Metering and mixing system for adhesive bonding of automotive components

DOPAG implements a globally uniform and process-safe application

In automotive production today, a high number of components are bonded together. This not only makes the vehicles lighter, it even increases safety in accidents. Compared to welded cars, they perform better in crash tests. For example, body and interior components, windows and even engine components are bonded. In order for the bonding to hold reliably and have a long service life, exact metering and mixing of the adhesive is important. DOPAG has developed an individual solution for a globally operating automotive supplier.

The metering and mixing system is used in the production of tailgates and highgates. A plastic component has to be bonded to a metal or composite plate. The eldomix metering and mixing system from DOPAG is used, which is ideally suited for bonding applications and can be easily integrated into the highly automated production lines of the automotive industry. A two-component polyurethane is metered and mixed. During the application, a robot places a bead around the trim of the tailgate at a speed of 300 cc/min with high precision.

Precise and process-reliable metering

In the automotive industry, high accuracy with only extremely narrow tolerances as well as high process reliability and reproducibility are required. Because of this, and because of the sensitive material, DOPAG placed the entire mixing head of the eldomix at the end of the robot arm in the design process. As a result, the deviations of the measured values from the set parameters are only very slight and all requirements for metering accuracy can be met. With the eldomix, it is possible to meter a very challenging material at a high flow rate and to maintain a very narrow error rate.

For optimum control and process monitoring, material pressure regulators and gear flow meters are used. The material pressure regulators reduce the pressure of the conveyed material to the required working pressure. The gear flow meters enable an accurate measurement of the current material flow and thus ensure extremely precise application. Gear metering pumps with servo drives are used for material supply and mixing process. Even slight changes in temperature could lead to overpressure or fluctuations in the mixing ratio. The material cannot be heated. To ensure a constant temperature, the entire material supply is located in an air-conditioned cell. Thanks to the observance of all these requirements, a continuously high dosing accuracy and repeatability can be guaranteed.

Dispensing system will be globally implemented

The automotive supplier has production sites in more than 30 countries. Production lines are planned once and then implemented worldwide. As a manufacturer who is also active worldwide, DOPAG is able to fulfil exactly this requirement and replicate the metering and mixing system at all desired final locations worldwide. For the automotive supplier, this was a decisive reason for the partnership with DOPAG, in addition to the individual design. Should modifications to the system be necessary due to changing requirements, DOPAG will implement these worldwide on all systems in use and in the future.