Wacker Launches New Silicone Adhesives

Munich, Germany-based Wacker Chemie AG has launched new silicone products for use in wound dressings and prosthetics products. Among the new products are the Sipluran 2112 silicone adhesive, touted to be compatible with skin, developed specifically for the production of advanced wound dressings; and the Silpuran 2438 ADH silicone adhesive, which is meant to be suitable for bonding textiles and siliconized composites of the kind typically employed in prosthetics.

The 2112 adhesive is an addition-curing silicone gel—two part silicones which require the mixture of a silicone polymer with a catalyst to initiate the cure. It consists of two pourable components which cure to form a low-modulus, flexible silicone adhesive that adheres gently to the skin. The silicone adhesive is transparent and pourable; no byproducts are released during curing; it is soft and flexible in order to fit tightly but gently over skin, aligning well to irregularities; and breathable and water-repellant, claims Wacker.

The 2438 adhesive is also addition-curing, but is not a gel but a silicone rubber. It is cured at 80 to 120 °C after the A and B components have been mixed. The resulting elastomer, according to Wacker, is a medium-hard elastomer that has a value of 38 on the ISO 868 measure of silicone hardness. Officials note that the material has a high tensile strength and a high tear strength. It can reportedly be stretched up to 400 percent of its original length.

These properties make the 2438 adhesive well suited for immobilizing cured silicone rubbers and for flexible bonding of textile surfaces, according to the company. The new adhesive can bond molded parts made from these materials without the need for priming. Due to its high tear strength, the cured silicone adhesive layer can tolerate high levels of mechanical stress, including that generated when bonded parts rub against each other. The adhesive can be used to create highly flexible bonds between molded silicone parts and textiles for use in prosthetics and orthotics. It is pourable and can be processed both manually and in semi-automated processes. In addition, it has a pot life of one hour at room temperature and cures to a translucent elastomer without releasing any byproducts.

The company claims that none of the products in the Silpuran line have organic plasticizers and stabilizers in their content.