheet.

Anti-skid qualities

Some patterns have a type of mesh with special qualities that not only make the surface non-skid, but also give the expanded metal water and wind repellent qualities.
Ideal for secondary operations

DNT Expanded Metal is ideal for secondary operations. To save time and to help reduce your costs DNT offers to handle the secondary operations for you. It could be flattening, bending, welding, hot dip galvanising, painting or anodising of the DNT Expanded Metal.

DNT SUGAR SCREENS

VACUUM FILTER SCREENS

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

DNT Mud filter screens are available with accurate hole perforation, manufactured with uniformity in flatness and straightness for high durability and easy mounting into caulking joints. 

Hole size: 0.50 mm  (0.020") 

Centre:  1.09 mm  (0.043") 

Open area:  19.6%* 

MATL.  Stainless
Thickness:  0.30 - 0.40 mm  (0.012"-0.016") 


Find out more

WEDGE WIRE SCREENS

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

 

S.S. Stationary wedge wire screen for sugar juice filteration
DNT make wedge wire screens are suitable for variety of applications such, as sugar coal, mining processing cement etc. The screen surface is either made of looped wires assemble on cross rods or all welded constructions.

A high open area, non clogging filter surface & high precision slots are typical of wedge wire filtration products. These screens are available in slit opening starting from 0.25mm & can be delivered as per customers requirement.

Find out more

BACKING SCREENS CENTRIFUGAL

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

DNT offers selection of screens which provide excellent support to working screen & maximum flow of molasses. a) Wire mesh of brass & stainless steel 304 They are usually used as supporting screens & can be made though wire in stainless steel & brass. They can be made as per customer specification. Wire mesh or wire netting is a process of knitting the wire to form an inter-link that forms a net type product which is primarily used in filtration process. b) Stabbed liner of stainless steel & brass stabbed liner are made with round & triangular holes parallel. Stabbed liner gives complete output of material.

Find out more

ELECTROFORMED NICKEL SCREENS

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Since 1995 DNT  has built up a name as producer of electroformed quality screens for continuous centrifuges. DNT is worldwide known as a supplier of all types of centrifugal screens 

DNT is the original developer and world’s largest manufacturer of high quality chrome-plated electroformed nickel screens for continuous centrifuges. Having been working with the largest sugar production companies and leading sugar machine manufacturers, DNT provides the industry with an unparalleled extended program for sugar screens. Currently we carry 4 general types of sugar screens for continuous centrifuges.

Find out more

DNT CENTRIFUGAL SCREENS

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Working screens / Centrifugal screens


DNT offers various types of centrifugal screens in high quality materials with precision slot and round hole perforations. The DNT Working screens are supplied with precision aligned lock-lap joints for easy installation. 

BRASS LINER

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

Brass, Copper and SS Screens – Round Hole –  These are used as working screen with lock-lap joints and middle screen liners. These screens are available as to be fitted to basket (Liners) for Continuous type and with lock-lap joints for Batch Type machines as required.

Brass, Copper and SS Screens – Conical Slot Hole – These are used frequently for batch type as working screens or for continuous type as middle screens/liners.

Middle & Backing Screens- SS or Brass Dovex screens are used in accordance with the basket size as a middle screen (Batch) and as a backing screen (Continuous & Batch). The screens are slightly different from normal wire-mesh.

PERFORATION AND MORE

SECONDARY OPERATIONS

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

We are able to offer you a range of secondary operations for example flattening, cutting, forming, rolling and welding. 

Complete solutions

As a result of the combination of our specialized machines and our network of professional partners we are able to produce prime quality products and solutions - from the custom made perforated sheet to the fully formed and coated part.
Cutting

We can cut and shape the perforated sheet to meet the needs of your final application, by shearing, water jet cutting or laser cutting.

Our punching/laser machines can combine laser cutting, punching and forming in a combined process. This offers the following competitive advantages:

  • Optimal and reliable results in laser cutting
  • Precise and constant performance in punching
  • Distinguished quality
  • Complicated shapes, special engraving and complex perforated areas

Leveling

For some applications a high degree of flatness of the sheet or coil is required. We offer leveling according to your requirements.  
Rolling and forming

We can roll, bend and form your perforated sheets, using special tooling where necessary, to meet your requirements. Please feel free to contact us for further information.
Welding

Depending on your specifications we are able to offer fabrications produced in our in-house welding equipment.
Other secondary operations

Above we have listed a few of the secondary operations we can provide. Please feel free to contact us for any other needs.

GALVANISING

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

If protection against corrosion is required for carbon steel perforated sheets and parts, hot dip galvanising ensures the best possible solution. 

 

By close cooperation with our subcontractors we have built up a large experience within hot dip galvanizing and knowledge of how to obtain the best results.
When to use hot dip galvanized sheets

  • Generally if a lasting corrosion protection is needed.
  • For outdoor use or use in humid and corrosive environments such as swimming baths.
  • If painted/coated perforated sheets are required to be used in corrosive, humid or outdoor environments.

Advantages of hot dip galvanising 

  • Smooth and uniform coating.
  • Sharp edges and corners are protected optimally.
  • The coating is very robust and can withstand minor bumps and bruises in connection with the mounting, transportation etc.

Disadvantages of hot dip galvanizing

  • Limitation of the product size.
  • Risk of distortion.

Perforated sheets suitable for hot dip galvanising

  • Carbon steel cold rolled and hot rolled sheets with a minimum thickness of 1.5 mm.
  • Perforated sheets with holes that are = or > 6.0 mm in diameter (if hot dip galvanising of perforated sheets is required for sheets with holes less than 6.0 mm, e.g. R 5.0 mm or R 4.0 mm, additional investigation is required).

Sheets and fabrications are hot dip galvanized according to AN ISO. Please feel free to contact us for more information.

POWDER AND WET COATING

DNT GROUP, NICKEL SCREENS, BRASS LINER, VACUUM FILTER SCREENS,MUD FILTER SCREENS, BACKING SCREENS

We will be pleased to arrange colour coatings of products supplied by DNT. There are many bright and opaque colours available if you choose a painted surface. 

Coated surfaces ensure an excellent protection against corrosion and an individual decorative look.

Before colour coating, perforated products must be treated appropriately to ensure the proper protection against corrosion. DNT can arrange such processes as passivating or hot dip galvanising.
The advantages of powder coating are:

  • A thick layer can be applied in one process (50-300 micron).
  • The finished result guarantees uniform surfaces.
  • Powder coating is less affected by mechanical wear and therefore easy to clean.
  • Long outdoor life with the right preliminary treatment. 
  • Wide choice of colours.
  • Materials with holes down to and including 1.0 mm diameter can be powder coated. (If the holes are smaller than 1.0 mm further investigation is required)
  • A more cost effective process than wet coating.

    The advantages of wet coating are:
  • A very elegant appearance / finish can be achieved.
  • Wet coating is very suited for materials to appear multi-coloured.
  • Very long outdoor life if the correct layer thickness is chosen.
  • Wide choice of colours.
  • Materials with holes down to and including 1.0 mm diameter can be wet coated. (If the holes are smaller than 1.0 mm further investigation is required)