Coating web materials efficiently with application systems

Anyone involved in the converting of web materials knows that the requirements are sometimes very specific. These often depend on various factors such as the material used and the industry. Application quantities can range from a few grams to several kilograms. Based on our knowledge of the versatility of coatings, we design our application systems to meet individual customer requirements. We offer a range of processes, one of which is guaranteed to be perfectly suited to your production requirements.

Need help coating your web materials? Then please contact us. We will be happy to advise you on suitable application systems and work with you to develop a concept that will add value to your production.

Overview

How do application systems work?

They function primarily as coating systems for the precise and uniform application of defined quantities of material to a substrate. Coating materials typically include paints, varnishes, adhesives or similar substances. Modern application systems also control various process parameters such as application speed, material quantity and film thickness. By providing a uniform coating, these systems help to minimise defects and improve product quality. They also enable the automation of the coating process, allowing manufacturers to organise their material processing more efficiently.

How do I choose the right application system?

The selection of a suitable application system is influenced by a number of factors. One of these factors is the type of coating material, particularly its viscosity and chemical properties. The nature of the substrate also plays a key role in the choice of system. Depending on the shape, size and other characteristics, certain application systems are more suitable than others.

Choosing the right application system also depends on the specific requirements of the coating. It is important to clarify the thickness, precision and uniformity required for the coating. Local production issues should also be considered. Different systems may have different production volumes or throughput rates.

Application areas of application systems

Application systems play a central role in various industries where materials are coated. At Krögel and for our customers, the following areas are of particular importance:

In the film and paper industry, application systems are used to coat films and papers with paints, varnishes and other coatings. They are also used to print packaging and produce laminated films.

In the textile industry, textiles are treated with dyes or varnishes and impregnated.

Different types of application systems

Spray equipment atomises the coating material into fine droplets and then applies them evenly to the substrate. This application system is therefore suitable for complex shapes and hard-to-reach areas, as a uniform coating is achieved. They also allow large areas to be coated quickly and save material, as the amount of material applied can be precisely metered.

In this process, the application system coats the carrier material with a fine powder. The coating material is applied via a scattering unit. This process is quite complex and must be adapted to the specific requirements.

In this process, two web-shaped base materials are joined together using a thermoplastic or adhesive. The material to be joined is melted by heat, converted to a viscous or plastic state and forced through an appropriate die geometry. Extrusion allows continuous operation and therefore high production rates. At the same time, material consumption is minimised while productivity remains high.

In this coating process, the machine pulls the web over a guide roller. At the same time, two counter-rotating rollers apply the liquid to the web. This process is particularly suitable for smooth and flat substrates. Large areas can be coated quickly and the thickness of the coating can be controlled very precisely.

Another coating technology is the ploughing process, which has been developed for coating the underside of horizontally running webs. The lower part of the so-called plough roller lies in a trough filled with the coating material. The plough roller, which rotates with or against the direction of production, ploughs the coating material from below onto the web running above. Height-adjustable deflector rolls, positioned before and after the ploughing roll, allow variable adjustment of the roll wrap. A lifting device can also be used to lift the material to be coated off the plough roller if required to avoid coating. Both high and low viscosity coatings can be applied. This type of coating is a cost effective coating option due to its simple design.

In this coating process, a rubber blanket carries the substrate horizontally under a doctor blade. This has the advantage that the coating can be applied without damaging the material. A support roller under the blanket and directly under the doctor blade provides a defined, adjustable gap.

The gap can be precisely adjusted to achieve the desired coating basis weight.

This coating option consists of a precision-machined doctor roller that can be set at a defined, adjustable gap to a table frame located underneath the roller.

In this type of coating, the system consists of a doctor blade that can be positioned at a defined distance from a table located underneath the doctor blade. The coating material is placed in front of the blade and is evenly distributed by the blade onto the substrate running between the blade and the table.

The substrate passes horizontally over two deflection rollers between which the air knife is positioned. The substrate is drawn under the blade by the vertical pressure of the air knife into the tensioned material stream. In this coating method, the coating material placed in front of the air blade is pressed directly into the usually open-pored substrate. This results in a deep or material penetrating coating. Air knife coating allows large areas to be coated quickly, efficiently and easily.

It combines the advantages of air knife and cylinder knife coating. The coating is applied directly one after the other using a combination of the two processes.

In contrast to air blade coating, the doctor blade is moved onto a rotating precision roller with a gap. The coating material is placed in front of the blade. The doctor blade and roller must be manufactured to a high degree of precision, depending on the required minimum coating quantities. By adjusting the doctor blade, a very precise gap can be achieved across the entire coating width. This allows an even and highly accurate coating with very low application rates.

This combines the advantages of air blade and cylinder blade coating. The coating is applied using a combination of both processes directly one after the other.

In this process, the coating system applies the material to the substrate in the form of dots. The dotted coating saves material, which can reduce production costs.

This coating variant combines the air knife system with the ploughing system and is used when the material needs to be coated on both sides.

Gallery

Examples of 100% custom-made systems

Hotmelt / extrusions coating
Kiss coater 3.200mm
Kiss roll 4.200mm ATEX
Kiss coater 4.400mm
Kiss roll 5.200mm
Kiss coater fibres
Kiss coater mobile 3.400mm
Powder dosing unit 2.400mm
Reverse-roll coater
Spray application
Coating unit AB 2.400mm
Plunge pool 5.200mm
Dip coating fibres
Table coating system AB 1.700mm
Gusset foulard

Technical details

Operating widths up to 5,800 mm
Speed of the machine up to 100 m/min
Coating materials Pastes, fluids, powders, hotmelt, ...
Application systems individually or in combination
Processing of wide range of materials and surface weights

Questions about our application systems

Do you have special requirements for coating your web materials? We can develop and implement the concept you need. Depending on the material you process or the application, we can offer you different solutions.

With us at your side, the path to a modern application system is open to you. Contact us to optimise your production. We are ready to work with you to develop an optimised system.