Brazing paste application methods
Screen and stencil printing
For selective application of brazing paste on flat parts with contour-sharp printing results on all layer thicknesses. One application is hole plates for Exhaust Gas Recirculation (EGR)-coolers.
Höganäs' pastes can be applied with standard screen printing equipment. The parts to be printed are fixed in a tool and then moved to precisely congruent position underneath the screen. A squeegee spreads the brazing paste onto the top of the screen, coating it with paste. The layer thickness is adjusted through paste selection and screen mesh size. After coating is completed, the screen moves down on top of the parts and a printing squeegee presses the screen onto the printing parts.
As a result, the paste is applied on the parts through the screen along the moving squeegee. The screen then releases the parts which are moved out of the printer for drying. After drying, the strong adhesion of the coating ensures simple part handling throughout successive processing and assembly.
If the print layout can be done by a stencil instead of a screen, the very same printer can be used for stencil printing application. Stencil printing is less time-consuming as it eliminates the paste-flooding step required for screen printing. The printing process can be automated to achieve high-volume output, and productivity can be scaled up by using multiple printings in a single print cycle.
Print it now
Turn to us for real-life paste application on your parts using screen and stencil printing. Our printer equipment provides the possibility of running pilot manufacturing and enables direct transfer of paste and process parameters to your production line. For increased productivity, it is possible to place several parts underneath the screen or stencil and print them in one print cycle.
This method enables high-speed paste application on various designs within layer thicknesses of 0.03 to 0.05 mm. For standard spray guns The powder and paste properties are well designed for standard spray guns. By using micro spray units the spray field can be controlled to areas in the size of a single tube width.
Speed and automating
Increase spraying speed by using multiple spray units. Spray speeds up to 100 m/min allow installations of inline spraying systems right after a tube mill. High-speed drying can be achieved by means of an infra-red beamer. By partnering with spray cabin suppliers, automating solutions are available right from the shelf.
High process reliability
Well designed paste properties ensure repeatable spraying applications with consistent smooth coatings, fast drying speed as well as strong adhesion to withstand transport and handling during assembly.
This is the most commonly used paste application technique for heat exchangers. External heat exchanger housing parts, for instance inlet and outlet tubes as well as holders, are almost always applied by dispensing.
A straightforward process
Apply paste with compressed air or, for better precision, by using a screw-dispensing unit. The paste is fed in accurate volumes through a needle onto the application area
and is applied adjacent to the brazing gap in the form of a dot or, by moving the dispenser over the part, as a line.
Clean and reliable
Your workspace can be kept clean since paste is delivered in cartridges for direct connection to a dispensing unit. The paste properties ensure no settlement and that paste always sticks after application, even on bevel and vertical surfaces.
Dispense it now
With our industrial robot and integrated screw dispensing unit, we provide automated dispensing application solutions for your assembly line. Test, application optimisation and qualification can be done in Höganäs PoP Centre in order to simplify the production process design and shorten your time to market.
Reduce paste consumption by applying thin coatings on selective part areas on for example flexible fins or turbulators.
Compared to spraying, roller coating application significantly reduces the total amount of required paste thanks to increased precision. A paste roller moves through a paste reservoir and absorbs paste to its surface while scrapers adjust the layer thickness. To transfer the paste from the roller to the fin tip or fin plateau, a belt feeds the applications along the paste roller. The amount of paste applied is adjusted through the thickness of the paste layer on the roller. For endless fins, double-sided coatings are recommended. In this process the fins are fed horizontally between two paste-coated rollers to achieve a simultaneous coating of both sides. After drying, the strong coating adhesion ensures simple part handling during subsequent processing and assembly.
Roll it now
The Höganäs PoP Centre provides real-life roller coating paste applications on your parts. The roller coating equipment can be used for production, providing the opportunity to run pilot series under the same setting as your production line. Roller coating application has been tested with Höganäs' paste in speeds up to 20 m/min with the possibility of multiplying productivity by parallel coatings on a single belt.
Make powder technology first choice
A key to successful product development and industrialisation is the intimate work with material, process and design. Höganäs can realise this by opening up for close collaborations in the Customer Development Centre.