1. Mixing the two components
The components A and B are mixed by weight in the above indicated ratio. The mixing can be carried out either by hand or using a low-speed electric or pneumatic mixer to minimise the introduction of air and to avoid any temperature increase.
It is also possible to use a special mixing and dispensing machine for the two silicone components. Further information is available upon request.

2. Degassing
The mixture should be degassed preferably at 30 to 50 mbar to eliminate any entrapped air. If a dispensing machine is used, the two components are degassed separately prior to mixing.
The silicone mixture expands to 3 to 4 times of its initial volume and bubbles rise to the surface. The bubbles progressively disappear and the mixture returns to its initial volume after 5 to 10 minutes. Wait a few minutes to complete the degassing and then flash the vacuum. The silicone is ready for pouring, either by gravity or under low pressure.
Note: Flashing the vacuum once or twice accelerates the degassing. It is recommended to use a container with a high diameter / height ratio.

3. Polymerisation
The system polymerises at . The curing may be slowed down at lower temperature and contrary accelerated by heat.
Contact with certain materials can inhibit the crosslinking. See list below:

  • Natural rubbers vulcanised with sulphur,
  • RTV 2 silicone elastomers catalysed with metal salts, e.g. tin-compounds,
  • PVC stabilised with tin salts and additives,
  • Epoxy resins catalysed with amines,
  • Certain organic solvents, e.g. ketones, alcohols, ether etc.

In case of doubts, it is recommended to test the substrate by applying a small quantity of the mixed silicone on a restricted area.


STORAGE -10°C < t < +30°C IN ITS ORIGINAL PACK STIR WELL BEFORE USENo special storage precautions noted. Material is stable under normal conditions. Avoid contact with oxidizing agents. Suitable containers: polyethylene. Plastic lined steel drum.Please consult the Safety Data Sheet of this product.


SILBIONE RT GEL 4115, 4220, 4222, 4521 LD A&B are two component silicone elastomers that crosslink at room temperature by polyaddition reaction. The polymerisation can be accelerated by heat.
The silicone materials are delivered as two low viscous liquid components, which once mixed and cured, transform into an elastic and resistant gel. Polymerisation occurs without formation of heat.


2 Part RTV



  • Excellent shock absorption
  • Very good pressure dissipation
  • Light weight grade available
  • Very good adhesion on PU films



  • Orthopaedic devices
  • Cushioning elements/mattresses


Asia Pacific;Europe Middle East Africa;Central and South America;North America

For information about Storage and Shelf Life for this product, please download the Technical Data Sheet.




Viscosity9000PairedCompISO 2555mPa.s




Viscosity9000PairedCompISO 2555mPa.s
ColorWhitePairedCompEuropean Pharmacopea






penetration_a142c699-2b17-4f82-882a-75f6253332edpenetration_a142c699-2b17-4f82-882a-75f6253332edPenetration190PairedMixISO 21371/10mm
pot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6apot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6aPot life57.5PairedMixmin





SILBIONE RT GEL 4521 PM BSILBIONE RT GEL 4521 PM B/our_offer/Product/90060266/90060265/SILBIONE-RT-GEL-4521-PM-B






















Othotics & Prosthetics & Prosthetics










All rights reserved © Elkem Silicones 2018