SM-40 Transparent Silicone Membranes

SM-40 Transparent silicone membranes combine flexibility with greater dimensional stability than softer silicone grades. With a hardness of 40 Shore A and elongation of up to 700%, the material follows curved and profiled surfaces while maintaining controlled pressure across the workpiece.

This grade is used for vacuum pressing, thermoforming, laminating, sublimation and composite processing. The category includes material cut from the roll, smaller sheets and ready-sized membranes for specific vacuum press models.

Technical Properties of SM-40 Transparent Silicone

• material: silicone rubber;
• compound: A-SU 40-79;
• hardness: 40 Shore A;
• elongation: up to 700%;
• tensile strength: 8 N/mm²;
• operating temperature: up to 200 °C;
• available thicknesses: 1, 2 and 3 mm;
• available widths: up to 2000 mm, depending on the product;
• surface: smooth;
• colour: transparent.

The transparent material makes it easier to check the position of the workpiece, film or other covering material beneath the membrane when the design of the press allows visual inspection. Its smooth surface provides uniform contact and does not leave a textile pattern on the processed material.

Why Choose a 40 Shore A Silicone Membrane?

SM-40 occupies a practical middle position between very soft silicone membranes and firmer grades. It is flexible enough to reproduce shaped surfaces but offers more resistance to stretching and deformation than SM-30.

This balance makes SM-40 suitable for production processes involving different workpiece sizes and geometries. It is particularly useful when a membrane must adapt to curved details without becoming excessively soft or difficult to control during installation and operation.

Choosing the Appropriate Membrane Thickness

The thickness of the membrane affects flexibility, shape reproduction, handling and resistance to mechanical loads. The available SM-40 Transparent variants serve different production requirements:

• 1 mm — provides maximum flexibility for detailed shapes, compact presses and applications with relatively low mechanical loads;
• 2 mm — a versatile choice offering a practical balance between flexibility and durability for regular vacuum pressing and forming;
• 3 mm — provides increased stability and mechanical resistance for larger presses and more demanding operating conditions.

The thinnest option is not automatically the best for every application. Deep profiles may require greater flexibility, while sharp edges, large workpieces and intensive production cycles may justify choosing a thicker membrane.

Applications of SM-40 Transparent Membranes

Depending on the selected thickness and dimensions, SM-40 Transparent membranes can be used for:

• thermoforming solid-surface materials;
• forming thermoplastics within the specified temperature range;
• processing composite materials;
• vacuum pressing and membrane pressing;
• veneering and laminating shaped wood-based components;
• manufacturing curved laminated parts;
• sublimation and heat-transfer processes;
• making flexible gaskets and technical components.

The maximum operating temperature of the membrane is 200 °C. The actual working temperature must also comply with the limits of the press, adhesive, film and processed material. Pressure, cycle duration and workpiece geometry should be considered when selecting the membrane.

Widths, Cut Lengths and Ready-Sized Membranes

SM-40 Transparent is available in several configurations. Standard industrial widths include 1600 and 1660 mm, while selected products with thicknesses of 2 and 3 mm are available in widths of up to 2000 mm. Smaller sheets and roll remnants are offered for compact equipment, testing, gasket production and other technical applications.

Material sold by length can be ordered from 1 m. The category also includes membranes cut to the dimensions of specific vacuum presses, reducing the preparation required before installation. Available thicknesses, widths and lengths vary between products and should be checked on the individual product page.

Compatibility with Vacuum Presses

Ready-sized SM-40 Transparent membranes are available for numerous vacuum presses, including equipment from ADAMIK, ARTEX, ATMOS, BARTH, Columbus, ELKOM, GLOBAL, Istra-A, MSM, ORMA, RIBEX, Vac-U-Clamp and WISCHT.

Press model compatibility should always be verified before ordering. Measure the existing membrane or confirm the dimensions of the membrane frame and clamping area, including the additional material required around the working surface.

If the required press model or membrane size is not listed, contact us with the working dimensions, required thickness and application details. We will help you select a suitable SM-40 Transparent membrane or prepare a custom-sized solution.