Metering and mixing technology protects sensitive electronics effectively against dust, dirt and moisture.
Whether it’s at home in the garage, beneath the carport or in the company car park, electric and hybrid cars need a flexible power supply at all times. A wallbox (wall charging station) offers a safe, efficient way to charge the batteries in vehicles. Depending on the location, the wallbox may be exposed to different environmental conditions. This includes dirt, dust and moisture, as well as rain, frost and heat in the case of outdoor installation. It is therefore particularly important that the sensitive electronic parts inside the wallbox are optimally protected.
The type of waterproofing used depends on different factors. For example, it depends on the connection or communication options offered by the wallbox (e.g. Ethernet), how the housing itself is constructed, and whether there are means of repair. PU gaskets are increasingly used in these cases.
PU gaskets offer secure protection
Gaskets made from polyurethane (PU) offer the most reliable protection for electronic parts. Here, the seal is applied to the inside edge of the housing. Once the housing parts are connected to one another, no more dirt, dust or moisture can get inside the wallbox thanks to the PU gasket.
The gasket can be applied in various ways. However, since long durability, reliability and strong adhesion are important factors for a wallbox, automated application – gasketing – is the best solution. During gasketing, the dual-component polyurethane is applied automatically to the component in a liquid state. It foams up and hardens very quickly at room temperature.
Gasketing with dynamicLine
DOPAG developed dynamicLine for the automated application of PU gaskets. It enables PU gaskets to be produced much faster, in higher quantities and also more cost-effectively. The dual-component polyurethane is metered, mixed and applied by means of a dynamic mixing head. There are two options for automated material application. The dynamic mixing head can be combined either with a linear robot or with an industrial robot. In the case of a linear robot, the components can be made available to the mixing head either manually via shuttle sliding tables or by means of a conveyor belt. It is also possible to position the component beneath a permanently installed mixing head with the aid of an industrial robot and start off in the form of a foam bead. With both automation solutions, it is possible to apply a gasket at several places in the wall charging station. The control unit can store several metering and positioning programmes. Furthermore, different discharge capacities with varying seal widths or heights can be selected. This enables PU gaskets to be applied efficiently, precisely and reliably in series.
Automated application offers numerous benefits:
- Efficient production and integration into existing production lines.
- The seal adheres firmly and permanently to the component.
- There are no coupling points or open notches like with manually inserted seals.
- Thanks to a controlled overlap, the start and end points of the foam bead merge.
The potting of electronics is, without doubt, the safest way of protecting the sensitive components, as the central module of the power electronics in a wallbox can be completely potted and then integrated into the housing. The hardened epoxy resin offers comprehensive protection against moisture, dust and dirt. The dual-component material can generally be processed with various DOPAG systems. The following metering technologies are available depending on the requirements of the application.
- eldomix gear metering system
- vectomix and variomix piston metering systems
- rotormix eccentric screw metering system
- dynamicLine dynamic mixing system
Depending on the material properties (fillers, abrasiveness, etc.) and process data (discharge rate, shot size), there are different metering and mixing systems available. These are designed and configured based on the specific requirements in question.
Flexible series production with automated solutions
DOPAG offers individually configured metering and mixing systems tailored to the customer’s specific requirements. This includes automation as well as the integration of pre-and post-treatment. Different solutions may be possible for automated potting depending on requirements. For example, multifunctional cells can be integrated into existing production lines. For example, the rotormix eccentric screw metering system is suitable for robot-aided material application and can be directly managed by the robot without an additional hose package. The experts at DOPAG also configure fully customised special systems with industrial robots for highly automated series production.