Consistent production of high-quality foam gaskets
Foam gaskets offer strong adhesion and long durability. A requirement for this is the precise metering and dynamic mixing of the material. The Italian company Fandis uses DOPAG’s dispensing technology in the production of components for control cabinets. The project was implemented together with the Italian sales partner DAFA.
Foam gasketing protects component interiors from moisture, dirt and other environmental influences. It seals control cabinets and their peripheral components, such as plastic casing and fan housing, locks and door handles. Consequently, the use of foam gasketing on these components is one of the traditional applications of the formed-in-place foam gasket (FIPFG).
The Italian company Fandis works in this industry. At its headquarters in Borgo Ticino (Italy) close to Lake Maggiore, the company produces components for the cooling and ventilation of switchgear, including ventilation grilles, filters and ventilators. Foam gasketing is required on various types of components. Fandis uses dynamicLine from DOPAG to produce this. The project was implemented together with the Italian sales partner DAFA in close cooperation with the Italian DOPAG subsidiary and the headquarters in Germany. DAFA has many years of experience in the FIPFG sector and is responsible for consulting, sales and service of the dynamicLine in Italy with the support of DOPAG Italia.
Flexible processing of multiple components
In choosing the system, the focus for Fandis was on high-quality foam gasketing and flexibility. The requirement: the foam gasketing needs to be applied flexibly and with consistent precision on components of different sizes. DynamicLine consists of a dynamic mixing system and a linear robot. In the FIPFG process, it is used to meter a dual-component gasketing based on polyurethane (PU) or silicone (SIL), mix this dynamically and then apply it automatically along a contour and on a flat surface directly onto the component. Fandis works with a low-viscosity PU foam. The material is administered into the groove of the ventilation grille and is then distributed here. After a certain reaction time depending on the material, the bead foams up and adheres firmly to the component.
A high-precision system is particularly important in the case of small seal geometries. This is not a problem thanks to the automated application. All metering and positioning programmes are stored on the control unit. They simply need to be activated and then start off in automatic mode. The conversion time is therefore very low and the programmes can be changed quickly, for example to switch quickly to another component.
A transfer system is connected to the linear robot. The components are brought into position under the linear robot via a conveyor belt, the assigned positioning programme starts via a signal exchange and the foam bead is applied. Another benefit is that, thanks to the automatically controlled overlap, the start and end points of the foam bead are seamlessly connected. There are no open spots or edges, as is the case with manually inserted seals. Furthermore, the automated application of the foam gasketing is environmentally friendly. There is less waste and the entire system is rinsed with water. No solvents are used.
As Fandis carries out its production in a large production hall, there can be large fluctuations in temperature at different times of the year. The DOPAG metering and mixing system was therefore also fitted with a temperature control unit for optimal material conditioning. The material containers and the pipes from the metering pump to the mixing head are double-walled and are flooded with a tempered liquid in the outer casing to ensure that the material supply has a constant temperature at the mixing head. This ensures consistent processing quality. Refill units of over 200 litres also ensure uninterrupted production.
The foam gasketing is applied to the smallest component in just five seconds, while it takes just over ten seconds for the larger components. Thanks to the short cycle times, high quantities can be produced in series with a consistent, reproducible quality.