Customized solutions for molded foaming of air filter gaskets

 

We carry out developments individually for your specific requirements

A wide range of technically reliable solutions for automotive air filters can be achieved by foam-in-place gaskets with the reference material FERMAPOR-K31-A-9846-12-VP2 and B-81 (B-component) made of 2-component polyurethane foam. By using an open mold into which the sealing material is introduced, square air filter frames can be produced, or even round shapes like e. g. the end caps on radial filters for commercial vehicles.

In this process, the filter medium is inserted into a prefabricated forming tool coated with release agent. The CNC-controlled MK 800 PRO precision mixing head of the DM 502 mixing and dosing machine fills the contour of the mold with the dynamically mixed -component polyurethane sealing foam. Depending on the process, the filter pack is inserted into the mold immediately afterwards, or has already been inserted before injection of the foam. The injected sealing material foams, expanding to several times its original volume and fills the mold contour with a positive fit. The polyurethane foam bonds to the outer edges of the filter pack to form a foam-in place frame gasket.

 

Industrial air filters with foam-in-place frames / end caps

 

Radial air filter with end caps provided with a foam-in-place polyurethane gasket
Cross-section of radial air filter showing the connection of filter pack and metal support frame to the PU foam.

After the material has cured, the air filter with the foam-in-place gasket can be removed from the mold for further processing in the manufacturing process.

To accelerate this curing process, the mold with the filter pack is run through an annealing oven shortly after injection of the material. The heat inside the oven cures the material faster.

The different reaction phases of the sealing foam in the chronological sequence

 

Reference material

    FERMAPOR K31-A-9846-12-VP2   
    FERMAPOR K31-B-81
Mixing ratio   3 : 1
Pot life time   35 sec.
Tack-free time   7 min.

Viscosity of the A component

  4.000 mPas
Density of foam   0.26 g/cm³
Hardness (Shore 00)   70
Temperature resistance   from -40 to + 80 °C

In addition to the reference products, we develop material systems according to your individual requirements. Influencing factors include pot life until start of foaming, curing time, and the viscosity, hardness and adhesion properties.
 


DM 502 mixing and dosing system with 3-axis linear robot for foam-in-place molding of air filter frames and the transfer belt for the feeding of parts

 

Flexible and fully automatic – fully in line with your requirements

In the reference configuration of the DM 502 mixing and dosing system as shown, the air filters placed in a mold are guided to the dosing station on a transfer belt arranged below the 3-axis linear robot. The highly dynamic LR-HD 3-axis linear robot handles the contour accurate CNC-controlled movement of the precision mixing head above the part to be processed.

Alternatively, the DM 502 can also be used as a sliding table system with the LR-HD 3-axis linear robot and WT 1-LEVEL shuttle table. Parts are picked up and processed here in continuous shuttle mode, operating in a single plane.

The CNC-controlled MK 800 PRO precision mixing head of the DM 502 mixing and dosing machine moves along the contour of the air filter, which has been inserted into the mold, and applies the 2-component FERMAPOR K31 polyurethane sealing foam into the circumferential mold cavity.

The injected material foams expanding to several times its original volume and fills the mold with a positive fit. After curing, the air filter with the foam-in-place gasket is removed from the mold for further processing in the manufacturing process.

In series production for large unit numbers, automatic refilling stations are generally used. These use agitators to ensure the optimal preparation and homogeneous consistency of the material. The refilling stations ensure that material is supplied continuously to the material pressure tanks, allowing fully automatic production processes. Capacitive sensors on the material pressure tanks monitor the filling level and control refilling. This means that the production process is not interrupted in the event of a material change.

The fail-safe DM 502 mixing and dosing machine can be operated easily and intuitively without much training. All dosing and process data are recorded automatically, allowing tracking and evaluation by the machine operator via the CONTROL 2 operating panel.

In all solutions, our main focus is on extremely reliable plant engineering, minimized maintenance times and consistent dosing quality.

 

Alternative machine configuration: DM 502 with MK 800 PRO with LR-HD
linear robot and WT 1-LEVEL shuttle table