Reliable bonding of filters

Automated metering and mixing technology for the production of plastic filter elements

In industry, filter and dust removal systems ensure clean and safe air in production halls. Herding Filtertechnik supplies numerous industries with the appropriate solutions. In April 1977, the company - Herding GmbH Filtertechnik - was founded by Walter Herding in Amberg, Germany. Today, it employs 250 people and has eight independent foreign subsidiaries and cooperations in nine other countries.

The company's real success story began with the invention and patent application in 1980 of the surface filtration process using rigid-body filter elements, which have a longer service life than conventional textile and paper filters.

With its employees, Herding is able to supply complete filter systems from a single source. This includes all services from requirements analysis, consulting, customer-specific design and planning, production, installation, commissioning to subsequent maintenance. The filter media of Herding GmbH Filtertechnik are used in all branches of industry, from the automotive industry to the food industry and cement plants. There they meet already all environmental requirements of tomorrow.

The base body (rigid body) consists of a sintered polyethylene PE. The surface of the Herding filter is formed by a microporous and hydrophobic PTFE coating, which is firmly embedded in the base body. To stabilize and secure the overall filter medium, a PE head is attached to each of its ends. This PE filter head component is bonded to the overall filter medium.

While the adhesive used to be applied via a portal system, today the solution using 6-axis robots is also automated, but much more flexible. This has enabled the discharge rate to be more than doubled. 

The relatively difficult-to-process highly viscous, thixotropic and abrasive material is applied to the PE heads by means of a DOPAG eldomix 603 metering and mixing system in a fixed mixing ratio and at constant processing temperatures. These are then manually fixed to the base body. The cycle time here is less than 10 seconds. 

"When we were looking for a partner, DOPAG was already known to us as a competent and reliable supplier of metering and mixing equipment. The professional preliminary tests in the technical center in Mannheim showed that we had made the right choice with DOPAG in terms of our partner," said a Herding spokesman. 

Product page of the metering and mixing system eldomix