Silicone is a material used in everything from dairy farm milking liners to industrial tubing and components, but have you ever wondered how it’s made? The process begins with something incredibly ordinary: sand.
The process of turning sand into silicone takes five main steps:
- Extracting silicone from sand
- Converting silicon into silanes
- Hydrolysis to create siloxanes
- Polymerisation into silicone
- Curing and shaping silicone
Below, we break down the full journey, from raw mineral to high-performance elastomer.
1. Extracting Silicon from Sand
The starting point for all silicone materials is silicon, a naturally occurring element found in silica (SiO₂), the main component of sand and rock. Silica is refined by heating it with carbon in an industrial furnace at temperatures over 1,500 °C.
This high-temperature reduction process removes the oxygen atoms, leaving behind metallurgical-grade silicon; a pure and highly stable base material.
See more: Silicone vs. Silicon: What’s the Difference?
2. Converting Silicon into Silanes
Next, the purified silicon is reacted with methyl chloride (CH₃Cl) in the presence of a copper catalyst. This chemical reaction produces a group of compounds called methyl chlorosilanes, the most important being dimethyldichlorosilane.
This is a crucial step because it introduces organic groups (methyl) to the silicon backbone, enabling the future flexibility of the silicone material.
3. Hydrolysis to Create Siloxanes
The methyl chlorosilanes are then treated with water in a process known as hydrolysis, which removes the chlorine atoms. This results in the formation of siloxanes; molecules made up of repeating units of silicon and oxygen atoms (Si–O–Si), forming the base structure of all silicone materials.
Depending on the molecular weight and structure, siloxanes can appear as fluids, resins or gums.
4. Polymerisation into Silicone
Through further processing, the siloxanes undergo polymerisation to form long-chain molecules, resulting in various types of silicone:
- Silicone oils (low viscosity)
- Silicone resins (used in coatings)
- Silicone rubbers (used for extrusions, mouldings, and seals)
For rubber applications, these polymers are blended with fillers, additives and cross-linking agents to prepare them for curing.
5. Curing and Shaping Silicone
Once the silicone compound is formulated, it is cured, either through addition curing (platinum-catalysed) or peroxide curing. This cross-links the polymer chains, transforming the material from a soft gum into a strong, elastic solid.
After curing, silicone can be extruded, moulded or calendared into finished products like tubing, gaskets, seals or sheets.
From Base Material to Custom Performance
Once silicone rubber is cured, it can be further tailored to specific applications by adjusting properties such as:
- Shore hardness (a measure of flexibility vs. rigidity)
- Colour (via pigmentation)
- Transparency
- Thermal resistance
- Chemical compatibility
At Silclear, we work with a range of custom silicone compounds, each engineered for specific performance needs; from soft, flexible grades ideal for peristaltic pumps to high-durometer formulations designed for structural sealing or extreme environments.
Check out our silicone products here
Conclusion
So, while silicone may start life as something as simple as sand, the journey it takes through high-temperature refining, chemical synthesis and precision engineering results in one of the most versatile and reliable materials in modern manufacturing.
Whether used in medical, dairy, food & drink or industrial applications, silicone continues to prove its value, and understanding how it’s made only deepens the appreciation for what it can do.
To find out more about silicone’s unique applications contact Silclear today on +44 (0)1425 610700, email info@silclear.com or get in touch here.
