Foamed Sealant Steps up Efficiency
Precise Sealing and Bonding for Filters
It is essential for filters to be fixed well and for filter frames to provide for density, so that no air can pass unfiltered. System supplier Sonderhoff Holding GmbH, Cologne, Germany, offers the corresponding dosing units and materials systems for adhesives, thus enabling the filter industry to meet these targets. Adhesive sealants on a PU basis are particularly interesting here, if applied as foam to bond and seal filter media.
At the Filtech 2018 trade show Sonderhoff will have their Smart-M dosing cell on display to show a state-of-the art application. The mixing head of the machine will apply the 2-component PU system (Fermadur type) over the entire surface of an MDF filter frame’s interior. The pleated filter sitting inside the filter frame is thus sealed to make it air-proof from all sides. Thanks to the cellular structure applied upon the filter, the required amount of adhesive material is reduced by up to 50 %. This saves money and weight. However, the system reliably meets the requirements in terms of adhesive and sealing properties.
The PU-based materials offer features such as low emission for low VOC (Volatile Organic Compounds) values in cleanrooms, antifungal or antibacterial properties, flame proofing according to UL94 HF1 for sealing foams or UL94 V0 for adhesive sealants, respectively. Heat-resistant silicone foams of the Fermasil product system are applied to seal air filters in the engine compartment at high temperatures.
Used especially for air conditioning units in vehicles, the sealing foam Fermapor K31 Low-Emission from Sonderhoff makes sure the filter is perfectly positioned at the air intake duct. What is more, low-emission PU systems, most of all, prevent air pollution with VOC emissions in the passenger compartment. For example, they meet Daimler’s DBL 5452-13 specification demanding target values of 100 µg for VOC emissions and 250 µg considering fogging behavior per gram of polyurethane.
The antifungal and antibacterial properties of filter adhesives and foamed gaskets make sure no microorganisms or mold are produced in the gaskets of filter frames of air conditioning units or in the fresh air intake areas of vehicles. The ILH institute in Berlin, Germany, concerned with air hygiene undertook investigations confirming this.
At the trade show, the components are fed into the dosing cell via a rotary index table, for user convenience. Inserting and operating positions change by 180° at a 1.5 s cycle. The dosing cell’s three-axis linear robot that applies the 2-component reactive materials operates along component edges in a traversing area up to 500 x 600 mm and up to a maximum component height of 250 mm. Working on component radii, Sonderhoff’s linear robot achieves a maximum acceleration of 5 m/s².
Sonderhoff Holding GmbH
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