ELASTOSIL® A 442
ELASTOSIL® A 442 is a one-component, thixotropic sealant intended for use where a soft, high elongation material is desired. ELASTOSIL® A 442 is particularly effective as an adhesive in applications where the bonded joint is subjected to relatively large movements in service.
- Tenacious adhesion to most metals, plastics, synthetic rubbers, glass and concrete
- Low modulus of elasticity for superior sealant joint movement capability
- Low compressive modulus, ideal for forming compression gaskets on covers and closures where low clamping pressures are essential
- Stays flexible between -65°F and 400°F
- Impervious to weathering and ultraviolet degradation
- Resistant to hot lubricating oils
- Causes little or no foam in lubricating oils
- Non-corrosive to ferrous metals
ELASTOSIL® A 442 can be bulk dispensed by hand or robot applicators with conventional drum and pail extruder pumps equipped with high pressure flexible fluid hoses. Caution! Hose pressure rating must exceed the maximum possible output of the pump and be moisture impermeable. Contact your Wacker Silicones representative for equipment recommendations. Surfaces to be bonded must be clean and free of oil, grease, soaps, dust, etc. Rubbers and plastics must be free of die lubricants and mold release agents. Certain plastics such as polypropylene require flame treatment to attain maximum adhesion. The surface cure of ELASTOSIL® A 442 may be greatly accelerated by exposure to a moist carbon dioxide rich atmosphere. A carbon dioxide level of one to two percent is sufficient to produce a skin-over time of two to three minutes. ELASTOSIL® A 442 is not recommended for use on polycarbonate or in direct contact with liquid gasoline, diesel fuel or hot engine coolant.
The performance of ELASTOSIL® A 442 is dependent upon many factors, including the application method, the thickness of the layer deposited, the substrate, the curing atmosphere, and the curing cycle.
skin should form over the surface it may be removed by careful skimming. Spray equipment and brushes
should be washed and wiped clean with naphtha or mineral spirits after use.
The adhesion of ELASTOSIL® A 442 to most substrates can be enhanced by a 30 second to one minute preheat cycle at 60-70°C before exposure to the UV source