Can Silicone rubber can be recycled?

 

Recycling of Silicone Rubber: Past, Present and Future: Attaining Sustainability

Ever since the starting of processing of Silicone Rubber we were curious about the recycling and reuse of Silicone rubber produced in the process as nonconformance, rejections, trial material etc., When the volumes gone up the leftover pieces, non-confirmed parts, line rejections also had gone up. This created a necessity for introduction of recycling or reuse of silicone rubber profiles, Molded parts, cured rubber pieces from extruder.

As Silicone Rubber is resistant to weathering, ozone, ultraviolet etc. due to its strong silicone bonds it cannot be broken on normal heat and temperature(You can read here for more details). Even above 250 degree Celsius makes it brittle, and on heating above that it gets converted to silicon oxide along with emitted gases of Carbon dioxide and others. The disposal of silicone can be achieved by simply burning it or heating it at higher temperatures but it’s a wastage of product and energy.

Many processes have been tried, improved and many has been in progress regarding the recycling and reuse of silicone rubber extruded and molded. In reuse you can grind the silicone rubber to small mesh sizes of 2-3 mm size and can be used as a mulch for different purposes as you plan. Grinded pieces can be combined with virgin material to make non critical parts, with lower dimensional tolerances of above 2mm and can be used in casting, molding or even extrusion with expertise in design and mixing. This will be the simplest, low energy spent sustainable practice which can be applied over the rejected part and piece. But for higher quantities this will not be suitable and cannot be utilized.

Another process is there where the scrap silicone rubber is pyrolyzed or treated to extract silicone oils to be used for industrial lubrication, here the material is processed in separate facility and is recycled to a new product.

Studies are happening on the depolymerization or un- vulcanization of silicone rubber chemically or through mechanical processes where the scrap cured silicone rubber is converted into reclaim like silicone rubber which can be added along with virgin material which will not cause any dimensional or property change during the particular process. Some patents have been filed, some announcements or news releases has been happened over the recycling of silicone rubber via chemical or mechanical depolymerization but it is yet to obtain an efficient route or standard commercial operation with full effect.

We are interested in the processing of scrap silicone rubber and its recycling side and are ready to prototyping if you have any ideas on the same. We have facilities for grinding the scrap to small pieces and provide the same as silicone rubber mulch, crumb or smaller sizes as required by the customer.

If you have any ideas on silicone rubber recycling or wish to know more about the same, never hesitate to contact.

Also new ideas on recycling of silicone rubber like HTV, LSR type will be posted over here in the coming sessions.