Flat membranes as a special customization
We manufacture each flat membrane individually according to a customer-specific drawing at our location in Rosenheim. As a mold-making manufacturer, we vulcanize your flat membrane into shape, so that more complex geometries are also possible that the classic cut-to-size product does not allow.
- Customised production
- Batch sizes 1 to 1 million units.
- Express production from 2 weeks
- 100% Reliability & proactivity
Flat membrane individually
adapted to your requirements
A flat membrane seals two spaces with different pressures or media hermetically and allows for a slight lift due to the elastic properties of the working surface. Due to its flat profile, the flat membrane is particularly suitable for slim installation spaces with limited space. In this case, the Vulcanisation In comparison to stamped or cut-to-size parts, the advantage is that, for example, a circumferential sealing bead can be implemented for clamping purposes or other connection geometries can be realized.
A circumferential ridge provides additional material length and increases the stroke without loading the working surface with traction.
Flat membrane with a ridge
A circumferential bead on the clamping edge provides static sealing to the housing and easy assembly by clamping.
Flat membrane with sealing bead
A fabric layer vulcanized into the flat membrane made of polyamide, polyester or aramid limits the stretching of the active area and allows higher differential pressures than an unreinforced version.
Flat membrane with tissue padding
We vulcanize the support plate, centering discs or threaded bolts in a material-locking manner into the flat membrane. This limits the deflection to the annular zone between the plate and the clamping ring.
Flat membrane with metal liner
Plastic inserts made of PA, PP or PC, which we also manufacture according to your specifications, absorb the force input, save weight compared to steel and remain corrosion-free in humid environments.
Flat membrane with plastic liner
Components weighing 0.01 g or less with wall thicknesses <0.5 mm for dosing and analysis technology, up to large-area membranes of 650 x 750 mm for expansion vessels and container technology.
Micro and large format membranes
Advantages of a Custom-made flat membrane compared to the stamping cut
Flat membranes are often produced as punched parts from sheet metal or by laser cutting. For simple applications, these solutions work well. If requirements increase, reinforced zones or special connection geometries are required that can only be produced as Rubber moulding or Silicone moulding are feasible.
- Custom-shaped indentations, edge geometries, and local thickenings are created in the tool in a single vulcanization step.
- Locally graded wall thicknesses, such as a thickened clamping edge, a bend-resistant seam and a reinforced center, are created without any joining processes in the tool.
- The marking of the component with a material abbreviation, article number or date stamp is created by adjustment directly in the cavity.
- Metal trays, plastic inserts or fabric layers are vulcanized together in a way that ensures a strong bond and are not glued, welded or screwed together.
Flat membrane -
individually made by GUME
- In-house toolmaking: moulds are created internally, with no external waiting times
- Express production possible: first samples already available in 2–3 weeks
- Flexible sizes and quantities
- Custom production from single items to large-scale series
Materials
for your flat membrane
Hardness, residual compressive deformation, force-displacement curves, temperature windows, and media resistance depend on the rubber compound used. We process all common elastomers and are happy to advise you on choosing the appropriate material that best meets your requirements.
Resistant to mineral oils, fats and oil-based compressed air from -30 °C to +110 °C. NBR flat membranes are often used in pressure switches, hydraulic reservoirs and pneumatic actuators.
They possess chemical resistance comparable to NBR and also higher temperature and aging resistance up to +150 °C.
For applications with hot water, steam and weather exposure from -50 °C to +130 °C, such as water fittings, expansion vessels and heating technology.
When in contact with fuels, acids and alkalis at temperatures up to +220 °C, they are used in chemical dosing pumps and process valves.
Physiologically harmless and FDA-compliant material with a possible temperature range of -50 °C to 220 °C.
High tear strength, high resistance to further tearing and good rebound elasticity up to +70 °C. NR flat membranes are usually used in assemblies with a high number of cycles and without oil contact.
Geometric adjustments
of rubber and silicone flat membranes
Membranes are usually designed to withstand a specified force-displacement curve under differential pressure. Since rubber requires disproportionately more force with increasing elongation, the characteristic curve of a flat membrane made of silicone or rubber has a flat and a steep region that can be influenced by various parameters.
01 / 04
Effective area
The effective area is the part of the membrane that performs the movement: in the planar flat membrane the entire clamped area, in designs with support plates the ring zone between the edge of the plate and the clamping diameter. Since the effective diameter enters the force quadratically, an increase in diameter is more effective at low operating pressures than an increase in pressure. At the same time, this increases the tensile stress on the membrane, which affects the wall thickness and, if applicable, the tissue inserts.
02 / 04
Wall thickness
The wall thickness of a flat membrane determines the pressure resistance and bending stiffness in the movement zone. A low wall thickness only exhibits a low restoring force and bending stress, but can only accommodate a limited differential pressure. Conversely, a higher wall thickness allows for higher pressures with higher bending stiffness.
03 / 04
Material hardness
The elastic modulus determines the slope of the flat membrane's characteristic curve. Softer mixtures stretch more strongly at the same pressure than harder ones. As the only of the four variables, the material allows a change in the result without adjusting the tool cavities.
04 / 04
Deformation
A planar membrane expands under load, thereby allowing for a lift, which is why the restoring force against the ends of the lift increases disproportionately. A shaped wedge or curved flat membrane uses additional material length and thus enables the effective area to be applied within a predefined bending zone, whereby the force profile remains approximately constant over a larger distance.
You have questions about
Flat membranes?
We have answers!
How is a flat membrane different from a roll membrane?
The flat membrane generates its stroke by deflecting and stretching the working surface, thus remaining limited to short distances. In the roller membrane, a cylindrical casing rolls off the piston, allowing for larger strokes with an approximately constant working surface. The flat membrane is constructed more flatly, requires no roller gap, and is the more economical construction option for short distances.
When is a bead in the flat membrane necessary?
As soon as the required lift exceeds the allowable strain of the working surface, adding a circumferential bead does the trick. This allows for additional movement reserve through the bending zone (additional material), instead of distributing the movement over the entire surface.
When is a flat membrane with a tissue liner useful?
If the differential pressure significantly stretches the active area or a high number of cycles at higher pressure is required, the use of a stabilizing tissue insert makes sense. The tissue is vulcanized between two rubber layers, so that it lies inside the membrane. However, the tissue limits the stretching of the active area, so a bead is usually added to maintain the flexibility of the flat membrane.
Can the working area and the lift be changed after the pattern has been created?
The working diameter, wall thickness, and edge geometry are created in the tool cavity and cannot be subsequently modified on the finished flat rubber membrane. Therefore, any changes are only possible by adjusting the tool. Since tool design and manufacturing are in-house, we perform tool modifications ourselves. Without any intervention from the toolmaker, it is possible to adjust the Shore hardness and rubber composition, for example, and thus modify the spring characteristic curve. Therefore, we determine the spring characteristic curve, stroke, and installation position together with you before starting the production of the tool.
What clamping force and what flange geometry can be achieved with a flat membrane?
The clamping on the clamping edge keeps the membrane against the applied differential pressure without pinching the cross-section. A too low clamping force can cause the flat membrane to slip. A too high clamping force can, under load, lead to cracking at the clamping edge. Therefore, we use a circumferential sealing bead to seal over the bead cross-section and clamp the membrane.
